TY - JOUR

T1 - Grassland species root response to drought

T2 - consequences for soil carbon and nitrogen availability

AU - De Vries, Franciska Trijntje

AU - Brown, Caley

AU - Stevens, Carly Joanne

PY - 2016/12

Y1 - 2016/12

N2 - Background and AimsRoot traits are increasingly used to predict how plants modify soil processes. Here, we assessed how drought-induced changes in root systems of four common grassland species affected C and N availability in soil. We hypothesized that drought would promote resource-conservative root traits such as high root tissue density (RTD) and low specific root length (SRL), and that these changes would result in higher soil N availability through decreased root N uptake, but lower C availability through reduced root exudation.MethodsWe subjected individual plants to drought under controlled conditions, and compared the response of their root biomass, root traits, and soil C and N availability, to control individuals.ResultsDrought affected most root traits through reducing root biomass. Only SRL and RTD displayed plasticity; drought reduced SRL, and increased RTD in small plants but decreased RTD in larger plants. Reduced root biomass and a shift towards more resource-conservative root traits increased soil inorganic N availability but did not directly affect soil C availability.ConclusionsThese findings identify mechanisms through which drought-induced changes in root systems affect soil C and N availability, and contribute to our understanding of how root traits modify soil processes in a changing world.

AB - Background and AimsRoot traits are increasingly used to predict how plants modify soil processes. Here, we assessed how drought-induced changes in root systems of four common grassland species affected C and N availability in soil. We hypothesized that drought would promote resource-conservative root traits such as high root tissue density (RTD) and low specific root length (SRL), and that these changes would result in higher soil N availability through decreased root N uptake, but lower C availability through reduced root exudation.MethodsWe subjected individual plants to drought under controlled conditions, and compared the response of their root biomass, root traits, and soil C and N availability, to control individuals.ResultsDrought affected most root traits through reducing root biomass. Only SRL and RTD displayed plasticity; drought reduced SRL, and increased RTD in small plants but decreased RTD in larger plants. Reduced root biomass and a shift towards more resource-conservative root traits increased soil inorganic N availability but did not directly affect soil C availability.ConclusionsThese findings identify mechanisms through which drought-induced changes in root systems affect soil C and N availability, and contribute to our understanding of how root traits modify soil processes in a changing world.

KW - Aboveground-belowground linkages

KW - Plant functional traits

KW - Plasticity

KW - Soil microbial properties

KW - Soil processes

KW - Climate change

U2 - 10.1007/s11104-016-2964-4

DO - 10.1007/s11104-016-2964-4

M3 - Journal article

VL - 409

SP - 297

EP - 312

JO - Plant and Soil

JF - Plant and Soil

SN - 0032-079X

IS - 1

ER -