نتایج جستجو برای: vegetation and fertility

تعداد نتایج: 16839774  

2006
A. M. J. Gerrits H. H. G. Savenije L. Hoffmann

In hydrological models, evaporation from interception is often disregarded, combined with transpiration, or taken as a fixed percentage of rainfall. In general interception is not considered to be a significant process in rainfallrunoff modelling. However, it appears that on average interception can amount to 20–50% of the precipitation. Therefore, knowledge about the process of interception is...

Journal: :international journal of fertility and sterility 0
lynda allouche toufik madani mohamed mechmeche laetitia clement allaoua bouchemal

background: sperm selection is generally used to describe methods for separation of spermatozoa for in-vitro-assisted reproduction. few studies reported relation in vivo fertility and semen parameters after selection of fertile spermatozoa; hence, our research attempt to assess different semen parameters after post-thaw (pt) or after selecting sperm sample (ssp), using density gradient separati...

Journal: :international journal of environmental research 2014
m. fathi m.r. masnavi

this paper discusses the importance of environmental aesthetics and scenic beauty of currentroadside vegetation in the highways, and the necessity for the contribution of users (motorists) preferences inthe integration of scenic beauty of roadside vegetation into its management plans. the results of a questionnairesurvey of motorist’s opinion on the landscape aesthetics and quality of some high...

Journal: :desert 0
h. azarnivand associate professor, faculty of natural resources, university of tehran, karaj, iran m.a. zare chahouki associate professor, faculty of natural resources, university of tehran, karaj, iran h. joneidi assistant professort, university of kurdestan, sanandaj, iran

one of the characteristics in iranian model of desertification potential assessment (imdpa) is vegetation. sincevegetation is very important factor in the degradation of land, so some indices were determined for this item in order toevaluate desertification potential of arid, semi arid and arid sub humid areas of iran. the indices included vegetationcondition, exploit and revegetation. to calib...

2016
Shuai Wang Qiubing Wang Kabindra Adhikari Shuhai Jia Xinxin Jin Hongbin Liu

Soil organic carbon (SOC) plays an important role in soil fertility and the global carbon cycle. A better understanding of spatial-temporal changes of SOC content is essential for soil resource management, emission studies, and carbon accounting. In this study, we used a boosted regression trees (BRT) model to map distributions of SOC content in the topsoil (0–20 cm) and evaluated its temporal ...

2011
D. W. Cole J. Compton P. S. Homann R. L. Edmonds H. Van Miegroet

Soil organic C or organic matter has been studied under various plant communities. In comparisons of similar soils having either grassland or forest vegetation, surface horizons of the forest soil may have lower levels of soil C (Ugolini and Schlichte, 1973; Almendinger, 1990) or higher levels (Jenny, 1980). Even between forest types, soil C may vary. Alban (1982) found the forest floor in a Po...

2017
Yuanzhi Li Bill Shipley

Can CSR theory, in conjunction with a recently proposed globally calibrated CSR ordination ("StrateFy"), using only three easily measured leaf traits (leaf area, specific leaf area and leaf dry matter content) predict the functional signature of herbaceous vegetation along experimentally manipulated gradients of soil fertility and disturbance? To determine this, we grew 37 herbaceous species in...

Journal: :Anais da Academia Brasileira de Ciencias 2013
Andreza V Neri Carlos E G R Schaefer Agostinho L Souza Walnir G Ferreira João A A Meira-Neto

This study was carried out in Paraopeba National Reserve. It aims to classify and evaluate the soil of the studied area and to verify the influence of soil attributes on vegetation by testing the following hypotheses: 1) under woodland physiognomies (Cerradão) the soil fertility is higher and the Al content lower; 2) open savanna occurs only in areas with high Al contents. For this purpose, rep...

2013
Olena Dubovyk Gunter Menz Christopher Conrad Elena Kan Miriam Machwitz Asia Khamzina

Advancing land degradation in the irrigated areas of Central Asia hinders sustainable development of this predominantly agricultural region. To support decisions on mitigating cropland degradation, this study combines linear trend analysis and spatial logistic regression modeling to expose a land degradation trend in the Khorezm region, Uzbekistan, and to analyze the causes. Time series of the ...

2015
M. Schönert E. Zillmann H. Weichelt J. U. H. Eitel T. S. Magney H. Lilienthal B. Siegmann T. Jarmer

The retrieval of crop biophysical parameters using spectral indices obtained from high temporal and spatial resolution satellite data, is a valuable tool to monitor crop growth and status. Tasseled Cap Features (TCFs) for RapidEye data were derived from spectral variances typically present in agricultural scenes. The TCF Greenness (GRE) was aligned to the spectral variance of vital vegetation, ...

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