Extreme-duration drought impacts on soil CO2 efflux are regulated by plant species composition
Long-duration drought can alter ecosystem plant species composition with subsequent effects on carbon cycling. We conducted a rainfall manipulation field experiment to address the question: how does drought-induced vegetation change, specifically shrub encroachment into grasslands, regulate impacts of subsequent drought on soil CO2 efflux (Rs) and its components (autotrophic and heterotrophic, Ra and Rh)?
We conducted a two-year experiment in Inner Mongolia plateau, China, using constructed steppe communities including graminoids, shrubs and their mixture (graminoid + shrub) to test the effects of extreme-duration drought (60-yr return time) on Rs, Rh and Ra.
Our results indicated that extreme-duration drought reduced net primary production, with subsequent effects on Rs, Rh and Ra in all three vegetation communities. There was a larger relative decline in Ra (35–54%) than Rs (30–37%) and Rh (28–35%). Interestingly, we found Rs in graminoids is higher than in shrubs under extreme drought. Meanwhile, Rh declines were largest in the shrub community. Although Ra and Rh both decreased rapidly during drought treatment, Rh recovered quickly after the drought, while Ra did not, limiting the Rs recovery.
This study suggests that plant species composition regulates several aspects of soil CO2 efflux response to climate extremes. This regulation may be limited by above- and below-ground net primary production depending on soil water availability. The results of this experiment address a critical knowledge gap in the relationship between soil respiration and plant species composition. With shrub encroachment into grasslands, total soil respiration is reduced and can partly offset the effect of reduction in productivity under drought stress.
KeywordsExtreme drought Soil CO2 efflux Autotrophic Heterotrophic Plant species composition Net primary production
This project was funded by the CAS Strategic Priority Research Programmer (A) (Grant No. XDA20050103 and XDA19030202) and the funds for International Cooperation and Exchange of National Natural Science Foundation of China (Grant No. 31761123001 and 31761143018). We also show great appreciation for two anonymous reviewer’s suggestions.
- Batima P, Dagvadorj D (2000) Climate change and its impacts in Mongolia. Natl agency Meteorol Hydrol environ Monit JEMR Publ Ulaanbaatar, Mong 227pGoogle Scholar
- Breshears DD, Cobb NS, Rich PM, Price KP, Allen CD, Balice RG, Romme WH, Kastens JH, Floyd ML, Belnap J, Anderson JJ, Myers OB, Meyer CW (2005) Regional vegetation die-off in response to global-change-type drought. Proc Natl Acad Sci 102:15144–15148. https://doi.org/10.1073/pnas.0505734102 CrossRefGoogle Scholar
- Ciais Ph, Reichstein M, Viovy N, Granier A, Ogée J, Allard V, Aubinet M, Buchmann N, Bernhofer Chr, Carrara A, Chevallier F, De Noblet N, Friend AD, Friedlingstein P, Grünwald T, Heinesch B, Keronen P, Knohl A, Krinner G, Loustau D, Manca G, Matteucci G, Miglietta F, Ourcival JM, Papale D, Pilegaard K, Rambal S, Seufert G, Soussana JF, Sanz MJ, Schulze ED, Vesala T, Valentini R (2005) Europe-wide reduction in primary productivity caused by the heat and drought in 2003. Nature 437(7058):529–533CrossRefGoogle Scholar
- Cornwell WK, Cornelissen JHC, Amatangelo K, Dorrepaal E, Eviner VT, Godoy O, Hobbie SE, Hoorens B, Kurokawa H, Pérez-Harguindeguy N, Quested HM, Santiago LS, Wardle DA, Wright IJ, Aerts R, Allison SD, van Bodegom P, Brovkin V, Chatain A, Callaghan TV, Díaz S, Garnier E, Gurvich DE, Kazakou E, Klein JA, Read J, Reich PB, Soudzilovskaia NA, Vaieretti MV, Westoby M (2008) Plant species traits are the predominant control on litter decomposition rates within biomes worldwide. Ecol Lett 11:1065–1071CrossRefGoogle Scholar
- Correia AC, Minunno F, Caldeira MC, Banza J, Mateus J, Carneiro M, Wingate L, Shvaleva A, Ramos A, Jongen M, Bugalho MN, Nogueira C, Lecomte X, Pereira JS (2012) Soil water availability strongly modulates soil CO2 efflux in different Mediterranean ecosystems: model calibration using the Bayesian approach. Agric Ecosyst Environ 161:88–100. https://doi.org/10.1016/j.agee.2012.07.025 CrossRefGoogle Scholar
- Davis MA, Grime JP, Thompson KEN (2000) Fluctuating resources in plant communities : a general theory of invasibility. 528–534Google Scholar
- Hester AJ, Miles J, Gimingham CH (1991) Succession from heather moorland to birch woodland. II. Growth and competition between Vaccinium myrtillus, Deschampsia flexuosa and Agrostis capillaris. J Ecol:317–327Google Scholar
- Jentsch A, Kreyling J, Elmer M, Gellesch E, Glaser B, Grant K, Hein R, Lara M, Mirzae H, Nadler SE, Nagy L, Otieno D, Pritsch K, Rascher U, Schädler M, Schloter M, Singh BK, Stadler J, Walter J, Wellstein C, Wöllecke J, Beierkuhnlein C (2011) Climate extremes initiate ecosystem-regulating functions while maintaining productivity. J Ecol 99:689–702. https://doi.org/10.1111/j.1365-2745.2011.01817.x CrossRefGoogle Scholar
- Kieft TL, Carleton S, White S, et al (1998) Temporal Dynamics in Soil Carbon and Nitrogen Resources at a Grassland-Shrubland EcotoneGoogle Scholar
- Knapp A, Briggs J, … SC-GC, 2008a Undefined shrub encroachment in north American grasslands: shifts in growth form dominance rapidly alters control of ecosystem carbon inputs. Wiley Online LibrGoogle Scholar
- Sanaullah M, Chabbi A, Girardin C, Durand JL, Poirier M, Rumpel C (2014) Effects of drought and elevated temperature on biochemical composition of forage plants and their impact on carbon storage in grassland soil. Plant Soil 374:767–778. https://doi.org/10.1007/s11104-013-1890-y CrossRefGoogle Scholar
- Selsted MB, Linden L, Ibrom A, Michelsen A, Larsen KS, Pedersen JK, Mikkelsen TN, Pilegaard K, Beier C, Ambus P (2012) Soil respiration is stimulated by elevated CO2 and reduced by summer drought: three years of measurements in a multifactor ecosystem manipulation experiment in a temperate heathland (CLIMAITE). Glob Chang Biol 18:1216–1230CrossRefGoogle Scholar
- Tielbörger K, Bilton MC, Metz J, Kigel J, Holzapfel C, Lebrija-Trejos E, Konsens I, Parag HA, Sternberg M (2014) Middle-eastern plant communities tolerate 9 years of drought in a multi-site climate manipulation experiment. Nat Commun 5:5102. https://doi.org/10.1038/ncomms6102 CrossRefPubMedCentralGoogle Scholar
- Tietjen B, Schlaepfer D, Bradford J, et al (2016) Climate change-induced vegetation shifts lead to more ecological droughts despite projected rainfall increases in many global temperate drylandsGoogle Scholar
- Zhou X, Wan S, Luo Y (2007) Source components and interannual variability of soil CO2 efflux under experimental warming and clipping in a grassland ecosystem. Glob Chang Biol 13:761–775Google Scholar