scholarly journals Land-use change to subsistence farming has negligible impact on birds in Zimbabwe

2021 ◽  
Author(s):  
J Stephen Pringle ◽  
Ngoni Chiweshe ◽  
Martin Dallimer
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Temporal Trends ◽  
Bird Species ◽  
Bird Communities ◽  
Habitat Modification ◽  
Small Scale ◽  
Feeding Guilds ◽  
Human Populations ◽  
Habitat Transformation

Habitat alterations that often accompany land-use change are one of the major drivers of global biodiversity losses. In Africa, these threats are especially severe, as this continent has the most rapidly growing of all human populations. Inevitably, increasing areas of land are being transformed for agriculture, including drought-prone drylands in southern and central Africa, despite often having poor soils. In Zimbabwe, a land reform programme provided a unique opportunity to study the biodiversity response to abrupt habitat modification in an extensive dryland area of mixed grassland and woodland savannah. Small-scale subsistence farms were created rapidly during 2001-2002 in formerly semi-natural savannah. We measured the changing compositions of bird communities in transformed and untransformed land over an 8-year period, commencing one decade after subsistence farms were established. Over the study period, repeated counts were made along identical transects in order to assess species’ population changes that may have resulted from trait-filtering responses to habitat disturbance. We recorded significantly increased abundances in both land-use areas, accompanied by increases in species diversity and functional redundancy. Temporal trends showed increased abundances across all feeding guilds, and in species of virtually all sizes. Influxes of new species did not increase functional traits’ diversity, and no species with distinctive traits appear to have been lost as a result of land-use change. Nearly two decades after habitat transformation, the bird communities in the transformed and untransformed areas had become more similar in composition. The broadly benign impact on birds of land conversion into subsistence farms is attributed to the relatively low-level of human activities and disturbance in the transformed land, and the large regional pool of non-specialist bird species.

Functional traits, land-use change and the structure of present and future bird communities in tropical forests

2014 ◽  
Vol 23 (10) ◽  
pp. 1073-1084 ◽  
Author(s):  
Tim Newbold ◽  
Jörn P. W. Scharlemann ◽  
Stuart H. M. Butchart ◽  
Çağan H. Şekercioğlu ◽  
Lucas Joppa ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Tropical Forests ◽  
Functional Traits ◽  
Bird Communities

Taxonomic, phylogenetic and functional homogenization of bird communities due to land use change

2019 ◽  
Vol 236 ◽  
pp. 37-43 ◽  
Author(s):  
Chenxia Liang ◽  
Guisheng Yang ◽  
Na Wang ◽  
Gang Feng ◽  
Fan Yang ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Bird Communities ◽  
Functional Homogenization

scholarly journals Ecological traits affect the response of tropical forest bird species to land-use intensity

2013 ◽  
Vol 280 (1750) ◽  
pp. 20122131 ◽  
Author(s):  
Tim Newbold ◽  
Jörn P. W. Scharlemann ◽  
Stuart H. M. Butchart ◽  
Çağan H. Şekercioğlu ◽  
Rob Alkemade ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Bird Species ◽  
Biodiversity Loss ◽  
Species Traits ◽  
Land Use Intensity ◽  
Ecological Traits ◽  
Human Land Use ◽  
Average Probability ◽  
Land Use Intensity Gradient

Land-use change is one of the main drivers of current and likely future biodiversity loss. Therefore, understanding how species are affected by it is crucial to guide conservation decisions. Species respond differently to land-use change, possibly related to their traits. Using pan-tropical data on bird occurrence and abundance across a human land-use intensity gradient, we tested the effects of seven traits on observed responses. A likelihood-based approach allowed us to quantify uncertainty in modelled responses, essential for applying the model to project future change. Compared with undisturbed habitats, the average probability of occurrence of bird species was 7.8 per cent and 31.4 per cent lower, and abundance declined by 3.7 per cent and 19.2 per cent in habitats with low and high human land-use intensity, respectively. Five of the seven traits tested affected the observed responses significantly: long-lived, large, non-migratory, primarily frugivorous or insectivorous forest specialists were both less likely to occur and less abundant in more intensively used habitats than short-lived, small, migratory, non-frugivorous/insectivorous habitat generalists. The finding that species responses to land use depend on their traits is important for understanding ecosystem functioning, because species' traits determine their contribution to ecosystem processes. Furthermore, the loss of species with particular traits might have implications for the delivery of ecosystem services.

scholarly journals Intermediate levels of wood extraction may facilitate coexistence of an endemic arboreal marsupial and Indigenous communities

Oryx ◽  
2021 ◽  
pp. 1-9
Author(s):  
Héctor González-Ancín ◽  
Manuel Spínola ◽  
José M. Mora-Benavides ◽  
Joel C. Sáenz ◽  
Alberto Paillacar ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Natural Resources ◽  
Plant Diversity ◽  
Indigenous Communities ◽  
Selective Logging ◽  
Small Scale ◽  
Intermediate Disturbance ◽  
Wood Extraction ◽  
Disturbed Site

Abstract Land-use change is a major driver of biodiversity loss. Large-scale disturbances such as habitat loss, fragmentation and degradation are known to have negative consequences for native biota, but the effects of small-scale disturbances such as selective logging are less well known. We compared three sites with different regimes of selective logging performed by Indigenous communities in the South American temperate rainforest, to assess effects on the density and habitat selection patterns of the Near Threatened endemic arboreal marsupial Dromiciops gliroides. We used structured interviews to identify patterns of wood extraction, which was 0.22–2.55 m3 per ha per year. In the less disturbed site only two tree species were logged, in the intermediately disturbed sites eight species were logged at low intensity, and in the most disturbed site seven species were logged intensively. The site with intermediate disturbance had the highest fleshy-fruited plant diversity and fruit biomass values as a result of the proliferation of shade-intolerant plants. This site also had the highest density of D. gliroides. These findings are consistent with Connell's intermediate disturbance hypothesis, suggesting that coexistence of people with nature is possible if wood extraction volumes are moderate, increasing plant diversity. Indigenous communities have sustainably used natural resources for centuries, but current rates of land-use change are becoming a significant threat to both them and their natural resources.

scholarly journals Comparative analysis of hydrologic signatures in two agricultural watersheds in east-central Illinois: legacies of the past to inform the future

2013 ◽  
Vol 10 (5) ◽  
pp. 6515-6558 ◽  
Author(s):  
M. A. Yaeger ◽  
M. Sivapalan ◽  
G. F. McIsaac ◽  
X. Cai
Keyword(s):  
Land Use ◽  
Comparative Analysis ◽  
Land Use Change ◽  
Low Flow ◽  
Series Data ◽  
Small Scale ◽  
Agricultural System ◽  
Current Response ◽  
The Past ◽  
Central Illinois

Abstract. Historically, the central Midwestern US has undergone drastic anthropogenic land use change, having been transformed, in part through federal government policy, from a natural grassland system to an artificially-drained agricultural system devoted to row cropping corn and soybeans. Current federal policies are again influencing land use change in this region with increased corn acreage and new biomass crops proposed as part of an energy initiative emphasizing biofuels. To better address these present and future challenges it is helpful to understand how the legacies of past changes have shaped the current response of the system. To this end, a comparative analysis of the hydrologic signatures in both spatial and time series data from two central Illinois watersheds was undertaken. The past history of these catchments is reflected in their current hydrologic responses, which are highly heterogeneous, more so in the extensively tile-drained Sangamon watershed. The differences in geologic history, artificial drainage patterns, and to some extent, reservoir construction, manifest at all time scales, from annual to daily, and spatially within the watersheds. These differences can also be seen in the summer low flow patterns, where the more tile-drained watershed shows more variability than does the more naturally drained one. Of interest is the scaling behavior of the low flows; generally as drainage area increases, small-scale heterogeneity decreases. This is not seen in the more tile-drained watershed, thus adding complexity to the problem of predicting the catchment response to future changes.

scholarly journals Agricultural expansion in African savannas – effects on diversity and composition of trees and mammals

2021 ◽  
Author(s):  
Hemant Tripathi ◽  
Emily Woollen ◽  
Mariana Carvalho ◽  
Catherine Parr ◽  
Casey Ryan
Keyword(s):  
Land Use ◽  
Species Richness ◽  
Land Use Change ◽  
Biodiversity Loss ◽  
Small Scale ◽  
Agricultural Expansion ◽  
Miombo Woodlands ◽  
Mammal Species ◽  
Β Diversity ◽  
Impact On Biodiversity

Abstract Land use change (LUC) is the leading cause of biodiversity loss worldwide. However, the global understanding of LUC's impact on biodiversity is mainly based on comparisons of land use endpoints (habitat vs non-habitat) in forest ecosystems. Hence, it may not generalise to savannas, which are ecologically distinct from forests, as they are inherently patchy, and disturbance adapted. Endpoint comparisons also cannot inform the management of intermediate mosaic landscapes. We aim to address these gaps by investigating species- and community-level responses of mammals and trees along a gradient of small scale agricultural expansion in the miombo woodlands of northern Mozambique. Thus, the case study represents the most common pathway of LUC and biodiversity change in the world's largest savanna. Tree abundance, mammal occupancy, and tree- and mammal-species richness showed a non-linear relationship with agricultural expansion (characterised by the Land Division Index, LDI). These occurrence and diversity metrics increased at intermediate LDI (0.3 to 0.7), started decreasing beyond LDI > 0.7, and underwent high levels of decline at extreme levels of agricultural expansion (LDI > 0.9). Despite similarities in species richness responses, the two taxonomic groups showed contrasting β-diversity patterns in response to increasing LDI: increased dissimilarity among tree communities (heterogenisation) and high similarity among mammals (homogenisation). Our analysis along a gradient of landscape-scale land use intensification allows a novel understanding of the impacts of different levels of land conversion, which can help guide land use and restoration policy. Biodiversity loss in this miombo landscape was lower than would be inferred from existing global syntheses of biodiversity-land use relations for Africa or the tropics, probably because such syntheses take a fully converted landscape as the endpoint. As, currently, most African savanna landscapes are a mosaic of savanna habitats and small scale agriculture, biodiversity loss is probably lower than in current global estimates, albeit with a trend towards further conversion. However, at extreme levels of land use change (LDI > 0.9 or < 15% habitat cover) miombo biodiversity appears to be more sensitive to LUC than inferred from the meta-analyses. To mitigate the worst effects of land use on biodiversity, our results suggest that miombo landscapes should retain > 25% habitat cover and avoid LDI > 0.75 – after which species richness of both groups begin to decline. Our findings indicate that tree diversity may be easier to restore from natural restoration than mammal diversity, which became spatially homogeneous.

scholarly journals Potential rents vs. potential lives

2020 ◽  
pp. 0308518X2097130
Author(s):  
Eric Clark ◽  
Annika Pissin
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Small Scale ◽  
Natural Environments ◽  
Rural Landscapes ◽  
Accumulation By Dispossession ◽  
Central Argument ◽  
The Baltic ◽  
The Cost ◽  
Rent Gap Theory

The seeking of potential rents directs flows of investment into built and natural environments, suffusing volatility into urban and rural landscapes, generating gentrification and other forms of land use change, and displacing lives and livelihoods to make space for ‘improvement’, ‘highest and best use’, ‘revitalization’, or the like. In this paper we argue that potential rents are captured at the cost of potential lives, and that rent gap theory, long central (and limited) to gentrification theory, is more widely applicable to the dynamics of land use change and uneven geographical development in capitalist societies. By reading David Harvey’s analyses of rent and accumulation by dispossession as a sophisticated formulation of rent gap theory, we relate the seeking and capturing of potential rents to the power of landed developer interests and a broadened conceptualization of rentiership. We furthermore relate the seeking of potential rents to an ideology of limitless accumulation, and the striving to rein in potential rents to ideas of degrowth and the need for a culture and a politics of limits. Brief vignettes from the ‘primary sector’ (fisheries in the Baltic Sea, dairy farming in Europe, and small-scale farming in Sweden) suggestively illustrate our central argument that the seeking and capturing of potential rents stand in stark opposition to potentials for wellbeing and flourishing of human and non-human lives. We conclude that constraining potential rents – founded as they are on faith in limitless growth – requires a culture of self-limitation and politically imposed limitations commensurable with post-capitalist societies.

Land-use change and floods: what do we need most, research or management?

2002 ◽  
Vol 45 (8) ◽  
pp. 183-190 ◽  
Author(s):  
Arne Tollan
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Flood Risk ◽  
Human Impacts ◽  
Management Strategies ◽  
Flood Management ◽  
Flood Damage ◽  
Flood Frequency ◽  
Small Scale ◽  
Infiltration Capacity

Land-cover change (urbanisation, deforestation, and cultivation) results in increased flood frequency and severity. Mechanisms include reduced infiltration capacity, lower soil porosity, loss of vegetation, and forest clearing, meaning lower evapotranspiration. Major research challenges lie in quantification of effects in terms of flood characteristics under various conditions, ascertaining the combined effects of gradual changes over long time periods, and developing model tools suitable for land-use management. Large floods during the 1990s gave a new focus on these problems. Reference is made to the Norwegian HYDRA research programme on human impacts on floods and flood damage. The paper concludes that land-use change effects on floods are most pronounced at small scale and for frequent flood magnitudes. Model simulations of effects of land-use change can now be used to reduce flood risk. Modern flood management strategies have abandoned the position that dams and dikes are the only answers to mitigating flood disasters. Today, the strategic approach is more often: do not keep the water away from the people, keep people away from the water. Flood management strategies should include flood warnings, efficient communication, risk awareness, civil protection and flood preparedness routines, effective land-use policies, flood risk mapping, … as well as structural measures.

scholarly journals Anomaly in the rainfall-runoff behaviour of the Meuse catchment. Climate, land use, or land use management?

2008 ◽  
Vol 5 (4) ◽  
pp. 1787-1819 ◽  
Author(s):  
F. Fenicia ◽  
H. H. G. Savenije ◽  
Y. Avdeeva
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Land Cover ◽  
Climatic Variability ◽  
Time Lag ◽  
Temporal Trends ◽  
Model Parameters ◽  
Land Use Management ◽  
Rainfall Runoff ◽  
The Way

Abstract. An anomaly has been found in the rainfall runoff behaviour of the Meuse. Ninety years of rainfall-runoff simulations show a consistent underestimation of the runoff in the period between 1930 and 1965. Different authors have debated possible causes for the anomaly, including climatic variability, land use change and data errors. None of the authors considered the way in which the land is used by for instance agricultural and forestry practises. This paper focuses on the possible effects of land use and land use management on the hydrological response of the Meuse catchment. In absence of detailed information on land use over the observation period, we adopted a fully "top-down" approach to the problem. The approach consists of a dynamic evaluation of a conceptual hydrological model and the interpretation of the temporal trends of model parameters. It appears that land use has had a considerable impact on the hydrological behaviour of the Meuse catchment. The time lag of the catchment has reduced markedly over time, possibly related to more intensive drainage and river training works. Moreover we hypothesise that forest rotation has had a significant impact on the evaporation of the catchment. These results contrast with previous studies, where the effect of land use change on the hydrological behaviour of the Meuse catchment was considered negligible, mainly because there was not sufficient change in land cover to account for it. Here we hypothesise that in the Meuse it was not the change of land cover that was responsible for hydrological change, but rather the way the land was managed.

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