Grasslands provide a number of ecosystem services for human society.Degradation of grasslands results in the loss of biodiversity and leads to the deterioration of ecosystem functions.In order to accurately assess the...Grasslands provide a number of ecosystem services for human society.Degradation of grasslands results in the loss of biodiversity and leads to the deterioration of ecosystem functions.In order to accurately assess the influence of grassland degradation on belowground ecosystems,we conducted experiments on a temperate steppe with different levels of degradation and investigated the influence of degradation on soil quality and soil biotic communities.Our results showed that grassland degradation significantly decreased soil quality,with lower values of soil quality index(SQI)observed in the degraded grassland than the meadow steppe and the grassland from the forest-steppe ecotone.Changes in the SQI along the grassland degradation gradient were positively correlated with soil carbon stock and the aboveground biomass,and negatively correlated with the root shoot ratio.Nematode trophic diversity and the ratio of fungal to bacterial PLFA were lower in the degraded grassland than the grassland from the forest-steppe ecotone.The dissimilarities in soil microbial and nematode community composition increased with the changes in soil quality index.Our results indicate that soil quality index based on the minimum data sets could effectively assess the influence of grassland degradation on soil biodiversity and ecosystem function.In order to effectively restore degraded grasslands,the key contributors to the soil quality,such as soil carbon,should be taken on priority basis for revitalizing the soil biodiversity and ecosystem function.展开更多
Rangeland degradation is a serious problem throughout sub-Saharan Africa and its restoration is a challenge for the management of arid and semi-arid areas. In Lake Baringo Basin of Kenya, communities and individual fa...Rangeland degradation is a serious problem throughout sub-Saharan Africa and its restoration is a challenge for the management of arid and semi-arid areas. In Lake Baringo Basin of Kenya, communities and individual farmers are restoring indigenous vegetation inside enclosures in an effort to combat severe land degradation and address their livelihood problems. This study evaluated the impact of enclosure management on soil properties and microbial biomass, being key indicators of soil ecosystem health. Six reseeded communal enclosures using soil embankments as water-harvesting structures and strictly regulated access were selected, varying in age from 13 to 23 years. In six private enclosures, ranging from 3 to 17 years in age, individual farmers emulated the communal enclosure strategy and restored areas for their exclusive use. Significant decreases in bulk density, and increases in the soil organic carbon, total nitrogen and microbial biomass contents and stocks were found in the enclosures as compared with the degraded open rangeland. In the private enclosures, the impact of rehabilitation on the soil quality was variable, and soil quality was in general lower than that obtained under communal management. The significant increase of absolute stocks of carbon, nitrogen and microbial biomass compared to the degraded open rangeland indicates the potential for the restoration of soil quality through range rehabilitation. Over-sowing with indigenous legume fodder species could improve total nitrogen content in the soil and nutritional value of the pastures as well.展开更多
基金This study was supported by the National Key Research and Development Program of China(2016YFC0500602)the National Natural Science Foundation of China(No.41877047).
文摘Grasslands provide a number of ecosystem services for human society.Degradation of grasslands results in the loss of biodiversity and leads to the deterioration of ecosystem functions.In order to accurately assess the influence of grassland degradation on belowground ecosystems,we conducted experiments on a temperate steppe with different levels of degradation and investigated the influence of degradation on soil quality and soil biotic communities.Our results showed that grassland degradation significantly decreased soil quality,with lower values of soil quality index(SQI)observed in the degraded grassland than the meadow steppe and the grassland from the forest-steppe ecotone.Changes in the SQI along the grassland degradation gradient were positively correlated with soil carbon stock and the aboveground biomass,and negatively correlated with the root shoot ratio.Nematode trophic diversity and the ratio of fungal to bacterial PLFA were lower in the degraded grassland than the grassland from the forest-steppe ecotone.The dissimilarities in soil microbial and nematode community composition increased with the changes in soil quality index.Our results indicate that soil quality index based on the minimum data sets could effectively assess the influence of grassland degradation on soil biodiversity and ecosystem function.In order to effectively restore degraded grasslands,the key contributors to the soil quality,such as soil carbon,should be taken on priority basis for revitalizing the soil biodiversity and ecosystem function.
基金the financial support provided by the Flemish Interuniversity Council (VLIR) of Belgium in favour of the first author
文摘Rangeland degradation is a serious problem throughout sub-Saharan Africa and its restoration is a challenge for the management of arid and semi-arid areas. In Lake Baringo Basin of Kenya, communities and individual farmers are restoring indigenous vegetation inside enclosures in an effort to combat severe land degradation and address their livelihood problems. This study evaluated the impact of enclosure management on soil properties and microbial biomass, being key indicators of soil ecosystem health. Six reseeded communal enclosures using soil embankments as water-harvesting structures and strictly regulated access were selected, varying in age from 13 to 23 years. In six private enclosures, ranging from 3 to 17 years in age, individual farmers emulated the communal enclosure strategy and restored areas for their exclusive use. Significant decreases in bulk density, and increases in the soil organic carbon, total nitrogen and microbial biomass contents and stocks were found in the enclosures as compared with the degraded open rangeland. In the private enclosures, the impact of rehabilitation on the soil quality was variable, and soil quality was in general lower than that obtained under communal management. The significant increase of absolute stocks of carbon, nitrogen and microbial biomass compared to the degraded open rangeland indicates the potential for the restoration of soil quality through range rehabilitation. Over-sowing with indigenous legume fodder species could improve total nitrogen content in the soil and nutritional value of the pastures as well.
