Defense Traits And Mechanisms Of Caragana Microphylla To Herbivory

Plants have long-term coevolution processes with herbivorous animals that already have a variety of adaptation strategies for their survival and growth environment.The top-down effect of the grazing affects the plant's ecological adaptation strategy,and the bottom-up effect of the nitrogen deposition through the soil nutrient cycle and soil nutrient level will also affect the plant's adaptation strategies have a significant impact.To study the response mechanism of grassland plants to herbivores,it is helpful to formulate scientific grazing policies and grassland utilization methods,so as to provide important theoretical basis for the restoration of degraded grassland and the improvement of grassland ecosystem primary productivity.At the same time,the change of the response strategy of plant to animal foraging has important theoretical and practical significance for the protection and prediction of grassland biodiversity.The interaction between grassland and herbivorous animal under the background of global climate change has important theoretical and practical significance.In this study,Caragana microphylla was collected from the Hulunbeier grassland in Inner Mongolia Autonomous Region.The response strategies of C microphylla under the background of nitrogen deposition were discussed from the aspects of morphology,physical defense and chemical defense through different fertilization levels and simulated foraging test in Songnen grassland ecological research station of Northeast Normal University.The main conclusions of this study are as follows:(1)In a nutrient-rich environment,such as nitrogen resources or nitrogen and phosphorus are rich,the plant may be through accelerated growth to resist the animal feed damage.(2)In a phosphor-rich environment,the plant may be protected against physical damage such as increased physical density or more secondary metabolites by increasing the defense of animals by increasing their defense.Simulated feeding had little effect on the length of C microphylla,but it could increase the thorn density under the condition of applying P.When N was applied,the thorn density decreased.(3)The resources acquired by plants from the environment are usually limited.Therefore,the way of plant feeding on animals varies with the environmental conditions,and the experimental results support the growth-differentiation hypothesis.In conclusion,this study clarifies the response of plants to feed and fertilization,and reveals the mechanism of response of plants to vegetative feeding by changing the allocation and defense strategies of plants in different vegetative environments.The results of this study show that the responses of plants to animal foraging are limited by soil nutrient conditions.In nitrogen or nitrogen-rich environments,plants are mainly resistant to animal foraging by increasing growth,but when rich in phosphorus often increasing the investment in defense against animal foraging,and there is a trade-off between growth and defense.The results of this study enrich the theory of plant-animal co-evolution.Under the background of nitrogen deposition,we can further improve our understanding of how grassland plants respond and respond to human activities.