Abstract
AbstractAimsMany rivers across the globe are severely impacted by changed flooding regimes, resulting in drastic shifts in vegetation, but the processes driving the exchange of flood‐sensitive and flood‐tolerant species are understood less. We studied the role of long‐term and recent flooding histories for riparian plant recruitment in response to various changes in flooding regime.LocationVindel River catchment (Northern Sweden).MethodsWe experimentally changed long‐term flooding regimes by transplanting turfs between high and low elevations in 2000 and in 2014 (n = 8 per treatment). We sowed seeds of five riparian species in both transplanted turfs and non‐transplanted controls and counted seedling numbers over two growing seasons. Further, we inventoried natural seedling frequencies in 190 plots in 19 reaches in 2013 and 2014, and related natural seedling numbers to plot flooding history in the period 2012–2014.ResultsWe observed effects of long‐term flooding history in the second year of the transplantation study (2015), but not in the first year. In 2015, turfs transplanted to locations with less flooding resulted in higher plant recruitment while transplantation to sites with more frequent flooding reduced recruitment compared to the controls. Since these differences were only found in recently transplanted turfs and not in older turfs, the legacy effect of long‐term flooding history can be transient. In the field seedling survey, similar differences were found between flooding‐history categories in 2013, but not in 2014, when the moisture conditions of the most recent year determined flooding. Further, lowest seedling numbers were observed when the previous flooding occurred in winter, and higher seedling numbers when floods occurred in spring or not at all.ConclusionsBoth long‐term and recent flooding histories can affect plant recruitment, and their influence should be taken into account when designing restoration projects.
Highlights
Plant communities are dynamic, subjected to continuous change due to species interactions, colonisation and extinction, aided by stochastic or predictable disturbances (Li & Pennings, 2016; Mahoney & Rood, 1998; Menge & Sutherland, 1987; Pennings & Callaway, 1992)
Flow regimes in the Vindel River catchment are characterised by spring floods in May or June, with the flood peak and duration depending on the amount of snow, spring temperatures, and how much the soil permeability is affected by frost
We found enhanced recruitment in the turfs at high elevation (TH) treatment compared to the controls (CL and Controls at high (CH)), while in the turfs at low elevation (TL) treatment, less seedlings were found compared to both controls (CL and CH)
Summary
Plant communities are dynamic, subjected to continuous change due to species interactions, colonisation and extinction, aided by stochastic or predictable disturbances (Li & Pennings, 2016; Mahoney & Rood, 1998; Menge & Sutherland, 1987; Pennings & Callaway, 1992). The interface between water and land along rivers and streams (riparian ecosystem) is one of these very dynamic and frequently disturbed ecosystems, and due to its important ecosystem services (Naiman & Décamps, 1997), understanding what shapes these species-rich plant communities has become critical. Such knowledge is increasingly important since almost all river systems worldwide are threatened by flow management and climate change that can drastically alter the flow regime (Hirabayashi et al, 2013; Nilsson, Reidy, Dynesius, & Revenga, 2005; Winemiller et al, 2016). We have limited insight in how processes such as germination and establishment lead to these changes (Beauchamp & Stromberg, 2007; Fraaije, ter Braak, Verduyn, Verhoeven, & Soons, 2015; Levine & Stromberg, 2001; Nilsson, Jansson, & Zinko, 1997; Ström, Jansson, Nilsson, Johansson, & Xiong, 2011)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
