Testing the plant growth-defense hypothesis belowground: do faster-growing herbaceous plant species suffer more negative effects from soil biota than slower-growing ones?

According to the growth-defense hypothesis in ecology, faster-growing plant species should suffer more from herbivores and pathogens than slower-growing species. Tests of this hypothesis have focused on aboveground plant tissues, herbivores, and pathogens; however, it should also apply to root defense. To test whether faster-growing species suffer more negatively from soil biota than slower-growing species, we estimated first-season growth rates of 34 herbaceous plant species and used weighted linear regressions to assess the relationship between growth rates and responses to being grown in sterilized versus unsterilized soil (biotic soil effects) and to growing in soil previously occupied by conspecifics versus a mixture of species (conspecific soil effects). We found a negative relationship between relative growth rate and biotic soil effects, with slower-growing species tending to suffer less or even benefit from the presence of soil biota, while faster-growing species were more nega...

生态学中的生长-防御假说（growth-defense hypothesis）提出，生长较快的植物物种相较于生长较慢的物种，更易受到植食动物与病原物的侵害。以往对该假说的检验多聚焦于植物地上组织、植食动物及病原物，但该假说同样应适用于根系防御。为验证生长较快的物种是否较生长较慢的物种更易受到土壤生物群（soil biota）的负面影响，本研究估算了34种草本植物的第一季生长速率，并采用加权线性回归（weighted linear regressions）分析，探究生长速率与两种响应的关联：一是植物在灭菌土壤与未灭菌土壤中生长的响应（即土壤生物效应（biotic soil effects）），二是植物在先前为同种植物定植的土壤与多物种混合土壤中生长的响应（即同种土壤效应（conspecific soil effects））。本研究发现相对生长速率（relative growth rate）与土壤生物效应呈负相关关系：生长较慢的物种往往受土壤生物的负面影响更弱，甚至可从中获益，而生长较快的物种则呈现出更强烈的负面（原文未完整表述）。