Ecological Response of Urban Forest Carbon Density to Site Conditions: A Case Study of a Typical Karst Mountainous Regions in Southwest China

Abstract

Understanding the ecological constraints of limiting the magnitude and the allocation of carbon density is critical for executing adaptive forest management programs and upgrading the size of carbon sinks. Taking a typical karst mountainous region Guiyang City as a case study area, this study computed the biomass of different forest types using the volume–biomass equations and mapped the carbon density distribution of forests. Furthermore, the random forest algorithm and spatial autoregression model were adopted to reveal the effects of site conditions on carbon density in karst forests. The results indicate that the forest ecosystems of Guiyang City had a high carbon sequestration potential, and there was a significant difference in the carbon density of forests in terms of space dimensions. Road density, 0 cm cation exchange capacity, and soil parent materials were the dominant factors determining the spatial distribution of homogeneous units with different levels of carbon density. This study underlines the urgency adapting to the growing conditions of forests in terms of complex site conditions, and provides a scientific basis for optimizing forest management practices, to maintain their carbon sequestration capacity under urbanization pressure and fragile habitats.

Keywords

• carbon density
• random forest
• site conditions
• spatial autoregression model
• urban forest