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Yang W.B.,Chinese Academy of Forestry | Tang J.N.,Chinese Academy of Forestry | Tang J.N.,Desertification Research Institute | Liang H.R.,Inner Mongolia Academy of Forestry Science | And 2 more authors.
Science China Earth Sciences | Year: 2014

Soil moisture is the key resource constraint in arid ecosystems, and has been a focus of research on restoration. However, quantitative studies on the contribution of rainfall to deep soil rainfall infiltration are lacking. In this study, we used the YWB-01 Deep Soil Infiltration Water Recorder which had been invented by ourselves to measure the quantity of rain infiltration into deep soil, 150 cm below ground, in four locations in China: Mu Us Sandy Land and Ulan Buh, Tengger, and Badan Jilin deserts over a 2-year period. We found: (1) Deep soil rainfall infiltration decreased progressively from east to west and from semiarid to arid areas, with two locations completely lacking rainfall infiltration. Heavy rain was important to deep soil infiltration in shifting sandy land of arid and semiarid areas. (2) Seasonal variation of infiltration was correlated with rainfall, with a time lag that was less apparent in areas with more rainfall. (3) For single intense rainfall events, infiltration maximums occurred 40-55 h after the rainfall, during which the infiltration rates increased rapidly before reaching a peak, and then decreased slowly. Continuous infiltration could last about 150 h. Rainfall infiltration was determined by the combined action of intensity, quantity and duration. Rainfall with low intensity, long duration, and large quantity was most favorable for deep soil infiltration. Our results can be used in water resource assessments and protection during eco-restoration in the arid and semiarid areas in China. © 2014 Science China Press and Springer-Verlag Berlin Heidelberg. Source

Zheng J.,Jiangxi Agricultural University | Wei X.,University of British Columbia | Liu Y.,Jiangxi Agricultural University | Liu G.,CAS Research Center for Eco Environmental Sciences | And 2 more authors.
Journal of Forestry Research | Year: 2016

In order to improve environment and relieve poverty, China has launched a series of major ecological engineering programs since the 1980s. These include the Natural Forest Conservation Program, the Sloping Cropland Conversion Program, the Desertification Combating Program, and the Protection Forest System Construction Program. There is a growing need to quantify the contributions of these programs to regional carbon stocks. However, the lack of widely accepted, robust methods is one of the key obstacles to quantification. The objective of this study was to review existing methods for quantifying regional carbon stocks and then recommend suitable ones for the Chinese ecological engineering programs. We expect that the recommended methods can be applied to elsewhere in the world where there are similar characteristics and objectives. © 2016, Northeast Forestry University and Springer-Verlag Berlin Heidelberg. Source

Yao G.,Beijing Forestry University | Ding G.,Beijing Forestry University | Zang Y.,Beijing Forestry University | Wang J.,Inner Mongolia Agricultural University | And 6 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2012

In order to provide theoretical supporting for land utilization planning and management in windy desert region, canonical discriminant analysis and factor analysis were used to distinguish and study the soil quality of two subsidence areas (SAs) respectively subsided in 2004 and 2005 in Bulianta coal mining area located at south rim of Maowusu desert. The results showed that soil moisture content, hardness, total N and P of the two SAs were significantly lower than control area (CA) (p<0.05). At partial slope positions with serious ground surface disturbance, volume weight declined remarkably (p<0.05) while soil porosity increased remarkably (p<0.05). Compared with the CA, total K and organic matter of the two SAs showed no significant variation (p>0.05), and available nutrient displayed an activating tendency on the whole. With the calculation by a canonical discriminant function which mainly reflects the disturbance degree of soil nutrient, sample plots of CA and SAs respectively subsided in 2005, 2004 can be divided into 3 grades, which including "no effect", "had effect" and "seriously effect". 11 soil quality indexes were summarized to 5 comprehensive factors by factor analysis, and comprehensive factor scores of soil quality of the sample plots in SAs were represented visually with radar diagrams and scatter diagrams. Canonical discrimination function distinguished the situation of soil quality of CA and each SA well, and factor analysis reflected characteristic of soil quality variance of each SA comprehensively and visually. Source

Chen G.-T.,Inner Mongolia Academy of Forestry Science | Zhang W.-J.,Inner Mongolia Academy of Forestry Science | Lv S.-H.,Chinese Research Academy of Environmental Sciences
2013 2nd International Conference on Agro-Geoinformatics: Information for Sustainable Agriculture, Agro-Geoinformatics 2013 | Year: 2013

As an important factor of ecology, vegetation is not only enduring the climate change but also has a feedback on climate change positively. It is a sensitive indicator for environment change. Climate is the uppermost factor deciding vegetation type and distributing on the earth, while vegetation is the brightest reflection and integration symbol about climate. Using the distribution of arid and humid regions of China, the typical semi-arid/semi-humid region(Xilamulun river) as a study areas. Xilamulun river has important ecological significance because it is ecological conservation and water source protection area of Northern china. As an index of denoting basin's vegetation cover, NDVI is influenced by many climatic factors such as precipitation and average air temperature. The influence of precipitation on vegetation coverage of xilamulun river basin was qualitatively analyzed using multi-temporal Landsat TM (MSS) image during the recent 10 years, and analyze the vegetation dynamic changes in xilamulun river basin and its relationship with human activities. Firstly, the influence of exterior factor, such as phonology and relative radiometric correction, on NDVI was removed by normalization of different period remote sensing image. Preliminary Comparison of coverage in Xilamulun river, The coverage appeared to have a increase trend from 2000 to 2010. Therefore, Through protracted efforts the basin has made great achievements in the protection and nurturing of the ecological environment, of which afforestation is an outstanding example. Analysis of dynamic changes of the vegetation covers in two phases from 2000 to 2005, 2005 to 2010, respectively. The vegetation cover showed an1 increased trend from 2000 to 2010, which increased significantly in 2000 to 2005. The spring and winter showed in the opposite direction change in 2000 to 2005, but the same direction change trend in 2005 to 2010 by synthesized analysis of relationship of precipitation and vegetation cover. There are also an opposite direction change trend in spring and fall in two phases. The main factors influencing the vegetation cover change is human activity rather than climate factors in 2000 to 2010. According to the comprehensive analysis of precipitation and related data of the protection of the ecological environment in Balin right banner, human activities were proven as the main reason of vegetation fraction change during 2000-2010, such as conversion of cropland to forest, ecological migration afforestation by the Balin right banner. Finally, the residual analysis of NDVI indicates that human activities have promoted or destroyed the vegetation cover in some areas of xilamulun river basin. Source

Yang W.,Desertification Research Institute | Yang W.,Chinese Academy of Forestry | Dong H.,Desertification Research Institute | Dong H.,Inner Mongolia Agricultural University | And 6 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2011

Low-covered vegetation is one of typical vegetation patterns in arid and semi-arid areas of China through a longterm natural succession. Conventional studies concluded that when vegetation cover arrives at 40%, sandland is fixed. When vegetation cover is from 20% to 40%, sandland is under semi-shifting and semi-fixing. However, in practice it has been found that at low vegetation coverage, the horizontal distribution pattern of shrubs can have marked effects on fixation of shifting sands. There have many artificial or natural sand-fixing woodlands in arid and semi-arid areas of China which vegetation cover was lower than 40%. This paper tests the hypothesis that the horizontal distribution pattern of sand-fixing woodland at low vegetation coverage has the same law as shrubs. We compared the windbreak and sand-fixing effects of woodland with 20% coverage between belted and random patterns. Results show: (1) Compared to wind speed in open field, the relative wind speed of belted pattern is lower than random pattern, with 53. 89% and 36. 82% reduction rate at 200cm and 50cm height respectively; (2) compared to relatively regular changes in belted pattern, the horizontal flow field of wind speed in random pattern is very complicated, mainly affected by spatial pattern of crown; (3) The wind speed in random pattern is 27.45% and 22.55% higher than that in open field at 50cm and 200cm height respectively, the local wind uplift forms a strong eddy; (4) Average surface roughness of the belted pattern is 1.01cm, about 5 times of random pattern; (5) On the whole, among belted patterns the first belt was showed significant effects in reducing wind speed; and the wind speed after the second belt was is lower than that after the first belt; but superposition benefit was not obvious of reduced wind speed effect one by one belts; (6) the belted pattern has local uplift function at the base of the first belts windward which has relatively strong erosion effect in the basal part of forest belt, and the root systems for most of trees were eroded down and outcropped in the first belt, and the sand flow through a region was accumulated at the lateral of crown behind the belt; (7) Random pattern exists many low roughness zones in random pattern matching with local wind uplift zones, the strong eddy in these local uplift zones is an important driving factor of blowout pits. Arid and semiarid areas occupy about one third of China territory with less than 400 mm of annual precipitation. Traditional approaches to ecosystem restoration in China have focused on afforestation with high stand density such as the Three Norths Shelter Forest System Project and the Sand Control Program. However, the long-term results of those practices have been proved economically costly and ecologically unsustainable to some extent, with groundwater shortage and soil erosion increasing. We conclude from our experiment that soundly horizontal distribution pattern of sand-fixing woodlands at low vegetation coverage can fix shifting sands effectively, which may be helpful to environmental improvement and sustainable development of arid and semiarid regions in China. Source

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