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- Kitamura, Keiko, et al.
(författare)
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Decline in gene diversity and strong genetic drift in the northward-expanding marginal populations of Fagus crenata
- 2015
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Ingår i: Tree Genetics & Genomes. - : Springer Science and Business Media LLC. - 1614-2942 .- 1614-2950. ; 11:3
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Tidskriftsartikel (refereegranskat)abstract
- The species distribution of Fagus crenata, or Japanese beech, in the Japanese archipelago shifted northward during phytogeographical changes that occurred during the Pleistocene and Holocene epochs. Presently, the continuous natural distribution of beech reaches north to the Kuromatsunai-Depression of Hokkaido Island, Japan. In addition, dozens of marginal patches and isolated individuals north of the continuous distribution have been observed. F. crenata grows remarkably well among these small-scattered northern marginal populations, which must have originated from seeds dispersed beyond the northern limit of the continuous beech forest. It is conceivable that the distribution of F. crenata is still in the process of expanding northward. We investigated the genetic structure of 33 beech populations to evaluate the population gene diversity at the leading northern edge of the range expansion. We analyzed 12 nuclear microsatellite loci in each of the 1,693 individuals. Genetic diversity parameters such as expected heterozygosity and allelic richness were clearly lower in the northernmost populations. We found genetic differentiation in the northernmost distribution range (F-ST=0.045, G(ST)'=0.242). STRU CTURE analysis revealed that the southwestern continuous populations consisted of homogeneous ancestral clusters. However, northeastern marginal populations consisted of mixtures of highly differentiated clusters with higher levels of genetic drift than found in the continuous populations.
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| 2. |
- Leclere, David, et al.
(författare)
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Bending the curve of terrestrial biodiversity needs an integrated strategy
- 2020
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 585:7826, s. 551-556
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Tidskriftsartikel (refereegranskat)abstract
- Increased efforts are required to prevent further losses to terrestrial biodiversity and the ecosystem services that it provides(1,2). Ambitious targets have been proposed, such as reversing the declining trends in biodiversity(3); however, just feeding the growing human population will make this a challenge(4). Here we use an ensemble of land-use and biodiversity models to assess whether-and how-humanity can reverse the declines in terrestrial biodiversity caused by habitat conversion, which is a major threat to biodiversity(5). We show that immediate efforts, consistent with the broader sustainability agenda but of unprecedented ambition and coordination, could enable the provision of food for the growing human population while reversing the global terrestrial biodiversity trends caused by habitat conversion. If we decide to increase the extent of land under conservation management, restore degraded land and generalize landscape-level conservation planning, biodiversity trends from habitat conversion could become positive by the mid-twenty-first century on average across models (confidence interval, 2042-2061), but this was not the case for all models. Food prices could increase and, on average across models, almost half (confidence interval, 34-50%) of the future biodiversity losses could not be avoided. However, additionally tackling the drivers of land-use change could avoid conflict with affordable food provision and reduces the environmental effects of the food-provision system. Through further sustainable intensification and trade, reduced food waste and more plant-based human diets, more than two thirds of future biodiversity losses are avoided and the biodiversity trends from habitat conversion are reversed by 2050 for almost all of the models. Although limiting further loss will remain challenging in several biodiversity-rich regions, and other threats-such as climate change-must be addressed to truly reverse the declines in biodiversity, our results show that ambitious conservation efforts and food system transformation are central to an effective post-2020 biodiversity strategy. To promote the recovery of the currently declining global trends in terrestrial biodiversity, increases in both the extent of land under conservation management and the sustainability of the global food system from farm to fork are required.
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