Wind intensity affects fine root morphological traits with consequences for plant-soil feedback effects

Abstract

Wind influences the development, architecture and morphology of plant roots and may modify subsequent interactions between plants and soil (plant-soil feedbacks – PSFs). However, information on wind effects on fine root-morphology is scarce and the extent to which wind changes plant-soil interactions remains unclear. Therefore, we investigated the effects of two wind intensity levels by manipulating surrounding vegetation height in a grassland PSF field-experiment. We grew four common plant species (two grasses and two non-leguminous forbs) with soil biota either previously conditioned by these or other species and tested the effect of wind on root:shoot ratio, fine root morphological traits as well as the outcome for PSFs. Wind intensity did not affect biomass allocation (i.e. root:shoot ratio) in any species. However, fine-root morphology of all species changed under high wind intensity. High wind intensity increased specific root length and surface area and decreased root tissue density, especially in the two grasses. Similarly, the direction of PSFs changed under high wind intensity in all four species, but differences in biomass production on the different soils between high and low wind intensity were marginal and most pronounced when comparing grasses with forbs. Because soils did not differ in plant-available nor total nutrient content, the results suggest that wind-induced changes in root morphology have the potential to influence plant-soil interactions. Linking wind-induced changes in fine-root morphology to effects on PSF improves our understanding of plant-soil interactions under changing environmental conditions.

Morphological Variation in Absorptive Roots in Downy Birch (Betula pubescens) and Norway Spruce (Picea abies) Forests Growing on Drained Peat Soils

“…The mean SRL also varied with distance gradient from the ditch, but it was only evident in birch. Similar to our result, Werger et al [44] showed that the effect of wind intensity on the fine root morphological traits, such as SRA, SRL, and RTD, was uniform in all grassland species. However, our results contradict previously reported species-specific root morphological responses to adverse soil conditions [23,45].…”

Plant-soil feedback: incorporating untested influential drivers and reconciling terminology

“…Plant traits can also be driven by environmental factors (Lienin and Kleyer 2012;Milanović et al 2020), thus affecting PSF processes. For example, Werger et al (2020) found wind-induced changes in root morphological traits affected the strength and direction of PSF. Similar to wind, aboveground herbivory was found to influence root morphology, which would most likely affect PSF (Heinze 2020).…”

Short wind pulses consistently change the morphology of roots, but not of shoots, across young plants of different growth forms

“…Although wind acts and stresses plants aboveground, plant responses appear both directly aboveground and indirectly belowground. For instance, wind effects were found to change morphological traits of shoots such as plant height (Feng et al 2019 ) and leaf morphology (Anten et al 2010 ) aboveground, but also root morphological traits (Werger et al 2020 ) belowground. As abiotic stress, wind and its intensity impacts species of all growth forms, including trees, grasses and forbs, at all life-stages.…”

“…These results suggest that wind stress by short wind pulses of different intensity promoted the development of thinner roots with increased SRL and SRSA. Besides effects on water and nutrient acquisition (Bardgett et al 2014 ), such changes in root morphology are suggested to increase anchorage (Burylo et al 2009 ; Werger et al 2020 ), as higher root length is assumed to provide better mechanical support (see Zhang et al 2021 ). Furthermore, the decreased RTD under wind action suggests that plants invest less root biomass to obtain given levels of surface area and length and, thus, have greater root–soil contact at less cost (Werger et al 2020 ).…”