The Global Digital Elevation Model produced from stereo images of Advanced Spaceborne Thermal Emission and Reflection Radiometer data (ASTER GDEM) covers land surfaces between latitudes of 83°N and 83°S. The Phased Array type L-band Synthetic Aperture Radar (PALSAR) onboard Advanced Land Observing Satellite (ALOS) collected many SAR images since it was launched on 24 January 2006. The combination of ALOS/PALSAR interferometric data and ASTER GDEM should provide the penetration depth of SAR data assuming ASTER GDEM was the elevation of vegetation canopy top. It would be correlated with forest biomass because penetration depth could be affected by forest density and forest canopy height. Their combination held great promises for the forest biomass mapping over large area. The feasibility of forest biomass mapping through the data synthesis of ALOS/PALSAR InSAR data and ASTER GDEM was investigated in this study. A procedure for the extraction of penetration depth was firstly proposed. Then three models were built for biomass estimation: (I) model only using backscattering coefficients of ALOS/PALSAR data; (II) model only using penetration depth; (III) model using both of them. The biomass estimated from Lidar data was taken as reference data to evaluate the three different models. The results showed that the combination of backscattering coefficients and penetration depth gave the best accuracy. The forest disturbance has to be considered in forest biomass estimation because of the long time span of ASTER data for generating ASTER GDEM. The spatial homogeneity could be used to improve estimation accuracy.

The ecosystem of national parks bears some cultural features. How the cultural ecosystem service functions are perceived by the public and how the cultural ecosystem service functions shape the public’s cognition have become urgent scientific questions. This paper performs a case analysis on the Qianjiangyuan National Park System Pilot Area, a representative national park in China, which clarifies the main types of cultural ecosystem service functions from the perspective of the landscape aesthetics benefits of community residents, and analyze the varied impacts of demographics on functional cognition. On this basis, the entropy weight method was adopted to evaluate the importance of each function. Fuzzy comprehensive evaluation was employed to assess the composite level of the cultural service functions. The results show that: (1) the community residents value the benefits brought by the national park the most in terms of the ecological improvement function, and the situation is consistent across the four towns/townships; by contrast, the community residents attach the least importance to the benefits in terms of system governance function. (2) Except for the years of local residence, the community residents’ cognition of different cultural ecosystem service functions may vary significantly, owing to factors like gender, age, education level, occupation, and annual mean income. (3) Concerning the importance of functional indices, the importance scores of the natural experience functions, humanistic concern functions, and social service functions are 0.3286, 0.3503, and 0.3211, respectively. The community residents had a moderate to high level of cognition for the cultural ecosystem service functions (3.99). The different types of functions can be sorted by effectiveness as: the social service functions (4.11) > natural experience functions (4.03) > humanistic concern functions (3.86). The research results provide a reference for improving the management level of national parks, and ease the increasingly prominent contradiction between people and land.

Grazing and cultivation are two important management practices worldwide that can cause significant soil organic carbon (SOC) losses. However, it remains elusive how soil microbes have responded to soil carbon changes under these two practices. Based on a four-decade long field experiment, this study investigated the effects of grazing and cultivation on SOC stocks and microbial properties in the semi-arid grasslands of China. We hypothesize that grazing and cultivation would deplete SOC and depress microbial activities under both practices. However, our hypotheses were only partially supported. As compared with the adjacent indigenous grasslands, SOC and microbial biomass carbon (MBC) were decreased by 20% or more under grazing and cultivation, which is consistent with the reduction of fungi abundance by 40% and 71%, respectively. The abundance of bacteria and actinomycetes was decreased under grazing but increased under cultivation, which likely enhanced microbial diversity in cultivation. Invertase activity decreased under the two treatments, while urease activity increased under grazing. These results suggest that nitrogen fertilizer input during cultivation may preferentially favor bacterial growth, in spite of SOC loss, due to rapid decomposition, while overgrazing may deteriorate the nitrogen supply to belowground microbes, thus stimulating the microbial production of nitrogen acquisition enzymes. This decade-long study demonstrated differential soil microbial responses under grazing and cultivation and has important applications for better management practices in the grassland ecosystem.