Relationship Between The Distribution Of Plant Communities And Soil Factors In The Northwest Of Liaoning

Natural vegetation types in our province includes 9 types, they were warm meadow steppe, temperate steppe, warm shrub-grasslands, warm grasslands, mountain meadow, lowland meadow, marsh, thin forest grasslands and scattered grass. Grass has 34 group and 129 grassland type. Grassland resources haven’t been investigated in more than 30 years since the late 70’s grassland resources census. In order to determine grassland resources status and changing trends in our province, by collecting basic data and selecting Liaoning northern forest steppe zone (Zhangwu, Kangping, Changtu, Faku) as a platform, this paper has investigated the plant resources and analyzed the community structure and the change of grassland styles. And on this basis,we selected teaching and research base of Shenyang Agricultural University in Al town in the north of Zhangwu as a platform, and studied the relationship between distribution of grassland communities and soil factors by principal component analysis (PCA). The main results are showed as follows:(1) 3 grassland types appeared in northern liaoning, they were warm grassland, mountainous meadow and lowland meadow grassland type has a total of 193 species, belonging to 46 families,133 genera. Generally, Gramineae (15.25%-21.43%), Asteraceae (13.82%-20.34%), legumes (10.17%-16.07%) were the dominant species. The highest frequency of species were:Cleistogenes squarrosa, Potentilla chinensis, Carex rigescens, Agropyron cristatum, Calamagrostis epigeios et al. Shrubs were Artemisia sacrorum, Lespedeza bicolor et al. Trees were Crataegus pinnatifida, Ulmus pumila, Populus davidiana. The perennial herbaceous species (47.46%-59.82%) were the dominant in terms of plant life type, those of annual plants(18%-37%) were at the second. Shrub was 5-24%, of which the west was more. Trees was 4.46-6.78%, which was opposed to shrub. There were little biennial herbs in warm meadow type, and woody liana of Ampelopsis japonica in mountain meadow.(2) There were Artemisia annua, Cleistogenes squarrosa and other kinds of grassland types in total of 32. Compared to 1980,1 species has reduced, and no differences was huge. But there was differences among grassland types.Grassland type of shrub was not apparent in 1980,but grassland type of Corylus heterophylla, Ulmus pumila, Rhamnus arguta was apparent in 2015. Bothriochloa ischaemum, Eleusine indica, Zoysia japonica of herbaceous plants was disappeared in 2015.(3) The order of 3 grassland species Shannon-Weiner index was lowland meadow type (1.76)< temperate steppe type(1.92)< mountain meadow type (1.936). The order of grassland species Simpson’s diversity index was lowland meadow type (0.595)< temperate steppe type (0.61)<mountain meadow type (0.64).(4) Besides the regional characteristic of Agropyron desertorum community apparent, there are Calamagrostisps eudophragmites and Artemisia frigida as the dominant species in warm steppe of Al forest-steppe belt.(5) Taking soil physical and chemical properties as variable, this paper studied by principal component analysis (PCA). The contribution of the first principle component (PC1) was 37.92%, which represents chemical properties: pH, total N, total P, et al. The contribution of the second principle component (PC2) was 24.36%, which reflects the composition of soil particles. Analysis has concluded that Agropyron desertorum community distributed in less sand content, clay content and total K was relatively high. Calamagrostisps eudophragmites was formed in high contents of pH, total N, total P, available K, SOM and Artemisia frigida was just the opposite. Total N and soil structure of particle composition were important factors which affected three kinds of communities.