fine sandy loam (fine-loamy, siliceous, semiactive, thermic Typic Paleudult) with a slope of 1–10% (Kerr et al. 1980). The other complex (92° 38 W, 31° 8 N at 66 m above sea level) is comprised of Beauregard silt loam and Malbis fine sandy loam (fine-loamy, siliceous, subactive, thermic Plinthic Paleudult) with a slope of 1–5%. Before harvesting, Study 2 was a closed canopy, mature, loblolly pi...

Plant species composition, species abundances, and species richness were strongly recruitment limited in a 4-yr experiment in which seeds of up to 54 species were added to patches of native grassland. Four field seasons after a one-time addition of seed, many added species were still present and reproducing, with plots seeded at the highest rate having species richness that was 83% greater and ...

Although the distribution and structure of pinyon-juiper woodlands in the southwestern United States are thought to be the result of historic fluctuations in regional climatic conditions, more recent increases in the areal extent, tree density, soil erosion rates and loss of understory plant diversity are attributed to heavy grazing by domestic livestock and interruption of the natural fire reg...

Herbivores are important drivers of plant species coexistence and community assembly. However, detailed mechanistic information on how herbivores affect dominance hierarchies between plant species is scarce. Here, we used data of a multi-site herbivore exclusion experiment in grasslands to assess changes in the cover of 28 plant species in response to aboveground pesticide. application. Moreove...

this research aimed to evaluate the effect of planting seasons (autumn and spring) on 10 accessions of two species of astragalus effusus and astragalus brachyodontus in the field condition (homand absard station, damavand). after preparing the seedbed, the plant species were planted on two lines in 2 m, where the spacing between the lines of each accession was 0.5 m, and the spacing between the...

While exotic plant species often come to dominate disturbed communities, long-term patterns of invasion are poorly known. Here we present data from 40 yr of continuous vegetation sampling, documenting the temporal distribution of exotic plant species in old field succession. The relative cover of exotic species decreased with time since abandonment, with significant declines occurring 20 yr pos...

abstract. the purpose of this study was to investigate the effects of topographical factors on the classification of grassland plant communities in the rangelands of ghorkhud, northern khorasan province, iran. for sampling, land units were specified. a floristic list was prepared using minimal area method based on the nested plot (braun-blanquet method). 116 10m2 furrows were selected. within e...

Understory plant communities play critical ecological roles in forest ecosystems. Both above- and below-ground ecosystem properties and processes influence these communities but relatively little is known about such effects at fine (i.e., one to several meters within-stand) scales, particularly for forests in which the canopy is dominated by a single species. An improved understanding of these ...

Two conservation goals of the early 20th century, extensive reforestation and reduced wildfire through fire exclusion, may have contributed to declining pollinator abundance as forests became denser and shrub covered. To examine how forest structure affects bees we selected 5 stands in each of 7 forest types including: cleared forest; dense young pines; thinned young pines; mature open pine wit...