A biodiversity evaluation framework for restoration of aquatic
macrophyte communities in shallow lakes driven by hydrological process
management: case study for the Baiyangdian Lake marsh
Abstract
Macrophyte community diversity and composition respond to ecosystem
conservation and local environmental factors. In this study, we
developed a multidimensional diversity framework for macrophyte
communities, including the taxonomic and functional alpha and beta
diversity. We used the framework to explore the relationships among
water level regimes and these diversity parameters in a case study of
China’s Baiyangdian Lake. Analysis of indicators of hydrologic
alteration divided the water level from 1959 to 2019 into four regimes
(dry, <6.42 m; low, 6.42 to 7.23 m; medium, 7.23 to 8.19 m;
high, >8.19 m). Alpha and beta diversity were significantly
higher in the medium regime than in the low and high regimes. Redundancy
analysis indicated that the maximum water depth significantly affected
taxonomic alpha diversity, and total nitrogen (TN) and chemical oxygen
demand (COD) concentration significantly affected functional alpha
diversity, respectively. Mantel tests showed that TN, Secchi depth, and
water depth in the high water level regime significantly increased the
total beta diversity and turnover components. TN was the main factor
that increased total taxonomic beta diversity. Interspecific competition
decreased with the decreasing range (variation) of TN values and
differed opposite with the variation of COD values in response to
increasing water level, and reached its maximum in the medium regime.
Ecosystem stability was promoted by maintaining high species richness
and evenness and high differences among communities, and by reducing
competition. Based on our results, the water level should be maintained
between the medium and high water level regimes to promote restoration
of the macrophyte community and improve ecosystem stability.