Analysis Of The Soil Moisture And Melica Przewalskyi Patches In The Degraded Alpine Grassland Of Qilian Mountains, China

Under the influence of the global Climate change，in the arid andsemi-arid regions of a single dominant populations in communities exist andflourish, plants adapt to the environment at the same time also changed itshabitat, the performance of a single dominant populations strong adaptabilityand its plasticity. Soil moisture is a major factor in the formation andevolution of vegetation pattern of spatial heterogeneity of soil moistureunderstanding of grassland plants in arid area on the response mechanism ofthe environment is important, on a smaller scale, vegetation status, soilmoisture spatial heterogeneity the main driving factor. Traditional statisticalmethods to investigate the spatial distribution of soil moisture prerequisite forresearch data must be statistically independent and uniformly distributed, butsoil moisture in space there is generally a certain spatial autocorrelation,spatial autocorrelation contains some useful information. In view of this, thispaper, the traditional statistics, statistical methods, and Moran’s I coefficientsof Northern of Qilian Mountains of Melica przewalskyi shallow profile of asingle dominant species patch (0-30) spatial heterogeneity of soil moisturefrom correlation between the spatial correlation scale, the establishment ofthe layers of soil moisture impact factor of the classic linear regression modeland spatial autoregressive model, the results are as follows:(1) The results show: the distribution of surface soil moisture andvegetation coverage was normal distribution, in0-30cm depth, there is a highdegree of spatial heterogeneity of soil moisture. Among them80.93~87.34%spatial heterogeneity is caused by the spatial autocorrelation part, and thedistance of spatial autocorrelation in vegetation coverage was found withindistance from4.09~6.91m; Melica przewalskyi patches spatial variabilityof soil moisture and vegetation cover functions are nonlinear models,reflecting the heterogeneity of soil moisture spatial distribution of resourcesas well as Melica przewalskyi aggregated distribution features, layers of soilmoisture has a strong spatial autocorrelation. Layers of soil moisture both showed patchy distribution pattern and there are a number of non-repeatcenter of high value and low-value areas.(2)0-10cm layer of soil moisture in the ground has good spatialcontinuity and the Melica przewalskyi cover space distribution showed strongsimilarity, which is more strongly as a result of the study area, soilevapotranspiration in Melica przewalskyi patch was a cluster-like distributionscale, the formation of dense grass carpet and litter composition effectivesurface cover, not only reduces the evaporation of soil moisture, and changethe spatial heterogeneity of soil moisture pattern.10-30cm layer of soilmoisture spatial heterogeneity is mainly due to the Melica przewalskyi patchare mainly concentrated in the10-20cm soil layer, the layer of soil moistureand surface compared to fragmentation degree of strengthening, there hasbeen a number of low-value areas;20-30cm soil layer Melica przewalskyiroots accounted for about20%of the total, the layer of soil moisture spatialpattern formation mechanism is more complex, less than the sampling scalerandom factors due to heterogeneity of soil moisture is greater than10-20cmlayer.(3) layers of soil moisture has space and spatial agglomerationcharacteristics of10-20cm layer of soil moisture spatial agglomerationcharacteristics compared to0-10cm and20-30cm soil layer is more obvious,which is by Gansu catarium special biological school characteristics.Degraded grassland in Melica przewalskyi invasion of grassland by cloninggrowth regulator to adapt to the habitat heterogeneity of soil moisture, and inthe process Melica przewalskyi also changed the pattern of native grasslandsoil moisture, and through underground roots on soil moisture formationcontrol, due to the differences in the distribution of vegetation root zone soilprofile depth response to the water are not the same.(4) in the0-10cm soil layer, soil moisture is mainly affected by theheight of the community.0-10cm soil, vegetation height positive significanteffect on soil moisture.10-20cm soil layer, Melica przewalskyi cover on soilmoisture highly significant negative correlation a higher concentration because higher coverage patch Gansu catarium distribution, higher density ofits underground roots on soil moisture absorption and utilization degree of thestronger, resulting in the10-20cm soil moisture and Melica przewalskyi coverwas highly significant negative correlation in the height of the20-30cm soillayer, the coverage of the northwest Stipa and community layer soil moistureis more significant.Through this study, Melica przewalskyi physiological integration bycloning and to some extent the impact of changes in soil moisture within thesmall-scale distribution patterns of spatial distribution of soil moistureredistribution, and thus habitat resources to achieve a greater level of use, butalso proactive towards higher spatial expansion of water resources and soilmoisture mutual response, greatly improved in arid habitats adaptability andcompetitiveness.