A Spanish version of this post is available here.
After years of research into the biodiversity value of agricultural countrysides, it has become clear that, while there is great potential to conserve wildlife alongside humanity in ‘working landscapes’, wildlife communities remain distinct from those in nature reserves. But can working landscapes ever support vulnerable, reserve-affiliated species? New research from Costa Rica by Karp et al. suggests they can; offering a new approach to help stave off the ongoing biodiversity crisis.
Karp and colleagues’ extensive empirical effort involved surveying birds at 150 sites in nature reserves and working landscapes composed of pastures, crop fields, and forest patches in the northwest of Costa Rica. Two years of surveys yielded ~10,000 observations of 150 species, from which Karp et al. built multi-species models to estimate the abundance of each species at each site.
The findings? Diverse bird communities did persist in crop fields and pastures. Yet, as expected, agricultural sites lacked the species of conservation concern typically found in forest reserves. Specifically, birds in agriculture were widely distributed, with twice the geographic range size of the species found in reserves.
Intriguingly, however, the bird communities found in privately-owned forests in working landscapes were indistinguishable from those in nature reserves. Just as many narrow-ranged species of greater conservation concern persisted in these privately-owned lands as in formal nature reserves. This was surprising as the privately-owned forests were twice as fragmented and much more disturbed by logging, fires and hunting than the forests in nature reserves. To Costa Rican birds, the simple presence of forest seemed to matter more than if a site was fragmented, with shorter trees, less dense understories, and fewer tree species.
These findings suggest that restoring forests in working landscapes may offer great opportunities for conserving Neotropical birds. The world’s governments and non-governmental organizations have already signed on to major forest restoration commitments. For example, in 2011, the Government of Germany and IUCN launched the Bonn Challenge to restore 150 M ha of degraded land worldwide – an area the size of Mongolia. Similarly, in Latin America, more than a billion US dollars have already been raised to restore 20 M ha of degraded land by 2020. A key question facing these initiatives, however, is where to target restoration efforts to maximize conservation outcomes.
To answer this question, Karp and colleagues went on to use their data to simulate forest restoration across Northwest Costa Rica and identify priority sites for future conservation actions. Doing so illuminated disproportionate benefits for sensitive, reserve-affiliated bird species when restoration strategies were targeted in wetter regions and in more forested landscapes. This aligns with the authors’ prior studies in the region which suggest bird species associated with wetter forests may be most vulnerable to future habitat conversion and climate change-induced drying.
Costa Rica has already seen unprecedented rates of reforestation over the last few decades, with many local farmers committing to forest conservation and restoration on their lands. Karp and colleagues are working closely with these local communities and conservation organizations, using these results to help inform ongoing reforestation initiatives, for example in the Corredor Biológico Hojancha Nandayure. More broadly, Karp et al.’s results suggest that, beyond creating new nature reserves, working with private landowners to conserve or restore forests in working landscapes represents a promising strategy for safeguarding vulnerable wildlife in the Neotropics.
Read the full article, Remnant forest in Costa Rican working landscapes fosters bird communities that are indistinguishable from protected areas, in Journal of Applied Ecology.