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Connectivity of the Asiatic wild ass population in the Mongolian Gobi.

Kaczensky P, Kuehn R, Lhagvasuren B, Pietsch S, Yang W, Walzer C - Biol. Conserv. (2011)

Bottom Line: Population genetics results identified two subpopulations and delineated a genetic boundary between the Dzungarian and Transaltai Gobi for which the most likely explanation are the mountain ranges separating the two areas.Home ranges and locations of 19 radiomarked wild asses support the assumed restricting effects of more productive habitats and mountain ranges and additionally point towards a barrier effect of fences.In the southwest Gobi, allowing for openings in the border fence to China and managing the border area as an ecological corridor would connect three large protected areas together covering over 70,000 km(2) of wild ass habitat.

View Article: PubMed Central - PubMed

Affiliation: Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria.

ABSTRACT
Long-distance migrations of wildlife have been identified as important biological phenomena, but their conservation remains a major challenge. The Mongolian Gobi is one of the last refuges for the Asiatic wild ass (Equus hemionus) and other threatened migratory mammals. Using historic and current distribution ranges, population genetics, and telemetry data we assessed the connectivity of the wild ass population in the context of natural and anthropogenic landscape features and the existing network of protected areas. In the Mongolian Gobi mean biomass production is highly correlated with human and livestock density and seems to predict wild ass occurrence at the upper level. The current wild ass distribution range largely falls into areas below the 250 gC/m(2)/year productivity isoline, suggesting that under the present land use more productive areas have become unavailable for wild asses. Population genetics results identified two subpopulations and delineated a genetic boundary between the Dzungarian and Transaltai Gobi for which the most likely explanation are the mountain ranges separating the two areas. Home ranges and locations of 19 radiomarked wild asses support the assumed restricting effects of more productive habitats and mountain ranges and additionally point towards a barrier effect of fences. Furthermore, telemetry data shows that in the Dzungarian and Transaltai Gobi individual wild ass rarely ventured outside of the protected areas, whereas in the southeast Gobi asses only spend a small fraction of their time within the protected area network. Conserving the continuity of the wild ass population will need a landscape level approach, also including multi-use landscapes outside of protected areas, particularly in the southeast Gobi. In the southwest Gobi, allowing for openings in the border fence to China and managing the border area as an ecological corridor would connect three large protected areas together covering over 70,000 km(2) of wild ass habitat.

No MeSH data available.


Related in: MedlinePlus

Relationship between biomass production (expressed in grams of carbon per square meter and year (gC/m2/years)) and human population- and livestock density (expressed as sheep forage units (sfu*)) in the 24 Gobi districts (sums) of Mongolia. *1 sfu is the amount of dry forage needed to feed an average Mongolian sheep for 1 year, which is approximately 365 kg (Fernandez-Gimenez 1999). The equivalencies for the other species are: 1 camel = 5 sfu, 1 horse = 7 sfu, 1 cow/yak = 6 sfu, 1 goat = 0.9 sfu.
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f0010: Relationship between biomass production (expressed in grams of carbon per square meter and year (gC/m2/years)) and human population- and livestock density (expressed as sheep forage units (sfu*)) in the 24 Gobi districts (sums) of Mongolia. *1 sfu is the amount of dry forage needed to feed an average Mongolian sheep for 1 year, which is approximately 365 kg (Fernandez-Gimenez 1999). The equivalencies for the other species are: 1 camel = 5 sfu, 1 horse = 7 sfu, 1 cow/yak = 6 sfu, 1 goat = 0.9 sfu.

Mentions: We purchased livestock numbers for all 24 Gobi districts (sums) from the Statistical Office of Mongolia for the year 2004 for the eastern Gobi and for the year 2007 for the western Gobi. We additionally obtained a digital layer with all sum boundaries and human inhabitants dating from 2002 (see Supporting Data Appendix S2). However, the Gobi districts are rather large (range: 7106–27,784 km2) and often expand into more productive mountainous habitat, particularly in the west. In addition, Mongolia does not have a common database with exact locational data on herder camp distribution, movement paths, and associated herd sizes. Furthermore, in the highly variable non-equilibrium Gobi ecosystem pasture quality, and thus human and livestock presence, can vary tremendously on an inter- as well as an intra-annual basis. Nevertheless, on average human population- and livestock densities in the Gobi clearly increase with higher biomass production (Fig. 2). In order to have a measure independent of administrational units we thus chose to use mean biomass production as a proxy for human and livestock densities.


Connectivity of the Asiatic wild ass population in the Mongolian Gobi.

Kaczensky P, Kuehn R, Lhagvasuren B, Pietsch S, Yang W, Walzer C - Biol. Conserv. (2011)

Relationship between biomass production (expressed in grams of carbon per square meter and year (gC/m2/years)) and human population- and livestock density (expressed as sheep forage units (sfu*)) in the 24 Gobi districts (sums) of Mongolia. *1 sfu is the amount of dry forage needed to feed an average Mongolian sheep for 1 year, which is approximately 365 kg (Fernandez-Gimenez 1999). The equivalencies for the other species are: 1 camel = 5 sfu, 1 horse = 7 sfu, 1 cow/yak = 6 sfu, 1 goat = 0.9 sfu.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3040789&req=5

f0010: Relationship between biomass production (expressed in grams of carbon per square meter and year (gC/m2/years)) and human population- and livestock density (expressed as sheep forage units (sfu*)) in the 24 Gobi districts (sums) of Mongolia. *1 sfu is the amount of dry forage needed to feed an average Mongolian sheep for 1 year, which is approximately 365 kg (Fernandez-Gimenez 1999). The equivalencies for the other species are: 1 camel = 5 sfu, 1 horse = 7 sfu, 1 cow/yak = 6 sfu, 1 goat = 0.9 sfu.
Mentions: We purchased livestock numbers for all 24 Gobi districts (sums) from the Statistical Office of Mongolia for the year 2004 for the eastern Gobi and for the year 2007 for the western Gobi. We additionally obtained a digital layer with all sum boundaries and human inhabitants dating from 2002 (see Supporting Data Appendix S2). However, the Gobi districts are rather large (range: 7106–27,784 km2) and often expand into more productive mountainous habitat, particularly in the west. In addition, Mongolia does not have a common database with exact locational data on herder camp distribution, movement paths, and associated herd sizes. Furthermore, in the highly variable non-equilibrium Gobi ecosystem pasture quality, and thus human and livestock presence, can vary tremendously on an inter- as well as an intra-annual basis. Nevertheless, on average human population- and livestock densities in the Gobi clearly increase with higher biomass production (Fig. 2). In order to have a measure independent of administrational units we thus chose to use mean biomass production as a proxy for human and livestock densities.

Bottom Line: Population genetics results identified two subpopulations and delineated a genetic boundary between the Dzungarian and Transaltai Gobi for which the most likely explanation are the mountain ranges separating the two areas.Home ranges and locations of 19 radiomarked wild asses support the assumed restricting effects of more productive habitats and mountain ranges and additionally point towards a barrier effect of fences.In the southwest Gobi, allowing for openings in the border fence to China and managing the border area as an ecological corridor would connect three large protected areas together covering over 70,000 km(2) of wild ass habitat.

View Article: PubMed Central - PubMed

Affiliation: Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria.

ABSTRACT
Long-distance migrations of wildlife have been identified as important biological phenomena, but their conservation remains a major challenge. The Mongolian Gobi is one of the last refuges for the Asiatic wild ass (Equus hemionus) and other threatened migratory mammals. Using historic and current distribution ranges, population genetics, and telemetry data we assessed the connectivity of the wild ass population in the context of natural and anthropogenic landscape features and the existing network of protected areas. In the Mongolian Gobi mean biomass production is highly correlated with human and livestock density and seems to predict wild ass occurrence at the upper level. The current wild ass distribution range largely falls into areas below the 250 gC/m(2)/year productivity isoline, suggesting that under the present land use more productive areas have become unavailable for wild asses. Population genetics results identified two subpopulations and delineated a genetic boundary between the Dzungarian and Transaltai Gobi for which the most likely explanation are the mountain ranges separating the two areas. Home ranges and locations of 19 radiomarked wild asses support the assumed restricting effects of more productive habitats and mountain ranges and additionally point towards a barrier effect of fences. Furthermore, telemetry data shows that in the Dzungarian and Transaltai Gobi individual wild ass rarely ventured outside of the protected areas, whereas in the southeast Gobi asses only spend a small fraction of their time within the protected area network. Conserving the continuity of the wild ass population will need a landscape level approach, also including multi-use landscapes outside of protected areas, particularly in the southeast Gobi. In the southwest Gobi, allowing for openings in the border fence to China and managing the border area as an ecological corridor would connect three large protected areas together covering over 70,000 km(2) of wild ass habitat.

No MeSH data available.


Related in: MedlinePlus