气候变暖对青藏高原腹地高寒植被的影响

第25卷第6期2005年6月生 态 学 报ACT A ECOLOGICA SINICAV ol.25,N o.6Jun.,2005气候变暖对青藏高原腹地高寒植被的影响王　谋1,李　勇2,黄润秋3,李亚林1(1.成都理工大学地球科学学院,2.成都理工大学油汽藏及开发工程国家重点实验室;3.成都理工大学环境与土木工程学院,四川成都　610059)基金项目:国家国土资源部国土资源调查资助项目(200213000002);自然科学基金重大研究计划资助项目(90102002);自然科学基金资助项目(40372084);四川省重点学科建设基金资助项目(SZD 0408)收稿日期:2004-05-31;修订日期:2004-12-20作者简介:王谋(1975～),男,博士生,从事生态环境及环境变化研究.E -mail :cdlgw m @21cn .com致谢:中国科学院西北高原生物研究所彭敏教授帮助鉴定研究区植物样品,瑞士理工大学Nich olas Jam es Rich ards on 博士对本文给予帮助,在此一并致谢Foundation item :project of C hina M inis try of Land and Resou rces (No .200213000002)and key pr oject of the National Natural Science Foundation of C hina (No .90102002,40372084);Key Lab .Foun dation of Sichuan (SZD 0408)Received date :2004-05-31;Accepted date :2004-12-20Biography :W ANG M ou ,Ph .D .candidate ,mainly engaged in climate change of Qingh ai -T ibet Plateau and its ecology an d environ ment responses .E -m ail :cdlgw m @21cn .com摘要:研究区高寒植被碳同位素组成的研究,表明气候环境对高原腹地植被具有明显的控制意义。

在此基础上,通过对研究区植被样方的研究,对该区植被在高原气候暖干化过程中的变化趋势进行了探讨。

提出暖干化的气候(环境是区域植被退化的主因,并对研究区植被退化速率进行了推算(14.2km /10a)。

以样方数据分析为依托,重新拟定了研究区内干旱湿润区分界线,获得该区植物碳同位素值拟合干湿界限的支持。

通过对年代间干湿分界线位置的比较,对高原气候暖干化模式下植被的退化趋势进行了模拟。

关键词:青藏高原腹地;高寒植被;碳同位素;环境条件;暖干化;适应文章编号:1000-0933(2005)06-1275-07　中图分类号:Q 143,Q 948　文献标识码:AThe effects of climate warming on the alpine vegetation of the Qinghai -Tibetan Plateau hinterlandWANG M ou 1,LI Yong 2,HUANG Run-Qiu 3,LI Ya-Lin 1　(1.College o fE arth S ciences ;2.N ational K ey L aboratory of Oiland Gas Reser voir Geology and Exp loitation ; 3.College o f E nv ironment and Civ il Eng ineering ,Ch engd u Univ ersity of Te chnology ,Cheng du610059,China ).Acta Ecologica Sinica ,2005,25(6):1275～1281.Abstract :T her e is g ro wing ev idence w ithin t he env ir onmental science co mmunity that o ur planet has enter ed a potentia lly catastr ophic phase of human-induced global climate w arming.Climatic st udies demo nstr ate that t he Q inghai-T ibetan P lateau has also ex hibited a w arm ing and dry ing tr end in r ecent decades.W e st udied an ar ea o n the T ibet an P latea u located in the tr ansitio n zo ne betw een A lpine M eado w and Alpine Steppe reg io ns.Such zones ar e hig hly sensitive to env ir onmental change and t he co nco mitant adjustment o f v eg etat ion in t hese hinter land ar eas of the plateau can reflect ada ptat ion o f plant eco lo gical systems to chang es in the climat ic setting .In o rder to demonstr ate whether the A lpine veg etatio n o f the study ar ea displa ys a r espo nse to chang ing enviro nment al conditio ns,and w hether the v ariatio n in the envir onmental co nditio ns is reflected in cha ng es in the phy siolog y and fo rms of the A lpine flor al a ssemblage,we studied t he car bon iso topic values of these plants.Car bon iso tope fra ct ionation var iat ions w ithin the plants can reflect ar id o r m oist env iro nment al co nditions attained dur ing the gr ow th period of the plants.We carr ied out a reg r ession analy sis on the ex periment al car bon isot ope results,ta king int o account their g eog r aphical posit ion.T he analytical results sho wed that the D 13C v alues of K .p y gmaea cor relate w ith the cha ng ing SE -NW tr end of precipita tion .(R =0.44603,n =29,p <0.05),w hich indicates that the v egeta tio n has adapted t o v ariatio ns in env ir onmental co nditio ns .We a lso sur vey edflor al assemblag es at sit es w ithin the tr ansit ion zones ,and carr ied out principal co mpo nent and clust er analy ses o n the veg etation indexes o f these sites to ident ify the mig ration o f t he boundar y betw een A lpine St eppe and A lpine M eadow caused by climate w arm ing and dr ying .T he mig r atio n o f the bounda ry indica tes the ex pansio n of the a rid zone at a r ate o f 14.2km per decade and t he a cco mpanied deg ener ation o f v egeta tio n in t he bro ader centr al Plateau area.T he spread o f t he A lpine Steppe has not o nly result ed in a dro p in the ov erall veg etatio n co ver age in this reg io n,but ha s also caused a dro p in the tot al bio mass of the sur face veg etation in the ar ea.Study o f the biomass of t he A lpine St eppe and A lpine M eadow communities sho ws that the to tal biomass of the A lpine St eppe community in the study area is 77%of that o f the A lpine M eadow community.Ba sed o n t he o bser ved responses o f flor al car bon isoto pic co mpo sitio ns to v ar ying env ir onmental influences,this study has been able to quantify the chang ing tr end o f veg etation ty pes and quality o n t he T ibetan Plateau during recent climate w arm ing and dry ing.T hr oug h the integr ation of pr evio us studies of pla nt eco lo gy in the study area w ith o ur o wn r esear ch,w e pr opose that the change t o a w ar mer and dr yer climatic env ir onment is the main cause o f pr og r essiv e degenerat ion o f the veg etation in the study ar ea.T aking into account cur r ent clima te chang e models,our simulat ions o f futur e changing surface v egetat ion dem onstrat e that if the war ming and dr ying tr end continues unchecked,the veg etation degener atio n rate will acceler ate.T his w ill not o nly hav e a neg ativ e influence o n t he bio diver sity o f the T ibetan P latea u,but the r eductio n o f the biomass of the sur face plants w ill also hav e a neg ative influence on the local pa st or al eco no my.Key words :Q inghai-T ibetan Plateau;car bon isoto pes;env ir onmental co ndit ions;g lo bal w arm ing;w ar ming and dr ying trend;veg etation adapta bility图1　研究区位置及主要植被类型[5]Fig.1　T he location of s tudy area an d it's major vegetation types [5] 近40a 的降水趋势表明,青藏高原年平均降水量在减少,尤其是夏季降水量减少显著。