It is a gas lab: Mechanisms of coexistence in woody plants
Members of the It is a gas lab, at the School of Ecology at Sun Yat-sen University have published an article in Ecology Letters with the title Mechanisms of coexistence: Exploring species sorting and character displacement in woody plants to alleviate belowground competition. Stavros Veresoglou is the first and co-corresponding author and Jingjing Xi (习靓靓), a PhD student in the lab, is the second and co-corresponding author. Josep Penuelas from CSIS-UAB is the third author. School of Ecology of Sun Yat-sen University is the first affiliation of the paper.
论文链接: https://onlinelibrary.wiley.com/doi/epdf/10.1111/ele.14489
The authors in this article present substantial evidence that mycorrhizal mutualisms trigger phenotypic adaptations in woody angiosperms that lower interspecific competition. Adaptations in the analysis take the form of both species sorting (Fig. 1) and character displacement (Fig. 2). They further make a special case on how infrequent it has been to observe character displacement in plants.
Fig. 1. Leaf area statistics over the mycorrhizal H’ index gradient. Information was averaged per location in relation to the three main mycorrhizal types and observed in both cases a heterogeneity of slopes which combined to the fact that the responses of AM and nonAM mycorrhizal types diverged present evidence for a species sorting across the mycorrhizal gradient. The takeaway from this figure, which can be generalized, at minimum, to both AM and nonAM trees, is that the weighted means of the traits we evaluate diverge as mycorrhizal diversity increases. This supports the idea of species sorting.
Competing species often develop distinct phenotypic traits when they coexist in the same areas (sympatry) compared to when they exist in isolation, a phenomenon known as character displacement. While character displacement has been well-documented in birds, fish, insects, and mammals, observations in plants have been limited. For woody plants, it is more likely that varying mycorrhizal association types, which significantly affect plant species' nutrient economy (Read & Perez-Moreno, 2003) and fitness, serve as drivers of character displacement, which is what motivated our analysis.
We compile data on plant traits and the mycorrhizal association state of woody angiosperms using a global inventory of indigenous flora. Our analysis reveals that species in locations with high mycorrhizal diversity exhibit distinct mean values in leaf area and wood density based on their mycorrhizal type, indicating species sorting. We also reanalyze a large dataset on leaf area to demonstrate that in areas with high mycorrhizal diversity, trees maintain divergent leaf area values, showcasing character displacement. Character displacement among plants is considered rare, making our observation significant. We compile data on plant traits and the mycorrhizal association state of woody angiosperms using a global inventory of indigenous flora. Our analysis reveals that species in locations with high mycorrhizal diversity exhibit distinct mean values in leaf area and wood density based on their mycorrhizal type, indicating species sorting. We also reanalyze a large dataset on leaf area to demonstrate that in areas with high mycorrhizal diversity, trees maintain divergent leaf area values, showcasing character displacement. Character displacement among plants is considered rare, making our observation significant.
Fig. 2. Boxplots of the slope (y axis) of the relationship with leaf area as a response and mycorrhizal H index as predictor across the three main mycorrhizal types (x axis). While the leaf area of AM and nonAM woody plants increases across the mycorrhizal diversity gradient, that of plant species with mixed mycorrhizal association strategies decreases giving rise to a character displacement. This figure shows that while tree species exclusively associating with arbuscular mycorrhizal (AM) fungi or those not establishing AM associations tend to increase their leaf area in sites with high mycorrhizal diversity, species exhibiting mixed association patterns tend to have lower leaf area. This reduction in leaf area should decrease the intensity of interspecific competition with the former two groups of species. These responses that alleviate competition in sites with high mycorrhizal diversity, where extensive interspecific competition occurs in relation to mycorrhiza, are a case of character displacement.
Based on our analysis it appears that the mycorrhizal mutualism triggers adaptations in woody angiosperms, that could reduce interspecific plant competition. Moreover, we contend that these phenotypic changes are ecologically significant. By addressing these inconspicuous ecological patterns and linking them to core ecological concepts, we have contributed to the understanding of an ecological process once considered rare in the plant kingdom, character displacement, across angiosperms.
作者简介
Jingjing Xi and Stavros Veresoglou are members of the it is a gas lab at the School of Ecology at Sun Yat-sen university. The expression “it is a gas” in English means that something is thoroughly entertaining. In the it is a gas lab, we work on greenhouse gases and we really enjoy ourselves (we are actually equipped with our own gas chromatograph). The focus of the lab is on global change biology and a lot of the ongoing research addresses mycorrhizas, symbiotic associations between the roots of terrestrial plants and fungi. For inquiries to join the lab please contact (inquiries can be in Chinese or in English) Junjiang Chen (陈俊江) at chenjj353@mail2.sysu.edu.cn.
