Department of Biology, Indiana University, Bloomington, Indiana, USA.
Department of Ecology, Evolution and Behavior, University of Minnesota, Saint Paul, Minnesota, USA.
Ecology. 2021 Dec;102(12):e03557. doi: 10.1002/ecy.3557. Epub 2021 Nov 4.
The plant soil feedback (PSF) framework has been instrumental in understanding the impacts of soil microbes on plant fitness and species coexistence. PSFs develop when soil microbial communities are altered due to the identity and density of a particular plant species, which can then enhance or inhibit the local survival and growth of that plant species as well as different plant species. The recent extension of the PSF framework to aboveground microbiota, termed here as plant phyllosphere feedbacks (PPFs), can also help to determine the impact of aboveground microbes on plant fitness and species interactions. However, experimental tests of PPFs during early plant growth are nascent and the prevalence of PPFs across diverse plant species remains unknown. Additionally, it is unclear whether plant host characteristics, such as functional traits or phylogenetic distance, may help to predict the strength and direction of PPFs. To test for the prevalence of litter-mediated PPFs, recently senesced plant litter from 10 native Asteraceae species spanning a range of life history strategies was used to inoculate seedlings of both conspecific and heterospecific species. We found that exposure to conspecific litter significantly reduced the growth of four species relative to exposure to heterospecific litter (i.e., significant negative PPFs), three species experienced marginally significant negative PPFs, and the PPF estimates for all 10 species were negative. However, neither plant functional traits, nor phylogenetic distance were predictive of litter feedbacks across plant species pairs, suggesting that other mechanisms or traits not measured may be driving conspecific negative PPFs. Our results indicate that negative, litter-mediated PPFs are common among native Asteraceae species and that they may have substantial impacts on plant growth and plant species interactions, particularly during early plant growth.
植物-土壤反馈（PSF）框架对于理解土壤微生物对植物适应性和物种共存的影响至关重要。当由于特定植物物种的身份和密度而改变土壤微生物群落时，就会形成 PSF，这可以增强或抑制该植物物种以及不同植物物种的当地生存和生长。最近，将 PSF 框架扩展到地上微生物群，称为植物叶际反馈（PPF），也有助于确定地上微生物对植物适应性和物种相互作用的影响。然而，在植物早期生长过程中对 PPF 进行实验测试还处于起步阶段，并且不同植物物种中 PPF 的普遍性仍然未知。此外，尚不清楚植物宿主特征（例如功能特征或系统发育距离）是否有助于预测 PPF 的强度和方向。为了测试凋落物介导的 PPF 的普遍性，最近使用 10 种具有不同生活史策略的本地菊科植物的已衰老植物凋落物来接种同种和异种种植物的幼苗。我们发现，与暴露于异种种群凋落物相比，暴露于同种凋落物显着降低了四个物种的生长（即显着的负 PPF），三个物种经历了略微显着的负 PPF，并且所有 10 个物种的 PPF 估计值均为负。但是，植物功能特征或系统发育距离均不能预测植物种间的凋落物反馈，这表明可能存在其他未测量的机制或特征会导致同种负 PPF。我们的结果表明，负的凋落物介导的 PPF 在本地菊科植物中很常见，它们可能对植物生长和植物物种相互作用产生重大影响，尤其是在植物早期生长过程中。
