Department of Wildland Resources and the Ecology Center, Utah State University, Logan, Utah 84322-5230, USA.
Plants, Soils and Climate Department and the Ecology Center, Utah State University, Logan, Utah 84322-4820, USA.
Ecology. 2017 Dec;98(12):3063-3073. doi: 10.1002/ecy.2011.
Plant soil feedbacks (PSFs) are thought to be important to plant growth and species coexistence, but most support for these hypotheses is derived from short-term greenhouse experiments. Here we use a seven-year, common garden experiment to measure PSFs for seven native and six nonnative species common to the western United States. We use these long-term, field-based estimates to test correlations between PSF and plant landscape abundance, species origin, functional type, and lifespan. To assess potential PSF mechanisms, we also measured soil microbial community composition, root biomass, nitrogen cycling, bulk density, penetration resistance, and shear strength. Plant abundance on the landscape and plant lifespan were positively correlated with PSFs, though this effect was due to the relationships for native plants. PSFs were correlated with indices of soil microbial community composition. Soil nutrient and physical traits and root biomass differed among species but were not correlated with PSF. While results must be taken with caution because only 13 species were examined, these species represent most of the dominant plant species in the system. Results suggest that native plant abundance is associated with the ability of long-lived plants to create positive plant-soil microbe interactions, while short-lived nonnative plants maintain dominance by avoiding soil-borne antagonists, increasing nitrogen cycling and dedicating resources to aboveground growth and reproduction rather than to belowground growth. Broadly, results suggest that PSFs are correlated with a suite of traits that determine plant abundance.
植物-土壤反馈（PSFs）被认为对植物生长和物种共存很重要，但这些假说的大多数支持都来自于短期的温室实验。在这里，我们使用了一个为期七年的共同花园实验，测量了美国西部七种本地和六种非本地常见物种的 PSFs。我们使用这些长期的、基于现场的估计来检验 PSF 与植物景观丰度、物种起源、功能类型和寿命之间的相关性。为了评估潜在的 PSF 机制，我们还测量了土壤微生物群落组成、根生物量、氮循环、容重、穿透阻力和剪切强度。景观上植物的丰度和植物的寿命与 PSFs 呈正相关，尽管这种效应是由于本地植物的关系。PSFs 与土壤微生物群落组成的指数相关。土壤养分和物理特性以及根生物量在物种之间存在差异，但与 PSF 无关。虽然由于只检查了 13 个物种，结果必须谨慎对待，但这些物种代表了该系统中大多数主要植物物种。结果表明，本地植物的丰度与长寿植物创造积极的植物-土壤微生物相互作用的能力有关，而短命的非本地植物通过避免土壤传播的天敌、增加氮循环以及将资源专门用于地上生长和繁殖而不是地下生长来维持优势地位。总的来说，结果表明 PSF 与决定植物丰度的一系列特征相关。
