Gaisberger, H.

Loo, J.

CGSpace

The challengeCentral Asia is the centre of origin and diversity for many species of global importance, including fruit and nut trees. Wild populations of walnut, apple and apricot are under serious threat from global factors, e.g. climate change, and factors associated with rural poverty such as livestock grazing pressure. Projections to determine the combined effects of threats on species distribution are therefore indispensable for effective conservation planning.  Our solutionWe developed a spatial threat model for wild apple, apricot and walnut populations in Kyrgyzstan, Tajikistan and Uzbekistan by combining occurrence data, freely accessible datasets, species distribution models, climate models and expert knowledge. National research partners calibrated the distribution models and rated the threat impact of overexploitation and overgrazing in specific locations on a five-point scale. We used spatial proxy layers and extrapolated the expert threat ratings to the distribution areas. The resulting threat maps allow one to predict, at the population level, where multiple threats are likely to have the greatest impact on the availability of suitable habitat.  The multi-threat approach helps to determine the most relevant threats in specific areas. This information is crucial to guide specific conservation and management actions. ResultsSpatial analyses indicate high threat levels for all species across the three countries. Overgrazing emerged to be the most important threat for walnut and apple whereas apricot is Our spatial analysis framework aims to predict, at the population level, where multiple threats (overexploitation, overgrazing, landslides, fragmentation and predicted climate change), superimposed on patterns of genetic and nutritional diversity, are likely to have negative impact on important indigenous fruit and nut tree species.Fruit tree genetic diversity in Central Asia: A spatial threat analysisCover Photo: Wild walnut forest in Uzbekistan. Credit: Bioversity International/H.GaisbergerUZBEKISTAN REPUBLICAN RESEARCH AND PRODUCTION CENTER OF ORNAMENTAL GARDENING AND FORESTRY (UZB)Figure 1 – Study area with 21 sampled walnut populations. Within each population, 30 individual trees were sampled at regular intervals (50 m). Credit: Bioversity International/H.Gaisberger likely to be most affected by the impacts of climate change. Also apple seems sensitive to climate change, especially the populations in Tajikistan and in the south of Uzbekistan, whereas walnut results indicated a lower influence of warming temperatures in the near future. Overexploitation, which includes harvesting fruits, timber and fuelwood, is the second most important threat for walnut but is likely to be less important for apple and apricot. Fragmentation is an important threat for apricot as only small patches of wild populations are left, whereas walnut and apple populations are still relatively large. Landslides play a significant role only in a relatively small part of the distribution range. The threat patterns of the single threats across the three countries are not homogenous and therefore conservation strategies should be population- and threat-specific.Potential for impactThe results of the spatial threat analyses as well as the genetic and nutritional analysis will be published for each species separately in a peer-reviewed journal. The findings of the threat analysis have been shared with national research partners through presentations during several project meetings. The visual representation of threats and their predicted impact in maps with different threat levels, makes the results easily accessible and understandable to forest managers and policymakers in the three countries. The threat model can be applied anywhere as long as appropriate spatial data and knowledgeable experts are available.Figure 2 – Spatial threat analysis workflow. Credit: Bioversity International/H.GaisbergerBioversity International is a CGIAR Research Centre. CGIAR is a global research partnership for a food-secure future. www.cgiar.orgBioversity International is registered as a 501(c)(3) non-profit organization in the US. Bioversity International (UK) is a Registered UK Charity  No. 1131854. www.bioversityinternational.orgContacts:Bioversity InternationalVia dei Tre Denari, 472/a00054 Maccarese (Fiumicino), Italy Tel. (+39) 06 61181 bioversity@cgiar.orgFigure 3 – Predicted impact of overgrazing on wild apple populations. Credit: Bioversity International/H.GaisbergerFigure 4 – Predicted impact of climate change on wild apricot populations. Credit: Bioversity International/H.Gaisberger

Fruit tree genetic diversity in Central Asia: a spatial threat analysis

https://cgspace.cgiar.org/bitstream/handle/10568/88057/Spatial%20analysis_final.pdf?sequence=1&isAllowed=y

Fruit tree genetic diversity in Central Asia: a spatial threat analysis

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