全球变化背景下伊犁山地草原苦豆子无性系种群生活史的响应及调节机理

Global warming and nitrogen deposition are the crucial problems that people face nowadays.Those problems will continue to influnce the environment which is the base on human beings' survival,so that globle warming and nitrogen deposition have become the focus of the research in globle change.Sophora alopecuroides is a tipical perennial clone and dominant species on the Ili upland meadow, which is a familiar kind of poisonous and harmful plant in this area. Just because of its strong adaptation to divergent environment, this project take S. alopecuroides as the research object. According to systemic natural and experimental researches with site experiment, simulating experiment and simulation on the mathematical model, the project use infrared ray heat instrument to simulate the effects of global warming and nitrogen deposition on life history adaptation and the regulation mechanism based on population and physiological ecology characteristics of S.alopecuroide population. Primary contents are as follows:effects of simulated warming and nitrogen depositon on the spatial and temporal dynamics,such as the compositions and dynamics of vegetative and sexual modules of populations, population regeneration and regulation of all types of buds;the adaptability of life history pattern under the background of simulated warming and nitrogen,such as the reproductive phenology,clone growth regulation and allocation strategies,reproductive capacity,and so on; the characteristics and strategies of seeds germination under the simulated warming and nitrogen deposition background,physiological mechanism of seedlings' tolerance to saline alkali and drought stresses. Based on above researches,the models of plant population dynamics will be established, reproductive strategy will be analyzed.The research will reveal the perfect adaptation strategies and its regulation mechanism of S. alopecuroides population life history under the simulated warming and nitogen deposition environment in the Ili upland meadow.The results of the project wild provide some scientific basis for production practice in the management and controll for poisonous or harmful species,enven the sustainable development and utilization of ecological system.

气候变暖和氮沉降作为全球变化的两大突出现象已经发生，并将继续影响人类赖以生存的环境，引起越来越多人的关注，已成为该领域研究的热点。本项目拟以新疆伊犁山地草原广布的优势种无性系植物苦豆子（Sophora alopecuroides）为研究对象，应用野外定点实验、模拟实验和数学模型等方法，开展模拟氮沉降和增温条件下苦豆子种群生活史的响应与适应调节的种群生态和生理生态学研究。主要内容包括：模拟增温与氮沉降对苦豆子无性系种群时空动态影响研究；种群生活史格局的响应研究；种子萌发与幼苗耐受性的实验生理生态学研究。目的在于揭示全球变化条件下苦豆子萌发、生长、繁殖与分配等生活史格局差异性、规律性，建立全球变化背景下的植物生活史策略的定量分析方法。在生产实践上，为伊犁山地草原中苦豆子等有毒有害植物的管控以及生态系统可持续发展和利用提供科学依据。

气候变暖和氮沉降作为全球变化的两大突出现象已经引起越来越多人的关注，已成为该领域研究的热点。本项目拟以新疆伊犁山地草原广布的优势种无性系植物苦豆子（Sophora alopecuroides）为研究对象，开展模拟氮沉降和增温条件下苦豆子种群生活史的响应与适应调节的种群生态和生理生态学研究。结果表明：（1）苦豆子果实成熟后可以持续留存在植冠层，形成显著的持久性的植冠种子库,而土壤种子库为长久型土壤种子库，二者均是种群更新和蔓延的重要来源。（2）在苦豆子的生长初期，苦豆子对对N和P较高的利用率，且其入侵对群落生境的土壤理化性质均能产生显著影响，这些都可能是苦豆子入侵性强的主要原因之一。（3）在苦豆子种子萌发过程中，增温处理对苦豆子的种子萌发率并没有产生显著的促进作用, 胚根伸长生长被显著促进, 苗高显著被促进，幼苗的根系生长被抑制；苦豆子的总生物量受增温的影响不显著，但增温改变了苦豆子幼苗各构件间生物量的分配格局；在不同形态氮处理中，以100%KNO3+0%NH4Cl处理对促进幼苗生长的效果最显著；在幼苗的建成过程中，子叶损伤是苦豆子幼苗建成的瓶颈。（4）轻度模拟N沉降处理促进了群落中植物的生长, 促进了生物量生产；模拟N沉降可显著促进苦豆子生长，增加生物量积累，提高苦豆子种群的高度；氮沉降增加了无性系种群分株根茎节间芽、根茎顶芽和分蘖节芽的输出；使用OTC进行增温则不利于休眠芽动员为活性芽，而增温与氮沉降交互作用则效果不显著；氮沉降显著增加了地上部构件的生物量，促进了营养生长；N添加后苦豆子花序的抽穗、开花、结实期、种子成熟期均有不同程度的延迟，对种群的生殖单株数及其单株的花轴数没有显著影响。同时，氮沉降可显促进花穗轴的长度，增加结实率，显著降低无效豆荚比例，并显著提高种子的千粒重。