TY - JOUR

T1 - The effect of elevated CO2 concentration and nutrient supply on carbon-based plant secondary metabolites in Pinus sylvestris L.

AU - Heyworth, C. J.

AU - Iason, G. R.

AU - Temperton, Vicky

AU - Jarvis, P. G.

AU - Duncan, A. J.

PY - 1998/7/1

Y1 - 1998/7/1

N2 - This study investigated changes in carbon-based plant secondary metabolite concentrations in the needles of Pinus sylvestris saplings, in response to long-term elevation of atmospheric CO2, at two rates of nutrient supply. Experimental trees were grown for 3 years in eight open-top chambers (OTCs), four of which were maintained at ambient (~350 μmol mol-1) and four at elevated (700 μmol mol-1) CO2 concentrations, plus four open air control plots. Within each of these treatments, plants received either high (7.0 g N m-2 year-1 added) or low (no nutrients added) rates of nutrient supply for two years. Needles from lateral branches were analysed chemically for concentrations of condensed tannins and monoterpenes. Biochemical determinations of cellulase digestibility and protein precipitating capacity of their phenolic extracts were made because of their potential of importance in ecological interactions between pine and other organisms including herbivores and decomposers. Elevated CO2 concentration caused an increase (P < 0.05) in dry mass per needle, tree height and the concentration of the monoterpene α-pinene, but there were no direct effects of CO2 concentration on any of the other chemical measurements made. High nutrient availability increased cellulase digestibility of pine needles. There was a significant negative effect of the OTCs on protein precipitating capacity of the needle extracts in comparison to the open-air controls. Results suggest that predicted changes in atmospheric CO2 concentration will be insufficient to produce large changes in the concentration of condensed tannins and monoterpenes in Scots pine. Processes which are influenced by these compounds, such as decomposition and herbivore food selection, along with their effects on ecosystem functioning, are therefore unlikely to be directly affected through changes in these secondary metabolites.

AB - This study investigated changes in carbon-based plant secondary metabolite concentrations in the needles of Pinus sylvestris saplings, in response to long-term elevation of atmospheric CO2, at two rates of nutrient supply. Experimental trees were grown for 3 years in eight open-top chambers (OTCs), four of which were maintained at ambient (~350 μmol mol-1) and four at elevated (700 μmol mol-1) CO2 concentrations, plus four open air control plots. Within each of these treatments, plants received either high (7.0 g N m-2 year-1 added) or low (no nutrients added) rates of nutrient supply for two years. Needles from lateral branches were analysed chemically for concentrations of condensed tannins and monoterpenes. Biochemical determinations of cellulase digestibility and protein precipitating capacity of their phenolic extracts were made because of their potential of importance in ecological interactions between pine and other organisms including herbivores and decomposers. Elevated CO2 concentration caused an increase (P < 0.05) in dry mass per needle, tree height and the concentration of the monoterpene α-pinene, but there were no direct effects of CO2 concentration on any of the other chemical measurements made. High nutrient availability increased cellulase digestibility of pine needles. There was a significant negative effect of the OTCs on protein precipitating capacity of the needle extracts in comparison to the open-air controls. Results suggest that predicted changes in atmospheric CO2 concentration will be insufficient to produce large changes in the concentration of condensed tannins and monoterpenes in Scots pine. Processes which are influenced by these compounds, such as decomposition and herbivore food selection, along with their effects on ecosystem functioning, are therefore unlikely to be directly affected through changes in these secondary metabolites.

KW - Carbon-nutrient balance

KW - Elevated CO

KW - Pinus sylvestris L.

KW - Tannins

KW - Terpenes

KW - Biology

KW - Ecosystems Research

UR - http://www.scopus.com/inward/record.url?scp=0031815788&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/1bb399a1-068d-344a-9c1f-b40235443bdd/

U2 - 10.1007/s004420050526

DO - 10.1007/s004420050526

M3 - Journal articles

AN - SCOPUS:0031815788

VL - 115

SP - 344

EP - 350

JO - Oecologia

JF - Oecologia

SN - 0029-8549

IS - 3

ER -