Environmental variation as a key process of co‐existence in flood‐meadows

Abstract

Question How does the species composition and functional structure of flood‐meadows change over time during a period with strong variations in flooding frequency and height? Location Flood‐meadows at the northern Upper Rhine, Germany. Methods From 1998 to 2004 annually, and again in 2008, species composition and above‐ground biomass were studied in 46 permanent plots located along a flooding gradient ranging from frequently flooded Magnocaricion to rarely flooded Arrhenaterion meadows. The plots were situated in the functional floodplain (natural) and in the fossil floodplain on the land side of high winter levees (anthropogenic altered). Temporal variation of the functional structure was analysed based on community‐weighted mean traits. Results Productivity and functional structure varied markedly over the study period and between the functional and fossil floodplain. During the study period two contrasting extreme events occurred: a summer flood in 1999 and a drought period after 2003. After the flood in 1999, species composition and functional structure of the studied flood‐meadows shifted towards the species composition of wetter sites. Flooding reduced species richness in the functional floodplain, but not in the fossil floodplain. Conclusions Flood‐meadows in the Upper Rhine fully recover from extreme disturbance events within a time frame of less than 10 yr. Environmental fluctuations and disturbances, enabling the co‐existence of species with contrasting ecological requirements are a key factor for the preservation of plant biodiversity in flood‐meadows.

Human impact on plant biodiversity in functional floodplains of heavily modified rivers – A comparative study along German Federal Waterways

“…An increase in species and habitat diversity could be achieved by an alteration of the flooding regime to a more diverse and/or natural state (Naiman and Turner, 2000). Also Mathar et al (2015) identified a dynamic flood regime as one of the most important factors for adequate diversity in floodplain meadows.…”

“…The high diversity of natural floodplain systems is mostly due to the complexity of dynamic habitats (Allan, 2004;Ernoult et al, 2006;Mathar et al, 2015), which is a consequence of frequent disturbance by flooding, while single floodplain habitats are not necessarily species-rich (e.g. Phragmites or Phalaris reeds, Moelder and Schneider, 2011).…”

Resource partitioning confirmed by isotopic signatures allows small mammals to share seasonally flooded meadows

“…River floodplains, affected by periodic floods, are productive and heterogeneous habitats (Mathar, Kleinebecker, & Hölzel, ), suitable for small mammals (Wijnhoven, Smits, Van der Velde, & Leuven, ). After recovery from the detrimental influences of floods, the abundance of small mammals in river floodplains is high for a given period of time (Golet, Hunt, & Koenig, ).…”

Multi-Source Uncertainty Analysis in Simulating Floodplain Inundation under Climate Change

“…For the following description of inundation in the study area, we used two inundation characteristics: the number of inundation days per year and the mean duration of an inundation period. Those metrics are useful when considering further consequences for example for flood meadow species composition, as those are influences by the inter-annual variation of flooding and droughts and the duration of flooding [62,63].…”