Anthropogenic Influences.

Every lake has a set mixing regime that is influenced by lake morphometry and environmental conditions. However, human influences in the form of land use change, warming temperatures, and changes to weather patterns have been shown to alter the timing and intensity of stratification in lakes around the globe. These changes can further alter the fish, zooplankton, and phytoplankton community composition, in addition to creating gradients that alter the availability of dissolved oxygen and nutrients.  There are a number of ways in which human land use change influences lake stratification and subsequently water conditions. Urban expansion has led to the construction of roads and houses in close proximity to previously isolated lakes, a factor that has ultimately resulted in increased runoff and pollution. The addition of particulate matter to lake bodies can lower water clarity, resulting in stronger thermal stratification and overall lower average water column temperatures, which can eventually affect the onset of ice cover. Water quality can also be influenced by the runoff of salt from roads and sidewalks, which often creates a benthic saline layer that interferes with vertical mixing of surface waters. Further, the saline layer can prevent dissolved oxygen from reaching the bottom sediments, decreasing Phosphorus recycling and affecting microbial communities.  On a global scale, rising temperatures and changing weather patterns can also affect stratification in lakes. Rising air temperatures have the same effect on lake bodies as a physical shift in geographic location, with tropical zones being particularly sensitive. The intensity and scope of impact depends on location and lake morphometry, but in some cases can be so extreme as to require a reclassification from monomictic to dimictic (ex Great Bear Lake). Globally, lake stratification appears to be more stable with deeper and steeper thermoclines, and average lake temperature as a main determinant in the stratification response to changing temperatures. Further, surface warming rates are a much higher magnitude than bottom warming rates, again indicating stronger thermal stratification across lakes.  Changes to stratification patterns can also alter the community composition of lake ecosystems. In shallow lakes, temperature increases can alter the diatom community while in deep lakes, the change is reflected in the deep chlorophyll layer taxa. Changes in mixing patterns and increased nutrient availability can also affect zooplankton species composition and abundance, while decreased nutrient availability can be detrimental for benthic communities and fish habitat.

References.

Aquatic Science Hypoxia Freshwater ecosystems Water column

Lake stratification is the separation of lakes into three layers: The thermal stratification of lakes refers to a change in the temperature at different depths in the lake, and is due to the change in water's density with temperature. Cold water is denser than warm water and the epilimnion generally consists of water that is not as dense as the water in the hypolimnion. However, the temperature of maximum density for freshwater is 4 °C. In temperate regions where lake water warms up and cools through the seasons, a cyclical pattern of overturn occurs that is repeated from year to year as the cold dense water at the top of the lake sinks. For example, in dimictic lakes the lake water turns over during the spring and the fall. This process occurs more slowly in deeper water and as a result, a thermal bar may form. If the stratification of water lasts for extended periods, the lake is meromictic.


History.

Triple P, or the "Positive Parenting Program", was created by Matthew R. Sanders and colleagues, in 2001. at the University of Queensland in Australia and evolved from a small “home-based, individually administered training program for parents of disruptive preschool children” into a comprehensive preventive intervention program (p. 506). This program was inspired by health promotion programs aimed at impacting people at the population level. The overall goal of the program is to enhance the knowledge, skills, and confidence of parents in order to prevent behavioral, emotional, and developmental problems in children and adolescents.

Program elements.

Overview.

There are five developmental periods that are targeted from infancy to adolescence. At each developmental period, the range of the program can be either broad and target the entire population or it can be specific and target only at-risk children. The program addresses social contexts that influence parents’ daily life: mass media, primary health care services, child care and school systems, work sites, religious organizations, and the broader political system (p. 507). The multilevel nature of the program is designed to increase efficiency, minimize costs, and ensure dissemination. The design also maximizes usage of existing community resources.

Programs.

In addition to the program for younger children (Standard Triple P), there are versions of Triple P for families with specific needs, including parents of adolescents (Teen Triple P), parents with a child with a disability (Stepping Stones Triple P) and parents who are separated or divorced (Family Transitions Triple P).)

Research.

Evidence for the effectiveness of intervention programs can be divided into two types. One type is impact studies where the aim of the evaluation is to demonstrate a statistically significant improvement in outcomes on a population, which can be attributed to the intervention. A second type is qualitative studies which aim to illuminate the mechanisms through which program participants can access the resources and help offered in the program to achieve better outcomes.  Nowak and Heinrichs (2008) conducted a meta-analysis that analyzed findings of 55 research studies on the Positive Parenting Program and found reliable positive effects of the program across all settings (initial levels of problems and countries) for child behavior problems, parenting behavior, and parental well-being. Parents’ relationship quality also significantly improved as a result of the program. The findings were unable to establish whether positive child effects were due to an increase in positive behavior or a decrease in problematic behavior. According to the authors, the results of the meta-analysis indicated the program’s “ability to effect meaningful improvements in parents and children” (p. 114). Furthermore, Triple P has also been provided to families in the United Kingdom where neglect is a concern. The findings from this service showed that, on average the children who participated in the evaluation experienced improved emotional and behavioural outcomes. However this positive change could not be attributed to Triple P because a control group had not been established.  A critical 2012 systematic review and meta-analysis of these interventions revealed many small, underpowered and poorly-controlled studies, with substantial risk of reporting bias, triggering a response from a group including many Triple-P authors. Another commentary in the same journal claimed the response did not adequately address the critique and indicated that commitments to such programmes by policy-makers needs to be based on sound evidence, or risks wasting money. A later meta-analysis by a group including Triple-P authors was published in 2014 claiming widespread benefits in the short and long term.  Qualitative research studies have also illuminated some of the ways in which programs can help individual parents. An evaluation of the Triple P intervention highlighted how many parents were able to improve the way in which they related to their children after having received advice about how to be clear and boundaries with their children, and in some cases after having tried and seen the effects of such approaches for themselves, first-hand, and often for the first time.

Triple P is a parenting intervention with the main goals of increasing the knowledge, skills, and confidence of parents and reducing the prevalence of mental health, emotional, and behavioral problems in children and adolescents. The program was originally specifically tailored for at risk children and parents, but there are now different levels of Triple P designed to work together as a broad, universal, public health approach. This program is based on principles of community psychology.


Overview.

Due to their value-free approach, legal realists are opposed to natural law traditions. Legal realists contend that these traditions are historical and/or social phenomena and that they should be explained by a variety of psychological and sociological hypotheses. They also oppose any form of linguistic turn in jurisprudence. They regard the linguistic turn, when applied to law, as a sort of 'emasculation' (Enrico Pattaro) of legal phenomena. This is because legal realists conceive legal phenomena as psychical phenomena, and, notably, as a form of moral motivation of human behavior, which should be investigated with the methods of psychology and/or neurosciences. This means that legal realists oppose most versions of contemporary legal positivism.  A further difference from all sorts of legal positivism is that legal realists refuse to confine their investigations to state law and/or positive law. Moreover, legal realists have a conception of law that stretches far beyond legal pluralism—so popular in many versions of classical and contemporary sociology of law. This is one of the reasons why legal realism cannot be regarded as a sort of sociology of law (other reasons being: legal realists' psychologism and their refusal of the linguistic turn—a turn that affected, too, sociology of law). Apart from Max Weber (who, owing to a variety of reasons, is mostly conceptualized as sociologist rather than as a legal realist), there are two strands of legal realism in this sense: Scandinavian legal realism, founded by Axel Hägerström (1868–1939), and Polish-Russian legal realism, founded by Leon Petrażycki (1867–1931). Both realisms, owing to their similarities (and despite their founders' ignoring one another), are sometimes referred to as 'continental legal realism' (in the singular).  In English-speaking countries the phrase 'legal realism' has often a somewhat different and more restricted meaning. It is used to refer to a conception of adjudication rather than of law in general. However, some legal realists in this other sense, including the founder of this movement, Oliver Wendell Holmes Jr., reduced law to the activity of courts and other state officials, thus proposing a kind of naturalistic and value-free reduction of law (a conception, though, that all Continental legal realists would reject, "inter alia", as excessively narrow). It is to this other kind of legal realism—also called 'American legal realism'—that this article is devoted.  American legal realists (henceforth: realists) believe that there is more to adjudication than the mechanical application of known legal principles to uncontroversial fact-finding as legal formalism believes. Some realists believe that one can never be sure that the facts and law identified in the judge's reasons were the actual reasons for the judgment, whereas other realists accept that a judge's reasons can often be relied upon, but not all of the time. Realists believe that the legal principles that legal formalism treat as uncontroversial actually hide contentious political and moral choices.  Realism was treated as a conceptual claim for much of the late 20th century due to H. L. A. Hart's misunderstanding of the theory. Hart was an analytical legal philosopher who was interested in conceptual analysis of concepts such as the concept of 'law'. This entailed identifying the necessary and sufficient conditions for the use of the concept 'law'. When realists such as Oliver Wendell Holmes pointed out that individuals embroiled in the legal system generally wanted to know what was going to happen, Hart assumed that they were offering the necessary and sufficient conditions for the use of the concept 'law'. Nowadays, legal theorists tend to recognise that the realists and the conceptual lawyers were interested in different questions. Realists are interested in methods of predicting judges with more accuracy, whereas conceptual lawyers are interested in the correct use of legal concepts.  Legal realism was primarily a reaction to the legal formalism of the late 19th century and early 20th century, and was the dominant approach for much of the early 20th century. It succeeded in its negative aspiration of casting doubt upon formalist assumptions that judges always did what they said so that it is often said that 'we are all realists now.' However, realism failed in its positive aspiration of discovering a better way of predicting how judges would behave than relying on the reasons given by judges.  A theory of law and legal reasoning that arose in the early decades of the twentieth century broadly characterized by the claim that law can be best understood by focusing on what judges actually "do" in deciding cases, rather than on what they say they are doing. The central target of legal realism was legal formalism: the classical view that judges don't make law, but mechanically apply it by logically deducing uniquely correct legal conclusions from a set of clear, consistent, and comprehensive legal rules. American legal realism has aptly been described as "the most important indigenous jurisprudential movement in the United States during the twentieth century". Though most legal scholars today would agree that some aspects of legal realism were misguided or over-stated, its enduring influence on legal thought and legal education has been profound.

Forerunners.

Although the American legal realist movement first emerged as a cohesive intellectual force in the 1920s, it drew heavily upon a number of prior thinkers and was influenced by broader cultural forces. In the early years of the twentieth century, formalist approaches to the law had been forcefully criticized by thinkers such as Roscoe Pound, John Chipman Gray, and Benjamin Cardozo. Philosophers such as John Dewey had held up empirical science as a model of all intelligent inquiry, and argued that law should be seen as a practical instrument for advancing human welfare. Outside the realm of law, in fields such as economics and history, there was a general "revolt against formalism," a reaction in favor of more empirical ways of doing philosophy and the human sciences. But by far the most important intellectual influence on the legal realists was the thought of the American jurist and Supreme Court Justice Oliver Wendell Holmes, Jr.

Oliver Wendell Holmes Jr..

Holmes is a towering figure in American legal thought for many reasons, but what the realists drew most from Holmes was his famous prediction theory of law, his utilitarian approach to legal reasoning, and his "realist" insistence that judges, in deciding cases, are not simply deducing legal conclusions with inexorable, machine-like logic, but are influenced by ideas of fairness, public policy, and other personal and conventional values.  All these themes can be found in Holmes's famous 1897 essay, "The Path of the Law". There Holmes attacks formalist approaches to judicial decision making and states a pragmatic definition of "law": "The prophecies of what the courts will do in fact, and nothing more pretentious, are what I mean by the law". If law is prophecy, Holmes continues, we must reject the view of "text writers" who tell us that law "is something different from what is decided by the courts of Massachusetts or England, that it is a system of reason that is a deduction from principles of ethics or admitted axioms or what not, which may or may not coincide with the decisions".  Holmes next introduces his most important and influential argument, the "bad-man" theory of law: "[I]f we take the view of our friend the bad man we shall find that he does not care two straws" about either the morality or the logic of the law. For the bad man, "legal duty" signifies only "a prophecy that if he does certain things he will be subjected to disagreeable consequences by way of imprisonment or compulsory payment". The bad man cares nothing for legal theorizing and concerns himself only with practical consequences. In the spirit of pragmatism, Holmes suggests that this is a useful way of laying bare the true meaning of legal concepts.  The utilitarian or instrumentalist flavor of "The Path of the Law" also found favor with the realists. The purpose of the law, Holmes insisted, was the deterrence of undesirable social consequences: "I think that the judges themselves have failed adequately to recognize their duty of weighing considerations of social advantage." Before the Civil War, this conception of adjudication as a form of social engineering had been widely shared by American judges, but in the late nineteenth century it had fallen out of favor. One of the aspirations of both Holmes and the realists was to revive it.

Key themes.

Drawing upon Holmes and other critics of legal formalism, a number of iconoclastic legal scholars launched the legal realist movement in the 1920s and 30s. Among the leading legal realists were Karl Llewellyn, Jerome Frank, Herman Oliphant, Underhill Moore, Walter Wheeler Cook, Leon Green, and Felix Cohen. Two American law schools, Yale and Columbia, were hotbeds of realist thought. Realism was a mood more than it was a cohesive movement, but it is possible to identify a number of common themes. These include:

Criticisms.

Legal realism had its heyday from the 1920s to the 1940s. In the 1950s, legal realism was largely supplanted by the legal process movement, which viewed law as a process of "reasoned elaboration" and claimed that appeals to "legislative purpose" and other well-established legal norms could provide objectively correct answers to most legal questions. In his 1961 book "The Concept of Law", British legal theorist H. L. A. Hart dealt what many scholars saw as a "decisive blow" to legal realism, by attacking the predictive theory of law that many realists had taken over from Holmes. Hart pointed out that if a law is just a prediction of what courts will do, a judge pondering the legal merits of a case before him is really asking, "How will I decide this case?" As Hart notes, this completely misses the fact that judges use legal rules to "guide" their decisions, not as data to predict their eventual holdings.  Many critics have claimed that the realists exaggerated the extent to which law is "riddled" with gaps, contradictions, and so forth. The fact that most legal questions have simple, clear-cut answers that no lawyer or judge would dispute is difficult to square with the realists' strong claims of pervasive legal "indeterminacy". Other critics, such as Ronald Dworkin and Lon Fuller, have faulted legal realists for their attempt sharply to separate law and morality.

Influence and continuing relevance.

Though many aspects of legal realism are now seen as exaggerated or outdated, most legal theorists would agree that the realists were successful in their central ambition: to refute "formalist" or "mechanical" notions of law and legal reasoning. It is widely accepted today that law is not, and cannot be, an exact science, and that it is important to examine what judges are actually doing in deciding cases, not merely what they say they are doing. As ongoing debates about judicial activism and judicial restraint attest, legal scholars continue to disagree about when, if ever, it is legitimate for judges to "make law", as opposed to merely "following" or "applying" existing law. But few would disagree with the realists' core claim that judges (for good or ill) are often strongly influenced by their political beliefs, their personal values, their individual personalities, and other extra-legal factors.

Legal realism and the European Court of Human Rights.

A statistical natural language processing method has been applied to automatically predict the outcome of cases tried by the European Court of Human Rights (violation or no violation of a specific article) based on their textual contents, reaching a prediction accuracy of 79%. A subsequent qualitative analysis of these results provided some support towards the theory of legal realism. The authors write: "In general, and notwithstanding the simplified snapshot of a very complex debate that we just presented, our results could be understood as lending some support to the basic legal realist intuition according to which judges are primarily responsive to non-legal, rather than to legal, reasons when they decide hard cases."

Legal realism is a naturalistic approach to law. It is the view that jurisprudence should emulate the methods of natural science, i.e., rely on empirical evidence. Hypotheses must be tested against observations of the world.


Bias circuit requirements.

The bias circuit stabilizes the operating point of the transistor for variations in transistor characteristics and operating temperature. The gain of a transistor can vary significantly between different batches, which results in widely different operating points for sequential units in serial production or after replacement of a transistor. By the Early effect, the current gain is affected by the collector–emitter voltage. Both gain and base–emitter voltage depend on the temperature. The leakage current also increases with temperature. A bias network is selected to reduce effects of device variability, temperature, and voltage changes.  A bias circuit may be composed of only resistors, or may include elements such as temperature-dependent resistors, diodes, or additional voltage sources, depending on the range of operating conditions expected.

Signal requirements for class-A amplifiers.

For analog operation of a class-A amplifier, the Q-point is placed so the transistor stays in active mode (does not shift to operation in the saturation region or cut-off region) when input is applied. For digital operation, the Q-point is placed so the transistor does the contrary – switches from the "on" (saturation) to the "off" (cutoff) state. Often, the Q-point is established near the center of the active region of a transistor characteristic to allow similar signal swings in positive and negative directions.

Thermal considerations.

At constant current, the voltage across the emitter–base junction "V" of a bipolar transistor "decreases" by 2 mV (silicon) and 1.8 mV (germanium) for each 1 °C rise in temperature (reference being 25 °C). By the Ebers–Moll model, if the base–emitter voltage "V" is held constant and the temperature rises, the current through the base–emitter diode "I" will increase, and thus the collector current "I" will also increase. Depending on the bias point, the power dissipated in the transistor may also increase, which will further increase its temperature and exacerbate the problem. This deleterious positive feedback results in thermal runaway. There are several approaches to mitigate bipolar transistor thermal runaway. For example, The circuits below primarily demonstrate the use of negative feedback to prevent thermal runaway.

Types of bias circuit for class-A amplifiers.

The following discussion treats five common biasing circuits used with class-A bipolar transistor amplifiers:

Fixed bias (base bias).

This form of biasing is also called "base bias or fixed resistance biasing". In the example image on the right, the single power source (for example, a battery) is used for both collector and base of a transistor, although separate batteries can also be used.  In the given circuit,  Therefore,  For a given transistor, V does not vary significantly during use. As V is of fixed value, on selection of R, the base current I is fixed. Therefore, this type is called "fixed bias" type of circuit.  Also, for the given circuit,  Therefore,  The common-emitter current gain of a transistor is an important parameter in circuit design, and is specified on the data sheet for a particular transistor. It is denoted as β on this page.  Because  we can obtain I as well. In this manner, operating point given as (V,I) can be set for given transistor.  Advantages:  Disadvantages:  Usage:  Due to the above inherent drawbacks, fixed bias is rarely used in linear circuits (i.e., those circuits which use the transistor as a current source). Instead, it is often used in circuits where the transistor is used as a switch. However, one application of fixed bias is to achieve crude automatic gain control in the transistor by feeding the base resistor from a DC signal derived from the AC output of a later stage.

Collector feedback bias.

This configuration employs negative feedback to prevent thermal runaway and stabilize the operating point. In this form of biasing, the base resistor formula_1 is connected to the collector instead of connecting it to the DC source formula_2. So any thermal runaway will induce a voltage drop across the formula_3 resistor that will throttle the transistor's base current.  From Kirchhoff's voltage law, the voltage formula_4 across the base resistor formula_1 is  By the Ebers–Moll model, formula_7, and so  From Ohm's law, the base current formula_9, and so  Hence, the base current formula_11 is  If formula_13 is held constant and temperature increases, then the collector current formula_14 increases. However, a larger formula_14 causes the voltage drop across resistor formula_16 to increase, which in turn reduces the voltage formula_4 across the base resistor formula_1. A lower base-resistor voltage drop reduces the base current formula_11, which results in less collector current formula_14. Because an increase in collector current with temperature is opposed, the operating point is kept stable.  Advantages:  Disadvantages:  which is the case when  Usage: The negative feedback also increases the input impedance of the amplifier as seen from the base, which can be advantageous. Due to the gain reduction from feedback, this biasing form is used only when the trade-off for stability is warranted.

Fixed bias with emitter resistor.

The fixed bias circuit is modified by attaching an external resistor to the emitter. This resistor introduces negative feedback that stabilizes the Q-point. From Kirchhoff's voltage law, the voltage across the base resistor is  From Ohm's law, the base current is  The way feedback controls the bias point is as follows. If V is held constant and temperature increases, emitter current increases. However, a larger I increases the emitter voltage V = IR, which in turn reduces the voltage V across the base resistor. A lower base-resistor voltage drop reduces the base current, which results in less collector current because I = β I. Collector current and emitter current are related by I = α I with α ≈ 1, so the increase in emitter current with temperature is opposed, and the operating point is kept stable.  Similarly, if the transistor is replaced by another, there may be a change in I (corresponding to change in β-value, for example). By similar process as above, the change is negated and operating point kept stable.  For the given circuit,  Advantages:  The circuit has the tendency to stabilize operating point against changes in temperature and β-value.  Disadvantages:  which is approximately the case if  Usage:  The feedback also increases the input impedance of the amplifier when seen from the base, which can be advantageous. Due to the above disadvantages, this type of biasing circuit is used only with careful consideration of the trade-offs involved.  Collector-Stabilized Biasing.

Voltage divider biasing or emitter bias.

"The voltage divider is formed using external resistors" R and R. The voltage across R forward biases the emitter junction. By proper selection of resistors R and R, the operating point of the transistor can be made independent of β. In this circuit, the voltage divider holds the base voltage fixed independent of base current, provided the divider current is large compared to the base current. However, even with a fixed base voltage, collector current varies with temperature (for example) so an emitter resistor is added to stabilize the Q-point, similar to the above circuits with emitter resistor. The voltage divider configuration achieves the correct voltages by the use of resistors in certain patterns. By manipulating the resistors in certain ways you can achieve more stable current levels without having β value affect it too much.  In this circuit the base voltage is given by:  formula_40 voltage across formula_41 formula_42  Also formula_45  For the given circuit,  Advantages:  Disadvantages:  which is approximately the case if  where R || R denotes the equivalent resistance of R and R connected in parallel.  Usage:  The circuit's stability and merits as above make it widely used for linear circuits.

Voltage divider with AC bypass capacitor.

The standard voltage divider circuit discussed above faces a drawback – AC feedback caused by resistor R reduces the gain. This can be avoided by placing a capacitor (C) in parallel with R, as shown in circuit diagram. The result is that the DC operating point is well controlled, while the AC-gain is much higher (approaching β), rather than the much lower (but predictable) value of formula_49 without the capacitor.

Emitter bias.

When a split supply (dual power supply) is available, this biasing circuit is the most effective, and provides zero bias voltage at the emitter or collector for load. The negative supply V is used to forward-bias the emitter junction through R. The positive supply V is used to reverse-bias the collector junction. Only two resistors are necessary for the common collector stage and four resistors for the common emitter or common base stage.  We know that,  V − V = V  If R is small enough, base voltage will be approximately zero. Therefore, emitter current is,  Ie = (V − V)/R  The operating point is independent of β if Re » R/β  Advantages:  Disadvantages:  This type can only be used when a split (dual) power supply is available.

Class-B and AB amplifiers.

Signal requirements.

Class B and AB amplifiers employ 2 active devices to cover the complete 360 deg of input signal flow. Each transistor is therefore biased to perform over approximately 180 deg of the input signal. Class B bias is when the collector current I with no signal is just conducting (about 1% of maximum possible value). Class-AB bias is when the collector current I is about 1/4 of maximum possible value. The class-AB push–pull output amplifier circuit below could be the basis for a moderate-power audio amplifier. <br> A practical amplifier circuit  Q3 is a common emitter stage that provides amplification of the signal and the DC bias current through D1 and D2 to generate a bias voltage for the output devices. The output pair are arranged in class-AB push–pull, also called a complementary pair. The diodes D1 and D2 provide a small amount of constant voltage bias for the output pair, just biasing them into the conducting state so that crossover distortion is minimized. That is, the diodes push the output stage into class-AB mode (assuming that the base-emitter drop of the output transistors is reduced by heat dissipation).  This design automatically stabilizes its operating point, since overall feedback internally operates from DC up through the audio range and beyond. The use of fixed diode bias requires the diodes to be both electrically and thermally matched to the output transistors. If the output transistors conduct too much, they can easily overheat and destroy themselves, as the full current from the power supply is not limited at this stage.  A common solution to help stabilize the output device operating point is to include some emitter resistors, typically an ohm or so. Calculating the values of the circuit's resistors and capacitors is done based on the components employed and the intended use of the amplifier.

Bipolar transistors must be properly biased to operate correctly. In circuits made with individual devices (discrete circuits), biasing networks consisting of resistors are commonly employed. Much more elaborate biasing arrangements are used in integrated circuits, for example, bandgap voltage references and current mirrors. The voltage divider configuration achieves the correct voltages by the use of resistors in certain patterns. By selecting the proper resistor values, stable current levels can be achieved that vary only little over temperature and with transistor properties such as β.


Composition.

The composition of raw water is naturally variable, but commonly contains one or more of the following significant contaminants, in the form of dissolved ions, particles and living organisms: Other, less common, contaminants of raw water include: These contaminants can be harmful to humans if they drink raw water containing them, or if the water is not treated properly before consumption. The contaminants can also have an effect on the local ecosystem. For example, endocrine disrupting chemicals can have harmful effects on fish populations living in natural lakes and rivers. These growing health concerns have led to the development of guidelines, such HACCP (Hazard Analysis and Critical Control Points), for the production of safe drinking water from wastewater and raw water, and research into sustainable water supply alternatives

Treatment.

Raw water can be used for many purposes, such as cooling water, water for rinsing and chemical production, purified water, and drinking water. However, due to the possible contaminants, raw water must be treated before it is allowed for human consumption or industrial use. There are several steps involved in the treatment of raw water, and different methods in which it can take place.

Reverse osmosis.

Reverse osmosis has been used for the production of demineralised water for over 30 years. In reverse osmosis, water is transported across a membrane under high pressure, leaving a product that consists mainly of water and a concentrate containing most other components such as minerals and unwanted residues. Many contaminants, including iron, manganese, ammonium, traces of pesticides and medicines, organic micro pollutants, and radioactive particles can be removed with reverse osmosis alone. This efficiency has made reverse osmosis the primary method of water purification, often being used in combination with other methods, as a final treatment. A downside to reverse osmosis is that the removing of most minerals from water can have negative effects on its taste. Minerals are sometimes added to drinking water that was already filtered to improve its taste.

Conventional pre-treatment.

The conventional treatment method for water purification is a complex, multistage process that was used for many years. It generally consists of five primary steps. First, raw water is adjusted for alkalinity and pH with the addition of hydrated lime and carbon dioxide. Second, particulate matter is congregated with aluminum sulphate and other coagulants, such as polymers, which the water flows in a cascade that mixes the chemicals and raw water with the coagulants. Third, the water is slowly mixed in clarifiers where larger particles settle down to the bottom and are periodically removed (sedimentation). Fourth, water is directed from the clarifiers to the filters (e.g. anthracite and sand filter) to entrap any smaller particles that survived the clarification process. Finally, sodium hydroxide is added to adjust the final pH/alkalinity, sodium hypochlorite for disinfection and fluoride for fluoridation. This process is often used as a pre-treatment method while another processes, such as reverse osmosis, is used for the final treatment. A disadvantage of this method is its use of chemicals, such as ozone, flocculents, hydrogen peroxide, lime, and chlorine for the filtration process. These chemicals could be dangerous if used incorrectly or if they remained in the water after complete treatment. This requires special precautions, and each step of the process has to be controlled to achieve an overall optimal performance. The need for a complex control system for conventional treatment can result in it being financially costly. This has led to the development of alternative pre-treatment and treatment methods for raw water.

Ultrafiltration.

Ultrafiltration is a membrane filtration process and provides an alternative to conventional pre-treatment. In this method water is only pre-filtered with a common screen filter before being filtered at high pressure through a membrane, separating the water from contaminants within it. Ultrafiltration can be used on its own for water purification or as a pre-treatment for reverse osmosis. Its advantages over conventional pre-treatment include: very high water quality independent of the contaminants in the initial raw water, a plant that is simpler in design and more flexible, which makes it easier to automate, lower use of chemicals, and final product free of viruses and microorganisms.

Biofilm pre-treatment and Bio-diatomite Dynamic Membrane Reactor.

The biofilm membrane filtration method is used to remove harmful chemical by-products, such as NH4+-N, total nitrogen, and dissolved organic matter, that could form from disinfection processes. Biofilm Pre-treatment is a necessary step for water treatment in many parts of world due to its low operation cost and effectiveness at pollutant removal. In this process microorganisms remove contaminants in raw and wastewater that are harmful to humans, but nutrients to them. Bio-diatomite dynamic membrane reactor filtration combines dynamic membrane technology for wastewater treatment, and microbial colonies that form diatomite particles to purify water. These methods are under development in China as part of addressing the country's pollution problems.

Turbidity.

Turbidity is how murky or hazy water seems due to suspended particles. The more suspended particles, the higher the turbidity. Turbidity is used to visually measure water quality. In raw water, turbidity is very common. High amounts of turbidity in raw water is due to:

Turbidity and health concerns.

During high turbidity peaks, pathogens are more commonly found in raw water. This can contribute to the spread of illnesses. When turbidity increases, reported hospital visits for the elderly (65+) with gastrointestinal illnesses also increase. Even places with water filtration systems that meet standards can have an endemic of gastrointestinal illness, or waterborne infectious diseases. Those hospitalized represent a small percentage of total morbidity caused by these illnesses.

Controlling turbidity.

Controlling the land surrounding raw water sources is key to reducing turbidity. Areas of high sediment resuspension and erosion need attending regularly, and screens and other devices are needed to catch suspended particles. Screens that trap particles and debris must be cleaned consistently. Flushing out water pumps should be done when demand is lowest. This gives time for the water to settle, and decrease turbidity before is it needed in high amounts. "Turbidity reduction is best achieved when the water is run through a series of chemical and physical treatment methods before reaching the filter".

Bottled products.

Around 2017 untreated spring water, described as "naturally probiotic" raw water, became a commercial product distributed through health food shops, but experts have raised public health concerns about the possible occurrence of harmful bacteria, viruses, and parasites such as "Giardia". One raw water business in the United States has even claimed that methods used by bottled and spring water producers could change the molecular structure of water. The fad was mocked on "The Daily Show" in April 2018 in a segment that included an interview with Marion Nestle.

Raw water is water found in the environment that has not been treated and does not have any of its minerals, ions, particles, bacteria, or parasites removed. Raw water includes rainwater, ground water, water from infiltration wells, and water from bodies like lakes and rivers.


Life.

Among his local contemporaries of Kittilä in Lapland he had the reputation of a drunken artist masturbating at home and painting furiously. He is said to have felt haunted both by his perverse urges and the provincial and narrow-minded mental perimeter of his northern hometown.  While he lived there, his abode was a tiny studio cabin which was closer to a shack than a house. He wired it for electricity by drawing a long extension cable from a nearby house. He called it his "Getsemane" after the biblical site, or sometimes his "castle in the clouds".  Upon his death two rumours spread in the local community. One that he had in a drunken stupor collapsed into a snowbank, and died from exposure. The other that he had hanged himself. The latter was more understandable, since several of his self-portraits featured a hangman's noose around his neck, and several other of his paintings also used the symbology of hanging.  The real circumstances of his death – lying in bed with pneumonia, without anyone checking to see how he was doing – were perhaps, and regrettably more fitting to an artist, but not to the figure they knew.  During his life he had many artist friends such as Reidar Särestöniemi, but only two real supporters; his mother, and a soul-mate/muse he found in Maj-Lis Pitkänen.  Maj-Lis was actually the sister of Kalervo Palsa's childhood sweetheart Maaret for whom he maintained a long-lasting unrequited torch of love, quite openly writing about it in his letters to her and her sister and eventually sisters husband.  After his death Maj-Lis fought a protracted and bitter battle to raise an appropriate cenotaph for "Kalle". The monument was sculpted by the Finnish artist and Maj-Lis's husband, Pekka Pitkänen. The statue, shaped like a stylized seed or bullroarer was viewed by the parish as being pagan, or even representing female sexual organs. Many voices proclaimed that it was a mistake to let the "pervert" be buried into holy ground to begin with.  Over time, the notables from Kittilä, who once strenuously opposed the monument, have instead begun to express pride that an internationally renowned artist was a local boy.

The art of Kalervo Palsa.

Kalervo Palsa used an incredibly varied palette of techniques and materials even including housepaint. The subjects with the richest content, generally received the most hurried and crude treatment. The over 1000 self-portraits on the other hand generally were treated at the very least with competent technique.  Mostly the works explore in graphic detail the dark side of humanity in general and his native northern regions specifically. Grotesque sexuality, sadism, homosexuality, bisexuality and a general emotional frigidity paraphilia reflect his own inner turmoil and were perhaps a reaction to the mental atmosphere of his hometown.  Palsa did have a brief fling with abstract art while staying in New York City, but as he recounts in his diary, that phase came to an abrupt halt when one day he saw a passed out black man sprawled on a subway bench.  Besides Hieronymous Bosch, his work has been compared to that of Frida Kahlo.

Influences.

Palsa drew a great deal of influence from both the lives and works of numerous painters, writers and philosophers. Painters who influenced him include Magritte and Vincent van Gogh. His works include clear references to such people as Jean-Paul Sartre, Strindberg and Jean Genet, and many more subtle influences are listed on the first page of Eläkeläinen muistelee, where he mentions such kindred spirits as Jonathan Swift and Vladimir Lenin among many others.  Despite this brand of what might be called intertextuality, some researchers have noted that though he remained active in his work up to his death in 1987, his work did not show signs of the postmodernism evident in the work of many other artists of the time.

Huugo Kalervo Palsa (March 12, 1947 – October 3, 1987), or "Kalle", was a Finnish artist in a style that has been described as fantastic realism.


Digital alternatives.

The TETRA trunked radio standard was developed by the European Telecommunications Standards Institute (ETSI), as a digital alternative to analogue trunked systems. However, TETRA, with its enhanced encryption capability, has developed into a higher tier (public safety) product, currently mainly used by governments, some larger airports and government-owned utilities.  DMR (digital mobile radio), and dPMR (digital private mobile radio) are more recent ETSI-standards for digital mobile radio using two-slot TDMA and FDMA respectively. The Tier 3 standard for these systems defines a trunking protocol very similar to MPT1327 and is intended as a potential migration path for existing and perhaps future trunking customers. Tier 3 equipment is (late 2011) now becoming available, so the impact on TETRA and MPT 1327 is yet to be seen, but may well be significant. However, it is unlikely that in terms of cost that the complicated new DMR/dPMR equipment will be able to compete with the simpler MPT1327 equipment for some time, if ever.  It is worth noting that whilst many comparisons are made between Digital and Analog radio technologies, when it comes to applying these arguments to MPT1327, many of the distinctions become blurred, since MPT1327 with its digital control channel, already offers most of the features being offered by the DMR/dPMR/TETRA counterparts.  Furthermore, most MPT1327 systems are engineered to a far higher standard than conventional FM systems, partially due to the lack of CTCSS within the standard. As such arguments with regards to "noisy FM audio quality", can become misleading, since the squelch levels tend to be set rather high on MPT1327 systems, such that weak/noisy signals do not generally open the mute.

MPT1327 advantages and features.

The advantage of MPT 1327 over TETRA is the increased availability, lower cost of equipment, the ease of installation, the familiarity with the equipment, and many believe that MPT 1327 is superior to TETRA, due to its uncompressed FM audio, and greater receiver sensitivity. MPT1327 control channel signalling is more resilient, since the TETRA protocol uses a complex modulation scheme that requires a far higher Signal to Noise ratio to function than 1,200 bit/s FFSK signalling.  Systems based on MPT 1327 only require one, but usually use two or more radio channels per site. Channels can be 12.5 or 25 kHz bandwidth, and can be any variety of channel spacings, with 6.25 kHz or 12.5 kHz being typical. At least one of these channels is defined as the control channel (CCH) and all other channels are traffic channels (TCs) used for speech calls.  A typical installation will have around 6–10 channels. A 7-channel trunk, correctly engineered, is capable of handling in excess of 3,000 mobile units. The capacity of the system increases dramatically with the number of traffic channels. For example, 1 traffic channel with queuing can not handle many customers, perhaps 2 minicabs with 20 mobiles. In effect this would be a CBS with queuing. However, a 7 channel trunked system can handle 40 minicabs with 20 mobiles with ease. The Erlang formulas are typically used for calculating system capacity.

Spectrum efficiency.

Whilst MPT 1327 systems, unlike DMR or dPMR, do not employ digital speech compression to gain any Spectral Efficiency (voice channels per 6.25 kHz), there are several methods used that increase the Spectrum Efficiency (Erlangs per square kilometre, per 6.25 kHz).  A spectrum efficiency advantage over a 4-slot TDMA system like TETRA is in areas where a low-traffic network is required. The absolute minimum TETRA installation would require one carrier, carrying one CCH and three traffic channels, using up 25 kHz of bandwidth. The absolute minimum MPT1327 assignment is a single non-dedicated control channel, utilising 12.5 kHz, in most cases.  A non-dedicated control channel can be used as a traffic channel when all the other traffic channels are busy. This can be useful if the site is part of a multi-site network and has a very low traffic profile as the site could have a single channel rather than at least two freeing up one channel for use elsewhere. The disadvantage is loss of queuing, and data cannot be sent on the control channel whilst it is in traffic mode. A non-dedicated CCH should not be used as a "reserve tank" for a busy site as the lack of signalling will seriously affect the operation of the site.

Time-shared control channels and channel pooling.

Some MPT 1327 networks can also time-share control channels, which can be useful if the network has limited frequency availability, as it frees up channels for use as traffic channels, which can also be pooled across sites so the network capacity follows the traffic. This is another advantage of MPT 1327 (and dPMR) over TDMA-based systems such as TETRA and DMR, which cannot pool traffic channels so efficiently (if at all). The disadvantage of using a time-shared CCH is that it slows down registration and calls and requires some customization of the registration process, so is only useful if the network has a patient user community!

Control channel cycling.

The control channel can also be set to cycle, so each channel in turn becomes a control channel, say every ten minutes it will change. The advantage of this is that the base does not have to be rated at 100% duty cycle and does not get so hot. However, this can cause problems with queuing, affects registration and control channel acquisition times. Most base stations have a 100% duty-cycle rating, but this function can be useful if local Regulatory rules do not permit Continuous CCH operation. In countries where dedicated channels for trunked systems are not possible or availability is limited it is also possible to actively manage the use of traffic channels based on co-channel use, i.e. to avoid interfering with other users by using "friendly" channel acquisition protocols.

Speech and data.

Speech is sent as narrowband frequency modulation. Data messages between mobiles and the network are exchanged on the control channel at 1,200 bits per second using FFSK signalling, or a specific "modem call", known as "non-prescribed data" can be established, whereby free-form 1,200 baud data can be exchanged on a traffic channel without tying up the control channel. With the use of special modems, the speed can be 19,200 bit/s. This, along with Short Data Messaging and Status Messaging via the control channel makes an MPT1327 network ideal for managing AVL for asset management, meter reading and SCADA networks, the advantage being that the network can be used for this sort of application whilst still carrying voice traffic.

Numbering.

Each subscriber in an MPT-1327 trunked radio network has a unique call number. This call number (address) is a compound number consisting of a prefix (three digits), the fleet number and the subscriber's call number within the fleet. Different numbering schemes work differently, for example Zetron uses the first two digits of the Ident as the fleet number, and the last two digits as the unit number. Idents in the 6,000–6,999 range are typically used to establish group calls. After it has been entered the call number will be converted in the mobile to a 20-bit address. The numbering rules are clarified and expanded by supplementary standards such as MPT-1343.  For the duration of his call a subscriber is exclusively allocated a traffic channel from the available pool. If all channels are occupied, the call will be queued. If the control channel has become a traffic channel, like in the case of a non-dedicated control channel, the call will be queued in the radio, although radio queuing loses the first come, first served effect, so if there are seven units queuing, the last unit to queue may get a traffic channel first.

The different types of communications on an MPT-1327 network and their definitions.

Calls.

Broadcast calls can be used to make announcements to the entire customer base on a trunked system. For example, if work is to be carried out on the trunked system, the owner of the system can initiate a Broadcast Call which calls every mobile on the system. However, the mobiles may not have talk entitlement, so the PTT may not work. By this means the owner can announce to all customers a short period of inoperation due to maintenance.

MPT 1327 is an industry standard for trunked radio communications networks. First published in January 1988 by the British Radiocommunications Agency, and is primarily used in the United Kingdom, Europe, South Africa, New Zealand, Australia and even China. Many countries had their own version of numbering/user interface, including MPT1343 in the UK, Chekker (Regionet 43) in Germany, 3RP (CNET2424) in France, Multiax in Australia, and Gong An in China.


History.

Documents record the Old High German name "Oadalrich" or "Uodalrich" from the later 8th century in Alamannia. The related name "Adalric" (Anglo-Saxon cognate "Æthelric") is attested from the 6th century (Athalaric King of the Ostrogoths; Æthelric of Bernicia). The name of Agilolfing duke Odilo (fl. 709–748) may represent a short form of the name.  Count Udalrich I (fl. 778–814), a son of Gerold of Vinzgau, founded the Alamannic Udalriching dynasty, ancestral to the counts of Bregenz. The given name occurred frequently in the Alamannic Hunfriding dynasty in the 9th to 10th centuries; examples include Odalric, Count of Barcelona (fl. 850s) and Odalric, Count of Thurgau (fl. 920s). The name is recorded in an Icelandic form as "Óðalríkr" only in the later medieval period.  In the Middle High German period the name generally commemorated Saint Ulrich, Bishop of Augsburg (c. 890 – 4 July 973), who twice defended Augsburg from attacks by Magyars.  The Swiss Reformer Ulrich Zwingli etymologized his given name as "Huldrych" ("Huldricus, Huldaricus"), i.e. "rich in grace". In the wake of Zwingli, during the 16th century and well into the 18th century, it became a fashion - especially for Protestant writers - to latinise the given name "Ulrich" as "Huldricus".  The name was popularly given in 20th-century Switzerland, especially from the 1940s to the 1960s, peaking at rank 16 in 1947, but dropping below rank 100 in 1972. In Czechoslovakia, "Oldřich " was popularly given in the 1940s to 1950s, peaking at rank 18 during 1946–1951.

Variants.

The German given name was adopted in Czech and Slovak as "Oldřich", "Oldrich" and in Scandinavian as "Ulrik", in Slovenian as "Urh", in Latvia as Uldis.  Common German hypocoristics are "Uli" or "Ulli" (Swiss "Ueli") and historically "Utz". A Czech/Solvak hypocoristic is "Volek" and a Polish one "Ryczek".  A feminine form "Ulrike, Ulrica" is recorded from the early modern period.

Ulrich (), is a German given name, derived from Old High German "Uodalrich", "Odalric". It is composed of the elements "uodal-" meaning "(noble) heritage" and "-rich" meaning "rich, powerful". Attested from the 8th century as the name of Alamannic nobility, the name is popularly given from the high medieval period in reference to Saint Ulrich of Augsburg (canonized 993). The surname Ulrich is most prevalent in Germany and has the highest density in Switzerland. This last name was found in the United States around the year 1840. Most Americans with the last name were concentrated in Pennsylvania, which was home to many German immigrant communities. Nowadays in the United States, the name is distributed largely in the Pennsylvania-Ohio region.


History.

The origins of Vianden date back to the Gallo-Roman age when there was a castellum on the site of the present castle. The original name of Vianden was Viennensis. The valley was covered in vineyards in Roman times, the first historical reference to Vianden was in 698 when there is a record of a gift in the form of a vineyard "in Monte Viennense" made by Saint Irmina to the Abbey of Echternach. Vianden possesses one of the oldest charters in Europe, granted in 1308 by Philip II, count of Vianden, from whom the family of Nassau-Vianden sprang, and who was consequently the ancestor of William of Orange.  In the Middle Ages, Vianden's craftsmen were recognised for their skills as tanners, drapers, weavers, barrelmakers, masons, locksmiths and goldsmiths. In 1490, they created guilds for their various trades. Over the years pig-farming and leathermaking became the major industry with the establishment of two tanneries at the end of the 19th century which finally closed in the mid-1950s. The castle was built between the 11th and 14th centuries and became the seat of the counts of Vianden. It was further developed until the 18th century but with the departure of the Counts of Luxembourg to the Netherlands combined with the effects of fire and an earthquake, it slowly deteriorated. The final blow came in 1820 when William I of the Netherlands sold it to a local merchant who in turn sold off its contents and masonry piecemeal, reducing it to a ruin. There were several attempts at restoration but these were hampered by problems of ownership. Still, the chapel which forms part of it was restored in 1849 by Prince Henry of the Netherlands, and during one of his visits to the town Victor Hugo lived in the castle for three months in 1871. Not until 1977, when Grand Duke Jean ceded the castle to the State, was it possible to undertake large-scale work, most of which has now been completed.  Vianden is also remembered as the site of multiple battles in World War II. In November 1944 it saw fierce combat between the Luxembourg Resistance and German forces. It was the last place in Luxembourg to be freed from the Germans in February 1945 when the Americans completed Luxembourg's liberation. A memorial to the west of the town, overlooking the castle, commemorates this final battle.  The first Boeing 747-8F built, RC501, is named "City of Vianden" and is operated by Cargolux Airlines.

Geography.

Vianden is a drive from Luxembourg town. It can also be reached by bus from Diekirch or Clervaux which have rail connections to the city of Luxembourg. There are also buses to Bitburg in Germany. Many visitors arrive by bicycle taking the signposted cycle tracks from the south along the Our valley.

Climate.

Like the city of Luxembourg, Vianden (altitude ca. 200 m) has a temperate climate with warm summers (average day temperature around 24°C, on occasion as high as 35 °C) and chilly winters (daytime average 5 °C but sometimes as low as −15 °C at night). Rainfall is moderate, but on average it rains less than 10 days per month. The prevailing wind is south-westerly. The summer evenings are particularly pleasant, often with temperatures of around 25 °C until 11 pm. Very occasionally there are short periods of drought but the vegetation seldom loses its rich green for very long. Daylight extends from about 5 am to 10.30 pm in June and from 8 am to 4.30 pm in December.  In the summer, temperatures can be quite warm and in the case that the preceding winter is particularly mild, there is a higher chance that insect populations will over-reproduce. During these summers, fruit fly and mosquito populations increase significantly becoming a nuisance for residents and tourists.

Economy.

The scenic atmosphere and various local attractions have made Vianden a popular tourist destination in Luxembourg with many tens of thousands of visitors every year, especially from the Netherlands, Belgium and Germany. With its 14 hotels, four campsites and youth hostel, there is a wide selection of accommodation. In addition, Vianden benefits from the large numbers of day-trippers who take advantage of its restaurants, cafés, souvenir shops and sports facilities. The economy is however not without problems. While the hydro-electric pumping plant continues directly and indirectly to provide employment for the local population, the closure of the Electrolux plant a couple of years ago has resulted in a considerable loss of jobs. The commune is now planning to encourage the establishment of skilled craft industries in the area by making land available for development.

Attractions.

Vianden is one of Luxembourg's main tourist centres with large numbers of holidaymakers and local visitors at all times of the year. In particular, the recently restored castle set spectactularly on the rocks above the town has become a museum which traces its history and its links with the royal families of Europe back to the Middle Ages. Then there are links with Victor Hugo who visited Luxembourg in 1862 and 1865 and spent a longer period in Vianden in 1871. His sketches and letters can be seen in the museum located in the house where he stayed next to the bridge over the Our. There is also a museum of arts and crafts (Musée d'Art rustique) and a doll and toy museum (Musée de la Poupée et du Jouet).  But many people just visit Vianden to wander through its hilly, historic streets or as a centre for walking, camping or cycling in the north of Luxembourg. There is a pleasant cycle route up the Sauer and Our valleys to Vianden and there are many signposted walks in the area.  During the summer months, a chairlift operates from the banks of the river in the lower part of the town taking you high above the castle with magnificent views over the landscape.  Vianden also has a number of annual events and celebrations. The most famous of these is the nut market in October when the local walnuts are on sale together with walnut cakes, walnut confectionery, walnut brandy and walnut liqueurs.  Finally, there is an interesting attraction a few kilometers to the north of Vianden, the Vianden Pumped Storage Plant, which provides pumped-storage hydroelectricity storage and generation systems to benefit from the surplus electric power at night, and provide extra energy during peak hours.

Historic monuments.

In addition to the castle, Vianden has a number of interesting historic monuments.

Coat of arms.

The arms of Vianden (see top right-hand box) have not changed since 1288 when Godefroid I adopted the arms of Louvain-Perwez. The city was granted the right to use the same arms sometime during the 14th century. The arms were registered in the "armorial général de France" in 1696 by order of the King of France.

Famous people.

Many royal families and heads of state have associations with Vianden or have at least visited it. However, several other figures are worthy of note:

Twin towns — sister cities.

Vianden is twinned with:

Vianden () is a commune with town status in the Oesling, north-eastern Luxembourg, with over 1,800 inhabitants. It is the capital of the canton of Vianden, which is part of the district of Diekirch. Vianden lies on the Our river, near the border between Luxembourg and Germany.


Definitions.

There are a number of definitions of this term. "Wired Style: Principles of English Usage in the Digital Age" defines the term as "the whole digital enchilada - interactive, cable, broadband, 500-channel [...] then-Senator Al Gore Jr. introduced it at a 1978 meeting of computer industry folk, in homage to his father, Senator Albert Gore Sr."  The "McGraw-Hill Computer Desktop Encyclopedia", published in 2001, defines the term as "a proposed high-speed communications system that was touted by the Clinton/Gore administration to enhance education in America in the 21st Century. Its purpose was to help all citizens regardless of their income level. The Internet was originally cited as a model for this superhighway; however, with the explosion of the World Wide Web, the Internet became the information superhighway".  The "Oxford English Dictionary" (OED) defines the term as "a route or network for the high-speed transfer of information; esp. (a) a proposed national fiber-optic network in the United States; (b) the Internet." The OED also cites usage of this term in three periodicals:  The working paper No.179, 1994, of the Center for Coordination Science at "Massachusetts Institute of Technology" describes the concept as follows: "The information superhighway directly connects millions of people, each both a consumer of information and a potential provider. (...) Most predictions about commercial opportunities on the information superhighway focus on the provision of information products, such as video on demand, and on new sales outlets for physical products, as with home shopping. (...) The information superhighway brings together millions of individuals who could exchange information with one another. Any conception of a traditional market for making beneficial exchanges, such as an agricultural market or trading pit, or any system where individuals respond to posted prices on a computer screen is woefully inadequate for the extremely large number of often complex trades that will be required."

Earlier similar phrases.

Some other people used the term "superhighway" in application to telecommunications even earlier.  In 1964, M. Brotherton in his book "Masers and Lasers; How They Work, What They Do" on p. 5, wrote about laser beams and used the term "superhighways" for communication.  In 1974, Nam June Paik used the term "super highway" in application to telecommunications, which gave rise to the opinion that he may have been the author of the term "information superhighway". In fact, in his 1974 proposal "Media Planning for the Postindustrial Society – The 21st Century is now only 26 years away" to the Rockefeller Foundation he used a slightly different phrase, "electronic super highway":  In 1972, Andrew Targowski presented the Polish National Development Program at the State Council for Informatics, which included the plan of developing the public computer network INFOSTRADA (INFO-STRADA), where autostrada means motorway in Polish. Later this plan and its topology were published in his book INFORMATYKA modele rozwoju i systemów (INFORMATICS, models of development and systems) "The building of new electronic super highways will become an even huger enterprise. Assuming we connect New York with Los Angeles by means of an electronic telecommunication network that operates in strong transmission ranges, as well as with continental satellites, wave guides, bundled coaxial cable, and later also via laser beam fiber optics: the expenditure would be about the same as for a Moon landing, except that the benefits in term of by-products would be greater."

Further reading.

Articles  Magazine covers

The information superhighway or infobahn was a popular term used through the 1990s to refer to digital communication systems and the Internet telecommunications network. It is associated with United States Senator and later Vice-President Al Gore.


Overview.

Historical and contemporary human activity has profoundly influenced the composition of forests in the densely populated region of Central Europe. Remaining forest in Central Europe today is not generally considered natural forest, but rather a cultural landscape created over thousands of years which consists almost exclusively of replacement communities. The oldest evidence of human and forest interaction in Central Europe is the use of hand axes about 500 thousand years ago. The degree of hemeroby (human influence) and the extent of the original natural state from so long ago is difficult to estimate. It is believed that during glacial times during the ongoing ice age Central Europe was largely deforested and, in the period of "natural" re-emergence of the forest, since the end of the last glacial period, the Würm glaciation (about 11 700 years BP), people began to play a part transforming the potential natural vegetation. Sedentary, Neolithic farmers of the Linear Pottery Culture, about 7 500 years ago, began to change the forested landscape massively.  Due to feudal structures, the power over and ownership of forests was not at all clear for many centuries, which resulted in widespread overexploitation. As a result, during the period 1750-1850 forests in Central Europe had been decimated, causing a serious lack of timber. Some contemporary reports even spoke partly of desert-like landscapes at that time.  During the late 19th and 20th centuries a huge amount of artificial reforestation was implemented.  Today's forest communities in central Europe are influenced by the usefulness of the individual tree species. Apart from a few remnants of "near-natural forest" the vast majority of today's Central European forests are either artificial forests or whose present composition has arisen as a result of active or passive human intervention. Far and away the most common are commercial timber forests, which may be more or less near-natural, with beech and oak, spruce and pine. "Ancient forests" in Central Europe refer to the few remaining stands that are neither currently used for forestry nor were exploited in historical times.  Even with these, certain types of human influence, for example, forest browsing, cannot be completely ruled out. The composition and dynamics of the old Central European forests must therefore be reconstructed from these relics, from forest research areas and natural forest cells after they have ceased to be used, and by comparison with forest types in similar climatic conditions that are still true virgin forests, especially the Hyrcanian Forest on the Caspian Sea.  There is almost no data on the density and the influence of megaherbivores in prehistoric times, only conjecture. According to many forest scientists and a number of hunters, perpetual forest structures, which are advantageous for the forestry industry and the ecology, cannot be established without strong hunting measures to cull the present-day herbivores, the red and roe deer ensuring a correspondingly low density of these herbivores. Excessive stocks of deer do not only harm the forest as a commodity, but also prevent the natural regeneration of the forest through selective browsing by the animals and therefore hinder its natural development.  The megaherbivore theory argues that larger densities of game should therefore be permitted, because it would create a half-open and diverse landscape. Apart from red and roe deer there are no large herds of herbivores today and they have few natural predators. In today's cultural landscape, the establishment of permanent forest is seen as an economic and ecological goal; herbivores roving over wide areas inflict economic damage and are therefore hunted. The grazing of wild megaherbivores is therefore limited, as a landscape conservation measure, to large nature reserves in which a species-rich and semi-open landscape is to be preserved and economic objectives are rated as less important.

Effects of ice ages.

Unusual climatic extremes began to occur during the Pliocene epoch, four million years ago. In the Pleistocene epoch that followed, these fluctuations culminated in a number of extensive ice ages, which ended, in central Europe, around 12,000 years ago. (For details, see the last glacial period and climate history.)  During these cold periods, the average temperature in Central Europe fell by up to 12 °C. The snowline in the Alps dropped by 1,200 metres to 1,400 metres. Between the Alpine glaciers and the Scandinavian ice sheet, with a thickness of up to 3,000 m, was a relatively narrow, ice-free belt.  Central Europe was unforested at this time, except for local wooded areas of steppe and tundra which were covered by frost-resistant birch and pine. The vegetation of this period is referred to as Dryas flora, after its flagship species, the mountain avens ("Dryas octopetala").

Extinctions.

Unlike the North American continent, whose mountain ranges are oriented in a north-south direction, the east-west running ranges in Europe blocked the retreat of forest species in the face of advancing ice sheets. This barrier led to the extinction of several species in Europe. In the early ice ages, horse chestnut ("Aesculum hippocastanum") and sweet gum ("Liquidambar") became extinct. The following cold period led to the extinction of sequoia ("Sequoia"), umbrella pine ("Sciadopitys", " Cryptomeria "), arborvitaes ("Thuja"), tulip trees ("Liriodendron") and Douglas fir ("Pseudotsuga"). Hemlock ("Tsuga") and hickory ("Carya") became extinct during the Quaternary glaciations in Central Europe.  In addition, of the numerous oak species only three were able to return to Germany and Central Europe from their refuge areas, namely the English oak ("Quercus robur"), sessile oak ("Q. petraea") and downy oak ("Q. pubescens"). By comparison, in North America there are over 80 species of oak. Other types lost considerably in their intraspecific genetic diversity during the return migration such as the white fir ("Abies alba").

Refuges.

Forest flora was pushed back slowly by climatic change. The refuges of the last ice age were probably but not exclusively in southern Europe. A few species on today's Atlantic coast between England and France could also have survived the cold spell of the forest steppes. Another area of retreat was east and southeast Europe. Unlike much of Scandinavia and Russia, the Carpathians remained ice-free. So some species were also able to survive here. But the classic refuge remained the Mediterranean region, where the sea made for a balanced climate and highly rugged mountain ranges partitioned different residual populations.

Return migration.

In the interglacials those species that had survived extinction gradually repopulated the region. These return migrations took place at different rates for different tree species. The determining factors for the speed with which tree species repopulated the clear areas, were e. g. the method of seed distribution, the duration of flowering, degree of frost resistance and their ability to absorb nutrients. The picture of these migrations can be reconstructed using pollen analysis.  First to advance were woody pioneer species that were quick to spread, such as birch and pine. They were followed by heat-loving species such as oak and elm. Finally they were followed by slower migrating woody species that evolved into a climax community (see cyclic succession). With the end of the interglacial period and the onset of cooler climates, these species then retreated to their refuges again or simply died out.

Most recent post-glacial period.

In the most recent section of the Quaternary period, the Holocene or postglacial epoch, the forests began to return, about 11 700 years ago, to the treeless, post-glacial steppes. Pollen analysis has largely clarified how this return migration happened. For Central Europe, there were ten phases as a rule (according to Franz Firbas), which are called pollen zones and given Roman numerals as part of the Blytt-Sernander sequence.  More recent works are increasingly often using their own pollen zone systems in order to better reflect local circumstances. The process of reforestation is fairly broadly consistent, but there are some regional differences due to local circumstances which are not discussed here in detail. Due to the migration rate (which for beech was about 260 metres/year) there is a temporal delay in the various phases from south to north.

Late Arctic period, Allerød and Younger Dryas.

This covers pollen zones I-III (approx 12,400 to the 9,500 BC) and roughly corresponds to the period of the late Paleolithic. Pioneer species in the early postglacial (Holocene) included various species of willow ("Salix"), but birch ("Betula") and pine ("Pinus") also gained a foothold again in Central Europe. Short-term fluctuations in temperature at the end of this phase stopped any further advancement of the forest.

Pre-interglacial (Preboreal) and early interglacial (Boreal).

In the Preboreal stage, corresponding to the beginning of the Mesolithic, birch and pine were the dominant species. From this time there were no more cold periods. Hazel ("Corylus") spread rapidly and found favourable growing conditions beneath the open stands of pine.

Middle interglacial (Atlantic).

At the end of the Middle Stone Age, average temperatures rose markedly. Phytosociologically this was the start of the Atlantic period. Previous tree species were displaced, especially by oak ("Quercus") and elm ("Ulmus"). Most of these species were demanding, particularly in terms of their need for nutrients and warmth. The less shade-tolerant pine, in particular, was forced onto poorer sandy sites and moors. The oak, accompanied by the elm and lime, now formed the most predominant stands in Central Europe, the mixed oak forest.  In this time, people went through the transition from a nomadic wandering people to the sedentary lifestyle of the Neolithic. The great houses of the Linear Pottery Culture already placed a high demand for wood on local forests which were still small and a few in number. No later than the Neolithic, the forest was being deliberately managed to produce logs.  During the Neolithic period more heat-loving deciduous shrubs spread out from their refuges in southern Europe back to Central Europe. Maple ("Acer") and ash ("Fraxinus") enriched existing stocks. The average temperatures were now 2-3 °C higher than today. The downy oak ("Quercus pubescens") returned to Germany again. Alder ("Alnus glutinosa") carrs arose in the marshy lowlands and spruce ("Picea abies") reached the Harz Mountains.

Late interglacial (Subboreal).

In the late interglacial the climated became cooler and wetter. For the first time since the last ice age beech ("Fagus sylvatica"), hornbeam ("Carpinus betulus") and silver fir ("Abies alba") are evident again.  During the Bronze Age the average temperature fell further. Beech trees advanced into the hitherto oak-dominated woods. During the Iron Age, from 1000 B. C. beech trees were threatening the oak population in almost all areas. Aided by the humid, maritime climate of Central Europe and an ability, even in old age, to add to its habitat, the beech (with its high crown plasticity) became the dominant tree species. On the drier sites (precipitation < 500 mm/yr) in the east the hornbeam assumed this role.  In the Central Uplands a mixed mountain forest developed as beech invaded it. The extremely shade-tolerant fir also succeeded in gaining a foothold in these forests and in several areas ousted the spruce and beech. It is possible that at this time the establishment of potential natural vegetation came to an end however as human settlement spread across Central Europe and large herds of herbivores were roaming around.

Post interglacial period (Sub-Atlantic).

As a result of falling average temperatures the distribution areas, e.g. of the downy oak, became divided. From now on the influence of settled human forms of settlement becomes increasingly noticeable. This gives us our modern which is controlled by altitudinal zonation.

Iron Age to Roman-Germanic period.

The first intensive use of forests began in the Celtic period with the expansion of agriculture and the smelting of metals. This increased during the Roman-Germanic period especially in the densely populated southwestern areas.

Forests in Germania.

Free Germania.

Publius Cornelius Tacitus described "Free Germania" (Germania magna) in the 1st century as ""terra aut silvis horrida aut paludibus foeda"" – a land, covered by horrid forests or loathsome bogs. Tacitus' Mediterranean homeland at that time had already been a cultural landscape for centuries, its forests cleared for fields, orchards and towns, to say nothing of the use of wood for home fires and maritime construction.  A land whose surface was probably 70% covered by forest and climatically different clearly impressed Roman observers. This impression can be seen in the names they gave it. Mountain ranges like the Black Forest were called "Silva Abnoba", not "Mons Abnoba". It may thus be deduced that at that time trackless low mountain ranges were still largely spared from human influence. But even on the plains there were still great, contiguous areas of forest. These were located especially between the settlement areas of the various Germanic tribes and were respected on both sides as a boundary.  Settlement areas included riparian forests and woods on rich soils. Initial incursions were made in order to build the settlements themselves. Next woods were cleared for farming and grazing. Timber felling for heating led to the further thinning of natural stands of trees around the settlements. Various forms of use, such as wood pasture, favoured mast-bearing trees like oaks ("Quercus") and beech ("Fagus"). In the vicinity of ore mining beech trees were probably felled over a wide area because fire from beech charcoal was needed to work metals.  Permanent towns and villages were, however, a rarity in Free Germania. Settlements would be abandoned after a period of time and biological succession set in. This enabled a return of vegetation to something resembling its natural state.

Roman-occupied Germania.

The forest in Roman-occupied Germania (the Roman provinces of Germania Superior and Inferior) was more intensively used than in the unoccupied area. The construction of towns, such as Mainz, Trier, Cologne and Xanten, needed appropriate quantities of timber. A continual supply of large stocks of timber was needed for household heating and the operation of Roman baths with their extensive under-floor heating and hot water basins.  After the conquest of all Germania had failed (due to the defeat of Varus in 9 AD) the Romans switched to a defensive strategy. This, too, demanded large quantities of timber. The construction of the "limes", over 500 kilometres long, which was predominantly a wooden rather than a stone redoubt, required a wide swathe to be cut through the forest from the Rhine to the Danube and wood was needed for construction of palisades and watchtowers.  The Roman engineers were careful, as far as possible, to follow the shape of the terrain with the "limes" and to inclose fertile soils. For example, the fertile Wetterau, opposite the Mainz was within the "limes"; the poor, pine-covered keuper soils south of the Odenwald were left beyond it however. Much of the beech and oak stock on nutrient-rich soil had to give way to agricultural fields and pasture land. At several places grassy and dwarf shrub heathlands emerged that have survived to the present day. The Romans also kept away from the plains with their unpredictable rivers. The alder ("Alnus glutinosa") carrs away from the rivers, however, were turned into grazing land.  In selecting sites for their settlements, the Romans also avoided dense coniferous forests, although mixed forest areas may still have been attractive. They prized softwood, however, especially that of silver fir ("Abies alba"), for construction and shipbuilding. Pine was felled in all accessible locations and transported over long distances (by rafting). Thus, the natural mountain forest in parts of the Alps, the Black Forest and the Vosges was divided.  The Romans brought familiar species of tree with them to Germania from the Mediterranean region; these included sweet chestnut ("Castanea sativa"), horse chestnut ("Aesculus hippocastanum") and walnut ("Juglans regia"). These species had died out in North Europe during the ice age. The trees were valued for their fruit. In addition, the robust timber of sweet chestnuts was used in wine growing.

"Völkerwanderung" - the Migration Period.

The Romans gradually gave way to growing pressure from the Germanic tribes. First, settlements on the right bank of the Rhine were abandoned after the defeat of Varus. And from the 2nd century several tribes broke through the border (the Marcomanni and Lombards). In the 4th and 5th centuries, the Germanic peoples finally overwhelmed the last remnants of the "Limes". Pollen analyses from this period show that agriculture came to a standstill in many areas. Abandoned Roman castells and manors became forest land.  Settlement patterns in the formerly occupied Germania changed. Permanent settlements were abandoned in favor of semi-sedentary settlement forms. If the forest and soil became exhausted around a settlement, its population moved on. As the population density decreased a succession of forest communities began again in many areas, which had been strongly influenced by the economies of the Roman settlers. The pollen analyses from this period show that the beech ("Fagus sylvatica") spread out widely again, both in the areas deserted by the Romans, and along the Pomeranian Baltic coast and to southern Sweden.  Roman colonization saw the first, drastic impact on the forest communities of Central Europe. It left forest-free areas that did not recover from grazing; the species structure in many forest communities was disrupted by selective use, and introduced species became part of the vegetation.

Middle Ages.

"Völkerwanderung" and the Middle Ages.

The expansion of the forests as villages were abandoned during the "Völkerwanderung" was followed by a period of forest clearance in the Early and High Middle Ages, accompanied by a largely uncontrolled use of timber through deforestation in the context of land acquisition as well as the use of forests as a reservoir for construction timber and firewood. These periods have affected the landscapes of Central Europe right up to the present and created our familiar cultural landscapes.  The so-called Little Ice Age, with its particularly cold periods from 1570 to 1630 and 1675 to 1715, which was associated with catastrophic crop failures and disease, led to the desettlement of large areas of land into which secondary forest spread. The destruction during and in the aftermath of 30 years of war - in many parts of Germany, the population only recovered to its 1600 level by 1800 or later - also led to the strong afforestation of formerly agricultural lands.

Forest development in the Middle Ages.

Proportion of forested land.

With the turmoil of the Migration Period, the forest spread into Central Europe again. In areas cultivated during Roman colonization, the forest often regained a foothold. Only at the end of the Migration Period did the area of settlement increase again, and permanent settlements soon developed especially on agronomically suitable soils.  Two intensive periods of forest clearing can be distinguished. The first lasted from about 500 to about 800 and the second from about 1100 to about 1300, the beginning of the crisis of the 14th century. Especially during the first clearance period, the Carolingian era, those areas that had already been developed by the Romans were resettled. Next, areas that were easily accessible and had fertile soils were colonized.  The high Central Upland ranges remained empty at this early stage. The first permanent settlements in the Black Forest for example only appear from about 1000, and the Harz was only crossed at this time by difficult footpaths. Riparian forests near rivers (such as B. am Rhein) remained unsettled due to the unpredictability of the river. Water meadow woods further from the river were used. After 800, the pace of settlement and deforestation faltered in Central Europe. The population did not increase significantly due to epidemics and the invasion of foreign peoples (Normans in the north and Magyars in the south).

Forest use in the Middle Ages.

Wood pasture.

As well as swine, large livestock (cattle and horses) were also driven into the forest creating areas of wood pasture, which had clearly negative consequences for forest tree communities. Unlike pigs, which preserved the character of the forest, large domestic animals destroyed the trees. "Overgrazed" forests quickly turned into scrub.  Particularly disastrous was the woodland grazing of sheep and goats. The latter in particular are able to destroy older trees thanks to their climbing skills. The grazing of goats in the forest was therefore forbidden in early forest regulations. But the prohibition was often ignored because sheep and goats, as domestic animals of the poorer sections of the population, contributed significantly to their survival.

Honey pasture.

Beekeeping in the Middle Ages was a major forest activity because honey was still the only sweetener for food until the 19th century. As a result, the rights for beekeeping were managed at a high level. This form of activity is mentioned, for example, in connexion with the Nuremberg Imperial Forest. The existence of honey hunting operations helped to protect the forest. Tree species such as lime, pussy willow, fir and also pine were particularly favoured by this type of work.

Forest tillage.

Forest tillage ("Waldfeldbau") was practised from the 11th century and varied according to the region. This form of agriculture was established after the better soils had already been exploited for farming. This type of agricultural "intermediate use" ("Zwischennutzung") had numerous variants, something that is reflected in the names they were given: "Hackwald, Hauberge, Reutberge, Birkenberge" and "Schiffelland" are the most common designations.  The importance of these forms of economy increased during the pre-industrial period. They were constantly improved and formed an elaborate system of secondary forest uses ("Lohrinde"), firewood and farming. For this, the trees were first cleared by fire or felling. After the soil had been worked with mattocks or ploughs, it was sown with rye, buckwheat or wheat.  Usually the soil yielded crops for no longer than a year. It was then turned into grazing land until trees grew up again from the stumps or from seed. This form of agriculture had a considerable impact on the composition of forest trees.

Resin collecting.

Resin collecting is one of the oldest forms of forest exploitation. The resin was collected from conifers, of which spruce and pine were preferred. Even this form of forest use caused considerable destruction. It hindered growth and weakened the vitality of entire stands of trees. As a result, early on resin collecting was restricted to stands that were not easily felled and transported i.e. those that were a long way from rivers. Because resin was a popular base material, such bans were ignored everywhere.

Firewood.

Even today, wood is still an important source of energy for mankind. In Central Europe it was replaced by coal during the course of the 19th century. In the Middle Ages there were two quite different uses for firewood from the forests - local and non-local. Locally there was only one requirement that had an unrestricted priority: the use of firewood for home fires. In addition, a range of industry processes required firewood as an energy source or as a raw material, for example: charcoal burning, glassmaking, salt production and mining with its associated hammer mills.

Charcoal burning.

Charcoal burning was carried out in all woods and forests. In woods that were closer to settlements greater care was taken to avoid forest fires and to use only lower value wood. In woods that were more distant from human habitation there were no such restrictions. Charcoal burning generally took place near small rivers and streams that were used to transport the charcoal. In the Middle Ages earthen kilns ("Erdmeiler") were exclusively used to produce charcoal.

Glassworks.

Glass was highly prized during the Middle Ages and was correspondingly valuable. Forest glassworks often had small settlements tied to them, where the families of the glassblowers lived. Glassworks needed a particularly large supply of wood and were often described in contemporary reports as "wood-eating businesses". Glassworks also needed charcoal burners and ash burners, who supplied important fuel for the manufacture of glass. 90% of the wood was used to make potash, the most important raw material for glassmaking; the remaining 10% for the actual glass smelting.

Saltworks.

In the Late Middle Ages the majority of salt deposits were transferred into the ownership of the territorial princes. That started an unrestrained extraction of this important economic commodity. Large quantities of wood were needed for the process of salt mining, both for the construction of galleries as well as for the boiling pans ("Sudpfannen") of the saltworks or salines. These took the largest proportion of wood.  How disastrous the extraction of salt was for some landscapes is illustrated by the example of the town of Lüneburg in North Germany. Before salt was discovered it was surrounded by dense forests, but during the course of salt mining all the woods were cleared. Only a heath landscape remained, a countryside that was further devastated by plaggen agriculture. During the 20th century much of the area to the southwest of Lüneburg became a British military training area, causing further destruction.

Mines.

Mining required three natural conditions: first, the presence of ores; second, large forests, needed for pit props and the wood for producing charcoal; and third, water power in the shape of rivers and streams. Smelting was carried out in the vicinity of the shaft. In the Harz, mining is mentioned as early as the 10th century. Because mining needed such large quantities of wood, its regulation was an early consideration and, by the end of the Middle Ages the first taxes were imposed on forests for their use in the mining industry. Forests in mining regions enjoyed a special status and, early on, their primary use for mining purposes was firmly established.

Timber and rafting.

Building and construction timber was exported to various parts of Europe from an early date. Popular types of wood, such as oak and conifers are recorded as being rafted down rivers to the Baltic Sea from the 13th century. Yew was especially prized because of its outstanding properties, especially its flexural strength, which was popular in the manufacture of weapons. In order to make bows, such as the English longbow, entire stands of yew were cleared in Austria. This species of tree was hated by carters because their draught animals died by eating its poisonous fruit.

Summary.

The consequences of medieval forest use may be summed up as follows: many cohesive forest areas were largely destroyed, due mainly to the felling of trees for firewood. Even the most remote forest areas were affected. What remained was a landscape whose devastation is still recognizable, for example, the treeless hill ridges, the moorland and the present distribution of tree species in the central European forests.  The dwindling forests that did not regenerate themselves led to erosion of the soils, including those suitable for agricultural, in the wake of which, fields and settlements had to be abandoned. The result was a shortage of supply, especially in time of war. Given the devastating effects of overexploitation arising for the reasons set out above, territorial lords imposed official regulations for the use of woodland, a case in point being the 1579 Hohenlohe Forest regulations.

Holznot.

"Holznot", an imminent or existing acute lack of wood as a raw material, has been a social problem since the 16th century. Due to the realization that coniferous forests naturally regenerate only with difficulty, the planting of conifer seeds was successfully attempted in the Middle Ages.  Large quantities of wood were needed as a source of energy in private households and in early industrial production, for example, in glassmaking, tanning, the production of soot and in mining (in pit construction to support tunnels against collapse).  In the Black Forest huge quantities of timber were tied together to form rafts and exported to the Netherlands, where the wood was needed for shipbuilding. Farmers have overexploited forests for centuries through grazing and to make straw. At the end of the 18th century, there were hardly any forests left in Germany (see Deforestation). Wood eventually became so scarce that, in winter, fence posts, steps and all kinds of wooden objects, that were expendable in the short term, were burned as firewood.

Today.

In places like Germany today, hunters pay fees to the landowner in whose forest they hunt. These fees are covered "inter alia" by the use or sale of meat or fur from the animals killed. The hunting of deer is particularly necessary in Central Europe, due to the absence of large carnivores. Without human intervention, certain plant species would be destroyed by selective feeding, which is already seriously endangering some species. For the same reason the goal of ecological forest management, which is moving away from monocultures towards stable mixed forests, has been threatened by high levels of deer. Often spruce which, compared to other tree species is less robust, experiences problems trying to rejuvenate itself on most sites where it grows today after having been artificially planted.

Typical types of European commercial forest.

Commercial forests today can be divided into various types, although due to the modern forestry industry, most people today only have mature forests in mind:

The history of the forest in Central Europe is characterised by thousands of years of exploitation by people. Thus a distinction needs to be made between the botanical natural history of the forest in pre- and proto-historical times—which falls mainly into the fields of natural history and Paleobotany—and the onset of the period of sedentary settlement which began at the latest in the Neolithic era in Central Europe - and thus the use of the forest by people, which is covered by the disciplines of history, archaeology cultural studies and ecology.