摘要
土壤酶在生态系统物质循环和能量流动中起着关键作用,研究土壤酶活性对于探讨生态系统功能有着重要意义.采用Biolog微平板技术,研究不同海拔(4300~5100 m)土壤酶活性和酶计量比的变化特征及影响机制.结果表明:与C循环密切相关的β-1,4-葡萄糖苷酶(βG)、与N循环密切相关的β-1,4-N-乙酰氨基葡萄糖苷酶(NAG)、L-亮氨酸氨基肽酶(LAP)以及与P循环密切相关的酸性磷酸酶(AP)活性均随海拔升高呈现先上升后下降的单峰变化趋势,整体表现出4800 m>4950 m>4400 m>4650 m>5100 m>4300 m;土壤N∶P酶活性比呈现与土壤酶活性相同的先上升后下降单峰变化趋势,在4950 m处达到最高值;而土壤C∶N和C∶P酶活性比表现出沿海拔升高逐渐增加的趋势.有机碳(SOC)、土壤全氮(TN)、土壤含水量与4种酶活性均呈显著正相关;年均温度与NAG、AP呈显著正相关;年降水量与NAG、AP呈显著负相关;土壤C∶P酶活性比、土壤N∶P酶活性比与年均温度、年降水量、植被Shannon多样性指数、植被丰富度指数、植被盖度和TN呈显著正相关.年均温、年降水量、植被丰富度、植被覆盖度、土壤全氮和溶解性有机碳显著影响土壤C∶N酶活性比.青藏高原草甸不同海拔土壤酶活性和酶计量比呈现显著的海拔差异,且高海拔地区存在一定的N限制.土壤酶活性海拔差异主要受到土壤含水量、TN、SOC、年降水量和年均温度的影响.
Soil enzymes play critical roles in material cycle and energy flow of ecosystems. Understanding soil enzyme activities is of great significance for exploring ecosystem functions. In this study, we investigated soil enzyme activities, stoichiometry and their driving factors at six different altitudes(4300-5100 m) on Qinghai-Tibet Plateau alpine meadow using Biolog microplate analysis. The results showed that β-1,4-glucosidase(βG) closely related to C cycle, β-1,4-N-acetylglucosaminidase(NAG) and L-leucine aminopeptidase(LAP) closely related to N cycle and the activity of acid phosphatase(AP), which was closely related to P cycle, all exhibited unimodal trends with increasing altitude, with the order of 4800 m>4950 m>4400 m>4650 m>5100 m>4300 m. Soil N:P enzyme activity ratio showed the same trend as soil enzyme activity, and reached the highest value at 4950 m, however, soil C:N and C:P enzyme activities ratios increased along the altitude. Pearson correlation analysis showed that SOC, TN and soil water content were significantly positively correlated with the activities of four types of enzymes. Mean annual precipitation was significantly negatively associated with the activities of NAG and AP. Mean annual precipitation, mean annual temperature, Shannon diversity, vegetation richness, vegetation coverage and TN affected ratios of soil C:P and N:P enzymes. Soil C:N activity ratio correlated with mean annual temperature, mean annual precipitation, vegetation richness, vegetation coverage, SOC and TN. In summary, soil enzyme activities and stoichiometry had remarkable difference along the altitude gradient on Qinghai-Tibet Plateau alpine meadow, with certain N limitation in high altitude areas. Soil water content, TN, SOC, mean annual precipitation and mean annual temperature were key factors driving such differences.
作者
黄海莉
宗宁
何念鹏
田静
HUANG Hai-li;ZONG Ning;HE Nian-peng;TIAN Jing(College of Resources and Environmental Sciences,National Academy of Agriculture Green Development,Ministry of Education Key Laboratory of Plant-Soil Interactions,China Agricultural University,Beijing 100193,China;Key Laboratory of Ecosystem Network Observation and Modeling,Institute of Geographic Sciences and Natural Resources Science,Chinese Academy of Sciences,Beijing 100101,China)
出处
《应用生态学报》
CAS
CSCD
北大核心
2019年第11期3689-3696,共8页
Chinese Journal of Applied Ecology
基金
国家自然科学基金面上项目(31770560)
国家自然科学基金国际合作项目(41571130041)资助~~