干旱风沙区不同植被恢复模式生态效应研究

发布时间：2018-04-13 05:51

本文选题：植被恢复 + 草地植物群落　；参考：《宁夏大学》2015年硕士论文

【摘要】：植被恢复是防治土地沙漠化扩张、缓解沙尘暴危害的关键,一直是生态学研究领域的焦点问题,尤其是干旱风沙区,其土地退化和荒漠化已成为全球性的重大生态环境问题,因此适宜的植被恢复模式对荒漠草原生态恢复和维持具有重要意义。本研究是在宁夏盐池县高沙窝镇二步坑行政村荒漠草原,选择封育草地、柠条补播草地、沙打旺补播草地三种恢复模式和未封育草地为对照,研究分析了三种恢复模式对植被、土壤、水分和地表气候方面的影响,运用灰色关联分析法来综合评价三种恢复模式的生态效应,并筛选出最适宜该区的恢复模式,以期对干旱风沙区草地生物多样性理论、管理实践和植被恢复等提供相关依据,为更好的选择适合当地情况的恢复模式奠定基础。主要研究结果与结论如下：(1)6—9月封育草地、柠条补播草地和沙打旺补播草地植物群落的高度、密度、频度、盖度和地上生物量均高于未封育草地；物种丰富度指数、Shannon-Wiener多样性指数和Pielou均匀度指数为：沙打旺补播草地封育草地柠条补播草地未封育草地,而生态优势度则呈相反的趋势；不同植被恢复模式植物群落稳定性从大到小依次为：沙打旺补播草地、封育草地、柠条补播草地和未封育草地,其中,沙打旺补播草地植物群落稳定性最好,但总体来看,三种植被恢复模式和未封育草地的植物群落均不稳定。(2)三种植被恢复模式均可降低土壤容重,有效改善草地土壤结构,增加土壤保水持水能力,尤其以沙打旺补播草地效果最好。0—40cm土层土壤有机质含量和速效钾含量为：封育草地柠条补播草地沙打旺补播草地未封育草地,土壤全氮和速效氮含量为：沙打旺补播草地柠条补播草地封育草地未封育草地,土壤速效磷含量为：封育草地沙打旺补播草地柠条补播草地未封育草地,土壤全盐含量和pH值以未封育草地最高。(3)不同植被恢复模式草地气温从高到低依次为：未封育草地、柠条补播草地、封育草地和沙打旺补播草地,14：00达到峰值,呈单峰曲线；相对湿度变化为：沙打旺补播草地封育草地柠条补播草地未封育草地,自8：00-20：00呈“V”型变化曲线；地表和地下0—5cm、5—10cm、10—15cm和15—20cm土壤温度变化一致,均为：未封育草地柠条补播草地封育草地沙打旺补播草地,最高值出现的时间以地表最早。(4)不同植被恢复模式草地5—12月土壤含水量为：未封育草地柠条补播草地封育草地沙打旺补播草地,随降水的变化浅层土壤水分波动较大；随土层深度的增加,不同恢复模式草地土壤含水量变异系数逐渐减小；封育草地和沙打旺补播草地随土层加深,土壤含水量增加,柠条补播草地深层土壤的含水量则相对较低。5—7月和11—12月,三种植被恢复模式草地和未封育草地的土壤水分均形成了负平衡,8—10月,土壤水分均为正平衡,且均以未封育草地正、负平衡最为明显。(5)不同植被恢复模式草地的关联度大小为：封育草地沙打旺补播草地柠条补播草地未封育草地,从各结构指标和功能指标分析,封育模式和沙打旺补播模式对植被的恢复改善作用效果较好,是干旱风沙区值得推广的植被恢复措施。
[Abstract]:Vegetation restoration is prevention of desertification, sandstorm hazard mitigation key, has always been a focus of research in the field of ecology, especially in arid sandy area, land degradation and desertification has become a major global environmental problems, so it is suitable for the vegetation restoration patterns on desert grassland ecological restoration and maintenance of this is of great significance. Study in Yanchi County of Ningxia Gao Sha Wo Zhen Keng Xing Zheng Cun two step desert steppe, choose grassland and Caragana reseeding grassland, Astragalus adsurgens reseeding grassland restoration model and three kinds of unenclosed grassland were studied three kind of recovery mode on vegetation, soil, and the effects of water surface climate, ecology the effect of applying the grey relational analysis to comprehensive evaluation of three kinds of recovery mode, and selected the most suitable mode of recovery in the region, in order to grassland in arid sandy area of biodiversity management theory. Practice and provide relevant basis for vegetation restoration, lay the foundation for a better recovery mode suitable for the local conditions. The main research results and conclusions are as follows: (1) 6 - September grassland, Caragana reseeding grassland and milkvetch reseeding grassland plant community height, density, frequency, coverage and aboveground biomass were higher than those in grazed meadows; species richness index, Shannon-Wiener diversity index and Pielou evenness index: Astragalus adsurgens grassland reseeding grassland Caragana reseeding grassland grazed grassland, while ecological dominance was opposite trend; different vegetation restoration patterns of stability of plant communities from large to small is as follows: Astragalus adsurgens reseeding grassland, grassland, grassland and Caragana overdrilling unenclosed grassland, the stability of grassland plant communities reseeding Astragalus adsurgens is best, but overall, three patterns of vegetation restoration and unenclosed grassland vegetation Community were not stable. (2) three patterns of vegetation restoration could reduce soil bulk density, improve soil structure, increase soil water retention and water holding capacity, especially with the best effect of Astragalus adsurgens reseeding grassland.0 40cm soil organic matter content and potassium content of Caragana mountain grassland reseeding grassland Astragalus adsurgens supplement grassland grazed grassland, soil total nitrogen and available nitrogen content: Astragalus adsurgens reseeding grassland Caragana reseeding grassland grassland grazed grassland, soil available phosphorus: Grassland reseeding grassland overdrilling Caragana adsurgens grassland grazed grassland, soil total salt content and pH value in an enclosure the grass is highest. (3) model of grassland temperature from high to low are different vegetation restoration: unenclosed grassland, Caragana reseeding grassland, grassland and milkvetch reseeding grassland, reached the peak at 14:00, showed a single peak curve; relative humidity change Astragalus adsurgens: reseeding grassland grassland Caragana reseeding grassland grazed grassland, since 8:00-20:00 showed "V" curve; surface and underground 0 - 5cm, 5 - 10cm, 10 - 15cm and 15 - 20cm soil temperature change, are: Caragana unenclosed grassland reseeding grassland grassland the sand at Wang reseeding grassland, the highest value of the time to the first surface. (4) 5 - December soil moisture model of grassland vegetation restoration: Caragana unenclosed grassland reseeding grassland fenced grassland reseeding grassland with Astragalus adsurgens, changes in precipitation and shallow soil moisture fluctuation; with the increase of soil layer the depth of the different restoration model of grassland soil moisture variation coefficient decreases; grassland and milkvetch reseeding grassland with soil depth, soil moisture increased, Caragana reseeding grassland soil water content is relatively low.5 in July and 11 in December, three kinds of vegetation Recovery mode of grassland and soil moisture in unenclosed grassland were formed a negative balance, 8 - October, soil moisture are balanced, and are in unenclosed grassland, negative balance is most obvious. (5) the correlation degree of grassland in different vegetation restoration: Grassland reseeding grassland. Caragana reseeding grassland grazed grassland, from the analysis of structural indicators and functional indicators, fencing and Sowing Patterns on the pattern of Astragalus adsurgens vegetation restoration effect is better, is worthy of promotion measures to restore vegetation in arid sandy area.

【学位授予单位】：宁夏大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S812

【参考文献】