Abstrat Water is the foundation of an arid ecological system, as the quantity and quality of surface water and groundwater determine its structure and function. The study on the relationship between water and ecosystem is the basis of ecosystem protection. Taking the Ejina delta, an extremely arid area located downstream of the Heihe River in northwestern China, as an example, this article give...

The diversity of the airborne pollen content of a city reflects its vegetation landscape at different spatial scales. Overall, it was estimated that the trapped pollen by a sampler placed about 15m height records 50% of the pollen grains releasing above the canopy of the trees and it comes from distance 250m or less, 45% coming from distance up to 5km and only 5% coming from distance longer to ...

New Zealand Journal of Ecology (1997) 21(2): 129-140 ©New Zealand Ecological Society these conceptual extremes should be seen as being endpoints of a range of possible situations, and not as discrete alternatives. It is therefore unlikely that an observed field situation would be completely described by any one of the models alone. More recently developed models use the conceptual extremes as c...

There is no single agreed definition of the term drylands. Two of the most widely accepted definitions are those of FAO and the United Nations Convention to Combat Desertification (UNCCD, 2000). FAO has defined drylands as those areas with a length of growing period (LGP) of 1–179 days (FAO, 2000a); this includes regions classified climatically as arid (Plate 1), semi-arid and dry subhumid. The...

In recent decades, the monitoring of vegetation dynamics has become crucial because of its important role in terrestrial ecosystems. In this study, a satellite-derived normalized difference vegetation index (NDVI) was combined with climate factors to explore the spatiotemporal patterns of vegetation change during the growing season, as well as their driving forces in China from 2001 to 2012. Ou...

New vegetation in barren areas offers possibilities for sequestering carbon in the soil. Arid and semi-arid areas (ASAs) are candidates for new vegetation. The possibility of agriculture in ASAs is reviewed, revealing the potential for cultivation by covering the surface with a layer of organic fibres. This layer collects more water from humidity in the air than does the uncovered mineral surfa...

Contrary to wetlands or moderate climates, the understanding of carbon exchange between ecosystem and atmosphere in arid and semi-arid environments is more challenging due to the sensible feedback of terrestrial ecosystems to environmental variability. Especially in the savannah regions of South Africa the biomes are strongly affected on the one hand by low and sporadic precipitation and on the...

Degradation of communal grazing land vegetation is a widespread problem throughout sub Saharan Africa and its restoration is a challenge for the management of many semi-arid areas. This study assessed the effectiveness of different age (young versus old) exclosures on species composition and diversity, biomass production and woody structure in northern Ethiopia. The species composition and dive...

The aim of this paper is to evaluate seed bank density and composition along a semi-arid gypsum gradient in Central Spain. Seed bank density was relatively high (16,214 seed/m) with a very clumped spatial distribution. Landform and microslope were the best predictors for seed density, indicating that density can be at least partly interpreted as a result of the physical processes regulating sec...