Jiuquan City is a typical ecologically fragile area in the arid areas of Northwest China, and unreasonable human activities directly affect the regional ecological security. Scientifically, it is necessary to construct an ecological landscape pattern on the basis of ecological security evaluation. This paper selected evaluation factors based on the perspective of “environmental base and human interference”, used spatial principal component analysis (SPCA) to comprehensively evaluate the regional landscape ecological security, and used the minimum cumulative resistance (MCR) model to construct the regional ecological security pattern. The results show that the overall ecological security level of the study area is low, and the area with a moderate safety level and below is 122,100 km2, accounting for 72.57% of the total area of the study area. The total area of the identified ecological source area is 6683 km2, the spatial distribution is extremely uneven, and it is extremely concentrated in the southern region; 32 ecological corridors with a total length of 3817.8 km are identified, of which corridor NO. 1–4 run through the Qilian Mountains, 11 oasis areas, and 14 nature reserves. The length of ecological corridors is 1376.1 km, accounting for 36.04% of the total. Forty-two ecological nodes are identified, and the central corridor area is more distributed; four ecological restoration zones are divided, including an ecological conservation zone, ecological improvement zone, ecological control zone, and ecological restoration zone, with areas of 34,380.3 km2, 61,884.4 km2, 21,134.4 km2, and 50,648.3 km2, respectively. Through the delineation of the urban ecological network pattern composed of source areas, corridors, and nodes, as well as the delineation of ecological restoration zones, the ecological security level of the study area will be effectively improved. Furthermore, a new method of ecological restoration zoning will be used, hoping to provide a useful reference for improving the quality of the ecological environment in arid areas and optimizing the spatial pattern of the land.

Research on Landscape Pattern Construction and Ecological Restoration of Jiuquan City Based on Ecological Security Evaluation

Soil nutrient contents and organic carbon (C) stability are key indicators for restoration of degraded grassland. However, the effects of long-term active restoration of extremely degraded grassland on soil parameters have been equivocal. The aims of this study were to evaluate the impact of active restoration of degraded alpine grassland on: (a) soil organic matter (SOM) mineralization; and (b) the importance of biotic factors for temperature sensitivity (Q(10)) of SOM mineralization. Soils were sampled from intact, degraded and restored alpine grasslands at altitudes ranging between 3,900 and 4,200 m on the Tibetan Plateau. The samples were incubated at 5, 15 and 25 degrees C, andQ(10)values of SOM mineralization were determined. Structural equation modeling was used to evaluate the importance of vegetation, soil physico-chemical properties and microbial parameters forQ(10)regulation. TheQ(10)of N mineralization was similar among intact, degraded and restored soils (0.84-1.24) and was higher in topsoil (1.09) than in subsoil (0.92). The best predictive factor of CO2-Q(10)for intact grassland was microbial biomass, for degraded grassland was basal microbial respiration, and for restored grassland was soil bulk density. Restoration by planting vegetation decreased theQ(10)of SOM mineralization as soil bulk density, the most important negative predictor, increased in restored grassland. TheQ(10)of SOM mineralization in topsoil was 14% higher than in subsoil because of higher microbial abundance and exo-enzyme activities. The NH(4)(+)content was greatest in intact soil, while NO(3)(-)content was greatest in degraded soil. The SOM mineralization rate decreased with grassland degradation and increased after long-term (>10 years) restoration. In conclusion, extremely degraded grassland needs proper long-term management in active restoration projects, especially for improvement of soil nutrients in a harsh environment.

Long‐term active restoration of extremely degraded alpine grassland accelerated turnover and increased stability of soil carbon

Optimization of landscape spatial structure aiming at achieving carbon neutrality in desert and mining areas

Effects of ecological restoration measures on vegetation and soil properties in semi-humid sandy land on the southeast Qinghai-Tibetan Plateau, China

Topography is a key factor that affects edaphic, climatic, and biotic factors directly or indirectly. Relationships between Compound Topographic Index (CTI) model and soil properties were investiga...

Determination of the relationship among compound Topographic Index (CTI), soil properties and land-use in karst ecosystems

Global warming poses a serious threat to the alpine grassland on the Tibetan Plateau. Ecological restoration is an effective measure for adapting to climate change and controlling desertification. ...

Meirong Tian

Papers

Can ecological restoration improve soil properties and plant growth in valley-slope sand dunes on southern Tibetan Plateau?

Stability and micro-topographic effects of Sophora moorcroftiana population on a restored alluvial fan, Southern Tibetan Plateau