A litterbag experiment of 12 weeks was conducted to study nitrogenmineralization process of prunings of six nitrogen-fixing hedgerowspecies in a dry valley of the Jinsha River. Prunigns wereincorporated into soil or u...A litterbag experiment of 12 weeks was conducted to study nitrogenmineralization process of prunings of six nitrogen-fixing hedgerowspecies in a dry valley of the Jinsha River. Prunigns wereincorporated into soil or used as mulch. The results indicated thatpruning N of the six hedgerow species was mineralized fast in thefirst week and then decreased slowly in the rest of the study period.When prunings were incorporated into soil, the amount of nitrogenmineralized by the end of the first week accounted for 69.9/100,58.2/100, 54.5/100, 43.0/100, 29.6/100 and 20.6/100 of the total N inprungins of Desmodium rensonii, Tephrosia candida, Leucaenaleucoephala, Albizia yunnanensis, Acacia dealbata, and Acaciamearnsii, respectively.展开更多
草地在大渡河干暖河谷植被恢复及植物群落演替中具有重要作用,而植被恢复的关键在于土壤质量。将大渡河干暖河谷泸定至汉源段,依据坡向划分为8个方位(北、东北、东、东南、南、西南、西、西北),分析了不同坡向和植被盖度草地的土壤理化...草地在大渡河干暖河谷植被恢复及植物群落演替中具有重要作用,而植被恢复的关键在于土壤质量。将大渡河干暖河谷泸定至汉源段,依据坡向划分为8个方位(北、东北、东、东南、南、西南、西、西北),分析了不同坡向和植被盖度草地的土壤理化性质,采用主成分分析法(Principal component analysis,PCA)对河谷区草地土壤质量进行了评价。结果表明:(1)影响河谷草地土壤质量的最小数据集(Minimum data set,MDS)指标包括非毛管孔隙度、土壤容重、有机质和碳氮比;(2)河谷从东北坡过渡到西南坡土壤质量逐渐降低,与南坡热而干旱的微气候使土壤矿化作用剧烈,而北坡适宜的光热和水热条件更有利于土壤中钾和磷的释放有关;(3)植被盖度与土壤质量呈正相关关系,随着草地植被盖度减少土壤质量逐渐降低。高植被盖度(>70%)土壤质量主要受非毛管空隙度影响,而低高盖度草地(<30%)主要受土壤容重影响;(4)河谷区草地土壤质量指数中间值分布较多,土壤肥力属于2—4级中等水平。大渡河干暖河谷区草地土壤质量较好,潜在肥力水平较高,有利于植物生长和植物群落正向演替,是植被人工恢复的重点区域。展开更多
基金Project supported jointly by the Chengdu Di Ao Science Foundation and the Sichuan Provincial Science Foundation for Young Scient
文摘A litterbag experiment of 12 weeks was conducted to study nitrogenmineralization process of prunings of six nitrogen-fixing hedgerowspecies in a dry valley of the Jinsha River. Prunigns wereincorporated into soil or used as mulch. The results indicated thatpruning N of the six hedgerow species was mineralized fast in thefirst week and then decreased slowly in the rest of the study period.When prunings were incorporated into soil, the amount of nitrogenmineralized by the end of the first week accounted for 69.9/100,58.2/100, 54.5/100, 43.0/100, 29.6/100 and 20.6/100 of the total N inprungins of Desmodium rensonii, Tephrosia candida, Leucaenaleucoephala, Albizia yunnanensis, Acacia dealbata, and Acaciamearnsii, respectively.
文摘草地在大渡河干暖河谷植被恢复及植物群落演替中具有重要作用,而植被恢复的关键在于土壤质量。将大渡河干暖河谷泸定至汉源段,依据坡向划分为8个方位(北、东北、东、东南、南、西南、西、西北),分析了不同坡向和植被盖度草地的土壤理化性质,采用主成分分析法(Principal component analysis,PCA)对河谷区草地土壤质量进行了评价。结果表明:(1)影响河谷草地土壤质量的最小数据集(Minimum data set,MDS)指标包括非毛管孔隙度、土壤容重、有机质和碳氮比;(2)河谷从东北坡过渡到西南坡土壤质量逐渐降低,与南坡热而干旱的微气候使土壤矿化作用剧烈,而北坡适宜的光热和水热条件更有利于土壤中钾和磷的释放有关;(3)植被盖度与土壤质量呈正相关关系,随着草地植被盖度减少土壤质量逐渐降低。高植被盖度(>70%)土壤质量主要受非毛管空隙度影响,而低高盖度草地(<30%)主要受土壤容重影响;(4)河谷区草地土壤质量指数中间值分布较多,土壤肥力属于2—4级中等水平。大渡河干暖河谷区草地土壤质量较好,潜在肥力水平较高,有利于植物生长和植物群落正向演替,是植被人工恢复的重点区域。
