Format: ORAL

Buntarou Kusumoto1, Takayuki Shiono2, Yasuhiro Kubota2

1 Faculty of Agriculture, Kyushu University, Japan 2 Faculty of Science, University of the Ryukyus

The East Asia-Southeast Asia-Australasian region constitutes a continuum of plant diversity hotspots across a broad latitudinal gradient, contributing significantly to global plant diversity. The higher latitudes in the region, including East Asia and Australia, are the richest source of botanical information (i.e. plant species occurrence records) in the world, while the lower latitudes present a global cold spot in such records. This spatial inequality of sample completeness has made it difficult to scrutinize the geographical patterns of plant diversity across the whole latitudinal zone of the region. Recent study reported bias-corrected diversity patterns of global woody plants, and reported a skewed latitudinal gradient in species diversity, peaking in the mid-latitudes of the Northern Hemisphere (southern China). A latitudinal diversity gradient is one of the best-recognized macroecological patterns, and its underlying mechanisms are considered to be due to energy/climatic gradients, and/or tropical niche conservatism, but no consensus has yet been reached. A thorough exploration of the drivers of the skewed latitudinal diversity patterns of woody plants in the region would provide further insight into the geographic, ecological, and evolutionary forces shaping biodiversity. In this presentation, I will introduce the results of the examination of the contribution of plant taxonomic components to the biased latitudinal diversity gradient. Then, I aim to identify taxonomic levels, groups, and areas to focus on and in the future and organize hypotheses to be tested in order to elucidate the mechanism of biased latitudinal diversity pattern.