134 research outputs found
Scanning and data extraction from crop collecting mission documents
Poster presented at TDWG 2009, Montpellier (France). 9 - 13 Nov 2009
Spatially explicit threat assessment to target food tree species in Burkina Faso
There is a general agreement on the need to ensure the in situ conservation and availability of valuable genetic resources of wild species that are important for food security and nutrition. In order to be able to adopt adequate conservation measures a spatial assessment
of their distribution and a sound analysis of the causes of and their sensitivity to threats
is required.
The ADA funded project “Threats to priority food tree species in Burkina Faso: Drivers
of resource losses and mitigation measures” gave us the opportunity to develop a spati-
ally explicit threat assessment methodology with focus on expert feedback, as there is no
comprehensive and standardised approach available at the moment. Relevant threats were
identified jointly with regional project partners from INERA and CNSF during meetings
in Ouagadougou in 2012 and 2013 and by means of a case study on farmers’ perception.
Once determined were the most important ones (overexploitation, overgrazing, fire, climate
change, cotton production and mining) we identified openly accessible datasets suitable to
represent the spatial patterns of threat intensities throughout the country. Now we needed
to transform the threat intensities into potential impact over the target species distribution
ranges.
To do so the distribution and threat sensitivity of 16 food tree species were assessed by 17
local and international experts by means of an online feedback survey that was specifically
developed for this project. These experts were asked to rate on a five point scale different
distribution models and the sensitivity to threats. The survey was analysed applying a
consensus method to identify the most consistent distribution model and threat specific
sensitivity rating on a species by species basis. The potential impact of climate change was
modeled using Global Circulation Models (GCM’s) deriving from the fifth assessment of
the Intergovernmental Panel on Climate Change (IPCC5) in 2014.
The results were then used to calculate and create individual and combined threat
potential maps that enable the identification of areas in Burkina Faso where species are
highly threatened. The spatial patterns of the threat levels provides evidence to prioritise
food tree populations with relative urgency for undertaking conservation actions
Conservation priorities for Prunus africana defined with the aid of spatial analysis of genetic data and climatic variables
Conservation priorities for Prunus africana, a tree species found across Afromontane regions, which is of great commercial interest internationally and of local value for rural communities, were defined with the aid of spatial analyses applied to a set of georeferenced molecular marker data (chloroplast and nuclear microsatellites) from 32 populations in 9 African countries. Two approaches for the selection of priority populations for conservation were used differing in the way they optimize representation of intra-specific diversity of P. africana across a minimum number of populations. The first method (Si) was aimed at maximizing genetic diversity of the conservation units and their distinctiveness with regard to climatic conditions, the second method (S2) at optimizing representativeness of the genetic diversity found throughout the species' range. Populations in East African countries (especially Kenya and Tanzania) were found to be of great conservation value, as suggested by previous findings. These populations are complemented by those in Madagascar and Cameroon. The combination of the two methods for prioritization led to the identification of a set of 6 priority populations. The potential distribution of P. africana was then modeled based on a dataset of 1,500 georeferenced observations. This enabled an assessment of whether the priority populations identified are exposed to threats from agricultural expansion and climate change, and whether they are located within the boundaries of protected areas. The range of the species has been affected by past climate change and the modeled distribution of P. africana indicates that the species is likely to be negatively affected in future, with an expected decrease in distribution by 2050. Based on these insights, further research at the regional and national scale is recommended, in order to strengthen P. africana conservation efforts
Genetic diversity of Parkia biglobosa (African locust bean) and its implications for conservation strategies
Parkia biglobosa is an African Savannah tree with a wide range from Senegal to Uganda between the latitudes 5 and 15° in the North of equator. It is well-known as an agroforestry tree but also as a medicinal and food tree. Seeds, barks, roots, leaves and flowers are used to treat more than 80 diseases and complaints while fermented seeds and pulp of fruits have highly nutritional and commercial values.
Understanding the level and distribution of genetic diversity of a widespread species such P. biglobosa is crucial for its conservation and sustainable utilisation. The genetic diversity and population structure were investigated using height nuclear microsatellites developed for the species. The sampling included 84 populations from twelve countries in West and Central Africa. The height microsatellite loci were highly polymorphic and did not show evidence of null alleles. A total of 217 alleles were revealed among the 1,610 genotypes of P. biglobosa. The number of alleles per locus was ranged from 17 to 50 with an average of 27 alleles per locus. The estimates of genetic diversity were moderate for the populations of extreme West Africa and Central Africa and were high to populations in the centre of West Africa. Individual-based assignment using admixture model with correlated allele frequencies revealed strong genetically structured populations across P. biglobosa range in West and Central Africa. The clustering analysis showed five most plausible subpopulations for the biogeographic study in West and Central Africa. Analysis of molecular variance partitioned the molecular variation 9.10% among groups, 2.71% among populations within groups and 88.19% within populations. Overall, the genetic differentiation among populations was moderate (FST=0.118; P<0.001). In regard to the distribution of intraspecific diversity, we also discussed the implications for conservation and sustainable use of the species
Identifying tree populations for conservation action through geospatial analyses
Rapid development of information and communication technologies has made it possible to easily collect georeferenced information on species and their environment, and to use it for analyzing biological diversity, its distribution and threats to it. Such analyses can importantly inform development of conservation strategies and priorities, especially across countries or species distribution ranges (Guarino et al. 2002). Data for spatial analyses on species or genetic diversity and its distribution are collected in specifically designed studies, obtained from existing records of species occurrence, or both. Observations may be complemented by species distribution modelling, where the potential occurrence of a species is predicted based on its documented geographic distribution and climate in those areas. Results on the distribution of diversity, documented or modelled, can then be compared, for example, with existing protected areas, rates of forest degradation, threats of environmental changes, or socio-economic indicators, to identify priority tree populations and tailor strategies for their conservation and sustainable use (Pautasso 2009). In this paper recent case studies on spatial biodiversity analyses across the tropics are presented, demonstrating how such analyses can help to identify most unique or most threatened populations of a tree species for conservation actions. Insights on initiating collaborative research on diversity and distributions of important Asian tree species are also discussed
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