Ecological Indicators (Jun 2021)
Developing an odonate-based index for prioritizing conservation sites and monitoring restoration of freshwater ecosystems in Rwanda
Abstract
Land use changes and the ways that natural resources are extracted and used pose severe threats to freshwater ecosystems globally. This is particularly pronounced in developing and densely populated countries, such as Rwanda. In-depth understanding of how ecosystems respond to threats could guide their restoration, conservation, and better management. The advancement of ecological monitoring tools is crucial for freshwater conservation. We developed and implemented an odonate-based tool, the Rwanda Dragonfly Biotic Index (RDBI), tailored to freshwater ecosystems in Rwanda as a metric to identify conservation priority sites and to monitor their restoration. The RDBI is determined based on three sub-indices: Distribution-Based Score (DBS), Threat-Based Score (TBS) and Sensitivity-Based Score (SBS). Species level-DBS increases from those that are widespread across all ecological zones to those that are restricted to only one ecological zone; TBS for a species ranges from those that are of least concern to those that are critically endangered, as per IUCN Red List; Species’ SBS increases from those thriving in a highly disturbed habitat to those occurring only in a relatively intact habitat. Using RDBI, we identified hotspot habitats for odonates in Rwanda and benchmark sites for restoration. Hotspots are defined based on species richness, presence of unique species, and RDBI scores. Benchmark sites for restoration are habitats with the highest RDBI in each ecological zone. The value of using RDBI in ecosystem monitoring rests on the fact that it can help identify priority sites for conservation, and it uses organisms that are charismatic and relatively easy to identify. This is essential for citizen engagement and drawing a long-term link between policymaking, on-the-ground practices, and impacts on freshwater ecosystems.
