نتایج جستجو برای: soil disturbance

تعداد نتایج: 222723  

2004
Arantzazu L. Luzuriaga Adrián Escudero José Miguel Olano Javier Loidi

Our main aim was to determine the contribution of the seed bank to vegetation regeneration following a disturbance consisting in a deep ploughing and a thorough homogenisation of a perennial grassland. In the seed bank prior to disturbance, seed distribution through the vertical soil profile was evaluated to determine the initial seed species structure. Then, several characteristics of the shal...

2001
KATHARINE NASH SUDING DEBORAH GOLDBERG

Many studies have documented that patterns of species composition change after gap creation, but few have addressed the processes responsible for this change. The idea of competitive reduction, that disturbance removes biomass, reducing competitive intensity and allowing competitively inferior fugitive species to colonize, has been widely accepted but rarely tested. We suggest an alternative hy...

2014
Stefanie Maaß Massimo Migliorini Matthias C Rillig Tancredi Caruso

Beta diversity describes how local communities within an area or region differ in species composition/abundance. There have been attempts to use changes in beta diversity as a biotic indicator of disturbance, but lack of theory and methodological caveats have hampered progress. We here propose that the neutral theory of biodiversity plus the definition of beta diversity as the total variance of...

2016
A. M. Nahlik M. S. Fennessy

Wetland soils contain some of the highest stores of soil carbon in the biosphere. However, there is little understanding of the quantity and distribution of carbon stored in our remaining wetlands or of the potential effects of human disturbance on these stocks. Here we use field data from the 2011 National Wetland Condition Assessment to provide unbiased estimates of soil carbon stocks for wet...

2011
P. Jeyakumar

Conservation agriculture (CA) integrates ecological management with scientific agricultural production. CA promotes minimal disturbance of the soil by tillage (zero tillage), balanced application of chemical inputs (only as required for improved soil quality and healthy crop and animal production), and careful management of residues and wastes. CA Promotes application of fertilizers, pesticides...

Journal: :Ecology letters 2007
Feike A Dijkstra Weixin Cheng

Decomposition of soil organic carbon (SOC) is the main process governing the release of CO(2) into the atmosphere from terrestrial systems. Although the importance of soil-root interactions for SOC decomposition has increasingly been recognized, their long-term effect on SOC decomposition remains poorly understood. Here we provide experimental evidence for a rhizosphere priming effect, in which...

2014
Wei Shangguan Peng Gong Lu Liang YongJiu Dai Keli Zhang

Rapid land-use change in recent decades in China and its impact on terrestrial biodiversity have been widely studied, particularly at local and regional scales. However, the effect of land-use change on the diversity of soils that support the terrestrial biological system has rarely been studied. Here, we report the first effort to assess the impact of land-use change on soil diversity for the ...

Journal: :مهندسی بیوسیستم ایران 0
مجید دهقانی دانشگاه شیراز، دانشکده کشاورزی، بخش مهندسی بیوسیستم سیدحسین کارپرورفرد هیئت علمی / دانشگاه شیراز

performance optimization of chisel tine was proposed by using a chisel plow with adjustable rake angle. effective treatments consisted of soil moisture at 0.5, 0.7 and 0.9 of plastic limit (pl), three rake angle of 30, 40 and 50 degree and speeds of to 3, 5 and 7 km h-1. the measured parameters included draft, soil disturbance area, soil upheaving area, clod mean weight diameter (mwd), specific...

2009
Yu Yoshihara Toshiya Okuro Bayarbaatar Buuveibaatar Jamsran Undarmaa Kazuhiko Takeuchi

In theMongolian steppes, livestock and burrowing rodents are the main animal modifiers of the habitat. Although grazing lands and rodent habitats overlap, the combined effects of livestock and rodent disturbance on spatial heterogeneity of plants and soil have rarely been evaluated. We established study plots at each of four sites: sites heavily grazed by livestock, with and without marmots, an...

2015
Adrian Ho Erik van den Brink Andreas Reim Sascha M. B. Krause Paul L. E. Bodelier

Alternate prolonged drought and heavy rainfall is predicted to intensify with global warming. Desiccation-rewetting events alter the soil quality and nutrient concentrations which drive microbial-mediated processes, including methane oxidation, a key biogeochemical process catalyzed by methanotrophic bacteria. Although aerobic methanotrophs showed remarkable resilience to a suite of physical di...

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