【摘要】 砂生槐是西藏特有植物 ,主要分布在雅鲁藏布江中游地区及拉萨河、年楚河等主要支流宽谷区。为评价高原海拔引起的水热条件变化对砂生槐繁殖和生长的影响 ,沿雅鲁藏布江河谷 6 0 0多公里海拔从 31 39m到 392 5 m的样带上 ,对砂生槐天然种群进行了调查。结果表明 :沿着高原河谷海拔升高的梯度 ,降水量由 6 0 0 mm下降到 4 0 0 mm,年平均气温由8.2℃下降到 5 .8℃ ,砂生槐的种群密度趋与增加 ,基径趋于减小 ,但植株高度和新枝长度并未随海拔升高呈明显升降变化。种子库密度、种子千粒重、实生苗密度、萌蘖苗密度也没有随海拔高度的变化而呈明显的升降变化。砂生槐适应海拔引起的水热条件的变化在生殖方面并为作出大的调整 ,但在适应风沙干扰方面表现了繁殖方式的调整 ,即在未受沙埋时 ,种子繁殖趋于占主导地位 ;在生境受到沙埋时 ,营养繁殖趋于占主导地位。繁殖方式的调整可能是砂生槐适应风沙干扰的最主要对策。更多还原

【Abstract】 Sophora moorcroftiana is an endemic shrub species in Tibet,which mainly distributes in the middle reaches area and several main tributaries’ wide valley such as Nianchu River and Lhasa River of Yalu Tsangbo River.In order to evaluate how water-heat changing induced by plateau altitude affects the growth and reproduction of S.moorcroftiana in Tibet Plateau,some parameters of growth and reproduction of the natural population at a transect from 3139 m to 3925 m above sea level,about 600 km in length,along the Yalu Tsangbo River were investigated.Also the relationships between the depth of sand-burying and some parameters of growth and reproduction of S.moorcroftiana respectively,were investigated to determine how S.moorcroftiana responses to sand-burying.The results are suggested as follows: In the middle reaches area,with an elevation of 3000 m over,of Yalu Tsangbo River,the rainfall decreases with elevation increasing,which is different with typical mountains where rainfall increases with elevation increasing;mean annual air temperature reduces at a rate of 0.25℃ per one hundred meter,whereas it reduces at a rate of 0.5～0.65℃ per one hundred meter with elevation increasing at typical mountains when elevation is 3000 m over. The population density increases and the basal diameter declines with altitude increasing.However,the height,length of new bud, density of seed bank,weight of one thousand seeds,density of seedling and sprouting do not obviously increase or decrease with altitude increasing. S.moorcroftiana reproduces by means of seedling under the condition that sand-burying does not occur,but tends to regenerate by means of sprouting once the sand-burying at its habitat occurs to some extent.However it does not adjust their reproduction to response to the change of altitude that may set off change of rainfall and air temperature,etc.Adjustment of reproduction way maybe a major strategy of S.moorcroftiana responsig to desertification environment.更多还原