A quarry is a surface mining operated place, which produces enormous quantifies of gravel, limestone, and other materials for industrial and construction applications. Restoration and revegetation of deserted quarries...A quarry is a surface mining operated place, which produces enormous quantifies of gravel, limestone, and other materials for industrial and construction applications. Restoration and revegetation of deserted quarries are becoming increasingly important. Three areas of a typical quarry in South China： terrace for crushed materials （terrace）, spoiled mound, and remaining side slope, were investigated, to compare the existing plant species and to study the relationship between environmental factors and revegetation. The plant species composition of these three areas was found to differ significantly after eight years of natural recovery. The typical plant communities found over them were composed of gramineous herbs, ferns, and shrubs. Soil organic matter, soil moisture, and soil bulk density were considered to be the major determining factors for vegetation succession. There existed abiotic and biotic thresholds during quarrying restoration. Suggestions had been presented that could have accelerated the process of natural recovery in quarries.展开更多
We estimated aboveground biomass carbon (TABC) and net carbon accumulation rates (TNEP) for trees in four major forest types based on national forest inventory data collected in 1994-1998 and 1999-2003. The four types...We estimated aboveground biomass carbon (TABC) and net carbon accumulation rates (TNEP) for trees in four major forest types based on national forest inventory data collected in 1994-1998 and 1999-2003. The four types were Pinus massoniana forest, Cunninghamia lanceolata forest, hard broad-leaved evergreen forest and soft broad-leaved evergreen forest. We analyzed variations in TABC and TNEP for five stand ages (initiation, young, medium, mature and old). In both time periods, estimated TABC in all four forest types increased consistently with forest stand age and the oldest stage had the largest TABC compared with other stages. Broad-leaved forests (hard and soft) had higher TABC than needle-leaved forests (Pinus massoniana and Cunninghamia lanceolata) for each of the five age stages. The difference of TABC between broad-leaved and needle-leaved forests increased with forest stand age. Comparison of estimated TNEP by age category indicated TNEP increased from the initiation stage to the young stage, and then decreased from the mature stage to old stage in all four forest types. TNEP for any particular stage depended on the forest type; for instance, broad-leaved forests at both the mature and old stages had greater TNEP than in needle-leaved forests. A logistic curve was applied to fit the relationship between TABC and forest stand age. In each period, correlations in all four forest types were all statistically significant (P < 0.01) with R2 > 0.95. TABC was therefore predicted by these regression functions from 2000 to 2050 and the mean TNEP during the predicted period was estimated to be about 41.14, 31.53, 75.50 and 75.68 gCm-2a-1 in Pinus massoniana forest, Cunninghamia lanceolata forest, hard broad-leaved forest and soft broad-leaved forest, respectively. Results from both forest inventory and regression prediction suggest broad-leaved forests are greater carbon sinks, and hence have greater carbon sequestration ability especially in the mature and old stages when compared to needle-leaved forests. Broad-leaved forests should have high levels of carbon sequestration when compared with needle-leaved forests in south China.展开更多
文摘A quarry is a surface mining operated place, which produces enormous quantifies of gravel, limestone, and other materials for industrial and construction applications. Restoration and revegetation of deserted quarries are becoming increasingly important. Three areas of a typical quarry in South China： terrace for crushed materials （terrace）, spoiled mound, and remaining side slope, were investigated, to compare the existing plant species and to study the relationship between environmental factors and revegetation. The plant species composition of these three areas was found to differ significantly after eight years of natural recovery. The typical plant communities found over them were composed of gramineous herbs, ferns, and shrubs. Soil organic matter, soil moisture, and soil bulk density were considered to be the major determining factors for vegetation succession. There existed abiotic and biotic thresholds during quarrying restoration. Suggestions had been presented that could have accelerated the process of natural recovery in quarries.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences (XDA05050205)
文摘We estimated aboveground biomass carbon (TABC) and net carbon accumulation rates (TNEP) for trees in four major forest types based on national forest inventory data collected in 1994-1998 and 1999-2003. The four types were Pinus massoniana forest, Cunninghamia lanceolata forest, hard broad-leaved evergreen forest and soft broad-leaved evergreen forest. We analyzed variations in TABC and TNEP for five stand ages (initiation, young, medium, mature and old). In both time periods, estimated TABC in all four forest types increased consistently with forest stand age and the oldest stage had the largest TABC compared with other stages. Broad-leaved forests (hard and soft) had higher TABC than needle-leaved forests (Pinus massoniana and Cunninghamia lanceolata) for each of the five age stages. The difference of TABC between broad-leaved and needle-leaved forests increased with forest stand age. Comparison of estimated TNEP by age category indicated TNEP increased from the initiation stage to the young stage, and then decreased from the mature stage to old stage in all four forest types. TNEP for any particular stage depended on the forest type; for instance, broad-leaved forests at both the mature and old stages had greater TNEP than in needle-leaved forests. A logistic curve was applied to fit the relationship between TABC and forest stand age. In each period, correlations in all four forest types were all statistically significant (P < 0.01) with R2 > 0.95. TABC was therefore predicted by these regression functions from 2000 to 2050 and the mean TNEP during the predicted period was estimated to be about 41.14, 31.53, 75.50 and 75.68 gCm-2a-1 in Pinus massoniana forest, Cunninghamia lanceolata forest, hard broad-leaved forest and soft broad-leaved forest, respectively. Results from both forest inventory and regression prediction suggest broad-leaved forests are greater carbon sinks, and hence have greater carbon sequestration ability especially in the mature and old stages when compared to needle-leaved forests. Broad-leaved forests should have high levels of carbon sequestration when compared with needle-leaved forests in south China.
