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1. chinaXiv:202005.00092 [pdf]

Land cover change and eco-environmental quality response of different geomorphic units on the Chinese Loess Plateau

SONG Yongyong; XUE Dongqian; DAI Lanhai; WANG Pengtao; HUANG Xiaogang; XIA Siyou
Subjects: Biology >> Botany >> Applied botany

Land cover in the Chinese Loess Plateau has undergone dramatic changes since the late 1980s. Revealing the trend in land cover change and eco-environmental quality response of different geomorphic units in this stage is a realistic requirement for promoting sustainable development of the Chinese Loess Plateau. Based on the data of geomorphic units and land cover in 1990, 2000, 2010 and 2018 of the Chinese Loess Plateau, we studied the trend of land cover change and eco-environmental quality response of different geomorphic units by using a significance index of land cover change, a proportion index of land cover change and an eco-environmental response model. The results indicated that from 1990 to 2018, the areas of forestland and construction land substantially increased, whereas those of cropland, grassland, wetland and unused land considerably decreased. Land cover change exhibited large geomorphic differences, and the main conversion of land cover was from cropland into other land types. Unstable trend of land cover change in the loess tablelands and sandy loess hills declined, whereas the unstable trends in the other geomorphic units enhanced. Eco-environmental quality varied among different geomorphic units. The expansion of construction land and degradation of forestland, grassland and wetland resulted in the deterioration of eco-environmental quality. The conversion of cropland and unused land into forestland and grassland, and the conversion of grassland into forestland were the main factors that drove the improvement of eco-environmental quality. The findings of this study may provide theoretical reference and support decision making for the optimization of land use structure and the improvement of eco-environmental quality on the Chinese Loess Plateau.

submitted time 2020-05-31 From cooperative journals:《Journal of Arid Land》 Hits7782Downloads490 Comment 0

2. chinaXiv:201903.00232 [pdf]

Conversion of cropland into agroforestry land versus naturally-restored grassland alters soil macro-faunal diversity and trophic structure in the semi-arid agro-pasture zone of northern China

LIU Rentao
Subjects: Biology >> Ecology

Restoration of cropland (termed 'Farm') after abandonment including shrubs (termed 'Shrub'), trees (termed 'Tree') and natural grassland (termed 'Grass') has become a routine process aimed to improve land productivity and control desertification. During this restoration process, soil macro-faunal diversity, and trophic structure were investigated at four types of sites (Farm, Shrub, Tree, and Grass) during growing season in the semi-arid agro-pasture zone of northern China. Results indicated that the Staphylinidae family was found to dominate at the Grass, Shrub, and Tree sites, whiles larval Pyralidae individuals were found at the Grass site only. The density of the omnivores (i.e., Formicidae family) was significantly (P<0.05) greater at the Grass site than at the Tree and Farm sites. The total density and richness of predator and phytophages were found to be markedly (P<0.05) greater at the Grass site than at the Farm site. Meanwhile, we found the taxon richness of predators was significantly (P<0.05) higher at the Shrub site than at the Farm and Tree sites. Compared with the Farm and afforested Shrub/Tree sites, the Grass site had greater density, taxon richness, and Shannon index (P<0.05). In conclusion, natural restoration of abandoned croplands toward grassland was an effective strategy relative to artificial afforestation for improvement of soil biological diversity. Moreover, planting shrub is a preferable measure in abandoned croplands for land development in the semi-arid agro-pasture zone of northern China.

submitted time 2019-03-28 From cooperative journals:《Journal of Arid Land》 Hits7701Downloads2820 Comment 0

3. chinaXiv:201712.00400 [pdf]

A field investigation of wind erosion in the farming–pastoral ecotone of northern China using a portable wind tunnel: a case study in Yanchi County

NAN, Ling; DONG, Zhibao; XIAO, Weiqiang; LI, Chao; XIAO, Nan; SONG, Shaopeng; XIAO, Fengjun; DU, Lingtong
Subjects: Geosciences >> Other Disciplines of Geosciences

The farming–pastoral ecotone in northern China is an extremely fragile ecological zone where wind erosion of cropland and rangeland is easy to occur. In this study, using a portable wind tunnel as a wind simulator, we conducted field simulated wind erosion experiments combined with laboratory analysis to investigate wind erosion of soils in trampled rangeland, non-tilled cropland and tilled cropland in Yanchi County, China. The results showed that compared with rangeland, the cropland had a higher soil water holding capacity and lower soil bulk density. The wind erosion rate of trampled rangeland was much higher than those of non-tilled cropland and tilled cropland. For cropland, the wind erosion rate of the soil after tilling was surprisingly less than that of the soil before tilling. With increasing of wind speed, the volume mean diameter of the eroded sediment collected by the trough in the wind tunnel generally increased while the clay and silt content decreased for all soils. The temporal variation in wind erosion of the trampled rangeland indicated that particle entrainment and dust emission decreased exponentially with erosion time through the successive wind erosion events due to the exhaustion of erodible particles.

submitted time 2017-12-08 From cooperative journals:《Journal of Arid Land》 Hits2084Downloads670 Comment 0

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