نتایج جستجو برای: shrubland

تعداد نتایج: 897  

2008
P. C. ALMOND J. J. ROERING M. W. HUGHES F. S. LUTTER C. LEBOUTEILLER

Vegetation change, whether it be of anthropogenic or climatic origin, can have dramatic effects on landscape form, processes and sediment yield. General conceptual models for relationships between climate, vegetation and sediment yield exist for whole landscapes, but no rigorous analysis of the effects of vegetation change on sediment transport, in the absence of overland flow, has been done fr...

2008
L. M. Montandon E. E. Small

The green vegetation fraction (Fg) is an important climate and hydrologic model parameter. A common method to calculate Fg is to create a simple linear mixing model between two NDVI endmembers: bare soil NDVI (NDVIo) and full vegetation NDVI (NDVI∞). Usually it is assumed that NDVIo is close to zero (NDVIo∼0.05) and is generally chosen from the lowest observed NDVI values. However, the mean soi...

2015
Shereif H. Mahmoud A. A. Alazba

The hydrological response to land cover changes induced by human activities in arid regions has attracted increased research interest in recent decades. The study reported herein assessed the spatial and quantitative changes in surface runoff resulting from land cover change in the Al-Baha region of Saudi Arabia between 1990 and 2000 using an ArcGIS-surface runoff model and predicted land cover...

2016
Terefe Tolessa Feyera Senbeta Moges Kidane

Landscape dynamics are common phenomenon in the human-dominated environments whereby it can be observed that the composition and configuration between landscape elements change over time. This dynamism brings about habitat loss and fragmentation that can greatly alter ecosystem services at patch, class, and landscape levels. We conducted a study to examine composition and configuration of fores...

Journal: :American journal of botany 1999
F Lloret M Verdú N Flores-Hernández A Valiente-Banuet

We investigated modes of regeneration of dominant species of the mexical vegetation after fire. The mexical shrubland shows a remarkable structural, morphological, and floristic similarity to Mediterranean-type vegetation and is considered a relict of the Madro-Tertiary Geoflora under a non-Mediterranean climate. This vegetation provides an ideal scenario to test the role of fire in Mediterrane...

Journal: :The Cryosphere 2022

Abstract. In Arctic ecosystems, increasing temperatures are driving the expansion of nitrogen (N) fixing shrubs across tundra landscapes. The implications this to biogeochemistry ecosystems critical importance and more work is needed better understand form, availability, transportation potential N from these a variety To gain insights into processes controlling within permafrost hillslope syste...

Journal: :Acta Ecologica Sinica 2021

以柠条锦鸡儿(Caragana korshinskii)灌丛引入形成荒漠草原-灌丛地镶嵌体为研究对象,选择其内部荒漠草地(DG)、草地边缘(GE)、灌丛边缘(SE)、灌丛地(SL)为试验样地,开展荒漠草原向灌丛地人为稳态转变过程土壤水分与植被变化特征研究。结果如下:各样地0-200 cm土层水分含量随着转变过程呈显著降低趋势(P<0.05),其中荒漠草地、草地边缘和灌丛边缘样地的土壤水分均在秋季雨水补充期增加,灌丛地由于深层土壤水分过度消耗而愈加降低,且灌丛边缘和灌丛地深层水分显著低于荒漠草地、草地边缘(P<0.05),垂直动态不显著;地上植被随样地转变除优势度指数表现为灌丛地多样性、均匀度、丰富度指数均显著低于各样地(P<0.05),多年生优势草本蒙古冰草(Agropyron mongolicum)、短花针茅(Stipa breviflora)逐渐被一年生草本刺藜(Dysphani...

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