Global patterns of tree density are contingent upon local determinants in the world’s natural forests
Jaime Madrigal‐González, Joaquín Calatayud, Juan Antonio Ballesteros‐Cánovas, Adrián Escudero, Luis Cayuela, Laura Marqués, Marta Rueda, Paloma Ruiz‐Benito, Asier Herrero, Cristina Aponte, Rodrigo Sagardia, Andrew J. Plumptre, S. Dupire, Carlos Iván Espinosa, Olga Tutubalina, Moe Myint, Luciano Pataro, Jérôme Lopez‐Saez, Manuel J. Macía, Meinrad Abegg, Miguel Á. Zavala, Adolfo Quesada‐Román, Mauricio Vega-Araya, Elena Golubeva, Yuliya Timokhina, Guillermo Bañares‐de‐Dios, Íñigo Granzow‐de la Cerda, Markus Stoffel
Abstract
Previous attempts to quantify tree abundance at global scale have largely neglected the role of local competition in modulating the influence of climate and soils on tree density. Here, we evaluated whether mean tree size in the world's natural forests alters the effect of global productivity on tree density. In doing so, we gathered a vast set of forest inventories including >3000 sampling plots from 23 well-conserved areas worldwide to encompass (as much as possible) the main forest biomes on Earth. We evidence that latitudinal productivity patterns of tree density become evident as large trees become dominant. Global estimates of tree abundance should, therefore, consider dependencies of latitudinal sources of variability on local biotic influences to avoid underestimating the number of trees on Earth and to properly evaluate the functional and social consequences.