Epiphytic macrolichen communities were compared among forest stand types in the Blue River watershed of western Oregon. Stand types were defined by stand structure, according to age classes of the younger tree cohort and remnant tree retention. Remnant trees were those in an older cohort that remained following a stand disturbance that initiated tree regeneration, such as a timber harvest or na...

calendula (calendula officinalis) is relatively cold tolerant plant, but in some years plant seriously injured due to harsh winter. in order to evaluate freezing tolerance of calendula an experiment was carried out at college of agriculture, ferdowsi university of mashhadin a factorial-completely randomized design with three replications and plants of two sowing dates (summer and autumn) were e...

the effect of grafting on yield and some other quantitative and qualitative characteristics of two green¬house cucumber cultivars, namely roberto and danito grafted on five rootstocks of shintoza, kiroshintoza (cucurbita maxima × c. moschata), cucurbita maxima (c. maxima cv. goriki), fig leaf gourd (c. ficifolia cv. korodome), and bottle gourd (lagenaria siceraria) was investigated in this stud...

BACKGROUND AND AIMS The dynamical system of plant growth GREENLAB was originally developed for individual plants, without explicitly taking into account interplant competition for light. Inspired by the competition models developed in the context of forest science for mono-specific stands, we propose to adapt the method of crown projection onto the x-y plane to GREENLAB, in order to study the e...

In the last decade, plant ecologists have focussed more on the occurrence of positive plant–plant interactions than ever before. Especially in severe environments, such as the Arctic, species removal experiments tend to find facilitative rather than competitive effects, casting doubt on the importance of competition under extreme growing conditions. Two approaches to measure plant–plant interac...