Entwicklung von Fichtenverjüngung im Lehrwald Sedrun der ETH Zürich (nördliche Zwischenalpen) | Development of Norway-Spruce Regeneration in the Training Forest of ETH Zurich in Sedrun, Canton of Grisons, Switzerland (Northern Intermediate Alps)
The development of planted Norway-spruce trees as well as the germination and self-seeding of natural regeneration were investigated on various forest locations on the north and south slopes between 1470 and 1800 m above sea level in the training forest of ETH Zurich in Sedrun, canton of Grisons, Switzerland.
Zu wenig Verjüngung im Schweizer Gebirgs-Fichtenwald: Nachweis mit einem neuen Modellansatz | A new modelling approach suggests insufficient regeneration in Swiss Norway spruce mountain forests
A be-value for tree regeneration cover was derived from a static model of a Norway spruce mountain selection forest and published data. If those assumptions that seem most realistic are adopted in the model, the be-value is 10% cover. According to data from the second Swiss National Forest Inventory, some 55% of the mountain forests in Switzerland with Norway spruce dominance do not meet this be-value. Due to the uncertainty of several assumptions in the model it is not possible to quantify precisely the lack of regeneration, but the extent of insufficient regeneration has been shown to be considerable. Abstract: Mit Hilfe eines statischen Gebirgsplenterwald- Modells und von Daten aus der Literatur wird fur den Gebirgs-Fichtenwald ein Sollwert des Jungwald-Deckungs- grades abgeleitet. Bei plausibel scheinenden Modellan- nahmen liegt der Sollwert bei 10%; er wird in rund 55% des Fichten-dominierten Gebirgswaldes in der Schweiz unter- schritten, wie ein Vergleich mit Daten aus dem zweiten Landesforstinventar zeigt. Einige Modellannahmen sind zwar unsicher und daher ist das genaue Ausmass des Verjun- gungsmangels unbekannt. Es wird aber nachgewiesen, dass dieser erheblich ist.
Geographic And Environmental Influence On Maya Settlement Patterns Of The Northwest Yucatan: An Explanation For The Sparsely Settled Western Cenote Zone
Most settlement pattern research and GIS analysis of the ancient Maya of the Northern Yucatan have focused on water availability in a dry landscape where cenotes are often the only water source. While water is of paramount importance, permanent settlement secondarily requires farmable soil, a resource often as precious as water in many parts of the Yucatan. The dynamics between these resources reveal areas of ideal settlement and more challenging landscapes for which the Maya developed strategies to overcome environmental conditions. A region of the southwest "Cenote Zone", however, appears to have presented the ancient Maya with insurmountably poor environmental conditions despite abundant water resources. The lack of dense population and stone architecture in this area emphasizes the lack of a simple correlation between cenotes and settlement. This thesis uses GIS analysis to identify and explore such problematic settlement areas to better understand the factors and complexities involved in the more successful settlements of neighboring regions. iv This work is dedicated to my late father, who first introduced me to the Mundo Maya through a visit to the ruins of Tikal at the age of nine, and who instilled in me strength, curiosity, and a love for exploring the world. v ACKLOWLEDGEMENTS I'd like to acknowledge Dr. Arlen Chase and Dr. Diane Chase for providing such outstanding opportunities and instruction, and for leading by example both in the field and in the classroom. Dr. John Walker for his eye-opening perspectives, GIS instruction, inspiring hard-working attitude, and patience in the field. Dr. Clifford Brown and Dr. Walter Witschey for their invaluable correspondence and for their contributions to mapping and GIS data of Maya sites.