摘要
利用小温棚升高气温 ,探讨气温升高对半干旱毛乌素沙地乡土旱生乔木旱柳幼苗的影响 ,以揭示像旱柳这样的乡土沙生乔木如何缓冲气温升高所带来的不利影响。水分饱和亏缺和失水系数均表现出随气温升高而降低的趋势 ,组织密度的变化趋势恰好相反 ;气温升高显著影响枝茎截面积比、叶干重茎截面积比、叶面积茎截面积比、叶干重枝截面积比和叶面积枝截面积比 ;叶死亡率和叶周转随气温升高呈现出降低趋势 ,而叶出生率和叶面积的变化格局为“钟形”曲线 ;气温升高促进分枝产生、增加分枝长度和角度 。
The Mu Us Sandland(107°20′~111°30′E,37°30′~39°20′N,1 300~1 600 m a.s.l.)is a very vulnerable ecotone.Climate change has been occurring dramatically in this area.For example,the mean annual air temperature increased by 0.5~1.8℃.Based on the prediction of GCM,if atmospheric CO\-2 concentration were doubled,the future mean annual air temperature would increase by 3.5~5.0℃ in the Mu Us Sandland.As a dominant xeric tree species,\%Salix matsudana\% will be intensively affected by the future climate change such as increased temperature and decreased precipitation.To explore how the species alleviate the disadvantages of air temperature rise that may occurs in the near future,a controlled experiment was done in which the air temperature was elevated by using small solar dome.We compared the effects of air temperature rise on the features of both water and architecture of \%S.matsudana.\%\;In April 1999,the authors collected two\|year\|old twigs(15 cm length)from the same maternal plant of \%S.matsudana\% in the Mu Us Sandland,then cut each twig into a growth container(about 9dm\+3)filled with homogenized topsoil from local natural habitats.Thus,the obtained \%S.matsudana\% cuttings shared the same genotype.45 days following the start of cutting,we selected the seedlings with similar size as experimental materials and put them into following treatments randomly.The full experimental design consisted of four treatments,namely,(1)whole plant growing under natural climate condition(T0),which was considered as a control;(2)whole plant growing under the solar dome with 15 pores(T1),in which air temperature increased by about 0.5℃;(3)whole plant growing under the solar dome with 10 pores(T2),in which air temperature increased by about 1.0℃;and (4)whole plant growing under the solar dome with 5 pores(T3),in which air temperature increased by about 1.5℃.The experiment ran from 17 May to 15 August.1999.During the experiment,the plants were watered and provided with nutrient solution as necessary.Leaf birth a
出处
《生态学报》
CAS
CSCD
北大核心
2001年第7期1084-1090,共7页
Acta Ecologica Sinica
基金
国家重点基础研究发展规划资助( G2 0 0 0 0 1 860 7)
国家杰出青年科学基金 ( 3982 51 0 6)
中国科学院"九五"重大研究( KZ 951 -
关键词
早柳
气温
水分特征
水力结构
叶种群
分枝
沙地
air temperature rise
branch
hydraulic architecture
leaf populations
Salix matsudanaKoidz
water traits
