نتایج جستجو برای: disturbing the upper soil layers

تعداد نتایج: 16137039  

2016
Wei Xu Minhui Hao Juan Wang Chunyu Zhang Xiuhai Zhao Klaus von Gadow

This study uses detailed soil and vegetation data collected in a 30-ha old-growth broad-leaved Korean pine forest to study the effect of soil properties on tree community structures. Spatial distribution patterns are simulated using a homogeneous Poisson process (HomP) and a homogeneous Thomas process (HomT). The simulated distributions are compared with the observed ones to explore correlation...

Journal: :international journal of environmental research 0
z. miletić institute of forestry, department for silviculture, plantation establishment and forest ecology, belgrade, serbia m. knežević faculty of forestry, department of forest ecology, belgrade, serbia s. stajić institute of forestry, department for silviculture, plantation establishment and forest ecology, belgrade, serbia o. košanin faculty of forestry, department of forest ecology, belgrade, serbia i. đorđević institute of forestry, department for silviculture, plantation establishment and forest ecology, belgrade, serbia

the effect of european black alder (alnus glutinosa l.) on the contents of carbon and nitrogen,exchangeable base cations, and plant available forms of phosphorus in the reclaimed mine soils formed bywaste deposition from opencast lignite mines was researched in central serbia. it was concluded that thegreatest part of dead organic residues reaching the soil under european black alder monocultur...

Journal: :تحقیقات جغرافیایی 0
احمد نوحه گر دانشگاه هرمزگان احمد نوحه گر دانشگاه هرمزگان احمد نوحه گر دانشگاه هرمزگان محمد کاظمی گروه آبخیزداری دانشگاه هرمزگان

in this research, the applicability of geographic information system (gis) and remote sensing (rs) techniques was tested to assess soil erosion risk with the icona erosion model. this study was carried out in the tange bostanak area because of its variety of diverse landforms, land uses and land covers. the erosion risk assessment phase of this model consists of seven steps that mainly use slop...

Journal: :آب و خاک 0
علی اکبر سبزی پرور حمید زارع ابیانه مریم بیات ورکشی

abstract soil temperature is one of the key parameters affecting most hydrologic and agricultural processes. therefore, its measurement and prediction is very crucial. so far, the statistical regression methods have been used for estimation of soil temperature for specific location encountering with lack or shortage of data. in this work, soil temperature data are estimated at six different dep...

Journal: :Zeitschrift fur Naturforschung. C, Journal of biosciences 1998
K Kloos U M Hüsgen H Bothe

Bacteria isolated from different layers of four soils of the Cologne area were analyzed for denitrifying, nitrifying and N2-fixing isolates by colony hybridization using gene probes. In the soils tested, the percentage of denitrifying bacteria among the total population isolated was 3-8% (in one case exceptionally 15%) and thus small. Denitrifying bacteria were particularly enriched in the uppe...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سمنان - دانشکده علوم انسانی 1392

the present study is an attempt to investigate the potential impact of inspirational quotes on improving english abstract vocabulary recall. to achieve this goal, a multiple choice language proficiency test of 60 items including vocabulary and grammar component was administered to a sample of 63 second-semester male and female students whose age ranged between 17 to 22 and they were studying en...

Journal: :Tree physiology 2008
Guillermo Goldstein Frederick C Meinzer Sandra J Bucci Fabian G Scholz Augusto C Franco William A Hoffmann

Biologists have long been puzzled by the striking morphological and anatomical characteristics of Neotropical savanna trees which have large scleromorphic leaves, allocate more than half of their total biomass to belowground structures and produce new leaves during the peak of the dry season. Based on results of ongoing interdisciplinary projects in the savannas of central Brazil (cerrado), we ...

2003
Xu Liang Eric F. Wood Dennis P. Lettenmaier

HAPEX-MOBILHY data, consisting of one year of hourly atmospheric forcing data at Caumont (SAMER No. 3, 43.68°N, 0.1°W) were used repeatedly to run the two-layer Variable Infiltration Capacity (VIC-2L) land-surface scheme until the model reached equilibrium in its water and energy balance. The equilibrium results are compared with one year of weekly soil moisture measurements at different depths...

ژورنال: علوم آب و خاک 2004
احمد جلالیان, , حسین خادمی, , حمیدرضا کریم‌زاده, ,

Clay minerals deserve special attention as they play a crucial role in many soils. The clay mineralogy of five gypsiferous soils from different landforms in eastern Isfahan was investigated using X-ray diffraction (XRD). In addition, soil aggregates and wind-deposited sediments were examined by scanning electron microscope (SEM) and analyzed by energy dispersive X-ray analyzer (EDX). The resul...

2000
Richard Wolkowski

Soil compaction is recognized as a yield limiting factor in crop production. Compaction problems continue to exist for several reasons, including; 1) the large size (mass) of agricultural vehicles; 2) increased operations on wet soils because of larger farm acreage and multi-axle driven equipment; and, 3) the lack of controlled traffic patterns in fields. Where compaction is identified as a pro...

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