Win-win opportunities combining high yields with high multi-taxa biodiversity in tropical agroforestry

Resolving ecological-economic trade-offs between biodiversity and yields is a key challenge when addressing the biodiversity crisis in tropical agricultural landscapes. Here, we focused on the relation between seven different taxa (trees, herbaceous plants, birds, amphibians, reptiles, butterflies, and ants) and yields in vanilla agroforests in Madagascar. Agroforests established in forests supported overall 23% fewer species and 47% fewer endemic species than old-growth forests, and 14% fewer endemic species than forest fragments. In contrast, agroforests established on fallows had overall 12% more species and 38% more endemic species than fallows. While yields increased with vanilla vine density and length, non-yield related variables largely determined biodiversity. Nonetheless, trade-offs existed between yields and butterflies as well as reptiles. Vanilla yields were generally unrelated to richness of trees, herbaceous plants, birds, amphibians, reptiles, and ants, opening up possibilities for conservation outside of protected areas and restoring degraded land to benefit farmers and biodiversity alike

Listening to a changing landscape: On site vegetation structure determines acoustic diversity in the biodiversity hotspot of NE Madagascar

edition: Program Bookstatus: publishe

Constraints on Rice Cultivation in Eastern Madagascar: Which Factors Matter to Smallholders, and Which Influence Food Security?

In the eastern rainforests of Madagascar, rainfed swidden rice cultivation remains prevalent despite efforts to encourage uptake of irrigated systems to reduce deforestation. We used agricultural surveys with a stratified sample of 171 households to investigate constraints on and productivity of irrigated and rainfed rice perceived by farmers, and actual rice yields. Irrigated rice plots had higher median yields (1.72 t/ha compared to 0.62 t/ha), but farmers perceived the type of rice cultivation they practised themselves as more productive, possibly reflecting differences in the land suitability, farmers experience, and other constraints. While some factors, such as pests and water, were mentioned to limit yields, access to fertiliser was not frequently mentioned by smallholders. Higher food security was related to irrigated rice farming, higher rice yields, and owning more livestock. Conservation initiatives need to target households with and without access to irrigable land to improve food security and reduce deforestation, as exclusively promoting a cessation of swidden agriculture is neglecting its cultural value and the scarcity of irrigable land in the region

Bird diversity and endemism along a land-use gradient in Madagascar: The conservation value of vanilla agroforests

status: Published onlin

Listening to a changing landscape: Acoustic indices reflect bird species richness and plot-scale vegetation structure across different land-use types in north-eastern Madagascar

New technologies like ecoacoustic surveys promise time and cost efficiency for biodiversity assessments, serve as a basis for effective conservation policies, and are particularly appealing for remote and highly diverse tropical areas. Acoustic indices facilitate the analysis of large acoustic datasets but no consensus on their performance has been reached yet. We evaluated the efficacy of four acoustic indices (Acoustic Complexity Index, Acoustic Diversity Index, Acoustic Evenness Index, Acoustic Entropy) for sound data analysis and biodiversity assessments inside a national park and the agricultural mosaic landscape of north-eastern Madagascar, a global biodiversity hotspot. We used self-built sound recorders to continuously record soundscapes on 80 plots across seven land-use types (old-growth forest, forest fragment, forest–derived and fallow-derived vanilla agroforest, herbaceous and woody fallow, rice paddy) and compared index values between land–use types, assessed the correlation with bird species richness as measured by point counts, and related the acoustic indices to plot- and landscape-scale parameters. The Acoustic Diversity Index, Acoustic Evenness Index (inverse) and Acoustic Entropy were highest in old-growth forest and lowest for rice paddies and fallow land. Index values for structurally similar land-use types did not differ significantly from each other. The correlation of the three acoustic indices with bird species richness was strongest during daytime (R²≥0.30). Differences in the index values were best explained by land-use type and vegetation density. Our results showed that all investigated indices except the Acoustic Complexity Index were suitable biodiversity indicators for a tropical, agricultural landscape. Soundscape diversity was positively affected by plot-scale vegetation structure, emphasizing the importance of forests and particularly old-growth forest for conservation. We demonstrated that acoustic indices and sound recordings are a useful tool for assessing biodiversity in tropical agricultural mosaic landscapes. To realize the full potential of ecoacoustics in conservation, sampling guidelines and user-friendly analysis packages will be key to facilitate a wider implementation.status: Published onlin

Win-win opportunities combining high yields with high multi-taxa biodiversity in tropical agroforestry

This repository includes data from the synthesis "Win-win opportunities combining high yields with high multi-taxa biodiversity in tropical agroforestry" from the interdisciplinary Diversity Turn in Land Use Project (German-Malagasy research project). Data assessed: 2017 and 2018 Location: SAVA region (north-eastern Madagascar). Studied land-use types: Old growth forest, Forest fragment, Fallows (Woody fallow; Herbaceous fallow), Forest-derived vanilla agroforest, Fallow-derived vanilla agroforest. Resolving ecological-economic trade-offs between biodiversity and yields is a key challenge when addressing the biodiversity crisis in tropical agricultural landscapes. Here, we focused on the relation between seven different taxa (trees, herbaceous plants, birds, amphibians, reptiles, butterflies, and ants) and yields in vanilla agroforests in Madagascar. Agroforests established in forests supported overall 23% fewer species and 47% fewer endemic species than old-growth forests, and 14% fewer endemic species than forest fragments. In contrast, agroforests established on fallows had overall 12% more species and 38% more endemic species than fallows. While yields increased with vanilla vine density and length, non-yield related variables largely determined biodiversity. Nonetheless, trade-offs existed between yields and butterflies as well as reptiles. Vanilla yields were generally unrelated to richness of trees, herbaceous plants, birds, amphibians, reptiles, and ants, opening up possibilities for conservation outside of protected areas and restoring degraded land to benefit farmers and biodiversity alike