岷江上游山地森林－干旱河谷交错带不同土地 利用类型土壤有机碳储量

生态交错带是全球气候变化的最敏感区域，因而对生态交错带不同土地利用类型土壤有机碳的研究，可为生态交错带土地利用和有效管理提供基础数据。岷江上游山地森林－干旱河谷交错带6种土地利用类型的土壤有机碳含量和有机碳储量均随土壤深度的增加而降低；土壤有机碳储量的大小顺序为天然川滇高山栎次生林（104.15±4.84t/hm²）>灌木林地（100.84±2.43t/hm²）>灌丛地（97.35±15.21t/hm²）>经济林（85.16±10.58t/hm²）>人工刺槐林（70.78±12.43t/hm²）>农耕地（56.56±7.21t/hm²）；农耕地转变为人工刺槐林和经济林后，其土壤有机碳储量分别增加了25.13%和50.56%；人为干扰以及交错带生态系统的脆弱性及其叠加效应是导致岷江上游山地森林－干旱河谷交错带不同土地利用类型土壤有机碳储量偏低的重要原因。

Soil Organic Carbon Storage under Different Land Use Types at Mountain Forest-Drought Valley Ecotone in the Upper Reaches of Minjiang River

Ecotone is a sensitive region for global climate change,and study on soil organic carbon under different land use types at ecotone could provide basic data for land management.Soil organic carbon content and storage were decreased with the soil depth increment under 6 land use types at mountain forest-drought valley ecotone in the upper reaches of Minjiang River.Soil organic storage followed the order of Quercus semicarpifolia secondary forest (104.15±4.84t/hm²) >shrubbery (100.84±2.43t/hm²) >shrub (97.35±15.21t/hm²) >economic forest (85.16±10.58t/hm²) >Robinia pseudoacacia plantation (70.78±12.43t/hm²) >farmland (56.56±7.21t/hm²).Soil organic carbon storage increased by 25.13% and 50.56%,respectively after farmland was converted into Robinia pseudoacacia plantation and economic forest.Jamming and frangibility of ecotone were the main reason for lower soil organic carbon storage under different land use types at mountain forest-drought valley ecotone in the upper reaches of Minjiang River.