Flooding interacting with clonal fragmentation affects the survival and growth of a key floodplain submerged macrophyte

• Published in: Hydrobiologia Vol. 806; no. 1; pp. 67 - 75
• Main Authors: Han, Yu-Qin, Wang, Li-Gong, You, Wen-Hua, Yu, Hai-Hao, Xiao, Ke-Yan, Wu, Zhong-Hua
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 2018; Springer; Springer Nature B.V
• Subjects: Aquatic plants; Biodegradation; Biomass; Biomedical and Life Sciences; Ecology; Flooding; Floodplains; Floods; Fragmentation; Freshwater & Marine Ecology; Growth; Hypotheses; Life Sciences; Photosynthesis; Photosystem II; Plants (botany); Primary Research Paper; Ramets; Submerged plants; Survival; Water depth; Yields; Zoology; Clonal integration; Submerged plants; Photosynthetic performance; Disturbance; Risk spreading
• ISSN: 0018-8158; 1573-5117
• DOI: 10.1007/s10750-017-3356-3

Flooding inducing mechanical disturbances may fragment submerged plants into pieces, suggesting that flooding and clonal fragmentation may interact and affect plant survival and performance. To test this hypothesis, clonal fragments of Vallisneria natans , each consisting of four interconnected ramets, were grown at different water depths (150, 300, and 400 cm) in a 9-week pond experiment, with stolon connections either intact, or partly severed or completely severed. Flooding (water depth ≥300 cm) severely reduced the maximum quantum yield of PSII ( F v / F m ), survival, and growth of V.   natans . At the control water depth (150 cm), clonal fragmentation did not affect plant photosynthetic performance, survival, and total biomass, whereas it greatly increased ramet production and significantly decreased biomass per ramet, suggesting that clonal fragmentation produced a pronounced trade-off between ramet size and number. Under flooding, clonal fragmentation severely decreased the photosynthetic performance, survival, and growth of V. natans , and these effects were stronger with heavier fragmentation and at higher water depths. These results support our hypothesis that flooding and clonal fragmentation can interact and negatively affect the survival and performance of submerged plants, which may be a part of the reason for the degradation and extinction of aquatic vegetation in flood-prone areas.