Spatial Pattern of Soil Fertility and its Influencing Factors in Longquan Mountain Urban Forest Park, Chengdu City

Exploring the spatial pattern and impact factors of soil fertility in Longquan Mountain Urban Forest Park can better guide the planning and management of the park, and provide scientific basis for ecological restoration and landscape configuration in this area. In this study, the spatial pattern of soil fertility in Longquan Mountain Urban Forest Park and its influencing factors were investigated and analyzed by sampling grid distribution points and combining the modified Nemerow formula as a quantitative calculation model of soil fertility. Our results were as follows: (1) The average content of available P was at the first level of the soil nutrient classification standard in the second national soil survey of China, while the average content of available K reached the forth level. The average content of soil organic matter and alkali-hydrolyzable nitrogen were both at the fifth level. (2) From the spatial pattern, the regions with good soil fertility were mainly distributed in the north of the study area, while that the poor soil fertility was mainly distributed in the central and southern part of the park. (3) The order of the soil comprehensive fertility index of different topography and land use types was plain > hill > low mountain, flat slope > gentle slope>slope > steep slope; for slope, the order was northwest > west > east > south > north > southwest > northwest > no slope direction > southeast; for slope position, the order was lower > middle=upper > valley department > the ground > the back; for land uses pattern, the order was cultivated land > orchard > bamboo land > mixed forest > pure forest > abandoned land > homestead land. Based on the soil comprehensive soil fertility status of Longquan Mountain Urban Forest Park, the areas with the soil fertility index of “good” should be protected, the areas with the soil fertility index of “medium” should be monitored and the natural restoration ability should be improved, the areas with the soil fertility index of “poor” should be mightily improved.