Elevation Shift in Abies Mill. (Pinaceae) of Subtropical and Temperate China and Vietnam—Corroborative Evidence from Cytoplasmic DNA and Ecological Niche Modeling

Abstract

The “elevational shift” scenario has been proposed as a model to explain the response of cold-adapted organisms to Quaternary climatic fluctuations in Europe and North America. However, the elevational shift model has not been well-explored in eastern Asia, which is more topographically complex than the other Northern Hemisphere biogeographic regions. Here, we evaluated the role of elevational shift in the closely related firs, or Abies Mill., of subtropical and temperate China. These firs are typical alpine trees with sensitivity to climate change. We tested the elevational shift hypothesis in firs of China using phylogeographic methods and ecological niche models. Our phylogeographic analyses comprised mitochondrial and chloroplast polymorphisms surveyed across 479 individuals from 43 populations representing 11 species. M1 of the 11 mitotypes and C1 of the 25 chlorotypes were inferred as the ancestral haplotype, and they had the widest distribution. The results of our phylogeographic survey revealed multiple centers of genetic diversity in distinct geographic regions and no latitudinal trend. Moreover, our results showed range expansions for seven taxa during the last glacial (64.9–18.2 or 32.5–9.1 kya), and this was consistent with the Quaternary fossil record of Abies in China. Taken together, our findings support a historical biogeographic pattern in firs of glacial expansions, probably through corridors at lower elevation, and interglacial fragmentations, through isolation at higher elevation peaks. Therefore, Abies in China probably undergoes elevational shift in response to climate change. Facing the forecasting global warming, the risk of several critically endangered firs was further enhanced as these species would have little escape space in situ to higher altitudes. According to our ENMs, we proposed an ex situ conservation strategy in the southern Hengduan Mountains region of south western China.

Climate change jointly with migration ability affect future range shifts of dominant fir species in Southwest China

“…Compared with other full‐migration projections, our optimistic forecast for A. recurvata was not consistent with the overall declining trend of the genus Abies as highlighted by Liu et al () and Shao et al (). Benefiting from future climate change, a large number of currently unoccupied areas in southern and western Sichuan will be potentially suitable for A. recurvata (Figure a).…”

“…Full migration trend of the genus Abies as highlighted by Liu et al (2018) andShao et al (2017). Benefiting from future climate change, a large number of currently unoccupied areas in southern and western Sichuan will be potentially suitable for A. recurvata (Figure 4a).…”

New infrageneric classification of Abies in light of molecular phylogeny and high diversity in western North America

“…While the taxonomic limits of the Abies genus are well known at the species‐ and infraspecific‐levels (Aguirre‐Planter et al, ; Vázquez‐García et al, ; Wang et al, ; Cinget et al, ; Shao et al, , ), its infrageneric classification remains unsettled (Liu, ; Farjon & Rushforth, ; Eckenwalder, ; Farjon, ). Most prior infrageneric classifications of Abies have either been restricted to particular geographic areas, such as North America, Japan, east Asia (e.g., Engelmann, ; Mayr, ; Patschke, ), or were based on a small number of morphological characters (e.g., Hickel, ‐08; Patschke, ; Landry, ).…”

Concealed truth: Modeling reveals unique Quaternary distribution dynamics and refugia of four related endemic keystone Abies taxa on the Tibetan Plateau

“…forrestii ) is considered as near‐threatened (Zhang, Katsuki, & Rushforth, ). Studies have suggested the taxonomic boundaries are well‐established at the species and intraspecific levels of the Abies genus (e.g., Aguirre‐Planter et al, ; Cinget, Lafontaine, Gérardi, & Bousquet, ; Shao & Xiang, ; Shao et al, ; Wang, Abbott, Ingvarsson, & Liu, ); however, their intrageneric classification is an active area of research (Eckenwalder, ; Farjon, ). These four taxa selected for study vary in their morphological traits and have dissimilar environmental requirements, according to information from other studies (e.g., China Forest Editorial Board, ; Guan & Zhou, ; Shao et al, ).…”

“…Knowledge of Quaternary refuge distributions of species long ago (Cao et al, ), as well as remaining refuge distributions under current climate change conditions (Tinner & Valsecchi, ), can inform the future protection of Abies trees against climate change. Several studies have addressed the biogeographic history of Abies species in the TP (e.g., Peng et al, ; Shao, Zhang, Phan, & Xiang, ; Xiang et al, ), but a thorough understanding of it still eludes us. This may be due, in part, to the lack of using integrative approaches that incorporate both palynological and phylogeographical data.…”