Land-use change is the most important driver of biodiversity loss
worldwide and particularly so in the tropics, where natural habitats are
transformed into large-scale monocultures or heterogeneous landscape
mosaics of largely unknown conservation value. Using birds as an indicator
taxon, we evaluated the conservation value of a landscape mosaic in
north-eastern Madagascar, a biodiversity hotspot and the center of global
vanilla production. We assessed bird species richness and composition by
conducting point counts across seven prevalent land-use types (forest- and
fallow-derived vanilla agroforests, woody and herbaceous fallow that are
part of a shifting cultivation system, rice paddy, forest fragment and
contiguous old-growth forest). We find that old-growth forest had the
highest species richness, driven by a high share of endemics. Species
richness and community composition in forest-derived vanilla agroforest
was similar to forest fragment, whereas fallow-derived vanilla agroforest
was most comparable to woody fallow. The open land-use types herbaceous
fallow and rice paddy had fewest species. Across forest fragment, vanilla
agroforests and woody fallow, endemic bird species richness was positively
correlated to landscape-scale forest cover. We conclude that both fallow-
and forest-derived vanilla agroforests play an important but contrasting
role for bird conservation in the landscape: Fallow-derived agroforests
are less valuable but take fallow land out of the shifting cultivation
cycle, possibly preventing further degradation. Conversely, forest-derived
agroforests contribute to forest degradation but may avoid total loss of
forest fragments. Considering the land-use history of agroforests may thus
be a promising avenue for future research beyond the case of vanilla. 1) Species-by-plot matrix from pointcounts
across seven land-use types in north-eastern Madgascar (80 plots in
total) 2) Plot
characteristics (location, elevation, basal area, number of large trees,
canopy cover, landscape-scale forest cover) Methods are described in the
paper: Martin, D. A.,
Andriafanomezantsoa, R., Dröge, S., Osen, K., Rakotomalala, E., Wurz, A.,
Andrianarimisa, A., & Kreft, H. (n.d.). Bird diversity and
endemism along a land-use gradient in Madagascar: the conservation value
of vanilla agroforests. Biotropica. No missing data in species-by-plot matrix. All plots have the
same sampling effort (2 x 40min). Plot characteristics
dataset has missing values for basal area of two plots.