Focal Species: A Multi‐Species Umbrella for Nature Conservation

TLDR

Species loss in productive landscapes requires determining the composition, quantity, and configuration of habitat elements, and the umbrella species concept suggests that meeting the needs of certain species can protect others while threats such as habitat loss, fragmentation, weed invasion, and fire drive this need. The study proposes a multi‑species approach to define landscape attributes and management regimes that satisfy biotic needs. The method groups at‑risk species by threat, selects the most sensitive species per threat to set minimum acceptable levels for habitat area, connectivity, composition, and management of processes such as fire, predation, or weed invasion. Designing and managing landscapes to satisfy the most demanding species ensures that the needs of all other species are also met.

Abstract

To prevent the further loss of species from landscapes used for productive enterprises such as agriculture, forestry, and grazing, it is necessary to determine the composition, quantity, and configuration of landscape elements required to meet the needs of the species present. I present a multi‐species approach for defining the attributes required to meet the needs of the biota in a landscape and the management regimes that should be applied. The approach builds on the concept of umbrella species, whose requirements are believed to encapsulate the needs of other species. It identifies a suite of “focal species,” each of which is used to define different spatial and compositional attributes that must be present in a landscape and their appropriate management regimes. All species considered at risk are grouped according to the processes that threaten their persistence. These threats may include habitat loss, habitat fragmentation, weed invasion, and fire. Within each group, the species most sensitive to the threat is used to define the minimum acceptable level at which that threat can occur. For example, the area requirements of the species most limited by the availability of particular habitats will define the minimum suitable area of those habitat types; the requirements of the most dispersal‐limited species will define the attributes of connecting vegetation; species reliant on critical resources will define essential compositional attributes; and species whose populations are limited by processes such as fire, predation, or weed invasion will define the levels at which these processes must be managed. For each relevant landscape parameter, the species with the most demanding requirements for that parameter is used to define its minimum acceptable value. Because the most demanding species are selected, a landscape designed and managed to meet their needs will encompass the requirements of all other species.