Effects of clonal integration on characteristics of free-floating and submerged plant communities under different nutrient conditions

Abstract

Individual-level effects of clonal integration have been extensively studied, but community-level effects remain poorly understood. We grew the free-floating or submerged plant communities with three speices dominated by free-floating Salvinia natans or submerged Vallisneria natans, respectively. The stolons of S. natans and V. natans were periodically severed, with not severed plant communities as control. The effects of clonal integration on the characteristics of different life-form plant communities under low versus high nutrient levels were examined. Results showed that clonal integration significantly increased the number of ramets in submerged plant communities but not in free-floating plant communities under two nutrient conditions. Clonal integration greatly decreased the growth of free-floating plant communities, changed their species composition, and increased their species diversity and evenness under high nutrient conditions but not under low nutrient conditions. In submerged plant communities, clonal integration and nutrient affected species composition independently but did not affect species diversity. The growth of submerged plant communities was only affected by nutrient. Our findings highlight the importance of nutrient and plant life form in the effects of clonal integration on aquatic plant community characteristics. Studies on the effects of clonal integration at the community level could provide references for the effective management of aquatic plant communities with different life forms and contribute to a better understanding of the importance of clonal integration in the field.