A systematic review of assessment and conservation management in large floodplain rivers - Actions postponed

Large floodplain rivers (LFRs) are currently threatened by high levels of human alteration, and utilization is expected to grow. Assessments to determine ecological condition should address the specific environmental features of these unique ecosystems, while conservation management requires balancing maintenance of good ecological condition with the ecosystem services provided by LFRs. However, a systematic evaluation of the scientific literature on assessment of ecological condition of LFRs and trade-offs to guide conservation management is currently lacking. Here, we reviewed 153 peer reviewed scientific articles to characterize methodological patterns and trends and identify knowledge gaps in the assessment of LFRs. Our review revealed that most approaches used classical biotic indices for assessing ecological condition of LFRs. However, the number of articles specifically addressing the peculiarities of LFRs was low. Many studies used watershed level surveys and assessed samples from small streams to large rivers using the same methodological protocol. Most studies evaluated the status of main stem river habitats only, indicating large knowledge gaps with respect to the diversity of river-floodplain habitat types or lateral connectivity. Studies related to management were oriented toward specific rehabilitation actions rather than broader conservation of LFRs. Papers relating to ecosystem services of LFRs were especially few. Most importantly, these studies did not distinguish the different functional units of river-floodplain habitat types (e.g. eupotamon, parapotamon) and their role in ecosystem services provision. Overall, the number of articles was too low for meaningful analyses of the relationships and tradeoffs between biodiversity conservation, maintaining ecological condition, and use of ecosystem services in LFRs. Our review highlights research gaps and emphasizes the importance of developing more holistic indicators of ecosystem condition, which better reflect landscape level changes in structure and functioning of LFRs. As human use of water and land increases, the need to develop more effective spatial conservation prioritization tools becomes more important. Empirical research in this field can aid in solving conflicts between socio-economic demands for ecosystem services and nature conservation of LFRs.