Bryophytes adapt to open-pit coal mine environments by changing their functional traits in response to heavy metal-induced soil environmental changes

Abstract

Plants have unique adaptability to heavy metal pollution. However, the adaptation strategies of bryophytes are still unclear. In order to better understand the response of bryophytes to different heavy metal and the adaptation mechanisms of different species to heavy metal pollution, we studied soil physicochemical properties, distribution of heavy metal elements, ecological risk assessment and the community structure, functional characteristics of bryophytes in large open-pit coal mines in Inner Mongolia. The results indicate that: (1) The soil in three open-pit mining areas currently does not pose an ecological risk from the heavy metal pollution, but high concentrations of Zn and Hg are found in most parts of the study area; (2) The presence of a single heavy metal drives the distribution of specific taxa of bryophytes. Apart from Hg, Pb, and Zn, all the other heavy metals significantly impact the community structure of bryophytes; (3) With the exception of Pb and Hg, all the other heavy metals have an influence on the functional traits of bryophytes; 4) Different taxa of bryophytes will adapt to changes in soil environments caused by heavy metal pollution by altering their functional traits (blades, leaf cells, or plant size).

Keywords: Adaptation strategy; Bryophytes; Functional traits; Heavy metals; Open-pit coal mine.