古尔班通古特沙漠6种荒漠草本植物的生物量分配与相关生长关系

选取古尔班通古特沙漠6种优势草本（2种短命植物，2种类短命植物，2种一年生长营养期植物），对比分析了生物量分配及相关生长关系的异同。结果表明：（1）粗柄独尾草（Eremurus inderiensis）和细叶鸦葱（Scorzonera pusilla）的地下生物量较高，根冠比分别为1.412、2.751；小花荆芥（Nepeta micrantha）、琉苞菊（Hyalea pulchella）和雾冰藜（Eremurus inderiensis）、角果藜（Scorzonera pusilla）的地下生物量均较小，根冠比无显著差异，分别为0.150，0.184，0.144，0.101；2种类短命植物具有相似的叶片生物量分配比例，但其余4种植物的叶片生物量分配比例均存在显著差异。（2）6种植物的根冠比随个体增大均呈异速减小，而叶片生物量分配比例与植株大小的关系不一致，表现为异速减少（如细叶鸦葱）或保持恒定（如粗柄独尾草）的趋势。（3）小花荆芥和琉苞菊的地下与地上生物量间为等速生长关系，而粗柄独尾草、细叶鸦葱、角果藜以及雾冰藜则呈现出个体越大地下生物量分配比例越少的格局（异速生长）；6种植物的地下与叶片生物量间均为等速生长关系，且具有共同的相关生长指数（1.035）。6种植物的根冠比和叶片生物量分配比例的差异不仅与物种自身的遗传特性有关，还受个体大小的影响；地下与地上生物量分配存在等速和异速生长的差异；叶片与地下生物量间具有相同的生物量分配速率，表现出对干旱荒漠环境的趋同适应。

Biomass Allocation and Allometric Relationships of Six Desert Herbaceous Plants in the Gurbantunggut Desert

Six dominant herbs, including two ephemeral plants (Nepeta micrantha and Hyalea pulchella), two ephemeroids (Eremurus inderiensis and Scorzonera pusilla) and two annual plants (Bassia dasyphylla and Ceratocarpus arenarius) were collected in the Gurbantunggut Desert, north-western China. And the biomass allocation and allometric relationships of the six species were investigated in this study. The results show that:(1) E. inderiensis and S. pusilla both allocated relatively more biomass to root and their root to shoot biomass ratio (R/S) were 1.412, 2.751. However, the root biomass of N. micrantha, H. pulchella and B. dasyphylla, C. arenarius were relatively small. The R/S of the four species showed no significant difference and their mean values were 0.150, 0.184, 0.144, 0.101, respectively. Two ephemeroid plants allocated the same ratio biomass to leaf, while the leaf biomass ratio (LBR) of the rest four species were different significantly. (2) R/S of the six species were declined significantly with increasing plant size, while LBR showed no consistent changing with increasing plant size, either decline or remain constant with changing plant size. (3) An isometric relationship between root and shoot were found for the two ephemeral plants (N. micrantha and H. pulchella), while other four species all showed allometric relationship between root and shoot (a>1.0, P<0.05). The six species showed isometric relationship between root and leaf, and a common allometric scaling exponent (1.035) were found. The study indicated that the difference on R/S and LBR for the six desert herbs were not only related to genetic property of species, but also affected by individual size. Additional, though there were difference on allomeric relationship between root and shoot among the six species, the same ratio of biomass allocation between root and leaf also indicated strong functional convergence to arid desert environment.