نتایج جستجو برای: semi steppe rangelands
تعداد نتایج: 147987 فیلتر نتایج به سال:
Carbon sequestration was estimated in a semi-arid grassland region in Central Kazakhstan using an approach that integrates remote sensing, field measurements and meteorological data. Carbon fluxes for each pixel of 1 × 1 km were calculated as a product of photosynthetically active radiation (PAR) and its fraction absorbed by vegetation (fPAR), the light use efficiency (LUE) and ecosystem respir...
The Issue Invasive species, widely distributed across the western United States, pose critical conservation challenges on both non-Federal and Federal rangelands. Two of the biggest threats to ecosystem stability and integrity in the Great Basin (most of Nevada, a large part of Utah, and smaller sections of Oregon, Idaho, and California) are invasive annual grasses, particularly cheatgrass and ...
Global warming is projected to continue, leading to intense fluctuations in precipitation and heat waves and thereby affecting the productivity and the relevant biological processes of grassland ecosystems. Here, we determined the functional responses to warming and altered precipitation in both typical and desert steppes. The results showed that watering markedly increased the aboveground net ...
The genetic diversity found in domestic breeds allows farmers to develop new characteristics in response to changes in the environment, the appearance of diseases, or of modifications in market conditions. Indigenous breeds often possess gene combinations and special adaptations (such as disease resistance, adaptation to harsh conditions or poor-quality feeds) not found in other breeds. Five Ro...
Land use change is one of the most important factors of global environmental change. So, understanding and predicting the causes, processes and consequences of land use and land cover has become a major challenge. The Remote Sensing and Geographic Information System (GIS) technologies can be used effectively to detect and quantify of land use changes and its effects on the environment. The pur...
Rangelands are the most common form of terrain WE PROPOSE A PARADIGM THAT in both the United States (where it accounts for 61% of all land surface) and the world (70% of all land surface). ENHANCES HETEROGENEITY Rangelands consist primarily of native plant communities managed, typically, for livestock production (Holechek et al. INSTEAD OF HOMOGENEITY TO PROMOTE 1998). Because they can embrace ...
At the last deglaciation Earth’s largest biome, mammoth-steppe, vanished. Without knowledge of the productivity of this ecosystem, the evolution of man and the glacialeinterglacial dynamics of carbon storage in Earth’s main carbon reservoirs cannot be fully understood. Analyzes of fossils 14C dates and reconstruction of mammoth steppe climatic envelope indicated that changing climate wasn’t a r...
Knowledge of food resource of the houbara which an endangered species would be a important step toward the preservation of this bird. Adequate study has not been done in this field and therefore the food sources of the houbara during the brooding season was studied in the central steppe of Iran. In order to determine the density of insect in plant communities the pitfall trap was used , positio...
This article provides a comparative characteristic of the probability severe and very strong droughts in certain segments growing season for 1971–2000 2001–2020 on natural zones Saratov region. The initial material was climatic data from meteorological stations Yield were taken statistical compilations. study found that frequency with GTC?0,5 increased comparison during cereals (May-July) by 13...
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