四种荒漠植物生物量分配对土壤因子的响应及异速生长分析.

The river basin of Ebi Lake represents a typical ecosystem in arid land, a sensitive area for global change and a key protected area for biodiversity. The study of the relationship among biomass allocation of above-ground and below-ground plant, response mechanism of edaphic factor, and allometry helps understand the plants' survival and optimization strategies in terms of soil conditions and ecological functions. With excavation as the method that gave us adequate biomass information and the physical and chemical properties of the soil, four desert plants in the research area were analyzed: Suaeda salsa, Seriphidium kaschgaricum, Horaninowia ulicina, and Alhagi sparsifolia, among which the biomass, its allocation ratio in response to the edaphic factor, and allometric models were compared. The results were as follows:(1)There were significant differences in the biomass and its allocation ratios among the four plants, with Seriphidium kaschgaricum having the largest above-ground and below-ground biomass, while Horaninowia ulicina the smallest; The R/S(root-shoot ratio)showed Alhagi sparsifolia > Horaninowia ulicina and Seriphidium kaschgaricum > Suaeda salsa(P<0.05).(2)The effect of edaphic factor on R/S analyzed with RDA showed that the interpretability of edaphic factors towards R/S in terms of the four plants were 16.3%, 24.8%, 33.1% and 35.4%, respectively. Among them, the soil total nitrogen had a positive correlation with the R/S of Horaninowia ulicina (P<0.05), and the soil moisture a significantly positive correlation with the R/S of Suaeda salsa(P<0.01).(3)The four plants all had significant correlations with regards to AGB-BGB(P<0.01), where the AGB-BGB of Seriphidium kaschgaricum had a pattern of isometric scaling(α=1), while both Horaninowia ulicina and Alhagi sparsifolia showed an allometric scaling of α=3/4, and Suaeda salsa belonged to the allometric scaling of a non-3/4 power exponent(α<1). All the four plants shared a common allometric scaling index(0.767). The above results indicate that the desert plants in Ebi Lake have functional convergence, and the characteristics of their spatial distribution are species-specific in response to edaphic factors. [ABSTRACT FROM AUTHOR]