Spatial Pattern and Interspecific Association of Natural Platycladus orientalis Population in Loess Hilly Region of Inner Mongolia
In order to explore the spatial distribution pattern and intra-specific correlation of Platycladus orientalis population in the Loess hilly region of Inner Mongolia,the natural Platycladus orientalis sparse forest in the typical Loess hilly region of Inner Mongolia was taken as the research object,and the spatial pattern of Platycladus orientalis population in different slope directions was analyzed using the point pattern combined with the complete spatial randomness,the heterogeneous Poisson model and the Poisson aggregation model of the single variable function,and the intra-specific grade was determined after the availability of the age class was determined by the fitting curve,a bivariate function was constructed to study the intra-specific correlation of Platycladus orientalis population.The results showed that the resources of regenerated seedlings were abundant,followed by young trees,and the number of mature trees was the least.The proportion of grade Ⅰ was as high as 27.79％,grade Ⅱ was 21.84％,and the cumulative proportion of grade Ⅲ to grade Ⅴ was 32.85％.The population distribution of each age class was pyramidal,and the population structure was stable,showing a steady growth trend.The quantity distribution of each age of 4～22 m,and the shady slope presents a small scale of 0～1 m aggregation distribution.The heterogeneous Poisson model showed that the slope direction had an impact on the aggregation degree of Platycladus orientalis population,and the Poisson aggregation model had an aggregation distribution within the range of 1～5 m,indicating that there was a certain relationship between species.There were 3 kinds of correlations in Platycladus orientalis species.The relationship between seedlings and adult trees was positive within 0～1 m of the scale of shady slope and semi-shady slope.The relationship between young trees and adult trees was completely in the confidence interval of sunny slope.The relationship between young trees and adult trees was negative at 6～7 and 3～4 m under the conditions of semi-shady slope and semi-sunny slope,respectively.The relationship between young trees and adult trees was negative at shady slope,semi-shady slope and semi-sunny slope,and the sunny slope was not negative relationship.To sum up,in addition to its own biological characteristics,the impact of microenvironment and intra-specific competition on the distribution of Platycladus orientalis population in the loess hilly area was also very important.Above results provided a basis for the planting and management of Platycladus orientalis and its habitat adaptability.
Platycladus orientalisspatial distribution patternintraspecific associationhabitat heterogeneity
万方数据
维普
