封育下退化伊犁绢蒿荒漠草地高光谱研究

发布时间：2018-04-28 19:13

本文选题：伊犁绢蒿 + 高光谱　；参考：《新疆农业大学》2016年硕士论文

【摘要】：从植被、土壤及光谱三个方面对封育后的伊犁绢蒿荒漠草地恢复状况进行研究,希望通过光谱研究对该类草地恢复状况进行监测。主要研究结果如下:(1)对群落植被及光谱研究可以发现,在同一退化梯度下,随着封育年限的增加,草地群落建群种伊犁绢蒿重要值增大,而植被生长期内短命植被及一年生植被从群落中逐渐退出。通过分析群落光谱特征可以发现,在植被生长期内群落光谱的植被吸收特征减弱,在成熟期只有封育10年的群落光谱具有明显的植被吸收特征;通过特征植被光谱可以发现,不同植被对围栏干扰响应不一致,在5月随封育年限增加伊犁绢蒿红边斜率显著大于未围封的红边斜率(P0.05),叉毛蓬与之相反(P0.01),而涩荠的红边斜率在围封与未围封间并无明显不同(P0.05);从植被生长期来看,特征植被可以分为三种类型:逃避型(涩荠)、耐旱型(木地肤)和休眠型(伊犁绢蒿)植被。通过光谱对群落数量指标的相关性分析,表明NDVI与高度、盖度和生物量间具有相关性,R2依次为0.17、0.32和0.36。(2)对伊犁绢蒿荒漠草地的土壤理化性质及光谱进行研究,结果显示土壤含水量在各土层随植物生长期呈递减趋势,5月与9月土壤含水量随围封年限延长总体上呈增加趋势,并对群落光谱和土壤含水量间关系进行建模,R2=0.63;土壤有机质随封育年限增加呈升-降-升的趋势,围栏内有机质在5月相对于围栏外随封育年限的延长呈递增趋势,封育7年、10年的差值在植物生长期内呈线性递减。通过室内土壤光谱及野外裸地光谱对土壤有机质进行建模,均取得较好效果,R2分别为0.64与0.38。研究表明草地土壤含水量及有机质对于草地恢复状况较为敏感,可用于该类草地封育状况的监测。(3)对群落的数量指标、群落NDVI和特征植物NDVI进行回归分析发现,3个指标均在5年时达到极值;而土壤含水量及有机质的相关分析,表明在10年左右达到最大值。结合植被、土壤的敏感指标可以得出结论,对于研究区这一退化状况下的伊犁绢蒿荒漠草地,在封育5年后草地植被即得到恢复,土壤恢复相对滞后,可以进行适当的利用。
[Abstract]:The restoration status of desert grassland of Artemisia yili after fencing was studied from three aspects of vegetation, soil and spectrum, and it was hoped that the restoration status of this kind of grassland could be monitored by spectral study. The main results are as follows: (1) under the same degradation gradient, the important value of Artemisia ellii, a species of grassland community, increased with the increase of the years of fencing under the same degradation gradient. But the short-lived vegetation and the annual vegetation gradually withdraw from the community during the vegetation growth period. By analyzing the spectral characteristics of the community, it can be found that the spectral absorption of the community decreases in the vegetative growth period, and the spectrum of the community with only 10 years of closure in the mature period has obvious characteristics of the absorption of the vegetation, and the characteristic spectrum of the vegetation can be found through the characteristic vegetation spectrum. The response of different vegetation to fence disturbance was not consistent. In May, the red edge slope of Artemisia Yili was significantly higher than that of unenclosed red edge slope (P0.05, P 0.01), but the red edge slope of Cardamine was not significantly different between the enclosed and unenclosed areas, and the vegetation growth period showed that the red edge slope of Artemisia yili was significantly higher than that of unenclosed red edge slope (P0.05), and that the red edge slope of Artemisia yili was significantly higher than that of unenclosed red edge slope (P0.05). The characteristic vegetation can be divided into three types: escape type, drought tolerant type and dormant type. The correlation between NDVI and height, coverage and biomass was found to be 0.170.32 and 0.36. 2, respectively. The soil physical and chemical properties and spectra of the desert grassland of Artemisia yili were studied. The results showed that the soil moisture content decreased with the growth of plants in each soil layer, and that in May and September the soil moisture content increased with the increase of the envelop life. The relationship between community spectrum and soil moisture content was modeled R2N 0.63.The soil organic matter increased with the increase of the fencing years, and the organic matter in the enclosure increased with the extension of the fencing years in May compared with that outside the enclosure. For 7 years, the difference of 10 years was decreased linearly in plant growth period. The soil organic matter was modeled by indoor soil spectrum and field soil spectrum. The results showed that the R2 was 0.64 and 0.38, respectively. The results showed that soil water content and organic matter in grassland were sensitive to grassland restoration, and could be used to monitor the fencing condition of grassland. Regression analysis of community NDVI and characteristic plant NDVI showed that the three indexes reached the maximum value in 5 years, while the correlation analysis of soil water content and organic matter showed that the maximum value was reached in about 10 years. Combined with vegetation, the sensitive index of soil can be concluded that the grassland vegetation was restored after 5 years of fencing, and the soil restoration was relatively lagged, so it can be used properly for the desertified grassland of Artemisia Yili under the condition of degeneracy in the study area.
【学位授予单位】：新疆农业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S812

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