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Abstract 1. In the tropics, smallholder farming characterizes some of the world’s most biodiverse landscapes. Agroecology as a pathway to sustainable agriculture has been proposed and implemented in sub-Saharan Africa, but the effects of agricultural practices in smallholder agriculture on biodiversity and ecosystem services are understudied. Similarly, the contribution of different landscape elements, such as shrub- or grassland cover, on biodiversity and ecosystem services to fields remains unknown. 2. We selected 24 villages situated in landscapes with varying landscape shrub- and grassland cover in Malawi. In each village, we assessed biodiversity of 8 taxa and ecosystem services in relation to crop type, shrub- and grassland cover and the number of agroecological pest management (APM) and agroecological soil management (ASM) on smallholder farm fields of different crop types (maize monoculture, maize-bean intercrop, and bean monoculture). 3. Increasing shrubland cover increased bee richness and altered carabid communities. Increased grassland cover decreased ant richness. Carabid richness increased in maize and intercrop but decreased in bean fields with increasing grassland cover. Carabid and parasitoid activity densities were higher in bean monocultures, but this was mediated by surrounding shrubland cover. Natural enemy activity in beans was especially high in landscapes with little surrounding shrubland. Possibly, this increased activity resulted in lower bean damage in monocultures compared to intercrop, whereas in maize, monocultures where more damaged, especially in landscapes high in grassland cover. In maize, APM was positively related to pest damage, and we find increased carabid activity and richness in fields with high maize damage. Increased ASM resulted in increased carabid richness and wasp activity density. 4. Synthesis and application: Our results suggest that maintaining biodiversity and ecosystem services on smallholder farms is not achievable with a “one size fits all” approach but should instead be adapted to the landscape context and the priorities of smallholders. Shrubland is important to maintain bee and carabid diversity, but legume cultivation beneficial to natural enemies could complement APM in landscapes with a lower shrubland cover. An increased number of ASM practices could lead to improved pest control whilst the effectiveness of APM needs to be re-evaluated. Keywords: agroecology, biodiversity, crop diversity, intercropping, landscape change, pest control, pollination, soil health.
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Local and landscape scale woodland cover and diversification of agroecological practices shape butterfly communities in tropical smallholder landscapes
The conversion of biodiversity‐rich woodland to farmland and subsequent management has strong, often negative, impacts on biodiversity. In tropical smallholder agricultural landscapes, the impacts of agriculture on insect communities, both through habitat change and subsequent farmland management, is understudied. The use of agroecological practices has social and agronomic benefits for smallholders. Although ecological co‐benefits of agroecological practices are assumed, systematic empirical assessments of biodiversity effects of agroecological practices are missing, particularly in Africa.In Malawi, we assessed butterfly abundance, species richness, species assemblages and community life‐history traits on 24 paired woodland and smallholder‐managed farmland sites located across a gradient of woodland cover within a 1 km radius. We tested whether habitat type (woodland vs. farmland) and woodland cover at the landscape scale interactively shaped butterfly communities. Farms varied in the implementation of agroecological pest and soil management practices and flowering plant species richness.Farmland had lower butterfly abundances and approximately half the species richness than woodland. Farmland butterfly communities had, on average, a larger wingspan than woodland site communities. Surprisingly, higher woodland cover in the landscape had no effect on butterfly abundance in both habitats. In contrast, species richness was higher with higher woodland cover. Butterfly species assemblages were distinct between wood‐ and farmland and shifted across the woodland cover gradient.Farmland butterfly abundance, but not species richness, was higher with higher flowering plant species richness on farms. Farms with a higher number of agroecological pest management practices had a lower abundance of the dominant butterfly species, but not of rarer species. However, a larger number of agroecological soil management practices was associated with a higher abundance of rarer species. Synthesis and applications: We show that diversified agroecological soil practices and flowering plant richness enhanced butterfly abundance on farms. However, our results suggest that on‐farm measures cannot compensate for the negative effects of continued woodland conversion. Therefore, we call for more active protection of remaining African woodlands in tandem with promoting agroecological soil management practices and on‐farm flowering plant richness to conserve butterflies while benefiting smallholders.
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- Award ID(s):
- 1852587
- PAR ID:
- 10511054
- Publisher / Repository:
- Data available via the Dryad Digital Repository https://doi. org/10.5061/dryad.5qftt dz9p (Vogel et al., 2023).
- Date Published:
- Journal Name:
- Journal of Applied Ecology
- Volume:
- 60
- Issue:
- 8
- ISSN:
- 0021-8901
- Page Range / eLocation ID:
- 1659 to 1672
- Subject(s) / Keyword(s):
- agroecology butterflies conservation landscape change Miombo woodlands smallholder agriculture sub-Saharan Africa
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1111/1365-2664.14446
