101 research outputs found

    A Toolkit for Resilience Evaluation of Land Use Alternatives in a Multifunctional Peri-Urban Landscape

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    Translating the concept of social-ecological resilience to practical applications in spatial planning remains challenging. The aim of this paper is to contribute to the scientific approach of spatial aspects of social-ecological resilience and adaptive capacity related to bioproductive space, with particular attention to food systems. We define ‘bioproductive space’ as all space providing ecosystem services through primary production processes and includes semi-natural as well as agricultural ecosystems. We argue that bioproductive space is resilient if it continues in delivering similar levels of ecosystem services under changing conditions. A toolkit was developed to explore spatial resilience of bioproductive space. The first stage in the toolkit is a spatially explicit evaluation of various ecosystem services for different land uses. In a second stage, bio-physical and socio-economic drivers or shocks are introduced that can influence the value society attributes to specific ecosystem services. Some of these variations are mostly society driven, e.g. changing bioenergy demand or more restrictive air quality targets. Others are rather driven by biophysical factors, like increasing need for buffering of extreme weather events under the impulse of global change. The third stage of the toolkit takes policy priorities into account. In a final stage, the output of the tool is synthesised by ranking the analysis results for different scnearios and policy priority settings. This toolkit allows spatial planners to explore and evaluate policy decisions against trade-offs between various land use alternatives, while taking ecosystem services into account. The toolkit is applied to a case study to demonstrate its use. Besides the potential for supporting policy makers, the toolkit provides useful feedback for adaptive farm and landscape management

    Revisiting Production and Ecosystem Services on the Farm Scale for Evaluating Land Use Alternatives

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    Land is a scarce resource and should be used in such a way that the increasing global demand for food and feed can be fulfilled, while ensuring sufficient levels of ecosystem services. While the demand on open space to deliver a multitude of services is increasing, drivers like global change and urbanization are undermining these services. Decision makers, from individual farmers to spatial planners, are in need of appropriate diagnostic tools to estimate trade-offs and synergies associated with land allocation and land use intensity decisions. This often implies trade-offs between food and biomass production and other non-provisioning ecosystem services. This paper presents an assessment on the farm scale using an integrated approach that combines spatial and economic analyses. It relies on the ecosystem services concept to evaluate land use alternatives. The analysis highlights current challenges to reach a societal optimal land allocation

    Potential tree species extinction, colonization and recruitment in Afromontane forest relicts

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    Tree species regeneration determines future forest structure and composition, but is often severely hampered in small forest relicts. To study succession, long-term field observations or simulation models are used but data, knowledge or resources to run such models are often scarce in tropical areas. We propose and implement a species accounting equation, which includes the co-occurring events extinction, colonization and recruitment and which can be solved by using data from a single inventory. We solved this species accounting equation for the 12 remaining Afromontane cloud forest relicts in Taita Hills, Kenya by comparing the tree species present among the seedling, sapling and mature tree layer in 82 plots. A simultaneous ordination of the seedling, sapling and mature tree layer data revealed that potential species extinctions, colonizations and recruitments may induce future species shifts. On landscape level, the potential extinction debt amounted to 9% (7 species) of the regional species pool. On forest relict level, the smallest relicts harbored an important proportion of the tree species diversity in the regeneration layer. The average potential recruitment credit, defined as species only present as seedling or sapling, was 3 and 6 species for large and small forest relicts, while the average potential extinction debt was 12 and 4 species, respectively. In total, both large and small relicts are expected to lose approximately 20% of their current local tree species pool. The species accounting equations provide a time and resource effective tool and give an improved understanding of the conservation status and possible future succession dynamics of forest relicts, which can be particularly useful in a context of participatory monitoring

    Influence of human activity patterns on epidemiology of plague in Western Usambara Mountains, Tanzania

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    Human plague has been a recurring public health threat in some villages in the Western Usambara Mountains, Tanzania, in the period between 1980 and 2004. Despite intensive past biological and medical research, the reasons for the plague outbreaks in the same set of villages remain unknown. Plague research needs to broaden its scope and formulate new hypotheses. This study was carried out to establish relationships between the nature and the spatial extent of selected human activities on one hand, and the reported plague cases on the other hand. Three outdoor activities namely, fetching water, collecting firewood and going to the market, were selected. Through enquiries the activity patterns related to these activities were mapped in 14 villages. Standard deviation ellipses represent the extent of action spaces. Over 130 activity types were identified and listed. Of these, fetching water, collecting firewood and going to the market were used for further analysis. The results indicate a significant correlation between the plague frequency and the size of these action spaces. Different characteristics of land use and related human activities were correlated with the plague frequency at village and hamlet levels. Significant relationships were found between plague frequency and specific sources of firewood and water, and specific market places

    Woody plant communities of isolated Afromontane cloud forests in Taita Hills, Kenya

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    In the Taita Hills in southern Kenya, remnants of the original Afromontane forest vegetation are restricted to isolated mountain peaks. To assess the level of degradation and the need for forest restoration, we examined how forest plant communities and their indicator species vary between and within remnant patches of cloud forest. We used ordinal abundance data to compare plant communities in eight forest fragments. We also analyzed data on the diversity and abundance of trees in 57 0.1 ha plots to compare tree communities within and between the largest two of these fragments, Ngangao (120 ha) and Mbololo (220 ha). The extant vegetation of the Taita Hills at landscape scale consists of secondary moist montane to intermediate montane forest. There was a high species dissimilarity between fragments (69%). Variation in species composition coincided with an abiotic gradient related to elevation. At plot level, secondary successional species and species of forest edges were most abundant and most frequent. Inferred clusters of plots almost entirely coincided with the two forest fragments. Indicator species associated with forest margins and gaps were more frequent in the smaller of the two forest fragments, while indicators for the larger fragment were more typical for less disturbed moist forest. Abiotic site variability but also different levels of disturbance determine site-specific variants of the montane forest. Conservation efforts should not only focus on maintaining forest quantity (size), but also on forest quality (species composition). Late-successional rainforest species are underrepresented in the woody plant communities of the Taita Hills and assisting restoration of viable populations of cloud forest climax tree species is urgently needed

    Open space cut into pieces: measuring fragmentation of open space in Flanders

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    Geographic distribution and ecological niche of plague in sub-Saharan Africa

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    <p>Abstract</p> <p>Background</p> <p>Plague is a rapidly progressing, serious illness in humans that is likely to be fatal if not treated. It remains a public health threat, especially in sub-Saharan Africa. In spite of plague's highly focal nature, a thorough ecological understanding of the general distribution pattern of plague across sub-Saharan Africa has not been established to date. In this study, we used human plague data from sub-Saharan Africa for 1970–2007 in an ecological niche modeling framework to explore the potential geographic distribution of plague and its ecological requirements across Africa.</p> <p>Results</p> <p>We predict a broad potential distributional area of plague occurrences across sub-Saharan Africa. General tests of model's transferability suggest that our model can anticipate the potential distribution of plague occurrences in Madagascar and northern Africa. However, generality and predictive ability tests using regional subsets of occurrence points demonstrate the models to be unable to predict independent occurrence points outside the training region accurately. Visualizations show plague to occur in diverse landscapes under wide ranges of environmental conditions.</p> <p>Conclusion</p> <p>We conclude that the typical focality of plague, observed in sub-Saharan Africa, is not related to fragmented and insular environmental conditions manifested at a coarse continental scale. However, our approach provides a foundation for testing hypotheses concerning focal distribution areas of plague and their links with historical and environmental factors.</p

    Land use determinants of small mammals abundance and distribution in a plague endemic area of Lushoto District, Tanzania

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    Small mammals are considered to be involved in the transmission cycle of bubonic plague, still occurring in different parts of the world, including the Lushoto district in Tanzania. The objective of this study was to determine the relationship between land use types and practices and small mammal abundance and distribution. A field survey was used to collect data in three landscapes differing in plague incidences. Data collection was done both in the wet season (April-June 2012) and dry season (August-October 2012). Analysis of variance and Boosted Regression Trees (BRT) modelling technique were used to establish the relationship between land use and small mammal abundance and distribution. Significant variations (p ≤ 0.05) of small mammal abundance among land use types were identified. Plantation forest with farming, natural forest and fallow had higher populations of small mammals than the other aggregated land use types. The influence of individual land use types on small mammal abundance level showed that, in both dry and wet seasons, miraba and fallow tended to favour small mammals’ habitation whereas land tillage practices had the opposite effect. In addition, during the wet season crop types such as potato and maize appeared to positively influence the distribution and abundance of small mammals which was attributed to both shelter and food availability. Based on the findings from this study it is recommended that future efforts to predict and map spatial and temporal human plague infection risk at fine scale should consider the role played by land use and associated human activities on small mammal abundance and distribution
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