Legacy effects of drought on plant–soil feedbacks and plant–plant interactions

Abstract

Interactions between aboveground and belowground biota have the potential to modify ecosystem responses to climate change, yet little is known about how drought influences plant-soil feedbacks with respect to microbial mediation of plant community dynamics. We tested the hypothesis that drought modifies plant-soil feedback with consequences for plant competition. We measured net pairwise plant-soil feedbacks for two grassland plant species grown in monoculture and competition in soils that had or had not been subjected to a previous drought; these were then exposed to a subsequent drought. To investigate the mechanisms involved, we assessed treatment responses of soil microbial communities and nutrient availability. We found that previous drought had a legacy effect on bacterial and fungal community composition that decreased plant growth in conspecific soils and had knock-on effects for plant competitive interactions. Moreover, plant and microbial responses to subsequent drought were dependent on a legacy effect of the previous drought on plant-soil interactions. We show that drought has lasting effects on belowground communities with consequences for plant-soil feedbacks and plant-plant interactions. This suggests that drought, which is predicted to increase in frequency with climate change, may change soil functioning and plant community composition via the modification of plant-soil feedbacks.

Drought and its legacy modulate the post‐fire recovery of soil functionality and microbial community structure in a Mediterranean shrubland

“…Some of the studied soil enzyme activities (acid phosphatase, among them) maintained reduced potential activity in soils previously exposed to drought, even 2 years after recovering the natural rainfall pattern. Kaisermann et al (), using a short‐term mesocosm experiment, also provided evidence that legacy effects of drought on soil microbial communities alter their functional capabilities when faced with subsequent drought. In addition, the legacy effect of drought observed in this study could also be due to the direct and indirect effect of drought on plant growth and community structure during the drought (Anderegg et al, ; Huang et al, ; Walter, Jentsch, Beierkuhnlein, & Kreyling, ), which is consistent with the findings of Parra & Moreno (; ) for this experimental site.…”

“…In general, legacy effects of reduced rainfall were important in affecting a number of ecosystem processes (Johnstone et al, ; Monger et al, ; Sala, Gherardi, Reichmann, Jobbagy, & Peters, ), while only recently these effects been studied in soil microbial community structure and functioning (Hawkes & Keitt, ; Wallenstein & Hall, ). So far, drought legacy effects have been investigated after short‐term (up to 3 years) (De Vries, Liiri, Bjørnlund, Bowker et al, ; De Vries, Liiri, Bjørnlund, Setälä et al, ; Allison et al, ; Göransson, Godbold, Jones, & Rousk, ; Fuchsluegr et al, 2016; Meisner, Rousk, & Bååth, ; Kaisermann, Vries, Griffiths, & Bardgett, ; Martiny et al, ; Legay et al, ), or long‐term (up to 13 years) periods of drought (Evans & Wallenstein, ; Rousk et al, ). The findings suggest that the expected magnitude of the legacy effects of droughts on terrestrial ecosystems likely depends on drought intensity, as well as on the duration and timing of the drought event (Hawkes & Keitt, ; Huang, Wang, Keenan, & Piao, ).…”

Plant functional groups mediate drought resistance and recovery in a multisite grassland experiment

“…In addition, grasslands with a high abundance of fungi have been shown to maintain larger soil nutrient pools during drying‐rewetting periods (Gordon et al, ; Martínez‐García, De Deyn, Pugnaire, Kothamasi, & van der Heijden, ). Shifts in plant–soil feedbacks and/or competition for N, which increase plant N uptake in the presence of fungi, may further enhance plant recovery after drought (Kaisermann, de Vries, Griffiths, & Bardgett, ).…”

Tipping point in plant–fungal interactions under severe drought causes abrupt rise in peatland ecosystem respiration

“…Although we generalise from a limited set of ecosystem functions over a short‐temporal scale, we cannot exclude that the system could follow a reverse pathway if the water level increases again (which is not currently the case, Fig. S11) or remains at the “dry stage” considering the legacy effects of drought on plant–soil interactions (Kaisermann, de Vries, Griffiths, & Bardgett, ). Anyhow, we provide empirical understanding about the mechanisms pushing ecosystems beyond a threshold in response to climate change.…”