Increases in subsistence farming due to land reform have negligible impact on bird communities in Zimbabwe

Abstract Habitat alterations resulting from land‐use change are major drivers of global biodiversity losses. In Africa, these threats are especially severe. For instance, demand to convert land into agricultural uses is leading to increasing areas of drylands in southern and central Africa being tra...

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Main Authors: Stephen Pringle, Ngoni Chiweshe, Martin Dallimer
Format: Article
Language:English
Published: Wiley 2022-02-01
Series:Ecology and Evolution
Subjects:
Online Access:https://doi.org/10.1002/ece3.8612
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author Stephen Pringle
Ngoni Chiweshe
Martin Dallimer
author_facet Stephen Pringle
Ngoni Chiweshe
Martin Dallimer
author_sort Stephen Pringle
collection DOAJ
description Abstract Habitat alterations resulting from land‐use change are major drivers of global biodiversity losses. In Africa, these threats are especially severe. For instance, demand to convert land into agricultural uses is leading to increasing areas of drylands in southern and central Africa being transformed for agriculture. In Zimbabwe, a land reform programme provided an opportunity to study the biodiversity response to abrupt habitat modification in part of a 91,000 ha dryland area of semi‐natural savannah used since 1930 for low‐level cattle ranching. Small‐scale subsistence farms were created during 2001–2002 in 65,000 ha of this area, with ranching continuing in the remaining unchanged area. We measured the compositions of bird communities in farmed and ranched land over 8 years, commencing one decade after subsistence farms were established. Over the study period, repeated counts were made along the same 45 transects to assess species' population changes that may have resulted from trait‐filtering responses to habitat disturbance. In 2012, avian species' richness was substantially higher (+8.8%) in the farmland bird community than in the unmodified ranched area. Temporal trends over the study period showed increased species' richness in the ranched area (+12.3%) and farmland (+6.8%). There were increased abundances in birds of most sizes, and in all feeding guilds. New species did not add new functional traits, and no species with distinctive traits were lost in either area. As a result, species' diversity reduced, and functional redundancy increased by 6.8% in ranched land. By 2020, two decades after part of the ranched savannah was converted into farmland, the compositions of the two bird communities had both changed and became more similar. The broadly benign impact on birds of land conversion into subsistence farms is attributed to the relatively low level of agricultural activity in the farmland and the large regional pool of nonspecialist bird species.
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spelling doaj.art-a1fc6dc9320e4ee39eb05c0031f7b9ad2022-12-22T03:02:30ZengWileyEcology and Evolution2045-77582022-02-01122n/an/a10.1002/ece3.8612Increases in subsistence farming due to land reform have negligible impact on bird communities in ZimbabweStephen Pringle0Ngoni Chiweshe1Martin Dallimer2Sustainability Research Institute School of Earth and Environment University of Leeds Leeds UKCIRAD Zimbabwe, c/o IUCN Zimbabwe Harare ZimbabweSustainability Research Institute School of Earth and Environment University of Leeds Leeds UKAbstract Habitat alterations resulting from land‐use change are major drivers of global biodiversity losses. In Africa, these threats are especially severe. For instance, demand to convert land into agricultural uses is leading to increasing areas of drylands in southern and central Africa being transformed for agriculture. In Zimbabwe, a land reform programme provided an opportunity to study the biodiversity response to abrupt habitat modification in part of a 91,000 ha dryland area of semi‐natural savannah used since 1930 for low‐level cattle ranching. Small‐scale subsistence farms were created during 2001–2002 in 65,000 ha of this area, with ranching continuing in the remaining unchanged area. We measured the compositions of bird communities in farmed and ranched land over 8 years, commencing one decade after subsistence farms were established. Over the study period, repeated counts were made along the same 45 transects to assess species' population changes that may have resulted from trait‐filtering responses to habitat disturbance. In 2012, avian species' richness was substantially higher (+8.8%) in the farmland bird community than in the unmodified ranched area. Temporal trends over the study period showed increased species' richness in the ranched area (+12.3%) and farmland (+6.8%). There were increased abundances in birds of most sizes, and in all feeding guilds. New species did not add new functional traits, and no species with distinctive traits were lost in either area. As a result, species' diversity reduced, and functional redundancy increased by 6.8% in ranched land. By 2020, two decades after part of the ranched savannah was converted into farmland, the compositions of the two bird communities had both changed and became more similar. The broadly benign impact on birds of land conversion into subsistence farms is attributed to the relatively low level of agricultural activity in the farmland and the large regional pool of nonspecialist bird species.https://doi.org/10.1002/ece3.8612biodiversity conservationDPCoAfunctional redundancyfunctional traitsland‐use changespecies' richness
spellingShingle Stephen Pringle
Ngoni Chiweshe
Martin Dallimer
Increases in subsistence farming due to land reform have negligible impact on bird communities in Zimbabwe
Ecology and Evolution
biodiversity conservation
DPCoA
functional redundancy
functional traits
land‐use change
species' richness
title Increases in subsistence farming due to land reform have negligible impact on bird communities in Zimbabwe
title_full Increases in subsistence farming due to land reform have negligible impact on bird communities in Zimbabwe
title_fullStr Increases in subsistence farming due to land reform have negligible impact on bird communities in Zimbabwe
title_full_unstemmed Increases in subsistence farming due to land reform have negligible impact on bird communities in Zimbabwe
title_short Increases in subsistence farming due to land reform have negligible impact on bird communities in Zimbabwe
title_sort increases in subsistence farming due to land reform have negligible impact on bird communities in zimbabwe
topic biodiversity conservation
DPCoA
functional redundancy
functional traits
land‐use change
species' richness
url https://doi.org/10.1002/ece3.8612
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AT ngonichiweshe increasesinsubsistencefarmingduetolandreformhavenegligibleimpactonbirdcommunitiesinzimbabwe
AT martindallimer increasesinsubsistencefarmingduetolandreformhavenegligibleimpactonbirdcommunitiesinzimbabwe