نتایج جستجو برای: m transects were located 25
تعداد نتایج: 4037256 فیلتر نتایج به سال:
livestock grazing and rangelands fire are important ecological disturbances influencing the vegetation and soil properties in rangelands ecosystem. this study was conducted to determine the effects of different burned treatments and distances from the water sources on some soil and vegetation properties of rangelands ecosystem. the experiment was conducted in lashgar dar rangelands. vegetation ...
interrupting the processes which control ecosystem resources has dramatic impacts on the rangeland conditions. to protect ecosystems and landscape, it needs to understand the ecosystem processes which regulate the ecosystem resources. as main components of ecosystems, patches and inter-patches play important roles in energy and materials cascade. ecologically, functional parameters such as stab...
Invertebrate seed predation is a potential ecosystem service that substantially reduces weed seeds in crop fields, decreasing the seedling emergence and, thus, limiting competition next season. It may, be considered as natural component of long-term management toolbox. This study aimed to measure post-dispersal invertebrate levels following relevant species Hungarian maize fields: Ambrosia arte...
Echinolaena inflexa (Poir.) Chase is an abundant C3 grass species with high biomass production in the Brazilian savanna (cerrado); Melinis minutiflora Beauv. is an African C4 forage grass widespread in cerrado and probably dis‐ placing some native herbaceous species. In the present work, we analysed seasonally the content and composition of soluble carbohydrates, the starch amounts and the abov...
The percentage cover and distribution of scleractinian corals were studied at two Iranian islands in the Persian Gulf. Survey techniques involved the use of 20-m line transects placed at 4-9 m depth interval, parallel to the shore. GIS based maps were employed to show the distribution of hard corals. In Farurgan Island, hard coral cover was concentrated in the west and north-west of the island,...
This study measured lead concentrations in both the outdoor air and household dust from houses located around a lead-acid battery repair shop. Such installations are one of the largest sources of lead exposure, since outdated technology is still used, coupled with the lack of strict air-quality control programs. Measurements of the air lead concentration around the repair shop were carried out ...
Dense vegetation can augment landscape biodiversity, promote recovery of surrounding ecosystems, and facilitate colonization. However, dispersal limits affect vegetation structure early in succession to a degree that is not widely appreciated. We studied two contrasting densely vegetated habitats located on Mount St. Helens to explore their effects on surrounding vegetation. We sampled refugia ...
We studied 11 gaps covered with beech saplings (< 1.30 m tall) in a reserve compartment (compartment 139, district one, Langa forest, watershed 36: Kazemrood) of the Caspian beech forest in N Iran. Two transects, each 2 m wide, were laid along the longest (N-S) and shortest (E-W) axis of each gap. Five micro sample plots, each 4 m2, were established: one at the center, and one at each corner. Q...
Seagrass is a flowering plant that lives in coastal areas In Indonesia there are 12 species, where seagrasses able to live at depth of 1-90 meters, seagrass growth influenced by several factors including the intensity sunlight. The purpose this study was observe cover, distribution, Importance Value Index (IVI) and correlation abiotic with Jhembangan Beach White Sand on Bawean Island, East Java...
In this study I investigated the hypothesis that alterations in macroalgal cover significantly influenced the growth rates of coral colonies on the fringing reefs of Discovery Bay, Jamaica. For colonies of Montastrea annularis, Porites astreoides, and Sidastrea siderea, radial growth rates were significantly (p<0.02) higher at Dairy Bull (where Diadema antillarum had removed macroalgal cover) t...
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