The effects of azalea lace bug, Stephanitis pyrioides (Scott), feeding injury on azalea growth and development were investigated using 'Girard's Rose' azaleas during a 2-yr field study in Georgia Low, medium, and high injury treatments, which corresponded to 6, 8, and 14% maximum canopy area injury, were compared with control azaleas that received no lace bug infestation. Flower number, whole-s...

Fossil data have been interpreted as indicating that Late Cretaceous tropical forests were open and dry adapted and that modern closed-canopy rain forest did not originate until after the Cretaceous-Tertiary (K/T) boundary. However, some mid-Cretaceous leaf floras have been interpreted as rain forest. Molecular divergence-time estimates within the clade Malpighiales, which constitute a large pe...

This study addressed the question: can herbivory by a medium size herbivore, black-tail jackrabbits (Lepus californicus), change dominance in desertified ecosystems dominated by two species of shrubs. Shrubs that were pruned by jackrabbits in plant communities dominated by creosotebush (Larrea tridentata) and tarbush (Flourensia cernua) were compared to shrubs not browsed by the rabbits. In the...

Question: Is the facilitative effect of nurse shrubs on early recruitment of trees mediated by a ‘canopy effect’ (microclimate amelioration and protection from herbivores), a ‘soil effect’ (modification of soil properties), or both? Location: Two successional montane shrublands at the Sierra Nevada Protected Area, SE Spain. Method: Seedlings of Quercus and Pinus species were planted in four exp...

Redwood National Park is comprised of large areas of overstocked stands resulting from harvest of the old-growth stands in the late 1940s to the 1970s. The Holter Ridge Thinning Study was initiated in 1978 to address this problem and examine the effects that thinning to varying spacing would have on forest development. Densities following thinning in 1979 ranged from 150 to 790 stems/acre with ...

Surface energy exchanges were measured in a sequence of five sites representing the major vegetation types in the transition from arctic tundra to forest. This is the major transition in vegetation structure in northern high latitudes. We examined the influence of vegetation structure on the rates of sensible heating and evapotranspiration to assess the potential feedbacks to climate if high-la...

There is less published research on ecosystems of forested rangeland in Iran. This research was conducted to investigate the forested rangeland area based on legal definition via comparison of indices species richness, diversity, and morphology of the trees and shrubs in Sabzkouh watershed, Chaharmahal Bakhtiari province, Iran. Quantitative characteristics of trees and shrubs were measured by 5...