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Abstract Changes in land use and land cover (LULC) due to agricultural expansion, commercial land management and other human‐driven modifications significantly influence the ecology of pathogens and vectors. This underscores the urgent need to understand how these respond to rapid and dynamic land use changes in these ecosystems and, critically, to identify strategies for mitigating their impacts.In tropical Central and South America, palm trees serve as primary habitats forRhodniuskissing bugs, vectors ofTrypanosoma cruzi, the etiologic agent of Chagas disease. This study investigates how LULC, weather and traits of the palmAttalea butyraceapredict the occurrence and infection ofRhodnius pallescens, integrating field data collection, molecular detection and spatial and hierarchical analyses across a rural landscape in Panama.Rhodnius pallescenswere collected from 46 palms in 11 communities with different landscape compositions including native forests, grasslands, successional forests and artificial structures. Robust occupancy modelling using land cover data at 10 m2resolution revealed that successional forest cover at 300 m spatial scale predicted greater occurrence ofR. pallescens, whereas native forest predicted lower occurrence. Quadratic models outperformed linear models, indicating occupancy peaks at intermediate land covers and palm tree traits.Real‐time PCR assays detectedTrypanosomainfections in 70% ofR. pallescensacross communities. Spatial autocorrelation analyses showed significant spatial clustering forT. cruzibut not forTrypanosoma rangeli. We used generalized additive mixed models to assess the influence of palm‐level and landscape‐scale attributes on parasite infection and identified significant nonlinear positive associations betweenT.cruziinfection and native forest and grassland, with high predictive accuracy (AUC = 0.90).Synthesis and applications. Findings here show that successional forest predicts greater kissing bug infestation risk in palm trees, whereas native forest predicts lower kissing bug occurrence but greater infection withT. cruzi. These insights can guide land use planning towards vegetation management practices that help minimizeT. cruzitransmission risks for rural communities. Importantly, vector surveillance should target forest‐grassland ecotones and consider forest successional stages near settlements, with intensified monitoring after disturbances; this approach is applicable to other vector‐borne pathogen systems shaped by land use change.
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Tillage agriculture and afforestation threaten tropical savanna plant communities across a broad rainfall gradient in India
Abstract The consequences of land‐use change for savanna biodiversity remain undocumented in most regions of tropical Asia. One such region is western Maharashtra, India, where old‐growth savannas occupy a broad rainfall gradient and are increasingly rare due to agricultural conversion and afforestation.To understand the consequences of land‐use change, we sampled herbaceous plant communities of old‐growth savannas and three alternative land‐use types: tree plantations, tillage agriculture and agricultural fallows (n = 15 sites per type). Study sites spanned 457 to 1954 mm of mean annual precipitation—corresponding to the typical rainfall range of mesic savannas globally.Across the rainfall gradient, we found consistent declines in old‐growth savanna plant communities due to land‐use change. Local‐scale native species richness dropped from a mean of 12 species/m2in old‐growth savannas to 8, 6 and 3 species/m2in tree plantations, fallows and tillage agriculture, respectively. Cover of native plants declined from a mean of 49% in old‐growth savannas to 27% in both tree plantations and fallows, and 4% in tillage agriculture. Reduced native cover coincided with increased cover of invasive species in tree plantations (18%), fallows (18%) and tillage agriculture (3%).In analyses of community composition, tillage agriculture was most dissimilar to old‐growth savannas, while tree plantations and fallows showed intermediate dissimilarity. These compositional changes were driven partly by the loss of characteristic savanna species: 65 species recorded in old‐growth savannas were absent in other land uses. Indicator analysis revealed 21 old‐growth species, comprised mostly of native savanna specialists. Indicators of tree plantations (nine species) and fallows (13 species) were both invasive and native species, while the two indicators of tillage agriculture were invasive. As reflective of declines in savanna communities, mean native perennial graminoid cover of 27% in old‐growth savannas dropped to 9%, 7%, and 0.1% in tree plantations, fallows and tillage agriculture, respectively.Synthesis. Agricultural conversion and afforestation of old‐growth savannas in India destroys and degrades herbaceous plant communities that do not spontaneously recover on fallowed land. Efforts to conserve India's native biodiversity should encompass the country's widespread savanna biome and seek to limit conversion of irreplaceable old‐growth savannas.
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- Award ID(s):
- 1931232
- PAR ID:
- 10487936
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Journal of Ecology
- Volume:
- 112
- Issue:
- 1
- ISSN:
- 0022-0477
- Page Range / eLocation ID:
- 98 to 109
- 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/10.1111/1365-2745.14221
