New field wind manipulation methodology reveals adaptive responses of steppe plants to increased and reduced wind speed

Abstract

Background Wind strongly impacts plant growth, leaf traits, biomass allocation, and stem mechanical properties. However, whether there are common whole-plant wind responses among different plant species is still unclear. We tested this null hypothesis by exposing four eudicot steppe species to three different wind treatments in a field experiment: reduced wind velocity using windbreaks, ambient wind velocity, and enhanced wind velocity through a novel methodology using wind-funneling baffles. Results Across the four species, wind generally decreased plant height, projected crown area, and stepwise bifurcation ratio, and increased root length and stem base diameter. In contrast, the response patterns of shoot traits, especially mechanical properties, to wind velocity were idiosyncratic among species. There was no significant difference in total biomass among different treatments; this might be because the negative effects on heat dissipation and photosynthesis of low wind speed during hot periods, could counteract positive effects during favorable cooler periods. Conclusions There are common wind response patterns in plant-size-related traits across different steppe species, while the response patterns in shoot traits vary among species. This indicates the species-specific ways by which plants balance growth and mechanical support facing wind stress. Our new field wind manipulation methodology was effective in altering wind speed with the intended magnitude. Especially, our field wind-funneling baffle system showed a great potential for use in future field wind velocity enhancement. Further experiments are needed to reveal how negative and positive effects play out on whole-plant performance in response to different wind regimes, which is important as ongoing global climatic changes involve big changes in wind regimes.

Huff and puff and blow down: invasive plants traits response to strong winds at the Southern Oceanic Islands

“…By contrast, T. officinale gathers more light resources but with reduced height, which corresponds to a medium growth strategy. As also demonstrated by Zhang et al (2021), on steppe plants, I and height displayed common response patterns across our three species, while SLA response varies among species. Wind generates these differences in leaf morphology either through mechanical stress or through enhanced water stress by reducing boundary layers at the leaf surface (Onoda and Anten 2011).…”

“…However, no intraspecific differences in stem density between plants from windy versus sheltered microhabitats were recorded. These findings highlight changes in plants' growth strategies toward stress avoidance rather than tolerance, in line with previous works testing plant responses to wind (Jaffe and Forbes 1993, Zhang et al 2021, reviewed by Gardiner et al 2016. Working with plants from other sub-Antarctic Islands (Iles Crozet), Bazzichetto et al (2020) also found that low stature discriminated invasive from non-invasive alien plant species, and this morphological feature may strongly contribute to explain the greater geographic expansion capacities of nonnative plants at this archipelago.…”

The role of floral traits in community assembly processes at high elevations in the Himalayas

“…As for the former, we assume that low‐temperature stress, lower soil fertility, stronger UV radiation, as well as stronger winds prevailing at higher elevational sites (Körner, 2021) select for plants that invest more resources per unit of FDA. In alpine regions, flowers adapt in response to wind‐induced mechanical perturbations, as heavier flowers have more mechanical tissue that supports the floral unit, making the structures more flexible (Cordero et al, 2007; Zhang et al, 2021). Furthermore, we speculate that smaller SFA values in the upland communities, similarly to leaves (Körner, 2021; Sakai & Larcher, 1987), might stem from the larger pools of nonstructural carbon and pubescence in the corresponding species, as a part of their frost‐tolerance strategy.…”

The role of floral traits in community assembly process at high elevations in Lesser Himalaya

“…2) as well as stronger winds (Körner, 2021) at higher elevational sites select for plants that invest more resources per floral display area unit. In alpine regions, flowers adapt in response to wind induced mechanical perturbations, as heavier flowers have more mechanical tissue that supports the floral unit, making the structures more flexible and aerodynamically stable (Cordero et al, 2007; Zhang et al, 2021). The larger flower display area might be also adaptive in cold alpine climates as it positively correlated with a flowers’ passive heat accumulation (Dietrich and Körner, 2014).…”