Reconstructing a plant biodiversity tree

In the face of modern climate change, conservation depends on an understanding of what influences regional and global plant diversity. The plant biodiversity observed today is at least partially due to prehistoric climate patterns that influenced evolutionary history. And yet, questions remain regarding the large-scale biodiversity ramifications of ongoing climate shifts.

EU-funded researchers recognised that molecular and taxonomic relationships (phylogenies), compared with contemporary species distributions, could answer some questions. Working on the project 'Plant biodiversity of China in a changing world: Evolution and conservation' (PDIVCHINA), researchers focused on massive datasets for the Quercus and Rhododendron genera.

PDIVCHINA's results suggest prehistoric factors affected modern Quercus and Rhododendron distribution. In particular, where species' ranges decreased, evidence of prehistoric influence increased. Similarly, the high diversity of Rhododendron species can be attributed in part to serious climate shifts in the late Eocene and early Oligocene.

Additionally, PDIVCHINA developed extensive phylogenies for woody plant families, along with genus-level phylogenies of 70 families. In analysing these evolutionary relationships, PDIVCHINA found explicit results. South-eastern China hosts the oldest species; moving northward, there is a trend towards younger species.

PDIVCHINA also mapped the species distribution of 7 680 woody plants. With these maps in hand, researchers investigated how plants would respond to four distinct climate change scenarios. Intensive heterogeneity is most likely, and the Tibetan Plateau is likely to experience an advent of woody species, while southern China would lose these. Interestingly, PDIVCHINA predicted that phylogenetic diversity could be conserved at the family level, but species-level loses are to be expected.

Addressing contemporary conservation challenges, the researchers mapped China's biodiversity hotspots. They also assessed the relative phylogenetic diversity of China's endangered woody plants. PDIVCHINA then evaluated the socioeconomic and ecosystem services associated with woody plants within and outside the nation's natural reserves. The research team concluded that forest conservation is linked to rural poverty, and must therefore be included in rural development strategies.

PDIVCHINA has provided the world a refined picture of how climate shifts may affect plant biodiversity and the behaviour of humans who live near endangered plant species. Such comprehensive awareness is essential for scientists and policymakers tasked with conserving China's natural heritage.