| 青藏高原东缘高寒草甸土壤氮矿化初探 |
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| 引用本文： | 陈懂懂,孙大帅,张世虎,杜国祯,史小明,王向涛.青藏高原东缘高寒草甸土壤氮矿化初探[J].草地学报,2011,19(3):420-424. |
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| 作者姓名： | 陈懂懂 孙大帅 张世虎 杜国祯 史小明 王向涛 |
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| 作者单位： | 1. 中国科院西北高原生物研究所, 青海西宁, 810008;2. 兰州大学干旱与草地生态重点实验室, 甘肃兰州, 730000;3. 西藏大学农牧学院, 西藏林芝, 860000 |
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| 基金项目： | 国家自然科学基金重点项目(40930533)，国家自然科学基金面上项目 |
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| 摘 要： | 通过对甘南州境内高寒草甸在4个放牧强度(禁牧、轻牧、中牧和重牧)和5个海拔梯度(3050,3180,3570,3600,3910 m)下的土壤氮矿化速率分析测定,并对室内和原位培养所得净氮矿化率进行比较,以期为确定该区合理的草地放牧管理措施,以及深入研究和系统评价高寒草甸生态系统碳、氮循环提供基础依据。结果表明:原位培养下,放牧强度的增强促进了土壤氮的矿化;室内培养所得土壤净氮矿化率大于原位培养净氮矿化速率,说明在适宜温度和湿度(22℃和40%~60%的田间持水量)条件下,氮矿化速率较高;作为土壤质量的一种度量,土壤氮矿化潜力在禁牧处理下较高(0.53 mg·kg-1·d-1),而在重牧处理下较低(0.36 mg·kg-1·d-1);随着海拔升高,氮矿化潜力呈"V"字型变化,而原位培养下的氮矿化率与海拔梯度呈显著负相关关系(R=-0.672,P<0.01)。处于强度放牧下的草地土壤氮素周转加快,造成土壤氮素水平下降;现阶段高海拔区土壤可看作养分的储存库,如果气候变化加剧,该养分库可能变成温室气体的源。
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| 关 键 词： | 放牧强度 海拔梯度 净氮矿化 青藏高原 |
| 收稿时间： | 2010-10-12 |
Soil N Mineralization of An Alpine Meadow in Eastern Qinghai-Tibetan Plateau |
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| CHEN Dong-dong,SUN Da-shuai,ZHANG Shi-hu,DU Guo-zhen,SHI Xiao-ming,WANG Xiang-tao.Soil N Mineralization of An Alpine Meadow in Eastern Qinghai-Tibetan Plateau[J].Acta Agrestia Sinica,2011,19(3):420-424. |
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| Authors: | CHEN Dong-dong SUN Da-shuai ZHANG Shi-hu DU Guo-zhen SHI Xiao-ming WANG Xiang-tao |
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| Institution: | 1. Northwest Plateau Institute of Biology, Chinese Academy of Sciences, Xining, Qinghai Province 810001, China;2. Key Laboratory of Arid and Grassland Ecology under the Ministry of Education, Lanzhou University, Lanzhou, Gansu Province 730000, China;3. College of Agricultural and Animal Husbandry, Tibet University, Linzhi, Tibet 860000, China |
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| Abstract: | This study reports an understanding of the N mineralization in soil of an alpine meadow in Qinghai-Tibet Plateau(Gannan Tibetan Autonomous Prefecture,Gansu Province),the net N mineralization rates in soil under four grazing treatments(No grazing,Light grazing,Moderate grazing and Heavy grazing) were determined from both indoor and in-situ incubation.The net N mineralization rates in soil from 5 different altitudes(which are 3050,3180,3570,3600,3910 m) were also determined.Results showed that the net N mineralization rate obtained from the indoor incubation was larger than that from the in-situ incubation,which indicated that the N mineralization rate was increased under appropriate temperature and moisture.Grazing increased the N mineralization under the in-situ incubation.Soil N mineralization potential was higher under the no-grazing treatment(0.53 mg·kg-1·d-1),and lower under the heavily-grazing treatment(0.36 mg·kg-1·d-1) compared to control.The N mineralization potential showed a "V" type with the elevation increasing.The net N mineralization rate in soil under in-situ incubation was negatively correlated with elevation(R=-0.672,P<0.01).Conclusions are that severe grazing accelerates the turnover rate of nitrogen in soil,thus causes the soil nitrogen level decreasing.Therefore,the high altitude soil may be the nutrient pool at present. |
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| Keywords: | Grazing intensity Altitudinal gradient Net N mineralization Qinghai-Tibetan Plateau |
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