Dataset Information

Seed germination schedule and environmental context shaped the population genetic structure of subtropical evergreen oaks on the Yun-Gui Plateau, Southwest China.

ABSTRACT: The evergreen broadleaved forests (EBLFs) of Southwest China have a long-term stable environment and support a diverse flora, thus forming a global biodiversity hotspot. However, the key drivers that have shaped the genetic diversity patterns of species in these EBLFs are not well understood. Quercus delavayi, Q. schottkyana, and Q. kerrii are sympatric oak species with different seed biological traits that are typical for these EBLFs. This study combined multilocus phylogeography and ecological niche modeling to screen 33 Q. delavayi populations. Their population genetic structure was inferred in comparison with previous studies on Q. schottkyana and Q. kerrii. The seed germination traits of all three species were also investigated. cpDNAs showed a significant phylogeographic structure in Q. delavayi, which was not detected in Q. schottkyana or Q. kerrii. Quercus delavayi, Q. kerrii, and Q. schottkyana exhibited different pollen-to-seed migration ratios (r?=?219, 117, and 22, respectively), which are linked to the germination schedules of acorns. The distributions of Q. delavayi and Q. schottkyana remained long-term stable since the last glacial maximum (LGM) with a similar nSSR genetic gradient change along latitude. Instead, Q. kerrii experienced a prominent range expansion since the LGM with genetic diversification between the East and the West of the Tanaka line due to environmental heterogeneity. These results identify seed traits and environmental heterogeneity as two key drivers that shape the population genetic structure of EBLF trees in Southwest China. These should be considered in regional forestry conservation and management.

SUBMITTER: Xu J

PROVIDER: S-EPMC7028733 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Seed germination schedule and environmental context shaped the population genetic structure of subtropical evergreen oaks on the Yun-Gui Plateau, Southwest China.

Xu Jin J Song Yi-Gang YG Deng Min M Jiang Xiao-Long XL Zheng Si-Si SS Li Ying Y

Heredity 20191126 3

The evergreen broadleaved forests (EBLFs) of Southwest China have a long-term stable environment and support a diverse flora, thus forming a global biodiversity hotspot. However, the key drivers that have shaped the genetic diversity patterns of species in these EBLFs are not well understood. Quercus delavayi, Q. schottkyana, and Q. kerrii are sympatric oak species with different seed biological traits that are typical for these EBLFs. This study combined multilocus phylogeography and ecological ...[more]

PMID: 31772317

Similar Datasets

Project description:The transition from tropical to subtropical (warm temperate) evergreen forests is more clearly apparent in East Asia, from Nepal to the western Pacific coast, than elsewhere in the tropics. We review the nature of this transition and hypothesize the physical, ultimately climatic, factors that may maintain it, with a special focus on how the increasing instability and warming of climates will affect these forests. A primary climatic mediator of the transition is proposed, thereby offering a testable hypothesis for the climate-forest transition relationship. What is known of this transition is summarized in context of the primary climatic mediators of elevational zonation of forest formations in equatorial Asia to the tree line, in the Himalaya at the India-Indo-Burma northern tropical margin, and as both elevational and latitudinal zonation in southern China. Consequent secondary edaphic and other physical changes are described for the Himalaya, and hypothesized for southern China. The forest ecotones are seen to be primarily defined by tree floristic change, on which account changes in structure and physiognomy are determined. The montane tropical-subtropical transition in the Himalaya is narrow and observed to correlate with an as yet ill-defined frost line. A distinct tropical-subtropical transition forest is recognized in the southwest China mountains. There is a total change in canopy species at the Himalayan ecotone, but subcanopy tropical species persist along an elevational decline of c. 400 m. The latitudinal transition in South China is analogous, but here the tropical subcanopy component extends north over ten degrees latitude, albeit in decline. The tropical-subtropical transition is uniquely clear in East Asia because here alone a tropical wet summer-dry winter monsoon extends to 35° north latitude, encompassing the subtropical evergreen forest, whereas subtropical evergreen forests elsewhere exist under drier temperate summer climate regimes.

Project description:Quercus spp. (oaks) are generally intermediate in shade tolerance, yet there is large variation within the genus in shade tolerance and plasticity in response to varying resource availability. Ecophysiological knowledge specific to semi-evergreen Quercus spp. from subtropical maritime forests is lacking relative to temperate deciduous oaks. We studied the influence of light availability and plant competition on leaf physiology and performance of semi-evergreen Quercus virginiana on a barrier island along the US southern Atlantic coast. Seedlings were underplanted in pine (Pinus taeda) plantation stands with varying overstory density (clear-cut, heavy thin, light thin, and non-thinned; creating a gradient of understory light availability) and vegetation (no competition removal or herbaceous competition removal) treatments. After 2 years, seedling survival was higher with increasing light availability (clear-cut = heavy thin > light thin > non-thinned). Seedling growth (i.e., diameter, height, and crown width) increased similarly with increasing thinning intensity, while vegetation control was mainly beneficial to seedling growth in clear-cuts. These responses were partially explained by foliar nitrogen and leaf trait measurements, which followed the same pattern. Q. virginiana seedlings demonstrated high plasticity in their ability to acclimate to varying resource availability, as indicated by light response curves, specific leaf area, stomatal density, stomatal pore index, and maximum theoretical stomatal conductance. Light compensation and saturation points illustrated seedling capacity to increase net CO2 assimilation with increased light availability. Leaves on trees in the high light environment had the highest net CO2 assimilation, stomatal density, stomatal pore index, maximum theoretical stomatal conductance, and lowest specific leaf area. Although we demonstrated the relative shade tolerance of Q. virginiana in lower light environments (i.e., heavy and light thin plots), this semi-evergreen species shows high plasticity in capacity to respond to varying resource availability, similar to other Quercus spp. from mesic and Mediterranean environments.

Dataset Information

Seed germination schedule and environmental context shaped the population genetic structure of subtropical evergreen oaks on the Yun-Gui Plateau, Southwest China.

Publications

Seed germination schedule and environmental context shaped the population genetic structure of subtropical evergreen oaks on the Yun-Gui Plateau, Southwest China.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets