摘要
明确荒漠-绿洲过渡区土壤呼吸及其温湿度敏感性特征,对了解干旱、半干旱地区土壤碳循环有重要意义。本研究采用LI-8100土壤呼吸观测系统对河西走廊典型荒漠-绿洲过渡区荒漠梭梭林地、绿洲农田、人工杨树林地3种不同土地利用类型的土壤呼吸进行1年的观测。结果表明,3种土地利用类型全年平均土壤呼吸为人工杨树林地(2.20μmol CO_2·m^(-2)·s^(-1))>绿洲农田(1.61μmol CO_2·m^(-2)·s^(-1))>荒漠梭梭林地(0.40μmol CO_2·m^(-2)·s^(-1)),造成不同土地利用类型土壤呼吸显著差异的原因主要与土壤有机碳含量有关。Lloyd-Taylor指数模型能够较好拟合土壤呼吸季节性变化与温度的关系。3种不同土地利用类型的土壤呼吸均在低温时(非生长季)较高温时(生长季)对温度变化更敏感。在全年尺度上,不同土地利用类型的土壤呼吸与土壤温度呈极显著正相关(P<0.01);荒漠梭梭林地、绿洲农田的土壤呼吸与土壤水分呈极显著正相关(P<0.01),人工杨树林地土壤水分低于6%时和高于6%时,土壤呼吸与土壤水分分别呈极显著正相关(P<0.01)和显著负相关(P<0.05)。本研究结果为干旱区绿洲化过程土壤碳循环的研究提供了基础数据。
Clarifying the sensitivity of soil respiration to the variation of temperature and moisture in the desert-oasis region would be a great contribution to understanding soil carbon cycling in arid and semi-arid areas. In this study,we measured soil respiration using LI-8100 Soil Respiration Observation System as well as air temperature,soil temperature,and soil moisture under three different land use types（ Haloxylon ammodendron plantation,oasis cropland,and poplar plantation） in a desert-oasis region of Northwest China. The annual mean soil respiration was in order of H. ammodendron plantation（ 0.40 μmol CO2·m^-2·s^-1） 〈oasis cropland（ 1.61 μmol CO2·m^-2·s^-1） 〈poplar plantation（ 2.20 μmol CO2·m^-2·s^-1）,which was mainly driven by soil organic carbon content. The relationship between soil temperature and soil respiration was fitted by the Lloyd-Taylor model. Soil respiration in all those ecosystems was more sensitive to lower temperature（ non-growing season） than higher temperature（ growing season）. At year-round scale,soil respiration in the three ecosystems was positively correlated with soil temperature（ P〈0.01）. Furthermore,soil respiration in the H. ammodendron plantation and oasis cropland was positively correlated with soil moisture（ P〈0. 01）. Soil respiration in the poplar plantation was positively correlated with soil moisture when it was below 6%,but was negatively correlated with soil moisture when it was above 6%. Our results provide basic data for soil carbon cycling in the desert-oasis region.
作者
富利
张勇勇
赵文智
FU Li;ZHANG Yong-yong;ZHAO Wen-zhi(College of Geography and Environmental Science,Northwest Normal University,Lanzhou 730070,China;Linze Inland River Basin Research Station,Key Laboratory of Ecohydrology of Inland River Basin,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China）.)
出处
《生态学杂志》
CAS
CSCD
北大核心
2018年第9期2690-2697,共8页
Chinese Journal of Ecology
基金
中国科学院"西部之光"博士项目
国家重点研发计划课题(2017YFC0504304)
国家杰出青年基金项目(41125002)资助
关键词
荒漠绿洲区
土壤呼吸
季节变化
土地利用
温度
土壤水分
desert-oasis region
soil respiration
seasonal variation
land use
temperature
soilmoisture.
