Impact of cocoa agricultural intensification on bird diversity and community composition.

To meet the growing demand for chocolate, cocoa (Theobroma cacao) agriculture is expanding and intensifying. Although this threatens tropical forests, cocoa sustainability initiatives largely overlook biodiversity conservation. To inform these initiatives, we analyzed how cocoa agriculture affects bird diversity at farm and landscape scales with a meta-analysis of 23 studies. We extracted 214 Hedges' g* comparisons of bird diversity and 14 comparisons of community similarity between a forest baseline and 4 farming systems that cover an intensification gradient in landscapes with high and low forest cover, and we summarized 119 correlations between cocoa farm features and bird diversity. Bird diversity declined sharply in low shade cocoa. Cocoa with >30% canopy cover from diverse trees retained bird diversity similar to nearby primary or mature secondary forest but held a different community of birds. Diversity of endemic species, frugivores, and insectivores (agriculture avoiders) declined, whereas diversity of habitat generalists, migrants, nectarivores, and granivores (agriculture associates) increased. As forest decreased on the landscape, the difference in bird community composition between forest and cocoa also decreased, indicating agriculture associates replaced agriculture avoiders in forest patches. Our results emphasize the need to conserve forested landscapes (land sparing) and invest in mixed-shade agroforestry (land sharing) because each strategy benefits a diverse and distinct biological community.

Impacto de la Intensificación Agrícola del Cacao sobre la Diversidad y Composición de la Comunidad de Aves Resumen Para responder a la demanda creciente de chocolate, el cultivo de cacao (Theobroma cacao) se ha expandido e intensificado. Aunque esto es una amenaza para los bosques tropicales, las iniciativas de cacao sustentable en gran medida pasan por alto la conservación de la biodiversidad. Para proporcionar información a estas iniciativas, analizamos como la agricultura del cacao afecta a la diversidad de aves a escala de rancho y de paisaje mediante un metaanálisis de 23 estudios. Extrajimos 214 comparaciones de Hedges g* de la diversidad de aves y 14 comparaciones de la similitud de comunidades entre una línea de base de bosque y 4 sistemas de cultivo que cubren un gradiente de intensificación en paisajes con cobertura de bosque alta a baja, y sintetizamos 119 correlaciones entre características de cultivos de cacao y la diversidad de aves. La diversidad de aves declinó claramente en cultivos con poca sombra. Cultivos con >30% de cobertura de diversos árboles retuvieron una diversidad de aves similar a la de bosques primarios o maduros cercanos, pero presentaron una comunidad diferente. La diversidad de especies endémicas, frugívoras e insectívoras (evasoras de agricultura) declinó, mientras que la diversidad de generalistas de hábitat, migrantes, nectarívoras y granívoras (asociadas a agricultura) incrementó. A medida que decreció el bosque en el paisaje, la diferencia en la composición de la comunidad de aves entre bosque y cacao también decreció, lo que indica que las especies asociadas a la agricultura reemplazaron a las evasoras de la agricultura en los fragmentos de bosque. Nuestros resultados enfatizan la necesidad de conservar paisajes boscosos (conservación de tierras) e invertir en agroforestería de sombra mixta (compartición de tierras) porque cada estrategia beneficia a una comunidad biológica diversa y distinta.

Sustainable coffee: A review of the diverse initiatives and governance dimensions of global coffee supply chains.

With a global footprint of 10 million hectares across 12.5 million farms, coffee is among the world's most traded commodities. The coffee industry has launched a variety of initiatives designed to reduce coffee's contribution to climate change and biodiversity loss and enhance the socio-economic conditions of coffee producers. We systematically reviewed the literature on the sustainability and governance of coffee production and developed a typology of eleven sustainability initiatives. Our review shows that coffee sustainability research has focused primarily on the economic outcomes of certification schemes. The typology expands our knowledge of novel sustainability initiatives being led by coffee farming communities themselves, allowing for an improved consideration of power dynamics in sustainability governance. Sustainability initiatives governed by local actors can improve sustainability outcomes by empowering local decision makers to assess direct risks and benefits of sustainable practices to the local environment, economy, and culture.

Conservation of Neotropical migratory birds in tropical hardwood and oil palm plantations.

Tropical forests in the Americas are undergoing rapid conversion to commercial agriculture, and many migratory bird species that use these forests have experienced corresponding populations declines. Conservation research for migratory birds in the tropics has focused overwhelmingly on shade coffee plantations and adjacent forest, but both cover types are now in decline, creating an urgent need to evaluate conservation opportunities in other agricultural systems. Here we compare how a community of 42 Neotropical migratory bird species and a subset of five conservation-priority species differ in usage and habitat associations among a secondary forest baseline and four expanding commercial plantation systems in Guatemala: African oil palm, teak, rubber, and mixed-native hardwoods. We found that mixed-native hardwood plantations supported the highest richness and diversity of all migrants and that the three hardwood plantation types generally outperformed oil palm in richness and diversity metrics. Despite this, oil palm supported high abundance of several common and widespread species also experiencing range-wide population declines and may therefore play an important role in conserving common species. Mature secondary forest hosted low abundance and diversity of the full migratory community, but high abundance and richness of conservation priority migrants along with native hardwood and teak plantations. Likewise, the percentage of forest cover on the landscape was positively associated with priority migrant abundance and richness but negatively associated with the abundance of migrants in general, highlighting how individual species within the broad group of Neotropical migratory landbirds respond differently to anthropogenic changes in land use. Across all cover types, the retention of tall overstory trees increased the abundance, richness, and diversity of all migrants, which indicates that vertical structural diversity and remnant trees are important habitat features for birds in agricultural landscapes. Our findings show that conservation opportunities exist in hardwood and oil palm plantations, though the species likely to benefit from conservation action will vary among plantation types. For the subset of conservation priority migrants, our results suggest that conservation efforts should combine strategies that retain and restore secondary forest, promote the adoption of native hardwood and teak plantations, and promote the retention of tall, remnant trees in agricultural landscapes.