Adaptive Strategies Of The Clonal Wetland Plant Bolboschoenus Planiculmis In Heterogeneous Environments Adaptive Strategies Of The Clonal Wetland Plant Bolboschoenus Planiculmis In Heterogeneous Environments

Bolboschoenus planiculmis is dominant species of several wetland plant communities, such as Zha Long nature reserve in Heilongjiang, Xiang Hai wetlands of state nature reserve in Jilin province and Momoge wetlands of state nature reserve. These wetlands have seasonal alternating processes between drought and wetness. During the moist season, Pahragmites australis and B. planiculmis are dominant populations; while during the dry season, leymus chinesis is the dominant population following xeromorphic community succession. The white crane of wetlands is mainly feed with corms of B. planiculmis. In recent years, as the population of B. planiculmis being destroyed in wetlands ecosystem, the habitat and food of white crane decreased year by year, which could be a serious threat to its survival.As B. planiculmis is a typical wetland plant, its habitats are closely related to water, especially moisture gradients of soil. The population of B. planiculmis is being degraded by deterioration of wetland water and soil resources. Thereby, biodiversity resources of wetlands might get lost. Previous studies on B. planiculmis were focused on distribution areas, biological characteristics such as reproductive characteristics and prevention measures; however, rather little is on its ecological adaptability, ecological features and response mechanisms to environmental factors. In the present study, we explored the ecological adaptability of B. planiculmis and investigated the physiological response mechanisms in three environmental stresses.The main results are described as follows:At the clonal level of soil nutrient and particle experiments soil experiment, nutrient heterogeneity (patch scale and contrast) and particle heterogeneity did not significantly affect the growth and morphology of B. planiculmis, particle size could significantly affect biomass, number of ramets, total rhizome length,spacer length and number of tubers of B. planiculmis, but root to shoot ratio was not significant. At the patch level, biomass, number of raments, total rhizome length and number of tubers of B. planiculmis were significantly greater in the nutrient-rich patches than in the nutrient-poor ones whereas spacer length (i.e., distance between adjacent ramets) was smaller. Particle size and the reaction between soil particle and particle heterogeneity were significantly affect biomass, number of ramets, total rhizome length and number of tubers, and grew the best of all in medium particle patch of small patch treatment.In soil moisture regimes experiment, biomass, rhizome length, number of corms, ramet height, total leaf length, spacers length and root to shoot ratio of the plants of flooding treatment were greater than drought treatment, but the number of ramets were not significant. Each physiological indexes of drought treatment and flooding treatment were significant and NPQ of flooding treatment were lower than drought treatment.Wetland plants plays an important role in structure and function of wetlands, therefore, protecting the habitat of B. planiculmis in wetlands is urgent. Researches on growth and morphological responses of B. planiculmis to environmental factors will be important for recovery the population of B. planiculmis, and maintaining healthy structure and functionalities of wetlands.