On February 6, 2025, a new paper using data from 21 ForestGEO Forest Dynamics Plots titled “Latitudinal scaling of aggregation with abundance and coexistence in forests” was published in Nature. Read on to learn more about the research and findings.
How can a multitude of tree species coexist? This was the question an international team of scientists* sought to answer. Spearheaded by Dr. Thorsten Wiegand from the Helmholtz Centre for Environmental Research (UFZ), the team used data from 21 ForestGEO forest dynamics plots^ to study this key forest science question. “The search for simple principles underlying the spatial structure and dynamics of plant communities is a long-standing challenge in theoretical ecology,” said Wiegand. The result of their research suggests that tropical and temperate forest tree species use variations in tree clustering patterns and species abundance to develop contrasting coexistence strategies.
The UFZ researchers were able to use ForestGEO data to analyze tree species distribution in their forests of study, and even the processes integral to these spatial patterns. They found that in tropical forests, rare tree species are more dispersed, while in temperate forests, there is little distinction in the clustering of common and rare species. This difference is largely influenced by the dispersal mechanisms of seeds and the role of mycorrhizal fungi. “Roughly 70 to 80 percent of tree species in the tropics are dispersed by animals, but much less in temperate forests,” said Wiegand. In tropical forests, mycorrhizal fungi protect trees from pests, shaping the distribution of species. The conclusion: “In tropical forests, mechanisms such as seed dispersal by animals lead to the observed patterns, while in temperate forests, the patterns are shaped by mycorrhizal fungi.”
The international team didn’t stop their research there. “[They] wanted to know under what circumstances tree species would be able to coexist,” said Andreas Huth, so they integrated observed spatial patterns into population models using spatially explicit simulations and novel mathematical theory to describe the population growth rate at low abundances. They were able to deduce that species with more neighbors of the same type have a greater chance of surviving and coexisting, and that there is a lower risk factor in general for species in temperate forest. “Overall, it turned out that species in tropical and temperate forests exhibit optimal – but contrasting - spatial structures that each promote coexistence,” concluded Wiegand.
As in many cases, Wiegand et al.’s results led to more questions. Their research has opened the door for further studies into forest dynamics and the stability of diverse ecosystems. Wiegand and Huth “want to substantially expand [their] methods and analyses, such as by taking into account the size of the trees, the immigration of species and more detailed species characteristics, as well as by using remote sensing data.” ForestGEO data will again prove useful to answer these questions.
Read the open-access publication in Nature here.
Check out the press release here.
Congratulations to Wiegand et al. on the publication of their research. Thank you to all ForestGEO scientists and collaborators who continually help create the ForestGEO plot databases.
*Publication authors: Thorsten Wiegand, Xugao Wang, Samuel M. Fischer, Nathan J. B. Kraft, Norman A. Bourg, Warren Y. Brockelman, Guanghong Cao, Min Cao, Wirong Chanthorn, Chengjin Chu, Stuart Davies, Sisira Ediriweera, C. V. Savitri Gunatilleke, I. A. U. Nimal Gunatilleke, Zhanqing Hao, Robert Howe, Mingxi Jiang, Guangze Jin, W. John Kress, Buhang Li, Juyu Lian, Luxiang Lin, Feng Liu, Keping Ma, William McShea, Xiangcheng Mi, Jonathan A. Myers, Anuttara Nathalang, David A. Orwig, Guochun Shen, Sheng-Hsin Su, I-Fang Sun, Xihua Wang, Amy Wolf, Enrong Yan, Wanhui Ye, Yan Zhu & Andreas Huth
^ForestGEO Forest Dynamics Plots in the study: Badagongshan, Baihua, Barro Colorado Island, Changbaishan, Chebaling, Dinghushan, Donglingshan, Fenglin, Fushan, Gutianshan, Harvard Forest, Heishiding, Mo Singto, Nabanhe, Qinling, Sinharaja, Smithsonian Conservation Biology Institute, Tiantong, Tyson Research Center, Wabikon, and Xishuangbanna.
