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Reforestation is very important in controlling land degradation and desertification. It has been established that the early diagnostics of the forest-growth conditions of soils and sustainability of forest plantations can be estimated by biogenic factors, such as the structure, dynamics, and functional activity of microbial complexes closely related to agrochemical soil indicators. The survival and sustainability of experimental forest plantations that were established in 1975 to 1978 on erosion-prone lands in the coastal zone of Shira Lake (Khakassia) have been studied. The forest growing properties of soils and the transformation of their fertility under the influence of stands have been evaluated. [ABSTRACT FROM AUTHOR]

Initial mapping of secondary succession in places disturbed by mining of the Khan Khentii Strictly Protected Area in Mongolia shows a possible innovative direction taken by afforestation in order to prevent further expansion of the Gobi Desert in northern Mongolia. The study results from the knowledge of secondary succession of mined areas, which are classified as the remains and consequences of prospecting and mining work dated to the Soviet times. Ongoing succession on sites affected by mining is very slow. In quarry dumps and canavas, herb layer has not been recovered despite the fact that the prospecting and mining activities had finished more than 30 years ago. Herbs biodiversity is very poor in these areas. Conversely, representatives of the tree layer, especially Larix sibirica and Populus tremula, are found far from the continuous forest; they colonized sites located within the aridized steppe. We assume that the main factor of successful tree growth on the mining activities remains consists in the humidity condensation due to and caused by the specific shape of the canavas and dumps. Trees prosperity on these extreme habitats can be ensured particularly in the early stages of growth when the tree roots are unable to reach the groundwater table. Detail mapping of quantitative and qualitative parameters of trees shows that the dump is an ideal shape of self-watering condensation mound for forest growth and can prevent the desertification as well. [ABSTRACT FROM AUTHOR]

Carbonate rocks distribute widely in China. The total area of the carbonate rocks is about 3,430,000 km, and the exposed area of the carbonate is approximately 13 % of China's territory. In 2003, soil loss in Yunnan, Guizhou, and Guangxi provinces reached 179,600 km, which is almost 40.1 % of the total area, causing rocky desertification. In this study, the erosion-creep-collapse mechanism of underground soil loss for the karst rocky desertification in Chenqi village, Puding county, Guizhou province is proposed. The mechanism occurs under the following geological environment: slope surface undulation, underlying bedrock surface fluctuation and thin and inhomogeneous soil overlying, overlying soil generation by bedrock weathering, underground karst development, and large groundwater depth and lying water table under the bottom of soils. The erosion-creep-collapse mechanism of underground soil loss in the karst slopes is explained as follows: power loss due to human cultivation activities that destroy the soil structure, hydraulic force formed by rainfall infiltration, wet-dry cycle generated by rainfall, erosion effect caused by rainfall penetration, creeping and flowing of plastic-stream soil, and collapse. The erosion-creep-collapse mechanism of underground soil loss has seven steps: disturbance of soils filled in underground karst cave by human activities, internal soil erosion and partial collapse caused by hydraulic power, internal free surface formation within the soil in the filled karst cave, internal soil creeping, soil pipe formation, soil pipe collapse, and ground surface collapse and filling. Soil loss develops slowly, and sudden transportation occurs by collapse. Soil loss can be explained by the proposed mechanism, and soil loss can be prevented by controlling soil collapse. [ABSTRACT FROM AUTHOR]

Desertification, land degradation in arid, semi-arid, and dry sub-humid regions, is a global environmental problem. With respect to increasing importance of desertification and its complexity, the necessity of attention to the optimal de-desertification alternatives is essential. Therefore, this work presents an analytic hierarchy process (AHP) method to objectively select the optimal de-desertification alternatives based on the results of interviews with experts in Khezr Abad region, central Iran as the case study. This model was used in Yazd Khezr Abad region to evaluate the efficiency in presentation of better alternatives related to personal and environmental situations. Obtained results indicate that the criterion 'proportion and adaptation to the environment' with the weighted average of 33.6% is the most important criterion from experts viewpoints. While prevention alternatives of land usage unsuitable of reveres and conversion with 22.88% mean weight and vegetation cover development and reclamation with 21.9% mean weight are recognized ordinarily as the most important de-desertification alternatives in region. Finally, sensitivity analysis is performed in detail by varying the objective factor decision weight, the priority weight of subjective factors, and the gain factors. After the fulfillment of sensitivity analysis and determination of the most sensitive criteria and alternatives, the former classification and ranking of alternatives does not change so much, and it was observed that unsuitable land use alternative with the preference degree of 22.7% was still in the first order of priority. The final priority of livestock grazing control alternative was replaced with the alternative of modification of ground water harvesting. [ABSTRACT FROM AUTHOR]

Sand encroachment is a serious problem in arid regions. Checkerboard barriers are commonly used as wind buffers and to stabilize soils at risk of desertification. These interventions can also improve soil nutrients. Checkboard sand barriers are widely used in arid regions, but different barrier types are seldom optimized for specific areas or land management objectives. This research studied how checkerboard barriers made of different types of materials influenced soil properties (soil organic carbon, available nitrogen, available phosphorus, available potassium, pH and soil moisture). These parameters were measured at various soil depths within test plots protected by eleven different types of checkerboard barrier material. Data were then analyzed by constructing a soil quality index (SQI) model based on coefficients identified by principal component analysis of soils at depths of 0-20, 20-40, 40-60 cm and for the complete 0-60 cm profile. The results generally found that barriers improve soil quality. They also showed significant variation in soil properties at different depths for different types of barrier material. For the 0-60 cm soil profile, barriers increased soil available nitrogen, available potassium, soil organic carbon and soil moisture but decreased soil available phosphorus and pH. The SQI values indicated that rice straw barriers optimized soil nutrients at soil depths of 0-20 cm, low vertical corn straw checkerboard barriers at soil depth of 20-40 cm, while 30 cm wide gravel checkerboard barriers optimized nutrients at 40-60 cm soil depth. Plots protected by low vertical branch barriers showed the greatest overall soil quality improvement for the complete 0-60 cm profile. This study found that corn straw, clay, 30 cm wide gravel and low vertical branch barriers can significantly protect and restore soils on the eastern edge of the Tengger Desert. [ABSTRACT FROM AUTHOR]