Ecological Stoichiometric Characteristics and Response Relationships between Dominant Plant Species and Soil on the Slopes of the Beijing-Hong Kong-Macao Expressway

Abstract

Ecological stoichiometry is a key indicator of the degree of plant responses to environmental factors. Research examining plant ecological stoichiometry is conducive for improving the ecological environment. Although the research objects for ecological stoichiometry are diverse, there is a lack of research investigating the special ecosystems of highway slopes. Twelve representative plant communities in the Zhengzhou-Xinxiang section of the Beijing-Hong Kong-Macao Expressway were selected. Pearson correlation coefficient analysis and redundancy analysis (RDA) were used to determine the plant-soil relationship and the response of plants in this region to environmental factors. The findings indicated that distinct variations exist in the ecological stoichiometry of various plant communities and are primarily influenced by environmental factors. The mean concentrations of soil carbon (C), nitrogen (N), and phosphorus (P) were below the domestic soil standards. Conversely, the average levels of C, N, and P in the leaves of plants surpassed the global averages for vegetation. The levels of C, N, and P in the soil at the mid-slope location, along with their stoichiometric ratios, were elevated compared to those at other slope positions, indicating a relatively higher nutrient status at the mid-slope. Redundancy analysis revealed that plant stoichiometry was predominantly influenced by soil total phosphorus (TP) and exhibited a positive correlation. In summary, the impacts on both vegetation and soil varied significantly across the different slopes. By utilizing these characteristics, targeted artificial interventions can be implemented to foster favorable environmental conditions for these elements, and this is beneficial for improving expressway slope ecosystems.

Keywords: expressway, plant chemical properties, soil chemical properties, landscape improvement