Determinants and relationships of above- and below-ground plant traits in typical marsh wetlands in northern China

Abstract

Background and Aims Plant traits are the results of plant evolutionary and environmental drivers operating at different scales. Although the relationship between above- and below-ground traits of terrestrial plants has been advanced, little is known about above- and below-ground traits of wetland plants, their relationship and influencing factors across a large scale. Methods Species coverage, and above- and below-ground plant traits were measured in nine typical marsh wetlands of northern China. Differences in plant traits at both species- and community-level among wetlands and between low and high soil moisture conditions, correlations between above- and below-ground traits of clonal plants, and the influencing environmental factors were analyzed. Results Plant traits at both species- and community-level were significantly higher in Daihai and Qingtongxia wetlands than that in other wetlands, which was influenced by combined effects of precipitation, soil nutrients, and temperature. Plant traits at both levels were generally higher under high than low soil moisture conditions. At the species level, the coordinated relationships were found between above- and below-ground traits of clonal plants under both low and high soil moisture conditions across all wetlands; while a trade-off relationship was found between internode diameter and length of clonal plants. Conclusions Plant traits exhibited the similar pattern among wetlands at both levels, but performed better at high soil moisture conditions in marsh wetlands. Coordinated relationships between above- and below-ground traits will be further clarified whether such coordination can be also seen in other wetland ecosystems.