Mapping of biodiversity hubs and key ecosystem services as a tool for shaping optimal areas for conservation

was declared a Ramsar Wetland of International Importance on 1st December 2005. Some 82 bird’s species have been recorded within the marsh and its vicinity [28]. Before colonization, the conservation practice in Rwanda was no different to other many parts of Africa, firmly rooted in a body of beliefs, such as the totemic system that had extended the perception of the self to animal and plant species [29]. Later after the country’s independence in 1962, PA man- agement duty was attributed to the Rwandan Office of Tourism and National Parks (ORTPN) in 1973, the institutional reformation in 2013 revised ORTPN’s old assignment into the new mandate of the department of tourism and conservation of the Rwanda Development Board (RDB) [30]. 2.3 Rwanda ‘s priority habitats, biodiversity hubs and mapping 2.3.1. Identification of Rwanda’s priority habitats & mapping. To establish Rwanda’s priority habitats types, we considered six established categories as important Rwandan habitat types to protect. They are: Urban areas, High mountain tops, Non-protected natural forest, Lakes and river + buffer zone, Swamps + buffer zone, PA. For each of these habitats we have assigned weights values according to their priority and ecological importance. Sites were ranked on the basis of three simple prioritisation protocols: 1) Species richness; 2) An index derived from the predominance of species with IUCN Red List status {IUCN Red List Catego- ries are: EX—Extinct, EW—Extinct in the Wild, CR—Critically Endangered [CR(PE)—Criti-

cally Endangered (Possibly Extinct), CR(PEW)—Critically Endangered (Possibly Extinct in the Wild)], EN—Endangered, VU—Vulnerable, LR/cd—Lower Risk/conservation dependent, NT—Near Threatened (includes LR/nt—Lower Risk/near threatened), DD—Data Deficient, LC—Least Concern (includes LR/lc—Lower Risk, least concern)} [31]; 3) An irreplaceability index used for determining the priority of sites for conservation [32]. The scores -1, 1, 2, 3, 4, and 5 were assigned to describe the category’s relative importance. Urban area was assigned with a negative weight (penalization), because it is considered as the source of pollution that might cause future degradation of habitat quality. Forests play a vital role for biodiversity conservation, and provide incentives to solve socie- tal and economic well-being, whether through offering food and wood, creating income and employment, or by providing environmental services such as water and soil conservation, and climate mitigation [33]. Particularly, tropical forests significance in the global carbon cycle has led to the consideration and recognition of forest-based climate change mitigation measures in the international climate negotiations, agreements and policy frameworks [34] such as Reduced Emissions from Deforestation and Degradation (REDD) [35]. Tropical wetlands are also one of the most carbon (C) rich ecosystems in the world, their organic-rich soils contain exceptional large C stocks, damage to these fragile ecosystems, which rather take thousands of

years to build up becomes a major source of greenhouse gas emissions. Besides, the loss of aboveground biomass and decomposition of organic material following their green cover’s dis- turbance causes the release of considerable amounts of CO2 to the atmosphere. Their vulnera- bility to land use, and numerous other ecosystem services (ES) they provide make wetlands a point of increasing interest for participation in climate change mitigation strategies, such as Reduced Emissions from Deforestation and Degradation (REDD+) [36, 37]. 2.3.2. Identification of Rwanda biodiversity hubs & mapping. We identified Rwanda’s biodiversity concentration stages at district level. This assignment wouldn’t be settled without recourse to the official shapefile of the administrative division of Rwanda into 30 districts. We have compiled an exhaustive biodiversity inventory data from a range of sites in different dis- tricts of Rwanda, and subdivided living organisms into 6 taxonomic groups: Mammals, Birds, Fish, Reptiles, Amphibians, and Plants. We unfortunately could not include invertebrates, PLOS ONE How do old national parks cope with regenerating conservation mission? PLOS ONE | https://doi.org/10.1371/journal.pone.0253151 August 17, 2021 5 / 20