刈割对赛里木湖周边山地草甸草地植物多样性的初步研究

发布时间：2018-05-16 23:20

本文选题：赛里木湖 + 山地草甸　；参考：《新疆农业大学》2015年硕士论文

【摘要】：赛里木湖以其神奇秀美的自然风光享誉国内外,其水域面积达458 km2,湖面海拔2073 m,是新疆面积最大、海拔最高的冷水湖。每年夏季,这里五彩缤纷的美景吸引着来自世界各地的游客,是新疆无人不知、无人不晓的4A级风景旅游区,也是名副其实的国家湿地公园和国家级重点风景名胜区。近年来,由于不合理利用和过度开发,赛里木湖周边天然草地出现不同程度的退化,主要表现为草地生产力下降,植被出现次生演替等。本文以赛里木湖西侧天山羽衣草(Alchemilla tianshanica)、禾草、杂类草型的山地草甸草地为对象,采用野外调查与室内分析相结合的方法,通过α物种多样性测度,独立样本t检验、Spearman秩相关分析等方法,研究刈割对赛里木湖周边山地草甸草地群落特征、多样性及再生速度的影响,确定草地合理利用时间和理论载畜量,为赛里木湖周边草地合理利用及可持续发展提供科学依据。主要结果如下:1、刈割仅对天山羽衣草、禾草、杂类草山地草甸草地植被地上生物量的影响效果显著(P0.05),而对物种多样性的影响不显著;不同经济类群(根茎疏丛禾草、小豆科草、小莎草类草和杂类草)的植物刈割后在高度、地上生物量和组成比例上均发生了变化;刈割对Margalef丰富度指数、Shannon-Wiener多样性指数与地上生物量的关系表现显著相关,而对Simpson多样性指数、Pielou均匀度指数与地上生物量的关系影响较弱,整体表现为三种结果,即正相关、负相关和无相关关系。2、山地草甸植物的生长(再生)速度有三种表现形式,即单峰型、双峰型和三峰型。刈割对峰值出现的大小、时间和次数有一定的影响。不刈割处理中,珠芽蓼(Polygonum viviparum)、草原老鹳草(Geranium pratense)呈单峰曲线,天山羽衣草、苔草(Carex sp.)呈双峰曲线,禾草呈三峰曲线;而刈割处理后,5种植物均呈双峰曲线;牧草在刈割后15 d的再生速度大都高于刈割后30 d及以后的再生速度,禾草在不同时期刈割的再生速度均明显大于天山羽衣草、珠芽蓼、草原老鹳草和苔草,从8月中下旬开始,牧草生长基本处于停滞状态。3、牧草生长主要集中在返青以后的生长初期,6月至7月初,绝对生长速率(AGR)0,地上生物量一直处于增长状态;7月中下旬开始,AGR0,则为生长衰退阶段。围栏内外鲜草产量均在7月中旬达到最大值,围栏内产量是围栏外产量的3倍左右;围栏内牧草的干鲜比值在6月3日至8月1日基本保持在30%-40%之间,随后开始升高,植株水分含量少,适宜用作打草场。4、2014年鲜草理论载畜量较2013年均同比下降7.87%,而干草均同比增长39.39%。全年利用时,2014年鲜草理论载畜能力较2013年同比增长8.70%,干草同比下降27.78%,季节草场利用时,2014年鲜草理论载畜能力较2013年同比增长12.5%,干草同比下降23.08%,表明2014年鲜草理论载畜能力较2013年弱,而干草理论载畜能力强。。
[Abstract]:Selimu Lake is famous at home and abroad for its magical and beautiful natural scenery. Its water area is 458km2 and its surface elevation is 2073 m.It is the largest and highest cold water lake in Xinjiang. Every summer, the colorful scenery here attracts tourists from all over the world. It is a 4A class scenic spot in Xinjiang. It is also a national wetland park and a national key scenic spot. In recent years, due to unreasonable utilization and overexploitation, the natural grassland around Selimu Lake has been degraded to varying degrees, mainly as follows: the productivity of grassland decreased, the vegetation appeared secondary succession and so on. In this paper, Alchemilla tianshanicaer, grass, mixed grass type mountain meadow grassland on the west side of Selimu Lake is taken as an object. The method of combining field investigation with indoor analysis is used to measure the diversity of a species. The independent sample t test and Spearman rank correlation analysis were used to study the effects of cutting on the characteristics, diversity and regeneration rate of meadow community in the mountainous meadow around Selimu Lake, and to determine the reasonable utilization time and theoretical stock capacity of grassland. It provides scientific basis for rational utilization and sustainable development of grassland around Selimu Lake. The main results are as follows: 1. The effect of mowing on the aboveground biomass of Eupatorium tianshanensis, grasses and hybrids in mountain meadow was significant (P 0.05), but the effect on species diversity was not significant, and there were different economic groups (rhizome, grass, legume). After cutting, the plant height, aboveground biomass and composition ratio changed, and the relationship between Margalef richness index Shannon-Wiener diversity index and aboveground biomass was significant. However, the relationship between Simpson diversity index and aboveground biomass was weak, and there were three kinds of results: positive correlation, negative correlation and no correlation. There were three forms of growth (regeneration) rate of mountain meadow plants. That is, single peak type, double peak type and three-peak type. Mowing has a certain effect on the magnitude, time and times of peak value. In the unmowing treatment, Polygonum viviparum, Geranium pratense, Geranium pratense, showed a single peak curve, Carex sp. and Carex sp.) There were bimodal curves in forage, three peaks in grasses, and bimodal curves in five plants after cutting, and the regeneration rate of forage at 15 days after cutting was higher than that at 30 days after cutting and after cutting. The regeneration rate of grass at different stages was obviously higher than that of Eupatorium tianshanensis, Polygonum hydropiper, Geranium wilfordii and Carex spp., which began in the middle and late August. The growth of forage was basically at a standstill. The growth of forage was mainly in the early stage after turning green. From June to the beginning of July, the absolute growth rate of AGR0 and the aboveground biomass of AGR0 had been increasing, and the growth of AGR0 was the stage of growth decline since the middle and late July. The yield of fresh grass inside and outside the fence reached its maximum in mid-July, and the yield inside the fence was about three times that of the yield outside the fence, and the dry and fresh ratio of forage inside the fence kept basically between 30% and 40% from June 3 to August 1, and then began to increase. Because of its low water content, it is suitable to be used as pasture. 4. The theoretical stock carrying capacity of fresh grass in 2014 is 7.87% lower than that in 2013, while the hay is 39.39% higher than the same year last year. During the whole year, the capacity of carrying livestock in the theory of fresh grass in 2014 was 8.70% higher than that in the same period of 2013, and that in hay was 27.78% lower than in the same period of 2013. When using seasonal pasture, the capacity of carrying livestock in theory of fresh grass in 2014 increased by 12.5% compared with the same period in 2013, and that in hay decreased 23.08%, indicating the theory of fresh grass in 2014. The capacity of carrying livestock is weaker than that of 2013. And the hay theory has a strong ability to carry livestock.
【学位授予单位】：新疆农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S812

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