How much of the world is woody?

1.The question posed by the title of this paper is a basic one, and it is surprising that the answer is not known. Recently assembled trait datasets provide an opportunity to address this, but scaling these datasets to the global scale is challenging because of sampling bias. Although we currently know the growth form of tens of thousands of species, these data are not a random sample of global diversity; some clades are exhaustively characterised, while others we know little–to–nothing about. 2.Starting with a database of woodiness for 39,313 species of vascular plants (12% of taxonomically resolved species, 59% of which were woody), we estimated the status of the remaining taxonomically resolved species by randomisation. To compare the results of our method to conventional wisdom, we informally surveyed a broad community of biologists. No consensus answer to the question existed, with estimates ranging from 1% to 90% (mean: 31.7%). 3.After accounting for sampling bias, we estimated th...