Two new studies address a long-standing question in landscape conservation: should limited funds be allocated to enlarging existing protected areas, creating new and isolated protected areas, or increasing connectivity between protected areas? The studies focus on four hotspots for biodiversity located in Brazil, Tanzania, Nicaragua, and Mozambique. Taken together, one striking finding is that two conservation goals can be achieved simultaneously: conservation around existing protected areas can increase area and can interconnect existing reserves.
Rob Pringle argues that connecting existing protected areas is a pillar of conservation. In The Área de Conservación Guanacaste, Costa Rica, protected areas have grown to 1260 square kilometers of interconnected forest with successive land purchases beginning in 1966. These have been funded largely through private sources. Parque Nacional da Gorongosa, Mozambique now encompasses 5097 square kilometers, and has plans to increase its connectivity to other nearby protected areas. In both reserves, a key element of successful conservation has been consideration for needs of local communities in park maintenance and design. Considered in full, Pringle finds that connectivity is a feasible conservation option that is among the most likely to gain broad public support.
Newmark and colleagues show that relatively small areas of land acquisition can yield conservation of interconnected habitats that are 30 times larger. The authors modify the traditional species-area relationship to project the rate of species loss within habitat fragments, and find that though the first extinction will occur within seven years in existing fragments, the first extinction will take two to four times as long to occur in contiguous forest (15 years in the Eastern Arc Mountains of Tanzania and 30 years in the Atlantic Forest of Brazil). Targeted land acquisition to increase connectivity across these regions can therefore have large effects on the ability of species to persist over time.
The take home message across both studies and all four networks of protected areas is that connectivity conservation is a tangible aspiration. It delivers more bang for the buck in conservation of biodiversity, and has higher potential for success in the context of existing human communities.
Pringle, R. M. 2017. Upgrading protected areas to conserve wild biodiversity. Nature 546: 91-99.
Newmark, W.D., C.N. Jenkins, S.L. Pimm, P.B. McNeally, and J.M. Halley. 2017. Targeted habitat restoration can reduce extinction rates in fragmented forests. PNAS 114(36): 9635-9640.