scholarly journals Elevated alpha diversity in disturbed sites obscures regional decline and homogenization of amphibian diversity

2021 ◽  
Author(s):  
D. Matthias Dehling ◽  
J Maximilian Dehling
Keyword(s):  
Large Scale ◽  
Natural Habitat ◽  
Alpha Diversity ◽  
Sub Saharan Africa ◽  
Eastern Africa ◽  
Gamma Diversity ◽  
Natural Habitats ◽  
Farmland Conversion ◽  
Frog Species ◽  
Amphibian Communities

Loss of natural habitat is one of the major threats for biodiversity worldwide. Habitat conversion not only changes diversity and species composition locally (alpha diversity) but might also lead to large-scale homogenization of species communities and decrease in regional species richness (gamma diversity). We investigated the effect of farmland conversion on amphibian communities in Rwanda and compared local and regional (country-wide) taxonomic, functional and phylogenetic diversity between natural and farmland sites (agricultural marais). Alpha diversity was higher in the disturbed farmland than in natural sites. However, species turnover among farmland sites was much lower than among natural sites, resulting in highly homogenized amphibian communities and much lower country-wide taxonomic, functional and phylogenetic gamma diversity in farmland compared to natural sites. The few frog species found in farmland were mostly disturbance-tolerant species that are widespread in Eastern Africa and beyond. In contrast, most of the regionally endemic frog species that make this region a continent-scale hotspot of amphibian diversity were found only in the natural habitats. Ongoing farmland conversion might lead to a loss of regional endemism and a widespread homogenization of species communities across sub-Saharan Africa.

scholarly journals Resource frontiers and agglomeration economies: The varied logics of transnational land-based investing in Southern and Eastern Africa

AMBIO ◽  
2022 ◽  
Author(s):  
Dilini Abeygunawardane ◽  
Angela Kronenburg García ◽  
Zhanli Sun ◽  
Daniel Müller ◽  
Almeida Sitoe ◽  
...  
Keyword(s):  
Spatial Data ◽  
Large Scale ◽  
Agglomeration Economies ◽  
Sub Saharan Africa ◽  
Eastern Africa ◽  
Track Record ◽  
Level Data ◽  
Forestry Investments ◽  
Sub Saharan ◽  
Investment Location

AbstractActor-level data on large-scale commercial agriculture in Sub-Saharan Africa are scarce. The peculiar choice of transnational investing in African land has, therefore, been subject to conjecture. Addressing this gap, we reconstructed the underlying logics of investment location choices in a Bayesian network, using firm- and actor-level interview and spatial data from 37 transnational agriculture and forestry investments across 121 sites in Mozambique, Zambia, Tanzania, and Ethiopia. We distinguish four investment locations across gradients of resource frontiers and agglomeration economies to derive the preferred locations of different investors with varied skillsets and market reach (i.e., track record). In contrast to newcomers, investors with extensive track records are more likely to expand the land use frontier, but they are also likely to survive the high transaction costs of the pre-commercial frontier. We highlight key comparative advantages of Southern and Eastern African frontiers and map the most probable categories of investment locations.

scholarly journals Experimental illumination of natural habitat—an experimental set-up to assess the direct and indirect ecological consequences of artificial light of different spectral composition

2015 ◽  
Vol 370 (1667) ◽  
pp. 20140129 ◽  
Author(s):  
Kamiel Spoelstra ◽  
Roy H. A. van Grunsven ◽  
Maurice Donners ◽  
Phillip Gienapp ◽  
Martinus E. Huigens ◽  
...  
Keyword(s):  
Large Scale ◽  
Negative Impact ◽  
Natural Habitat ◽  
Spectral Composition ◽  
Community Level ◽  
Artificial Light ◽  
Night Time ◽  
Natural Habitats ◽  
Set Up ◽  
The Impact

Artificial night-time illumination of natural habitats has increased dramatically over the past few decades. Generally, studies that assess the impact of artificial light on various species in the wild make use of existing illumination and are therefore correlative. Moreover, studies mostly focus on short-term consequences at the individual level, rather than long-term consequences at the population and community level—thereby ignoring possible unknown cascading effects in ecosystems. The recent change to LED lighting has opened up the exciting possibility to use light with a custom spectral composition, thereby potentially reducing the negative impact of artificial light. We describe here a large-scale, ecosystem-wide study where we experimentally illuminate forest-edge habitat with different spectral composition, replicated eight times. Monitoring of species is being performed according to rigid protocols, in part using a citizen-science-based approach, and automated where possible. Simultaneously, we specifically look at alterations in behaviour, such as changes in activity, and daily and seasonal timing. In our set-up, we have so far observed that experimental lights facilitate foraging activity of pipistrelle bats, suppress activity of wood mice and have effects on birds at the community level, which vary with spectral composition. Thus far, we have not observed effects on moth populations, but these and many other effects may surface only after a longer period of time.

scholarly journals Synchronous cycles of domestic dog rabies in sub-Saharan Africa and the impact of control efforts

2007 ◽  
Vol 104 (18) ◽  
pp. 7717-7722 ◽  
Author(s):  
Katie Hampson ◽  
Jonathan Dushoff ◽  
John Bingham ◽  
Gideon Brückner ◽  
Y. H. Ali ◽  
...  
Keyword(s):  
Large Scale ◽  
Domestic Dogs ◽  
Sub Saharan Africa ◽  
Domestic Dog ◽  
Eastern Africa ◽  
Prevention Measures ◽  
Persistent Problem ◽  
Canine Rabies ◽  
Continental Scale ◽  
The Impact

Rabies is a fatal neurological pathogen that is a persistent problem throughout the developing world where it is spread primarily by domestic dogs. Although the disease has been extensively studied in wildlife populations in Europe and North America, the dynamics of rabies in domestic dog populations has been almost entirely neglected. Here, we demonstrate that rabies epidemics in southern and eastern Africa cycle with a period of 3–6 years and show significant synchrony across the region. The observed period is shorter than predictions based on epidemiological parameters for rabies in domestic dogs. We find evidence that rabies prevention measures, including vaccination, are affected by disease prevalence and show that a simple model with intervention responses can capture observed disease periodicity and host dynamics. We suggest that movement of infectious or latent animals combined with coordinated control responses may be important in coupling populations and generating synchrony at the continental scale. These findings have important implications for rabies prediction and control: large-scale synchrony and the importance of intervention responses suggest that control of canine rabies in Africa will require sustained efforts coordinated across political boundaries.

scholarly journals Basic considerations on seasonal breeding in mammals including their testing by comparing natural habitats and zoos

2020 ◽  
Author(s):  
Marcus Clauss ◽  
Philipp Zerbe ◽  
Laurie Bingaman Lackey ◽  
Daryl Codron ◽  
Dennis W. H. Müller
Keyword(s):  
Life History ◽  
Large Scale ◽  
Seasonal Pattern ◽  
Natural Habitat ◽  
Life History Strategies ◽  
Special Focus ◽  
Natural Habitats ◽  
Fluctuating Resources ◽  
Resource Limitations ◽  
In The Wild

Abstract Seasonal reproduction is common in mammals. Whereas specific conditions triggering a seasonal response can only be identified in controlled experiments, large-scale comparisons of reproduction in natural habitats and zoos can advance knowledge for taxa unavailable for experimentation. We outline how such a comparison can identify species whose seasonal physiology is linked to photoperiodic triggers, and those whose perceived seasonality in the wild is the consequence of fluctuating resources without a photoperiodic trigger. This concept groups species into those that do not change their aseasonal pattern between natural habitats and zoos because they are not constrained by resources in the wild, those that do not change a seasonal pattern between natural habitats and zoos because they are triggered by photoperiod irrespective of resources, and those that change from a more seasonal pattern in the natural habitat to an aseasonal pattern in zoos because the zoo environment alleviates resource limitations experienced in the wild. We explain how detailed comparisons of mating season timing in both environments can provide clues whether a specific daylength or a specific number of days after an equinox or solstice is the likely phototrigger for a taxon. We outline relationships between life history strategies and seasonality, with special focus on relative shortening of gestation periods in more seasonal mammals. Irrespective of whether such shortening results from the adaptive value of fitting a reproductive cycle within one seasonal cycle (minimizing ‘lost opportunity’), or from benefits deriving from separating birth and mating (to optimize resource use, or to reduce infanticide), reproductive seasonality may emerge as a relevant driver of life history acceleration. Comparisons of data from natural habitats and zoos will facilitate testing some of the resulting hypotheses.

scholarly journals Following the outbreak: preliminary findings on the landscape effect on Dasineura oleae and its parasitoids in Central Italy

2021 ◽  
Author(s):  
Malayka Samantha Picchi ◽  
Elena Tondini ◽  
Nicola Albertarelli ◽  
Gaia Monteforti ◽  
Ruggero Petacchi
Keyword(s):  
Scale Effect ◽  
Large Scale ◽  
Gall Midge ◽  
Natural Habitat ◽  
Central Italy ◽  
Shannon Index ◽  
Small Scale ◽  
Olive Leaf ◽  
Parasitism Rate ◽  
Natural Habitats

Abstract Dasineura oleae (Angelini, 1831) (Diptera: Cecidomyiidae), the olive leaf gall midge, is a pest of olive crops that has never been problematic in Italy since 2016, when a massive infestation of this pest was reported in a small region of Central Italy. We selected infested olive orchards through farmers’ reports aiming at quantifying the pest infestation level and the parasitism rate in each site. Also, we aimed at exploring the landscape effect in both pest and parasitoids, using proportion of olive crops and semi-natural habitats, as well as the Shannon index as a measurement of the landscape diversity, estimated at four different scales (250m, 500m, 750m and 1000m buffers around the sampling points). Results showed different landscape effect depending on the organism and on the scale. We underlined a small-scale effect on the parasitism rate and a large-scale effect on the olive leaf midge mediated by the Shannon Index. Moreover, some preliminary results showed that the parasitism rate was high in sites where plants associated with D. oleae parasitoids were present in the adjacent semi-natural habitat. Further study should deepen and validate our findings on the effect of landscape and of the vegetation on natural enemies of D.oleae. These results should stimulate new approaches in the studying of the olive gall leaf midge as well as new suppression strategies.

scholarly journals Following the pest outbreak: preliminary findings on the landscape effect on Dasineura oleae and its parasitoids in central Italy

2021 ◽  
Author(s):  
Malayka Samantha Picchi ◽  
Elena Tondini ◽  
Nicola Albertarelli ◽  
Gaia Monteforti ◽  
Ruggero Petacchi
Keyword(s):  
Scale Effect ◽  
Large Scale ◽  
Gall Midge ◽  
Natural Habitat ◽  
Central Italy ◽  
Small Region ◽  
Shannon Index ◽  
Small Scale ◽  
Parasitism Rate ◽  
Natural Habitats

AbstractDasineura oleae (Angelini, 1831) (Diptera: Cecidomyiidae), the olive leaf gall midge, is a pest of olive crops that was not problematic in Italy until 2016 when a massive infestation of this pest was reported in a small region in central Italy. We identified infested olive orchards using farmers’ reports and quantified the pest infestation level and parasitism rate in each field. We also explored the effect of the landscape on both the pest and parasitoids using the abundance of olive crops and semi-natural habitats and the Shannon index, estimated at four different scales (250 m, 500 m, 750 m and 1000 m buffers around the sampling points). The results showed a small-scale effect on the parasitism rate and a large-scale effect on leaf infestation mediated by the Shannon Index. Moreover, some preliminary results showed that the parasitism rate was high in sites where plants associated with D. oleae parasitoids were present in the adjacent semi-natural habitat. Further studies are needed to validate our findings on the effect of landscape and vegetation on the natural enemies of D. oleae in order to develop new suppression strategies.

Impact of crop cycle on movement patterns of pest rodent species between fields and houses in Africa

2011 ◽  
Vol 38 (7) ◽  
pp. 603 ◽  
Author(s):  
Ara Monadjem ◽  
Themb'a A. Mahlaba ◽  
Nomfundo Dlamini ◽  
Seth J. Eiseb ◽  
Steven R. Belmain ◽  
...  
Keyword(s):  
Rhodamine B ◽  
Crop Production ◽  
Radio Telemetry ◽  
Sub Saharan Africa ◽  
Rodent Species ◽  
Eastern Africa ◽  
Pest Species ◽  
Natural Habitats ◽  
Post Harvest ◽  
Field Rodents

Context Rodent pests can have severe impacts on crop production in sub-Saharan Africa. In particular, the multimammate mouse Mastomys natalensis severely damages agricultural crops in southern and eastern Africa, leading to significant losses. Both its population ecology and breeding biology have been studied in agricultural and natural habitats. Population numbers erupt depending on the timing and amount of rainfall and may reach plague proportions, especially in agricultural settings, where it may become a serious pest. However, the ecology of this species, in particular its interactions with other species within the context of human settlement, is poorly understood. It may occasionally enter houses, but the degree to which it does so and the factors influencing this movement are not known. Aims We investigated the relationship between Rattus spp. and M. natalensis entering buildings in an agro-ecological setting. We predicted that M. natalensis would enter houses more readily when food availability was lowest in the surrounding fields, and when the larger Rattus spp. were absent. Methods We followed 40 individuals of M. natalensis in Swaziland and Namibia by radio-telemetry. Mice were captured in maize fields within 50 m of a homestead and fitted with radio-transmitters at three different times corresponding to different stages of crop development: pre-harvest, post-harvest and pre-planting. To corroborate the findings of the telemetry study, a non-toxic marker, rhodamine B, was mixed with standard bait and left at bait stations inside houses in 10 homesteads in Swaziland and Tanzania. Key results Mice remained in the fields during the entire period of study in Swaziland, but entered buildings in Namibia during the post-harvest stage, which may represent a period of food shortage for these mice in the field. Rodents captured after baiting with rhodamine B demonstrated that Rattus spp. predominated within the houses. A small number of rhodamine B-marked M. natalensis were captured outside the houses, the proportion declining with distance away from the houses. Conclusions These results suggest that in a typical rural African setting dominated by subsistence agriculture, Rattus spp. (when present) competitively exclude the smaller M. natalensis from entering houses. Implications Interactions between rodent pest species may be important in determining which rodent species enter houses in rural African landscapes. Consideration of such interactions may play an important role when developing pest management strategies.

scholarly journals Precision Agriculture for Resource Use Efficiency in Smallholder Farming Systems in Sub-Saharan Africa: A Systematic Review

2021 ◽  
Vol 13 (3) ◽  
pp. 1158
Author(s):  
Cecilia M. Onyango ◽  
Justine M. Nyaga ◽  
Johanna Wetterlind ◽  
Mats Söderström ◽  
Kristin Piikki
Keyword(s):  
Resource Use ◽  
Precision Agriculture ◽  
Large Scale ◽  
English Language ◽  
Management Practices ◽  
Smallholder Farmers ◽  
Management Strategies ◽  
Sub Saharan Africa ◽  
Smallholder Farming ◽  
Sub Saharan

Opportunities exist for adoption of precision agriculture technologies in all parts of the world. The form of precision agriculture may vary from region to region depending on technologies available, knowledge levels and mindsets. The current review examined research articles in the English language on precision agriculture practices for increased productivity among smallholder farmers in Sub-Saharan Africa. A total of 7715 articles were retrieved and after screening 128 were reviewed. The results indicate that a number of precision agriculture technologies have been tested under SSA conditions and show promising results. The most promising precision agriculture technologies identified were the use of soil and plant sensors for nutrient and water management, as well as use of satellite imagery, GIS and crop-soil simulation models for site-specific management. These technologies have been shown to be crucial in attainment of appropriate management strategies in terms of efficiency and effectiveness of resource use in SSA. These technologies are important in supporting sustainable agricultural development. Most of these technologies are, however, at the experimental stage, with only South Africa having applied them mainly in large-scale commercial farms. It is concluded that increased precision in input and management practices among SSA smallholder farmers can significantly improve productivity even without extra use of inputs.

scholarly journals Environmental Engineering Techniques to Restore Degraded Posidonia oceanica Meadows

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 661
Author(s):  
Luigi Piazzi ◽  
Stefano Acunto ◽  
Francesca Frau ◽  
Fabrizio Atzori ◽  
Maria Francesca Cinti ◽  
...  
Keyword(s):  
Large Scale ◽  
Natural Habitat ◽  
Cost Benefit ◽  
Cost Effective ◽  
Posidonia Oceanica ◽  
Environmental Engineering ◽  
Bottom Surface ◽  
Sessile Invertebrates ◽  
Set Up ◽  
Short Time

Seagrass planting techniques have shown to be an effective tool for restoring degraded meadows and ecosystem function. In the Mediterranean Sea, most restoration efforts have been addressed to the endemic seagrass Posidonia oceanica, but cost-benefit analyses have shown unpromising results. This study aimed at evaluating the effectiveness of environmental engineering techniques generally employed in terrestrial systems to restore the P. oceanica meadows: two different restoration efforts were considered, either exploring non-degradable mats or, for the first time, degradable mats. Both of them provided encouraging results, as the loss of transplanting plots was null or very low and the survival of cuttings stabilized to about 50%. Data collected are to be considered positive as the survived cuttings are enough to allow the future spread of the patches. The utilized techniques provided a cost-effective restoration tool likely affordable for large-scale projects, as the methods allowed to set up a wide bottom surface to restore in a relatively short time without any particular expensive device. Moreover, the mats, comparing with other anchoring methods, enhanced the colonization of other organisms such as macroalgae and sessile invertebrates, contributing to generate a natural habitat.

scholarly journals Family graveyards form underappreciated local plant diversity hotspots in China's agricultural landscapes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cheng Gong ◽  
Liangtao Li ◽  
Jan C. Axmarcher ◽  
Zhenrong Yu ◽  
Yunhui Liu
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Natural Habitat ◽  
Plant Species Richness ◽  
Agricultural Landscapes ◽  
Natural Habitats ◽  
Landscape Features ◽  
Habitat Islands ◽  
Local Plant ◽  
Ecological Functioning

AbstractIn the intensively farmed, homogenous agricultural landscape of the North China Plain, family graveyards form distinct cultural landscape features. In addition to their cultural value, these graveyards represent semi-natural habitat islands whose potential roles in biodiversity conservation and ecological functioning has remained poorly understood. In this study, we investigated plant species richness on 199 family graveyards of different ages and sizes. In accordance with biogeography theory, both overall and insect-pollinated plant species richness increased with area and age of graveyards. Even small graveyards show a strong potential for conserving local plant richness, and a mosaic of both large and small family graveyards could play an important role in the conservation of farmland biodiversity and related ecosystem functions. The launch of agri-environmental measures that conserve and create semi-natural habitats, in turn benefitting agricultural biodiversity and ecological functioning, has proven difficult in China due to the shortage of dispensable arable land. Given the great value of family graveyards as semi-natural habitats reflected in our study, we propose to focus preliminary efforts on conserving these landscape features as existing, widespread and culturally important semi-natural habitat islands. This would represent an effective, complementary policy to a subsequent re-establishment of other semi-natural habitats for the conservation of biodiversity and ecological functioning in agricultural landscapes.

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