Comparable sites \verc exam incd on Rahui Jsland. Lake Waikareiti, which is frct; of introduced mammals, and on the adjacent mainland, "which is not. The forest understorcy density'in NotllOfaglls fllscaf N. mem.iesii forest has been reduced on the mainland. In the mainland forest there arc fewer plants of Pscudopanax and Coprosma f;pp. and more p!ants of Dl'acophyllllln PY1'111/1idoleand Dic/....

In a free-air carbon dioxide (CO(2)) enrichment study (BangorFACE), Alnus glutinosa, Betula pendula and Fagus sylvatica were planted in areas of one-, two- and three-species mixtures (n = 4). The trees were exposed to ambient or elevated CO(2) (580 μmol mol(-1)) for 4 yr, and aboveground growth characteristics were measured. In monoculture, the mean effect of CO(2) enrichment on aboveground woo...

Ecological communities are structured in response to spatial and temporal variation of numerous factors, including edaphic conditions, biotic interactions, climatic patterns and disturbance regimes. Widespread anthropogenic factors such as timber harvesting can create long-lasting impacts, obscuring the relationship between community structure and environmental conditions. Minimally impacted sy...

Positive feedbacks in drivers of degradation can cause threshold responses in natural ecosystems. Though threshold responses have received much attention in studies of aquatic ecosystems, they have been neglected in terrestrial systems, such as forests, where the long time-scales required for monitoring have impeded research. In this study we explored the role of positive feedbacks in a tempera...

The aim of the paper is to apply point processes to root data modelling. We propose a new approach to parametric inference when the data are inhomogeneous replicated marked point patterns. We generalize Geyer's saturation point process to a model, which combines inhomogeneity, marks and interaction between the marked points. Furthermore, the inhomogeneity influences the definition of the neighb...

Mapping landscape variation in tree species richness (SR) is essential to the long term management and conservation of forest ecosystems. The current study examines the prospect of mapping field assessments of SR in a high-elevation, deciduous forest in northern Iran as a function of 16 biophysical variables representative of the area's unique physiography, including topography and coastal plac...

Rapid increases in global temperature are likely to impose strong directional selection on many plant populations, which must therefore adapt if they are to survive. Within populations, microgeographic genetic differentiation of individuals with respect to climate suggests that some populations may adapt to changing temperatures in the short-term through rapid changes in gene frequency. We used...

Fagus orientalis Lipsky tree leaves, which are abundant in Iran, were evaluated for removal of lead from aqueous solutions. The optimization strategy is carried out by using two level full factorial designs. Results of the two levels full factorial design (2) based on an analysis of variance demonstrated that the initial pH, contact time and concentration of biomass are statistically significan...

The composition and temporal variation in species recruitment were examined in relation to annual dendrochronological data to determine the historical development and successional history of an old-growth mixed-oak (Quercus) forest in northern Virginia, USA. A ridge site in the upland Piedmont, along the Potomac River, was used to survey the old-growth forest, which is dominated by Quercus alba...

the non-destructive meyer method was evaluated to determine the bark volume of beech (fagus orientalis lipsky) stands in north of iran. the sample size was 185 standing trees collected from 4 geographical aspects (north, south, west and east) aspects. the constant k values and bark thickness (2e mm) of 185 standing trees were used to calculate the bark volume by the meyer method. in this study,...