The 4-Dimensional Plant: Effects of Wind-Induced Canopy Movement on Light Fluctuations and Photosynthesis

Abstract

Physical perturbation of a plant canopy brought about by wind is a ubiquitous phenomenon and yet its biological importance has often been overlooked. This is partly due to the complexity of the issue at hand: wind-induced movement (or mechanical excitation) is a stochastic process which is difficult to measure and quantify; plant motion is dependent upon canopy architectural features which, until recently, were difficult to accurately represent and model in 3-dimensions; light patterning throughout a canopy is difficult to compute at high-resolutions, especially when confounded by other environmental variables. Recent studies have reinforced the expectation that canopy architecture is a strong determinant of productivity and yield; however, links between the architectural properties of the plant and its mechanical properties, particularly its response to wind, are relatively unknown. As a result, biologically relevant data relating canopy architecture, light- dynamics, and short-scale photosynthetic responses in the canopy setting are scarce. Here, we hypothesize that wind-induced movement will have large consequences for the photosynthetic productivity of our crops due to its influence on light patterning. To address this issue, in this study we combined high resolution 3D reconstructions of a plant canopy with a simple representation of canopy perturbation as a result of wind using solid body rotation in order to explore the potential effects on light patterning, interception, and photosynthetic productivity. We looked at two different scenarios: firstly a constant distortion where a rice canopy was subject to a permanent distortion throughout the whole day; and secondly, a dynamic distortion, where the canopy was distorted in incremental steps between two extremes at set time points in the day. We find that mechanical canopy excitation substantially alters light dynamics; light distribution and modeled canopy carbon gain. We then discuss methods required for accurate modeling of mechanical canopy excitation (here coined the 4-dimensional plant) and some associated biological and applied implications of such techniques. We hypothesize that biomechanical plant properties are a specific adaptation to achieve wind-induced photosynthetic enhancement and we outline how traits facilitating canopy excitation could be used as a route for improving crop yield.

Wind drives drought responses of green roof vegetation in two substrates

“…Under water deficit conditions, wind increased the rate of water loss from the system, leading to higher midday leaf temperatures, a more rapid drop in the efficiency of the photosynthetic apparatus, and accelerated rates of wilting and mortality in the three species tested. These main effects of wind were in line with findings in other studies showing that wind may accelerate desiccation of green roof systems and, directly or indirectly, affect plant performance [15, 16, 17, 18, 19].…”

“…The moderate wind in our study (3.7 m s −1 ) was not sufficient to have an impact on the morphological and physiological parameters of watered control plants [21]. The effect of wind on plants depends on many factors, including its velocity and duration, but also on local environmental conditions, and can vary from positive to no or adverse impacts [15]. Therefore, it is possible that, under conditions different from those tested in this study; the response of well-watered plants to wind may be slightly different.…”

“…The impact of wind on plants is extremely variable and largely depends on its speed, duration, and frequency combined with plant characteristics [14, 15]. The effect of wind on green roof vegetation can include acceleration of substrate desiccation through evaporation, induction of mechanical and morphological responses, changes in leaf microclimate, and disturbance of leaf gas and heat exchange [15, 16, 17, 18, 19]. Despite the importance of wind for water loss and its effect on vegetation performance, there is a lack of knowledge about how wind affects green roof vegetation either directly or through effects on the water balance.…”

The Impacts of Fluctuating Light on Crop Performance

“…Recent advances in ray-tracing algorithms facilitated by improved imaging and computational abilities have enabled models with greater ability to account for the actual structure of a crop canopy and more precise localization of light regimes (Song et al, 2013;Burgess et al, 2015). These models have been leveraged to produce a representation of the impact of wind speed, variability, and direction on intercanopy radiation regimes and the net assimilation of a wheat canopy (Burgess et al, 2016). This work reveals that an increase in light penetration into the canopy due to wind-driven canopy movement can increase total canopy carbon gain by up to 17% and raises interesting possibilities for the improvement of canopy photosynthesis through canopy structural modifications.…”

Impact of Post-Translational Modifications of Crop Proteins under Abiotic Stress

“…Research is being conducted to understand response characteristics of useful plants by obtaining data on global change in plant physiology [9]. Based on omics data represented by proteomic profiles, attempts for mathematical modeling of plant response mechanisms against stimulation were underway with a focus on the prediction of plant response under field conditions [10,11,12]. However, studies for crops have lagged behind those of the model species because of genetic diversity of important crops and resulting scarcity of genomic information or knowledge on response mechanisms in each species [13,14].…”