Analysis of genetic diversity and prediction of Larix species distribution in the Qinghai–Tibet Plateau, China

Larix resources in the Qinghai-Tibet Plateau have important ecological and economic values. However, the lack of genetic diversity background and related research hinders the development of conservation strategies. In this study, genetic diversity and distribution of five Larix species were investigated. Using 19 polymorphic microsatellite markers to study 272 representative individuals from 13 populations, the results show low genetic diversity at the population level, with variation explained mainly by differentiation among populations. The Larix populations were classified into two clades, one formed by eight populations, including three of the species in this study, L. kongboensis , L. speciosa , and L. potaninii var. australis . The other clade consists of five populations, including the other two species in this study, L. griffithii and L. himalaica . Genetic distance of the species was affected by geographical isolation and genetic diversity was mainly affected by altitude. The area suitable for Larix spp. decreased during the Last Glacial Maximum compared to the current distribution according to the niche model, but should increase in future climate scenarios (2050s), expanding westward along the Himalayas. These results provide an important scientific basis for the development of conservation strategies and further the sustainable utilization of Larix resources in the Qinghai-Tibet Plateau.