A data set of soil properties representing soil quality in the urban roadside tree system influenced by different anthropogenic activities

Soil in urban roadside tree system plays a major role as a growth media for trees and carbon sink for climate change mitigation. However, urban soils are under severe stressful conditions such as compaction, erosion, contamination, drought, etc., which lead to soil quality deterioration. Lack of data on urban soil properties and the effects of human activities on them is the main obstacle to sustainable management of urban soils. The objective of this study is to suggest a data set of soil properties which can represent soil quality in the roadside tree system influenced by various human activities. The study site was located along the main road (1.3 km in length * 45 m in width) in Suwon, South Korea. To investigate the effects of human activities, four subareas were selected including a construction, commercial, industrial and residential zones. Soil samples were collected from a depth of 0-10 cm using an auger (1.9 cm in diameter). Sieved and air-dried soil samples were used to measure eighteen physical, chemical and microbial parameters. In order to select a representative data set, three separate steps were conducted as follows: 1) analysis of variance (ANOVA) to select parameters which varied significantly among different zones, 2) principal component analysis (PCA) to obtain key parameters to explain data variabilities, and 3) a suggestion for a series of parameters selected based on two criteria; one criterion is to include at least one parameter from physical, chemical and biological properties, respectively, and another is to select a cost-effective and less labor-intensive parameter among the redundant variables. As a result of three-step analysis, water filled pore space (WFSP), soil strength, pH, organic matter (OM), sodium (Na), and fluorescein diacetate activities (FDA) were selected as a concise data set of soil properties in urban roadside tree system. Using these six parameters, soil quality indices (SQIs) were calculated and those in the residential zone were high relative to the other zones, which was consistent with data on tree vigor measured from the same zone. Further analysis on heavy metal contents might modify our current suggested data set and we will include discussion later.