CAJ | 학술논문

对祁连山海北地区矮嵩草(Kobresia humilis)草甸和金露梅(Potentilla fruticosa)灌丛草甸两种植被类型土壤热通量观测和比较分析发现:晴天两种植被类型区土壤热通量日变化均表现为单峰型,夜间低午后高;阴雨天土壤热通量变化复杂,随降水或云层厚薄波动剧烈.金露梅灌丛草甸土壤热通量的日变化较矮嵩草草甸更为平稳.两种草甸土壤热通量的月际变化同样表现为单峰型,12月最低(矮嵩草草甸和金露梅灌丛草甸分别为-40.27MJ/m~2和-16.85MJ/m~2)、6月最高(矮嵩草草甸和金露梅灌丛草甸分别为20.47MJ/m~2和18.98MJ/m~2).矮嵩草草甸与金露梅灌丛草甸土壤热通量的年总量差异明显,分别为-24.72MJ/m~2和48.10MJ/m~2.表现出前者由土壤深层向地表散热,而后者由地表向土壤深层输送热量.两种植被类型区不同时间尺度上的土壤热通量与冠层净辐射均有显著的线性相关关系.由于冠层厚度的影响,金露梅灌丛草甸土壤热通量所占净辐射的比例较小,同步性较差,反馈延时约2.5h,而矮嵩草草甸的土壤热通量与净辐射的相关性更加密切.
대기련산해북지구왜숭초(Kobresia humilis)초전화금로매(Potentilla fruticosa)관총초전량충식피류형토양열통량관측화비교분석발현:청천량충식피류형구토양열통량일변화균표현위단봉형,야간저오후고;음우천토양열통량변화복잡,수강수혹운층후박파동극렬.금로매관총초전토양열통량적일변화교왜숭초초전경위평은.량충초전토양열통량적월제변화동양표현위단봉형,12월최저(왜숭초초전화금로매관총초전분별위-40.27MJ/m~2화-16.85MJ/m~2)、6월최고(왜숭초초전화금로매관총초전분별위20.47MJ/m~2화18.98MJ/m~2).왜숭초초전여금로매관총초전토양열통량적년총량차이명현,분별위-24.72MJ/m~2화48.10MJ/m~2.표현출전자유토양심층향지표산열,이후자유지표향토양심층수송열량.량충식피류형구불동시간척도상적토양열통량여관층정복사균유현저적선성상관관계.유우관층후도적영향,금로매관총초전토양열통량소점정복사적비례교소,동보성교차,반궤연시약2.5h,이왜숭초초전적토양열통량여정복사적상관성경가밀절.
Based on the measurement of soil heat flux of Kobresia humilis and Potentilla fruticosa meadows at Haibei station,Qilian Mountains, the results indicated that the diurnal change of soil heat flux for both types of meadows in clear days was lower at night and higher in the afternoon, representing a single-peak distribution. And it was complex in rainy days, with drastic fluctuation caused by rain and cloud. Whether it was sunny or not, the diurnal change of soil heat flux for Potentilla fruticosa meadow was more stable and its extent was smaller for high canopy height and much soil water content in Potentilla fruticosa meadow,with respecting to Koresia humilis . The monthly change of soil heat flux which was lowest in December ( Kobresia humilis and Potentilla fruticosa meadows were -40.27MJ/m~2,-16.85MJ/m~2 respectively)and highest in June( Kobresia humilis and Potentilla fruticosa meadows were 20.47MJ/m~2,18.98MJ/m~2 respectively), appearing a single-peak distribution. The annual total soil heat flux for Kobresia humilis and Potentilla fruticosa meadows was significantly different and was -24.72MJ/m~2 and 48.10MJ/m~2 respectively. Both of the annual change of soil heat flux was relevant to the variations of plant growth,soil water,seasonal frozen soil,especially net radiation. Due to the difference of vegetation types and environment factors, Potentilla fruticosa meadows' soil heat flux was a smaller consumer of net radiation than that of Kobresia humili . However,the synchronicity between soil heat flux and net radiation was worse for Potentilla fruticosa ,whose delay feedback was 2.5 hours,longer than that of Kobresia humilis .