Correlating hydrologic reinforcement of vegetated soil with plant traits during establishment of woody perennials

Abstract

Background and aims Vegetation stabilizes slopes via root mechanical reinforcement and hydrologic reinforcement induced by transpiration. Most studies have focused on mechanical reinforcement and its correlation with plant biomechanical traits. The correlations however generally ignore the effects of hydrologic reinforcement. This study aims to quantify the hydrologic reinforcement associated with ten woody species and identify correlations with relevant plant traits. Methods Ten species widespread in Europe, which belong to Aquifoliaceae, Betulaceae, Buxaceae, Celastraceae, Fabaceae, Oleaceae and Salicaceae families, were planted in pots of sandy loam soil. Each planted pot was irrigated and then left to transpire. Soil strength, matric suction and plant traits were measured. Results Transpiration-induced suction was linearly correlated with soil penetration resistance for the ten species due to their different transpiration rates i.e. both suction and soil penetration resistance induced by Hazel and Blackthorn (deciduous) were five times greater than those by Holly and European Box (evergreens). Specific leaf area and root length density correlated with hydrologic reinforcement. The root:shoot ratio correlated best with the hydrologic reinforcement. Conclusions Specific leaf area, root length density and root:shoot ratio explained the tenfold differences in hydrologic reinforcement provided by the ten different species.

Plant age effects on soil infiltration rate during early plant establishment

“…Root samples were excavated and washed from the soil, with extra care taken not to discard finer roots. The measurements of the two plant traits followed the procedures reported in Boldrin et al (2017) and Liang et al (2017).…”

Comparative effects of soil resource availability on physiology and growth of Scotch broom (Cytisus scoparius) and Douglas-fir (Pseudotsuga menziesii) seedlings

“…Scotch broom is a generalist, possessing contrasting traits that enable it to both acquire limited soil water resources more effectively and reduce its demand for soil water during periods of scarcity -a plasticity that likely facilitates its global distribution across six continents (Potter et al, 2009). With a rapid biomass accrual (Fogarty and Facelli, 1999), a deep rooting habit (Allen and Allen, 1981), high evapotranspiration (Boldrin et al, 2017) and soil water depletion rates (Carter et al, 2018), Scotch broom is capable of high soil water capture and usage and is a strong competitor for soil water resources (Richardson et al, 2002;Watt et al, 2003a). At the same time, Scotch broom possesses several traits that make it tolerant and avoidant of drought conditions, including indeterminant growth, early-and lateseason soil water use, large root length density, low leaf area to root mass ratio, high stomatal density in the epidermis, delayed periderm formation, palisade parenchyma with highly developed intercellular airspaces in the outermost regions of the cortex, low specific leaf area, photosynthetic stems, and a drought-deciduous phenology (Bannister, 1986;Rejmanek, 1992, 1994;Matías et al, 2012;Boldrin et al, 2017;Carter et al, 2018).…”

“…With a rapid biomass accrual (Fogarty and Facelli, 1999), a deep rooting habit (Allen and Allen, 1981), high evapotranspiration (Boldrin et al, 2017) and soil water depletion rates (Carter et al, 2018), Scotch broom is capable of high soil water capture and usage and is a strong competitor for soil water resources (Richardson et al, 2002;Watt et al, 2003a). At the same time, Scotch broom possesses several traits that make it tolerant and avoidant of drought conditions, including indeterminant growth, early-and lateseason soil water use, large root length density, low leaf area to root mass ratio, high stomatal density in the epidermis, delayed periderm formation, palisade parenchyma with highly developed intercellular airspaces in the outermost regions of the cortex, low specific leaf area, photosynthetic stems, and a drought-deciduous phenology (Bannister, 1986;Rejmanek, 1992, 1994;Matías et al, 2012;Boldrin et al, 2017;Carter et al, 2018). Although Scotch broom has developed physiological adaptations that make it a strong competitor on an array of different sites, these traits make it particularly competitive on poorquality sites with coarsely textured, well-drained soils (Watt et al, 2003b).…”

Scotch broom (Cytisus scoparius) modifies microenvironment to promote nonnative plant communities

“…The dramatic annual fluctuation of precipitation characteristic of Mediterranean climates, like that of the PNW, results in soil water being a primary limiting resource during the growing season (Brubaker 1980). Scotch broom has been found to be a strong competitor for soil water in similar systems (Richardson et al 2002;Watt et al 2003) and to have a high evapotranspiration (ET) rate, owing to its large size (Boldrin et al 2017). Conversely, Scotch broom possesses several traits that make it tolerant and avoidant of drought conditions: high root length density, low leaf area to root mass ratio, low specific leaf area, photosynthetic stems, and a drought-deciduous phenology (Bannister 1986;Bossard and Rejmanek 1994;Matías et al 2012;Boldrin et al 2017).…”

“…Scotch broom has been found to be a strong competitor for soil water in similar systems (Richardson et al 2002;Watt et al 2003) and to have a high evapotranspiration (ET) rate, owing to its large size (Boldrin et al 2017). Conversely, Scotch broom possesses several traits that make it tolerant and avoidant of drought conditions: high root length density, low leaf area to root mass ratio, low specific leaf area, photosynthetic stems, and a drought-deciduous phenology (Bannister 1986;Bossard and Rejmanek 1994;Matías et al 2012;Boldrin et al 2017). As a result, Scotch broom is considered highly adapted to droughtprone, Mediterranean climates, likely facilitating its dominance of sites in those regions around the globe.…”