نتایج جستجو برای: grassland

تعداد نتایج: 10371  

Journal: :international journal of environmental research 2015
r. ekoungoulou x. liu s. niu

greenhouse gases emissions have increased during the last century due to human activities such as agricultural practices, fossil fuel burning and industrial practices. the formation of greenhouse gases, in particular n2o or co2 is strongly controlled by both soil temperature and soil humidity. laboratory experiment was conducted to assess the response of grassland and arable soils with regard t...

2007
Zhiming Liu Nanyan Ling

Grassland had been interpreted with the method that combined supervised and non-supervised classifications using Landsat data in autumns 1986, 1996 and 2000. The amelioration of algorithm promoted the accuracy. With the support of RS and GIS, spatial information of grassland landscape in west Jilin province from 1986 to 2000 was extracted, spatio-temporal dynamics of grassland and change of gra...

2017
Lawrence D. Igl Bart M. Ballard

We report on the habitat associations of 21 species of grassland birds overwintering in or migrating through southern Texas, during 1991-1992 and 1992-1993. Ninety percent of our grassland bird observations were made during winter and spring, and only 10% occurred during fall. Grassland species made up a high proportion of the total bird densities in grassland and shrub-grassland habitats, but ...

2015
Dandan Xu Xulin Guo

Grassland ecosystem is one of the largest ecosystems, which naturally occurs on all continents excluding Antarctica and provides both ecological and economic functions. The deterioration of natural grassland has been attracting many grassland researchers to monitor the grassland condition and dynamics for decades. Remote sensing techniques, which are advanced in dealing with the scale constrain...

ژورنال: علوم آب و خاک 2015
زرین کفش, منوچهر, شاهویی, سید صابر, ویسانی, وریا, پارسامنش, نوشین,

Reduction of quality and soil productivity due to organic carbon losses is one of the most important consequences of land use changes, that creates irreparable effects on the soil. To evaluate the land use effect on the amount of soil organic carbon in Vertisols, Sartip Abad series with extent of 1850 hectare in south of Bilehvar area in Kermanshah province was studied by using the completely r...

Journal: :ecopersia 2014
majid ajorlo ramdzani abdullah

water quality is a serious issue in tropical grasslands that must be addressed to ensure the continuity and sustainability of water resources. this study aimed to assess the stream water quality of tropical grassland under long-term moderate (2.7 animal unit ha-1 y-1 for 34 years) and short-term heavy (5 animal unit ha-1 y-1 for 2 years) grazing systems at catchment and farm scales in kuala lum...

2013
Liping Qiu Xiaorong Wei Xingchang Zhang Jimin Cheng

The grazing exclusion in degraded grassland has been extensively used to prevent the loss of grassland resources and to improve grassland services. The effects of grazing exclusion on C and N balance, however, have not been well addressed but are essential for assessing grassland C sinks, the sustainable use of grassland resources and the support of grassland services. To understand the respons...

Journal: :Journal of environmental management 2009
Birgit Reger Tim Mattern Annette Otte Rainer Waldhardt

Grassland age is increasingly recognised to be an indicator for present-day biodiversity, e.g. plant species richness, and is also important for other landscape functions. We developed a methodological approach to systematically assess the spatial distribution of grassland age in marginal European landscapes. This approach - applied to the Lahn-Dill Highlands (1270 km(2)), a marginal landscape ...

2013
Lu Wen Shikui Dong Yuanyuan Li Xiaoyan Li Jianjun Shi Yanlong Wang Demei Liu Yushou Ma

The deterioration of alpine grassland has great impact on ecosystem services in the alpine region of Qinghai-Tibetan Plateau. However, the effect of grassland degradation on ecosystem services and the consequence of grassland deterioration on economic loss still remains a mystery. So, in this study, we assessed four types of ecosystem services following the Millennium Ecosystem Assessment class...

2017
Cui Li Bo Xiao Qinghai Wang Ruilun Zheng Juying Wu

To provide more insights into the responses of the soil seed bank and vegetation to human disturbance intensity, we selected four land use types, including: native grassland (no human disturbance), abandoned artificial grassland (light human disturbance), artificial grassland (moderate human disturbance), and farmland (severe human disturbance) in a semi-arid climate of northern China. The spec...

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