نتایج جستجو برای: vegetation understory
تعداد نتایج: 49366 فیلتر نتایج به سال:
Although most temperate forests are actively managed for timber production, few data exist regarding the long-term effects of forest management on understory plant communities. We investigated the responses of understory communities to a factorial combination of silvicultural-thinning and nutrient-addition treatments maintained for 12–16 yr in a set of 21–27 yr old Douglas-fir (Pseudotsuga menz...
Even though many forest plants spend all or a significant portion of their lives in the forest understory, few studies have compared understory composition, structure, and resource availability among forests. We used standardized transect-based methods to compare small sapling densities (10•50 cm tall), understory vegetation cover, canopy openness, and nutrient availability in non-gap portions ...
The current unprecedented outbreak of mountain pine beetle (Dendroctonus ponderosae) in lodgepole pine (Pinus contorta) forests of western Canada has resulted in a landscape consisting of a mosaic of forest stands at different stages of mortality. Within forest stands, understory communities are the reservoir of the majority of plant species diversity and influence the composition of future for...
Moist and temperate Caspian forests are associated with a diversity of soil types and topography. Although, natural history and ecological attributes of the Caspian vegetation is well-documented, little is known about mycorrhizae of the Caspian (Hyrcanian) flora. Samples of herbaceous plant species were collected from 4 pre-determined altitudes (-13 upto about 1500m above sea level, appro...
PREMISE OF THE STUDY Elucidating the factors that determine the abundance and distribution of species remains a central goal of ecology. It is well recognized that genetic differences among individual species can affect the distribution and species interactions of dependent taxa, but the ecological effects of genetic differences on taxa of the same trophic level remain much less understood. Our...
The boreal forest is one of the largest terrestrial biomes on Earth. Conifers normally dominate the tree layer across the biome, but other aspects of ecosystem structure and dynamics vary geographically. The cause of the conspicuous differences in the understory vegetation and the herbivore-predator cycles between northwestern Europe and western North America presents an enigma. Ericaceous dwar...
As pinyon–juniper (specifically, Pinus monophylla and Juniperus osteosperma) woodlands in the western United States increase in distribution and density, understory growth declines and the occurrence of crown fires increases, leaving mountainsides open to both soil erosion and invasion by exotic species. We examined if the loss in understory cover that occurred with increasing tree cover was re...
At a wetland study site in Tuskegee National Forest, AL, resting female mosquitoes were collected from natural and artificial resting sites to identify species-specific resting sites and to evaluate various artificial resting sites for their utility in collecting resting mosquitoes. Natural resting sites included small tree cavities, large tree cavities, and understory vegetation. Artificial re...
The effect of tree diversity on productivity in subtropical forests in China is poorly understood. We investigated the biomasses of trees, understory vegetation, coarse roots, and fine roots with varying proportions of Pinus massoniana, mixed with other tree species in stands of the same age, to examine the effects of tree diversity. With an increase of P. massoniana proportion, the tree and un...
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