摘要
【目的】土壤碳氮磷元素是支撑高寒草地生态系统的关键,高寒草甸退化会改变土壤养分含量及分布规律,明确高寒草甸退化对土壤关键养分碳氮磷含量及其与酶活性之间相关性的影响可为退化高寒草甸的恢复提供理论依据。【方法】以东祁连山围封草地(FG)为对照,对轻度(LD)、中度(MD)和重度(SD)退化高寒草甸土壤有机碳、全氮、有效氮、全磷、有效磷含量,以及土壤碳氮磷转化相关的过氧化氢酶、脲酶、碱性磷酸酶活性进行研究。【结果】相比FG,退化基本导致高寒草甸土壤的有机碳含量升高,SD 0~10 cm土层有机碳含量最高,为82.1 g/kg;退化导致过氧化氢酶活性表现出下降的趋势,围封草地20~30 cm土层的过氧化氢酶活性最高,为23.35 mg/g,LD 10~20 cm土层的过氧化氢酶活性最低,为20.90 mg/g。退化导致土壤全氮含量降低,有效氮含量和脲酶活性显著升高,SD草地有效氮含量和脲酶活性均最高,分别为649 mg/k和3.47 mg/g,脲酶活性在FG和SD随土层加深而升高,但在MD和SD随土层加深而降低。4种类型草地全磷的变化范围为0.18~0.22 g/kg,退化对0~10 cm土层的全磷含量没有显著影响,而使0~10 cm土层,LD和MD的有效磷含量分别增加了152%和60%,而SD降低了32%,0~30 cm土层碱性磷酸酶活性升高,变化范围为0.52~0.62 mg/g。相关性分析表明,围封草地土壤有机碳与过氧化氢酶活性呈显著负相关,而轻度和重度退化未表现出有相关性;围封草地土壤全氮、有效氮含量与脲酶活性均没有相关性,而轻度和中度退化高寒草甸的脲酶活性与土壤有效氮含量存在显著正相关性;围封草地的土壤全磷、有效磷含量与碱性磷酸酶活性均成呈显著正相关,而退化草地未表现出明显的相关性。【结论】高寒草甸退化后改变了其关键养分与其相关酶活性之间的相关性,重度退化高寒草甸恢复中应考虑土壤磷素的投入。
【Objective】Soil carbon,nitrogen and phosphorus are of key importance to alpine grassland ecosys-tem,and alpine meadow degradation can change soil nutrients content and their distribution.Clarifying the effects of alpine meadow degradation on soil key nutrients carbon,nitrogen and phosphorus content and their correlation with enzyme activity can provide a theoretical basis for the restoration of degraded alpine meadows.【Method】Four types alpine meadows,including Fenced(FG)as a control,light degraded(LD),moderate degraded(MD)and serious de-graded(SD)alpine meadow,were selected to study the effects of alpine meadow degradation on soil key nutrients content,correlative enzymes activities as well as correlation of soil key nutrients to enzymes in growing season in the eastern Qilian Mountain area.Soil organic carbon,soil total and available nitrogen,soil total and available phosphorus,soil catalase activity,soil catalase,urease,and alkaline phosphatase activity were analyzed.【Result】Soil carbon con-tents increased after degradation compared with CK except for 10~20 cm depth in LD and 0~10 cm depth in MD,and soil carbon content of 0~10cm in SD was the highest,which was 82.1 g/kg.But soil catalase activity was de-clined after degraded,and it showed the highest in 20~30 cm in FG,the lowest value was in 10~20 cm in LD,the value was 23.35 mg/g and 20.90 mg/g respectively.The degradation resulted in the decrease of soil total nitrogen content,and the increase of available nitrogen content and urease activity.The highest available nitrogen content and urease activity were 649 mg/kg and 3.47 mg/g in SD grassland,respectively..Urease activity increased in FG and SD,but decreased in MD and SD with the soil depth.The value of urease activity varied from 0.18 g/kg to 0.22 g/kg.Alpine meadow degradation had no significant effect on soil total phosphorus of 0~10cm depth.Soil avail-able phosphorus of LD and MD increased,but SD decreased compared with FG.Soil available phosphorus of LD,MD and SD increased 152%、60%and-32%respectively in 0~10 cm dept.Soil alkaline phosphatase activity in-creased under degradation,ranging from 0.52 mg/g to 0.62 mg/g.The correlation analysis showed that soil the cor-relation between organic carbon content and catalase activity was significant in FG,but there was no significant corre-lation in LD and SD.There was no significant correlation between soil nitrogen content and urease activity in FG,but was significant in MD and MD.There was significant correlation between soil phosphorus content and alkaline phos-phatase activity in FG,but was no significant correlation in degraded meadows.【Conclusion】The correlation between soil key nutrients content and enzyme activity was changed after degradation in alpine meadows,and phosphorus addi-tion may be needed in the restoration of serious degraded alpine meadow.
作者
李亚娟
刘艳君
徐长林
鱼小军
史志翯
徐晶晶
LI Ya-juan;LIU Yan-jun;XU Chang-in;YU Xiao-jun;SHI Zhi-he;XU Jing-jing(College of Grassland Science,Gansu Agricultural University,Key Laboratory for Grassland Ecosystem,Ministry of Education,Grassland Engineering Laboratory of Gansu Province,Sino-U.S.Centers for Grazing Land Ecosystem Sustainability,Lanzhou 730070,China;Forestry Science and Technology Extension Station of Gansu Province,Lanzhou 730046,China)
出处
《草原与草坪》
CAS
CSCD
2024年第3期10-18,共9页
Grassland and Turf
基金
甘肃省高等学校创新能力提升项目(2019B-071)
甘肃省草原生态修复治理科技支撑项目(2021)。
关键词
草地退化
高寒草甸
土壤碳
土壤氮
土壤磷
土壤酶活性
grassland degradation
alpine meadow
soil organic carbon
soil nitrogen
soil phosphorus
soil en-zyme activity
