自然恢复和人工促进恢复对侵蚀退化生态系统碳贮量的影响比较

本研究以严重侵蚀退化马尾松林为研究对象,采取自然恢复和人工促进恢复2种措施对退化地进行修复,监测恢复前后生态系统碳贮量变化。结果表明:自然恢复和人工促进恢复后生态系统总碳贮量分别是恢复前的2.78和4.87倍,其中,植被层碳贮量分别是恢复前的14.30和30.87倍,土壤层碳贮量分别是恢复前的1.85和2.78倍。生态系统内土壤碳的恢复速率落后于植被。2种不同恢复措施相比,人工促进恢复的生态系统碳吸存速率显著快于自然恢复(P0.01),人工促进恢复后生态系统碳吸存速率是自然恢复的2.17倍,其中植被和土壤的吸存速率也分别是自然恢复的2.26倍和2.09倍。而且人工促进恢复后的退化系统,碳库在乔木层各器官的分配方式更符合健康生态系统的分配方式,系统功能和结构更加稳定,有利于系统后期恢复。因此,从退化生态系统恢复的紧迫性和长期性考虑,采取积极的人工促进恢复措施能维持退化系统快速、持续恢复。

Effects of Natural Restoration and Artificial Rehabilitation on Carbon Storage in Degraded Forest Ecosystems

Natural restoration and artificial rehabilitation were carried out in severely degraded Pinus massoniana forest ecosystems , and their carbon storage before and after recovery were investigated . The results showed that carbon storage in naturally restored and artificially rehabilitated ecosystems was 2.78 times and 4.87 times that of unrecovered ecosystems .Accordingly , carbon storage in vegetation in naturally restored and artificially rehabilitated ecosystem was 14.29 times and 30.87 times that of unrecovered ecosystem , but soil carbon storage was 1.85 times and 2.78 times that of naturally restored ecosystem .The recovery rate of soil carbon storage was lower than that of vegetation .Carbon sequestration rate in artificially rehabilitated ecosystem was 2.17 times as much as naturally restored＆amp;nbsp;ecosystem .Accordingly , the sequestration rate of vegetation and soil in artificially rehabilitated ecosys-tem were 2.26 and 2.09 times as much as the counterparts in naturally restored ecosystem .Besides , the carbon allocation in artificial rehabilitated ecosystem was more in accordance with the allocation re-gime of healthy ecosystem than naturally restored ecosystem , indicating that the structure and function of artificially rehabilitated ecosystem were solidly forming .To sum up , in terms of both the urgency and sustainability , active artificial rehabilitation measures , rather than natural restoration , can regener-ate the degraded ecosystem rapidly and in sustainable way .