狭叶锦鸡儿和小叶锦鸡儿灌丛沙堆的形态和发育及灌丛固沙能力的比较研究

测定了内蒙古高原荒漠草原区狭叶锦鸡儿（Caraganastenophylla）和小叶锦鸡儿（C．microphylla）不同大小灌丛的灌丛形态参数、沙堆形态参数和沙堆体积，目的是掌握这些锦鸡儿属植物灌丛的沙堆形态特征、沙堆发育特征和固沙能力随着灌丛发育的变化，比较这2种锦鸡儿属植物灌丛沙堆的形态、发育特征和固沙能力的差异．研究发现：狭叶锦鸡儿和小叶锦鸡儿沙堆都为圆锥状，灌丛和沙堆形态均无显著差异．狭叶锦鸡儿和小叶锦鸡儿的沙堆底面积、沙堆高度、沙堆体积和固沙效率均与地上枝条鲜重呈现显著线性正相关关系．在灌丛较小的时候，狭叶锦鸡儿固定沙堆底面积、高度、体积和固沙效率大于小叶锦鸡儿，当灌丛扩展到一定阶段时，小叶锦鸡儿大于狭叶锦鸡儿．狭叶锦鸡儿和小叶锦鸡儿灌丛高度和沙堆高度分别随其灌丛半径和沙堆半径的增大呈现对数曲线增大；灌丛和沙堆水平方向的扩展速度大于垂向生长速度；小叶锦鸡儿灌丛高度的扩展快于狭叶锦鸡儿，但沙堆高度发育比狭叶锦鸡儿慢．狭叶锦鸡儿和小叶锦鸡儿的沙堆半径与灌丛半径，沙堆高度与灌丛高度均呈现显著线性正相关关系．小叶锦鸡儿固定沙堆体积和固沙效率均大于狭叶锦鸡儿，但未达到显著水平．这些研究结果表明，锦鸡儿属植物灌丛形态决定沙堆形态，灌丛发育决定沙堆发育，灌丛地上生物量和灌丛生长形态决定沙堆体积和植物固沙能力．

Comparison of nabkha morphology, development and sand-fixing capability between C.stenophylla and C.microphylla

The relationships between the morphology of shrubs and nabkhas and sand-fixing capability for the two dominant Caragana species in the desert-steppe of the Inner Mongolia Plateau were explored.The results showed that C.stenophylla and C.microphylla nabkhas were conical.There was no significant difference in shrubs and nabkhas morphology between C.stenophylla and C.microphylla.Nabkhas’ bottom area,vertical scale,volume and sand-fixing efficiency were significantly correlated with shrub aboveground biomass.When shrubs were on the small size,the nabkhas’ bottom area,vertical scale,volume and sand-fixing efficiency of C.stenophylla were more than that of C.microphylla.But when shrubs expanded to a greater size,these parameters in two Caragana species were just the reverse.With the increased semidiameter of C.stenophylla and C.microphylla shrubs and nabkhas,their vertical scale increased respectively in logarithmic curves.And the development of shrubs and nabkhas was faster in horizontal scale than in vertical scale.While the development of nabkhas height in C.microphylla was slower than in C.stenophylla,the expansion of shrubs vertical scale in C.microphylla was faster than in C.stenophylla.The nabkha semidiameters of two Caragana species were significantly correlated with the shrub semidiameters,and the height of nabkhas and shrubs.For the sand-fixing efficiency and the fixed volume of nabkhas,C.microphylla was more than C.stenophylla,but the difference was not significant.All the results indicated that for the two Caragana species,nabkhas morphology was determined by shrubs’ morphology,the development of nabkhas was controlled by shrubs’ development,nabkhas volume and shrubs’ sand-fixing capability were determined by the aboveground biomass and the growth shape of shrubs.