Navigating the Biogeography of Short-forests in Global Drylands

The canopy height is pivotal in sustaining carbon cycling and upholding the ecological and biodiversity functions, which is also true or particularly the case for dryland ecosystems. Meanwhile, restorations in drylands have seen massive short-forests because of various reasons like insufficient water input. This study is committed to an exhaustive exploration of the biogeographic distribution and pivotal unknown determinants of short-forests in global drylands, offering indispensable insights for devising conservation strategies tailored to dryland forest vegetation. Here we divide satellite global dryland forests into the Tall-forests (17.30 ± 3.00 m) and the Short-forests (9.24 ± 2.57 m). The short-forests are ubiquitously distributed in global drylands, consist of 8.17% planted forests and 91.83% natural forests. These short-forests predominantly occur in ecosystems characterized by substantial climatic (temperature, precipitation) variations, impoverished soil textures, frequent human activities, and moderate to high elevations. Notably, within the short-forests, limitations on the canopy height of the natural forests appear to reach threshold values in specific factors earlier than in the planted forests such as Mean temperature of warmest quarter (11.73 ℃ vs. 12.64 ℃). Our discoveries explicate a nuanced comprehension of dryland short-forests, potentially serving as a crucial guide for informing future ecological restoration and sustainable management practices therein.