Traits explain sorting of C₄ grasses along a global precipitation gradient

Abstract

Explaining why species occupy different environments is a central goal of ecology and understanding how plant traits mediate plant-climate relationships provides a way of answering this question. At a global scale, primary productivity and species distributions are correlated with gradients of precipitation (Currie & Paquin, 1987; Leith, 1975). These patterns are thought to be mediated by trade-offs in species functional traits (Reich, 2014; Woodward, 1987). In habitats where water is not a limiting resource, competition excludes species and the ability to rapidly acquire resources and grow quickly is expected in the dominant species (Craine, 2009; Grime, 1977). However, species are known to separate along hydrological gradients (Silvertown et al., 2015) and soil water deficits can exclude plants that are not adapted to drought

Inter-Annual Climate Differences Supersede Grazing Effects on the Anatomy and Physiology of a Dominant Grass Species.

“…2, 3; Table 1; Table S1, 2) (Hoffman and Smith 2020; Bachle and Nippert 2021). In addition, decreased soil moisture availability reduces carbon assimilation, decreases nutrient uptake, and leads to reduced productivity (Lemoine et al 2018;Jardine et al 2021). Our data illustrate similar patterns, at the FHPP and KPBS sites, which received signi cantly less rainfall in the 2018 growing season than the subsequent year (Fig.…”

“…Andropogon gerardii can account for over 70% of annual biomass in the tallgrass prairie when ample rainfall is received (Weaver 1968;Smith and Knapp 2003). These dominant grasses thrive in their native habitats because each has evolved specialized functional traits as mechanisms of persistence within each region's disturbance regimes (Anderson 2006; Jardine et al 2021). These adaptations include but are not limited to: 1) large shallow rooting systems comprised of ne roots that quickly absorb water (Nippert and Knapp 2007;Nippert et al 2012); 2) belowground meristematic tissues ("bud banks") which provide new growth after senescence, re, and grazing (Dalgleish and Hartnett 2006;Ott and Hartnett 2015;Ott et al 2019); and 3) specialized leaf morphology and anatomy to maximize light capture and minimize water loss to combat drought (Hameed et al 2012;Nunes et al 2020).…”

Physiological responses to drought stress and recovery reflect differences in leaf function and anatomy among grass lineages

“…Low soil moisture negatively impacts growth, increases xylem tension, and decreases carbon assimilation [85,86]. The ability to mitigate and recover from drought is based on anatomical and physiological traits [87,88].…”

Climate variability supersedes grazing to determine the anatomy and physiology of a dominant grassland species

“…Dominant grasses thrive in their native habitats, because each has evolved specialized functional traits as mechanisms of persistence within each region's disturbance regimes (Anderson 2006;Jardine et al 2021). These adaptations include but are not limited to: (1) large shallow rooting systems comprised of fine roots that quickly absorb water (Nippert and Knapp 2007;Nippert et al 2012);…”

“…Dominant grasses thrive in their native habitats, because each has evolved specialized functional traits as mechanisms of persistence within each region’s disturbance regimes (Anderson 2006 ; Bachle et al 2018 ; Jardine et al 2021 ). These adaptations include but are not limited to: (1) large shallow rooting systems comprised of fine roots that quickly absorb water (Nippert and Knapp 2007 ; Nippert et al 2012 ); (2) belowground meristematic tissues (“bud banks”) which provide new growth after senescence, fire, and grazing (Dalgleish and Hartnett 2006 ; Ott and Hartnett 2015 ; Ott et al 2019 ); and (3) specialized leaf morphology and anatomy to maximize light capture and minimize water loss to decrease the drought effects (Hameed et al 2012 ; Nunes et al 2020 ).…”