Graduated PhD 2019
Effects of elevated CO2 on fine root dynamics and nutrient acquisition strategies under P-limitation
Rising levels of CO2 are expected to increase aboveground and belowground plant net primary production. However, any sustained CO2 enhancement of forest ecosystem NPP under elevated CO2 will require either the additional supply of limiting resources. Root production can represent up to one-third of annual productivity in terrestrial ecosystems and it has been observed that elevated CO2 can result in greater carbon (C) allocation to roots in forest ecosystems. In addition to increased investment in belowground biomass, other changes, for example, in root functional traits associated with water and nutrient uptake, may play an essential role in sustaining enhanced photosynthetic rates under eCO2. For instance, root morphology, distribution and activity are considered determinants of net primary production, belowground resource acquisition and competitive interactions, which ultimately will influence the capacity of forests to function as an effec¬tive long-term C sink. However, the extent of C investment in different strategies is likely to differ among plant functional types, with species differing in their requirements for, and ability to access, nutrients, allocate C and distribute their root system within the soil.
My research will try to elucidate the role of root system development and activity to support plant growth in P-limited forest ecosystems under elevated concentrations of CO2. The differential responses of plant species to the direct and indirect effects of elevated CO2 will lead to significant changes in plant root attributes, which will result in a shift in the species' nutrient foraging and mining strategies and, finally, in changes at the plant community-level.
Professor Sally Power and Dr Raul Ochoa-Hueso
Jiang M, Medlyn BE, Drake JE, Duursma RA, Anderson IC, Barton CVM, Boer MM, Carrillo Y, Castaneda-Gomez L, Collins L, Crous KY, De Kauwe MG, dos Santos BM, Emmerson KM, Facey SL, Gherlenda AN, Gimeno TE, Hasegawa S, Johnson SN, Kannaste A, Macdonald CA, Mahmud K, Moore BD, Nazaries L, Neilson EHJ, Nielsen UN, Niinemets U, Noh NJ, Ochoa-Hueso R, Pathare VS, Pendall E, Pihlblad J, Pineiro J, Powell JR, Power SA, Reich PB, Renchon AA, Riegler M, Rinnan R, Rymer PD, Salomon RL, Singh BK, Smith B, Tjoelker MG, Walker JKM, Wujeska-Klause A, Yang JY, Zaehle S, Ellsworth DS, (2020) 'The fate of carbon in a mature forest under carbon dioxide enrichment', Nature, vol.580, no.7802, pp 227-231
Ochoa-Hueso R, Pineiro J, Power SA, (2019) 'Decoupling of nutrient cycles in a Eucalyptus woodland under elevated CO2', Journal of Ecology, vol.107, no.6, pp 2532-2540
Collins L, Boer MM, de Dios VR, Power SA, Bendall ER, Hasegawa S, Hueso RO, Nevado JP, Bradstock RA, (2018) 'Effects of competition and herbivory over woody seedling growth in a temperate woodland trump the effects of elevated CO2', Oecologia, vol.187, no.3, pp 811-823
Hasegawa S, Pineiro J, Ochoa-Hueso R, Haigh AM, Rymer PD, Barnett KL, Power SA, (2018) 'Elevated CO2 concentrations reduce C-4 cover and decrease diversity of understorey plant community in a Eucalyptus woodland', Journal of Ecology, vol.106, no.4, pp 1483-1494
Ochoa-Hueso R, Hughes J, Delgado-Baquerizo M, Drake JE, Tjoelker MG, Pineiro J, Power SA, (2017) 'Rhizosphere-driven increase in nitrogen and phosphorus availability under elevated atmospheric CO2 in a mature Eucalyptus woodland', Plant and Soil, vol.416, no.s 1-2, pp 283-295
Piñeiro J, Ochoa-Hueso R, Delgado-Baquerizo M, Dobrick S, Reich PB, Pendall E, Power SA, (2017) 'Effects of elevated CO2 on fine root biomass are reduced by aridity but enhanced by soil nitrogen: A global assessment', Scientific Reports, vol.7, no.1, Article no.15355
Piñeiro J, Maestre FT, Bartolomé L, Valdecantos A, (2013) 'Ecotechnology as a tool for restoring degraded drylands: a meta-analysis of field experiments', Ecol. Eng., vol.61, pp. 133-144