Reconciling global priorities for conserving biodiversity habitat

Abstract

Degradation and loss of natural habitat is the major driver of the current global biodiversity crisis. Most habitat conservation efforts to date have targeted small areas of highly threatened habitat, but emerging debate suggests that retaining large intact natural systems may be just as important. We reconcile these perspectives by integrating fine-resolution global data on habitat condition and species assemblage turnover to identify Earth's high-value biodiversity habitat. These are areas in better condition than most other locations predicted to have once supported a similar assemblage of species and are found within both intact regions and human-dominated landscapes. However, only 18.6% of this high-value habitat is currently protected globally. Averting permanent biodiversity loss requires clear, spatially explicit targets for retaining these unprotected high-value habitats.

Keywords: community; condition; conservation; contextual intactness; ecosystem.

Fig. 1.

Conceptual depiction of the analytical approach to quantifying the contextual intactness for each terrestrial 1-km grid cell globally.

Fig. 2.

Contextual intactness of habitat for biodiversity. For each location, the proportion of habitat expected to have once supported a similar assemblage of species but is now in worse condition than the focal location (higher HFP). The result is averaged across three broad terrestrial taxonomic groups: vertebrates, invertebrates, and vascular plants.

Fig. 3.

Within a given level of HFP, there is wide variation in contextual intactness values for terrestrial biodiversity. For example, location A has low levels of disturbance but has a high proportion of similar habitat in wilderness areas. In contrast, location B has a higher level of HFP, but most of the areas with similar expected species assemblages are in even more highly modified areas. Data are a sample of 430,000 locations (1-km grid cells) shown as color density with kernel bandwidth of 0.75.

Fig. 4.

High-value biodiversity habitat across levels of HFP. Contextual intactness is represented across four HFP categories: wilderness (blue; HFP = 0), low disturbance (green; HFP = 1 to 3), modified (orange; HFP = 4 to 9), and highly modified (pink; HFP ≥ 10). Darker shades represent higher contextual intactness. Panels show greater detail for northwest North America (A), southeast Asia (B), southeast Amazonia (C), and southern Africa (D).