The past, present and future tasks of Hungarian dendrological research.
Hungarian dendrological research (research of living woody plants) has more than 200 years old history; the first general work by János Keresztély Grossinger was published in 1797. Further basic works in our time yet are: Forest Botany by Lajos Fekete and Sándor Mágócsy-Dietz (1896); and the chorological work, Distribution of trees and shrubs of sylvicultural importance in the region of Hungarian State by Lajos Fekete and Tibor Blattny (1913). A few dendrologists and many botanists have helped to get better knowledge of Hungarian dendroflora. From the point of view of taxonomy, chorology and habitat - which are interested by field botanists - it can be said that knowledge is fairly heterogeneous. There are sufficient information about most of the rare (protected/endangered) woody plants (an about 50 species) and the important adventives, above all invasive trees and shrubs (an about 10 species). From these two groups beyond there are only few taxa which can be said thoroughly worked up and known (e.g. Castanea sativa, Cornus mas, Fraxinus spp., Quercus spp.). List of the dendrotaxa, hardly known in the above-mentioned point of view is rich in species that are important for forestry or horticulture (e.g. Alnus glutinosa, Acer spp., Betula pendula, Corylusavellana and most of Salix spp.), supplemented with other species (e.g. Clematis vitalba, Colutea arborescens, Lonicera xylosteum, Padus avium, Sambucus nigra, Staphylea pinnata, Viburnum spp.).Followings can be asked from our field botanists: i) look for a specialist in cases of critical dendrotaxa; ii) a circumspect identification is necessary - especially in the case of leaves - by right of great number of samples from the adequate part of shoot; iii) keep in view frequent hybridization (e.g. in the case of Betula, Crataegus, Pyrus, Tilia), and frequent appearance of hybrids (e.g. Betula × rhombifolia, Cerasus × eminens, Salix × rubens); iv) appearance of interim forms are usually typical in the cases of species classified into aggregate species (e.g. Quercus petraea agg., Qu. pubescens agg.); v) take intraspecific taxa according to various ecological demands, area, morphological differences into consideration; vi) culture variations cannot be treat as an equal with the species (e.g. Populus spp., Salix spp.); vii) natural ↔ artificial area have to be separated; viii) lend a helping hand in getting taxonomical knowledge of hardly known dendrotaxa.
Leaf Growth and Photosynthetic Performance of Two Co-existing Oak Species in Contrasting Growing Seasons
Ecophysiological investigations of Quercus petraea and Quercus cerris were performed at the Sikfkut research site in the dry and humid growing seas ons of 2003 and 2004. The results suggested that leaf growth and the photosynthetic a pparatus of Q. petraea exhibited higher sensitivity to drought in 2003 than that of Q. cerris . In leaves of Q. petraea , chlorophyll content showed larger inter-annual and within-canopy variability than in those of Q. cerris . Fully developed leaves of Q petraea showed lower SLM which indicated higher leaf cell wall elasticity allowing them to maintain a water spending strategy, while high spec ific leaf mass (SLM) values reflected a water saving strategy for Q. cerris . Water use efficiency of Q. cerris was higher than in the case of Q. petraea , which may provide an advantage for this species i n dry periods. In the contrasting years the final leaf area and leaf mass of both species w ere determined by the amount of rainfall and temperature conditions during the period of early e xponential phase of leaf growth. As indicated by the low values of the Fv/Fm chlorophyll fluorescenc e parameter the photosynthetic apparatus of both species exhibited high susceptibility to abiotic st ress factors in early spring. A large VAZ cycle poo l indicated that zeaxanthin dependent heat dissipatio n was the main contributor to photoprotection of photosynthetic apparatus in young leaves but in ful ly developed leaves the relatively high light saturated ETR and low P max as well as the maintenance of high Fv/Fm even in s evere dry periods reflected the potential involvement of photorespira tory electron transport in photoprotection of both species in summer. Drought in 2003 may have resulted in serious depletion of dry matter reserves influencing the vitality of trees in following year . Q. petraea showed lower photochemical activity in the successive vegetation period after the dry year than Q. cerris which suggested lower tolerance to drought in the long term. oak / drought / leaf growth / photosynthesis / phot ochemical efficiency of PSII
Woodrow Wilson: The Essential Political Writings
Chapter 1 Preface Chapter 2 Introduction to Wilson's Political Thought Part 3 Progress and the Organic State Chapter 4 The State (chapters 1, 2, 13, 16) Chapter 5 "Christ's Army" Chapter 6 "Christian Progress" Part 7 Political Liberty and the Scope and Ends of Government Chapter 8 "Socialism and Democracy" Chapter 9 "A Calendar of Great Americans" Chapter 10 "Address on Thomas Jefferson" Chapter 11 "The Authors and Signers of the Declaration of Independence" Chapter 12 The New Freedom (chapters 1, 2) Part 13 Institutional Reform Chapter 14 "Cabinet Government in the United States" Chapter 15 Congressional Government (chapter 2 & conclusion) Chapter 16 Constitutional Government in the United States (chapters 3, 8) Chapter 17 "Wanted - A Party" Part 18 Political and Administrative Leadership Chapter 19 "Leaders of Men" Chapter 20 "The Study of Administration" Part 21 Foreign Policy Chapter 22 "War Message to Congress" Chapter 23 "Fourteen Points" Part 24 Appendix A. Chronology of Wilson's Academic Work and Other Selected Events Part 25 Appendix B. Selected Bibliography