Identifying priority areas for conservation: a global assessment for forest-dependent birds

Abstract

Limited resources are available to address the world's growing environmental problems, requiring conservationists to identify priority sites for action. Using new distribution maps for all of the world's forest-dependent birds (60.6% of all bird species), we quantify the contribution of remaining forest to conserving global avian biodiversity. For each of the world's partly or wholly forested 5-km cells, we estimated an impact score of its contribution to the distribution of all the forest bird species estimated to occur within it, and so is proportional to the impact on the conservation status of the world's forest-dependent birds were the forest it contains lost. The distribution of scores was highly skewed, a very small proportion of cells having scores several orders of magnitude above the global mean. Ecoregions containing the highest values of this score included relatively species-poor islands such as Hawaii and Palau, the relatively species-rich islands of Indonesia and the Philippines, and the megadiverse Atlantic Forests and northern Andes of South America. Ecoregions with high impact scores and high deforestation rates (2000-2005) included montane forests in Cameroon and the Eastern Arc of Tanzania, although deforestation data were not available for all ecoregions. Ecoregions with high impact scores, high rates of recent deforestation and low coverage by the protected area network included Indonesia's Seram rain forests and the moist forests of Trinidad and Tobago. Key sites in these ecoregions represent some of the most urgent priorities for expansion of the global protected areas network to meet Convention on Biological Diversity targets to increase the proportion of land formally protected to 17% by 2020. Areas with high impact scores, rapid deforestation, low protection and high carbon storage values may represent significant opportunities for both biodiversity conservation and climate change mitigation, for example through Reducing Emissions from Deforestation and Forest Degradation (REDD+) initiatives.

Figure 1. Frequency distribution (log scale) of 5-km cell impact scores.

Plot smoothed to aid visual interpretation.

Figure 2. Impact scores (a) and forest bird species richness (b) in each of the world's 2.2 million forested 5-km grid squares.

Areas in grey not forested.

Figure 3. Scatterplots for each ecoregion of maximum impact score and (a) total forest bird species richness, (b) percent loss of forest during 2000–2005, (c) percent forest in protected areas and (d) carbon stocks (averaged across only forested cells in each ecoregions).

Red lines indicate fitted GAMs.

Figure 4. Bivariate plots showing ecoregion-level impact score and (a) percent loss of forest during 2000–2005, and (b) percent forest unprotected.

Areas in white are non-forested ecoregions or lack data for one or both variables.

Figure 5. Bivariate plot showing 5-km cell level carbon stocks and rates of forest loss in the top quartile of cells for impact score.

Areas in white are non-forested ecoregions or lack data for one or both variables. Areas in grey represent forested or partly forested ecoregions that fall in the lower three quartiles in terms of their maximum impact score.