Getting to the root of restoration: considering root traits for improved restoration outcomes under drought and competition

Abstract

A foundational goal of trait-based ecology, including trait-based restoration, is to link specific traits to community assembly, biodiversity, and ecosystem function. Despite a growing awareness of the importance of belowground traits for ecological processes, a synthesis of how root traits can inform restoration of terrestrial plant communities is lacking. We reviewed and summarized existing literature focused on root traits in relation to plant performance measures (i.e. survival, establishment, productivity) in the contexts of drought and competition (including invasion). Root traits related to belowground resource acquisition (e.g. high specific root length, deep roots) are frequently related to drought avoidance (i.e. a plant strategy based on optimizing water uptake to maintain function), whereas studies relating root traits to drought tolerance (i.e. a plant strategy that allows plants to withstand low hydration) remain limited. More studies have linked root traits to plant competitive effects (i.e. the influence a plant has on neighbors) than to competitive responses (i.e. a plant's ability to resist the effects of neighbors). Because plants with acquisitive traits decrease resources to the detriment of neighbors, root traits associated with rapid resource acquisition (e.g. high specific root length) may be important for understanding competitive effects. Albeit more limited, research suggests root traits associated with resource conservation or stress tolerance (e.g. high root tissue density, high root diameter) may elucidate mechanisms related to competitive responses. Re-vegetation outcomes may be improved by considering root traits, but only if clear links are made between traits and plant performance in varied contexts.

Invasive annual grass interacts with drought to influence plant communities and soil moisture in dryland restoration

“…As both drought and B. tectorum seed addition in our study decreased soil moisture, it is possible that species that can tolerate or avoid low moisture conditions may be best suited to establish under both scenarios. Future studies that relate functional traits, particularly root traits, to ecosystem processes or plant performance (Suding et al 2008, Laughlin 2014, Garbowski et al 2020 b ) may inform species selection for dryland restoration threatened by both drought and invasive species.…”

Do soil depth and plant community composition interact to modify the resistance and resilience of grassland ecosystem functioning to drought?

“…The variable soil depth treatment did not conform to the idea that volume is directly linked with flux rate, however indicating that soil microsites do offer refugia that enables rapid recovery from drought and higher photosynthetic rates than uniform soil depths (Fridley et al., 2011 ). The differences in responses in variable soil depths compared with uniform offers nuance to the literature that shows that rooting depth is correlated with improved drought tolerance (Garbowski et al., 2020 ). In future studies considering contrasting soil depths, it would be beneficial to harvest the mesocosms by soil layer (in our case, slices of 7 cm).…”

“…Significance stars: *p < .05, **p < .01, ***p < .001 microsites do offer refugia that enables rapid recovery from drought and higher photosynthetic rates than uniform soil depths(Fridley et al, 2011). The differences in responses in variable soil depths compared with uniform offers nuance to the literature that shows that rooting depth is correlated with improved drought tolerance(Garbowski et al, 2020). In future studies considering contrasting F I G U R E 5 Effects of plant community composition and soil depth/heterogeneity on the Relative Distance Plasticity Index (RDPI) of plant traits in response to drought.…”

Trade-off Strategy of Three Dominant Species in Grazing Exclusion of Desert Steppe,china

“…During ecosystem, biomass increased with the increase of leaf nitrogen content, while decreased with speci c leaf area (Čierniková et al 2021;Yang et al 2011). Other studies have shown that speci c leaf area and leaf nitrogen content are positively relationship with biomass and leaf dry matter mass is negatively relationship with biomass (Garbowski et al 2020). Among the root functional traits, root diameter, root tissue density and root nitrogen content were positively correlated with biomass, while root length and speci c root length were negatively correlated with biomass (Hanisch et al 2020).…”