Leaf hydraulics, gas exchange and carbon storage in Pinus edulis and Juniperus monosperma, two tree species on opposite ends of the isohydry-anisohydry spectrum, were analyzed to examine relationships between hydraulic function and carbohydrate dynamics. Leaf hydraulic vulnerability, leaf water potential (Ψl ), leaf hydraulic conductance (Kleaf ), photosynthesis (A), stomatal conductance (gs) a...

Ground beetle assemblages were studied during 2003-08 in the Pisz Forest by comparing stands disturbed by a tornado to undisturbed control stands. The following exploratory questions were put forward. (1) How do the carabid assemblages change during six years following the tornado impact? (2) Does the carabid assemblage recovery begin during the six first post-tornado years? To assess the state...

Tree rings from three dendrochronologically dated bristlecone pines were analyzed for stable hydrogen isotopic composition. These trees give a continuous time series from 8000 years ago to the present that indicates the presence of a postglacial climate optimum 6800 years ago and a continuous cooling since then. The qualitative agreement between this record and records from other sources, such ...

To determine the effects of shade on biomass, carbon allocation patterns and photosynthetic response, seedlings of loblolly pine (Pinus taeda L.), white pine (Pinus strobus L.), red maple (Acer rubrum L.), and yellow-poplar (Liriodendron tulipifera L.) were grown without shade or in shade treatments providing a 79 or 89% reduction of full sunlight for two growing seasons. The shade treatments r...

Shoot elongation patterns of Pinus brutia Ten. were studied in six natural populations and 10 open-pollinated families within each population. The data were collected from a provenance-progeny trial that was thinned at Ages 13 and 17 years. Annual height increment was partitioned into first flush (spring shoot) and subsequent flushes (summer shoots) and the contribution of each to annual height...

Effects of varying the time of stem injection of gibberellin A4/7 (GA4/7) on male and female flowering in potted grafts of Pinus sylvestris L. in a greenhouse were monitored in two consecutive years. Flowering results for each application time were correlated with phenological characteristics and abiotic factors in an attempt to find reproducible indicators of the most effective time of GA4/7 t...

Soil and litter arthropods are important in many forest ecosystem processes where they help to regulate nutrient dynamics and soil quality, and are useful bioindicators of ecosystem condition and change. This study was initiated in response to concerns about possible decline in site productivity due to intensive forestry practices. We investigated the effects of tree harvesting and site prepara...

In high-diversity communities, rare species encounter one another infrequently and therefore may compete more intensely with common species or guilds for limiting space and resources. In addition, rare species may be strongly recruitment limited because of their low abundances. Under these conditions, stochastic dispersal and immigration history can have an important influence on community stru...

Restoration and management activities targeted at recovering biodiversity can lead to unexpected results. In part, this is due to a lack of understanding of how site-level characteristics, landscape factors, and land-use history interact with restoration and management practices to determine patterns of diversity. For plants, such factors may be particularly important since plant populations of...