退化高寒沼泽湿地对刈割和补播的响应

发布时间：2018-01-08 09:37

本文关键词：退化高寒沼泽湿地对刈割和补播的响应　出处：《青海大学》2017年硕士论文　论文类型：学位论文

【摘要】：本文以黄河源区退化高寒沼泽湿地为研究对象,在高寒沼泽湿地周围中度退化区和重度退化区,分别进行围栏刈割控制试验和补播处理控制试验,通过对植被群落特征和土壤营养状况影响进行测定,探讨高寒沼泽湿地退化原因以及补播恢复过程中的限制因子。主要结论如下:1、随着刈割强度的加强,植被高度、盖度和多样性指数呈现减小趋势,3种刈割强度(0%、50%、100%)之间差异不显著(P0.05)。随着刈割强度的加强,土壤质地小于0.01mm物理黏粒含量总体上呈现减少的趋势,土壤容重逐渐增大,各刈割强度之间差异不显著(P0.05)。刈割试验中,20cm土壤年含水量均高于10cm土壤含水量,10cm和20cm土壤含水量逐渐减小。随着刈割强度的加强5cm、15cm、25cm土壤年均温度逐渐减小。2、刈割试验中,土壤养分和pH在垂直方向上是逐渐降低的。随着刈割强度的加强,土壤养分和pH在逐渐较小,但是没有差异显著性(P0.05)。退化沼泽湿地中土壤微生物数量以放线菌占绝对优势,在垂直方向上表层土壤微生物数量远大于其它土层。不同刈割强度下微生物数量之间差异不显著(P0.05)。3、补播处理地中,随着补播牧草植株数量的增多,土壤质地(小于0.01mm物理黏粒含量)逐渐增大,土壤容重逐渐减小。总体来看土壤含水量在垂直方向上是逐渐增加,土壤含水量逐渐增加,土壤含水量在表层0-10cm处植株无与植株较多补播地量差异显著(P0.05)。4、补播处理样地中,土壤温度在垂直方向上是逐渐减小的。随着补播植株数量的增多,土壤温度逐渐增加,土壤温度在表层0-10cm处植物无(秃斑地)与植株较多补播地之间差异显著(P0.05)。土壤养分在垂直方向上是逐渐增加的,随着补播牧草植株数量的增多,全K2O、速效K和pH逐渐减小,速效K和pH在植株无和植株较多补播地之间差异显著;全N、全K2O、碱解N、速效P和有机质之间增加,全N速效P和有机质在植株无和植株较多补播地量差异显著(P0.05)。5、补播处理样地中,土壤微生物数量在垂直方向上是逐渐减小的,从植株无到植株较多补播地之间土壤微生物数量呈增加的趋势。6、以在不同植株密度中有显著差异性的8个指标作因子分析,结果表明土壤含水量、土壤温度和土壤电导率是限制补播处理样地植株密度的主导因子。
[Abstract]:In this paper, the degradation of alpine swamps in the source area of the Yellow River was studied. The fencing cutting control test and the supplementary sowing control experiment were carried out in the moderately degraded and severely degraded areas around the alpine swamp wetland. The effects of vegetation community characteristics and soil nutrient status on the degradation of alpine swamp wetland and the limiting factors in the process of restoration were discussed. The main conclusions are as follows: 1, with the increase of cutting intensity. The vegetation height, coverage and diversity index showed a decreasing trend. There was no significant difference among the three cutting intensities (P 0.05), and with the increase of cutting intensity, there was no significant difference. The physical clay content of soil texture less than 0.01 mm showed a decreasing trend, the bulk density of soil gradually increased, and there was no significant difference between different cutting intensity (P 0.05). The annual water content of 20cm soil was higher than that of 10cm and 20cm soil water content. With the increase of cutting intensity, the annual water content of 20cm soil was higher than that of 10cm soil water content and 20cm soil moisture content. The average annual temperature of 25cm soil decreased gradually. In cutting experiment, soil nutrient and pH decreased gradually in vertical direction. With the increase of cutting intensity, soil nutrient and pH gradually decreased. However, there was no significant difference (P0.05). Actinomycetes were dominant in soil microbes in degraded swamp wetlands. In the vertical direction, the number of microbes in surface soil is much larger than that in other soil layers, but the difference of microbial quantity under different cutting intensity is not significant (P0.05. 3). With the increase of the number of forage plants, the soil texture (less than 0.01 mm physical clay content) gradually increased, and the soil bulk density gradually decreased. In general, the soil moisture content increased gradually in the vertical direction. The soil water content increased gradually, and there was no significant difference between the soil moisture content and the plantlets in the topsoil 0-10cm. There was a significant difference in the amount of soil water content between the plants and the plantlets (P0.05N. 4). The soil temperature decreased gradually in the vertical direction, and the soil temperature increased gradually with the increase of the number of additional seeding plants. There was a significant difference between the soil temperature of 0 ~ 10cm between the plants and the plantlets with more supplementary seeding, and the soil nutrient increased gradually in the vertical direction. With the increase of the number of forage plants, the total K _ 2O, available K and pH decreased gradually, and the difference between available K and pH was significant between the plants without plants and with more plants. Total N, total K _ 2O, alkali-hydrolyzed N, available P and organic matter increased, and total N available P and organic matter were significantly different in the non-plant and more plantlet supplementary seeding land (P0.05N. 5). The number of soil microbes decreased gradually in the vertical direction, and the number of soil microbes increased from no plant to more supplementary seeding. The results showed that soil water content, soil temperature and soil electrical conductivity were the main factors limiting plant density in different plant densities.
【学位授予单位】：青海大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q948

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