نتایج جستجو برای: plants cover composition
تعداد نتایج: 551987 فیلتر نتایج به سال:
background & aim: identification, characterization and detection of medicinal plants chemical composition are very important for phytochemical scientific source. sumac is one of the medicinal plants in the world that uses for industrial and pharmacological application. in this study, chemical composition of rhus coriaria has been investigated. experimental: chemical composition of the matu...
PREMISE OF THE STUDY Serpentine soils have attracted the attention of evolutionary biologists for decades because of their high number of rare and endemic taxa, though less is known about the ecological factors that govern the diversity and composition of serpentine communities. Theory suggests that vegetation on these low-productivity soils will be relatively resilient to fire, the most common...
We evaluated the abundance of nonnative plants on fuel breaks and in adjacent untreated areas to determine if fuel treatments promote the invasion of nonnative plant species. Understanding the relationship between fuel treatments and nonnative plants is becoming increasingly important as federal and state agencies are currently implementing large fuel treatment programs throughout the United St...
Invasive alien plants (IAP) pose a major threat to biodiversity and have negative impact on the integrity conservation status of plant communities. Mediterranean dunes are widely exposed IAP, due their environmental heterogeneity anthropogenic pressures which they subjected. The current study explored possible existence critical thresholds IAP cover/abundance dune path impacts that may cause de...
Glacial retreat creates new habitat which is colonized and developed by plants and animals during the process of primary succession. While there has been much debate about the relative role of deterministic and stochastic processes during terrestrial succession, evidence from freshwater ecosystems remains minimal and a general consensus is lacking. Using a unique 27 years record of community as...
Planting Haloxylon aphyllum under oil mulches has frequently been used for stabilizing mobile sands in Iran for during the last three decades. This study is carried out in stabilized sandy desert of Samad Abad-e-Sarakhs to evaluate the implications of planting Haloxylon aphyllum on the vegetation and soil attributes. Sampling was carried out random-systematically in the representative areas of ...
Inputs of low molecular weight carbon (LMW-C) to soil - primarily via root exudates- are expected to be a major driver of microbial activity and source of stable soil organic carbon. It is expected that variation in the type and composition of LMW-C entering soil will influence microbial community composition and function. If this is the case then short-term changes in LMW-C inputs may alter pr...
Pyridine-type alkaloids are most common in Nicotiana species. To study the effect of alkaloid composition on bacterial community composition in floral nectar, we compared the nicotine-rich wild type (WT) N. attenuata, the nicotine biosynthesis-silenced N. attenuata that was rich in anatabine and the anabasine-rich WT N. glauca plants. We found that the composition of these secondary metabolites...
Seeds collected from trees, shrubs and lianas growing on Barro Colorado Island, Panama, were analyzed for their content of phenolic compounds, oxidative activities protein precipitation capacities. Proanthocyanidins hydrolysable tannins detected in one-third 189 studied species. The most oxidatively active group species the ones containing prodelphinidins ellagitannins whereas that had highest ...
BACKGROUND This study investigated the microclimatic behavior of different land cover types in urban parks and, the correlation between air temperature and land cover composition to understand how land cover affects outdoor thermal environment during hot summer. METHODS To address this issue, air temperatures were measured on four different land cover types at four observation sites inside an...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید