Ecological Stoichiometry Characteristics Of Two Species Of Halophytes And Their Habitat Soil Under Different Moisture-fertilization Gradients

Chemical elements in plants are the results of evolution of plants and their habitat environments in the long-term in mutual adaptation extremely,It not only can reflects the plants characteristics of resource use and allocation in its growth process,but also reflects the effective utilization of habitat environment.Arid zone plant nutrient elements and their stoichiometry is one of the hot issues of ecological research.In this article, in Ebinur Lake Wetland Natural Reserve, under different soil water conditions,Combined biological field experiment and chemical analysis, measured soil nutrient dynamics and spatial patterns of Apocynum venetum Linn. and Kalidium foliatum(Pall.) Moq. populations, Stoichiometry of plant nutrients and spatiotemporal dynamics,plant and soil nutrient correlations were analysed,through crossover fertilization experiment with different gradient of nitrogen and phosphorus revealed the formation mechanism of plant nutrient use characteristics and spatial pattern of stoichiometry to judge limiting factor. The results are as follows:1.Boom growing season,Apocynum venetum and Kalidium foliatum C, N, P nutrient element content distribution have differences in their different organs.Apocynum venetum: root> stem> leaf, Kalidium foliatum:stem> root> leaf for organic carbon; Apocynum venetum: leaf> stem> root, Kalidium foliatum: leaves> roots> stems for total nitrogen content; Apocynum venetum: stem> leaf> root, Kalidium foliatum: leaf> stem> root fortotal phosphorus.2.In different water condition,nutrient limitation of two kind of plants are different,with the loss of the soil water content, Apocynum venetum limited by N degree deepening, Kalidium foliatum is only limited by P.3.Along the decreasing water gradient, Apocynum venetum habitat soil organic carbon, total nitrogen, total phosphorus and total salt decreased, pH did not change significantly.Three layers of soil total nitrogen, total phosphorus, available phosphorus and pH did not change significantly, organic carbon content have the upper> middle> lower regular changes.4.Kalidium foliatum habitat soil total nitrogen, total phosphorus, available phosphorus, total salt did not change significantly, gradually increasing organic matter content. Three soil organic carbon, total nitrogen, total phosphorus, available phosphorus and pH did not change significantly.5.Along the decreasing water gradient, two kinds of plant leaves of C: N, N, P, C: P gradually reduced.6.At growing season in different gradient of fertilization has no significant effect with CK for C, N and P content change of the two plants.7.Plant nutrients reabsorption are has different circumstances in different plots after fertilization.Apocynum venetum Nitrogen resorption rate decreased with soil moisture content gradually declining, Kalidium foliatum Nitrogen resorption rate increasesed with soil moisture content decreased gradually rising; Phosphorus reabsorption rate of two plants was similar, with the reduction of the plots moisture content, phosphorus reabsorption rate increased.