Premium
Enriched atmospheric CO 2 and defoliation: effects on tree chemistry and insect performance
Author(s) -
Roth Sherry,
Lindroth Richard L.,
Volin John. C.,
Kruger Eric. L.
Publication year - 1998
Publication title -
global change biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.146
H-Index - 255
eISSN - 1365-2486
pISSN - 1354-1013
DOI - 10.1046/j.1365-2486.1998.00164.x
Subject(s) - maple , sugar , salicaceae , aceraceae , botany , biology , horticulture , woody plant , chemistry , food science
We examined the effects of CO 2 and defoliation on tree chemistry and performance of the forest tent caterpillar , Malacosoma disstria . Quaking aspen ( Populus tremuloides ) and sugar maple ( Acer saccharum ) trees were grown in open‐top chambers under ambient or elevated concentrations of CO 2 . During the second year of growth, half of the trees were exposed to free‐feeding forest tent caterpillars, while the remaining trees served as nondefoliated controls. Foliage was collected weekly for phytochemical analysis. Insect performance was evaluated on foliage from each of the treatments. At the sampling date coincident with insect bioassays, levels of foliar nitrogen and starch were lower and higher, respectively, in high CO 2 foliage, and this trend persisted throughout the study. CO 2 ‐mediated increases in secondary compounds were observed for condensed tannins in aspen and gallotannins in maple. Defoliation reduced levels of water and nitrogen in aspen but had no effect on primary metabolites in maple. Similarly, defoliation induced accumulations of secondary compounds in aspen but not in maple. Larvae fed foliage from the enriched CO 2 or defoliated treatments exhibited reduced growth and food processing efficiencies, relative to larvae on ambient CO 2 or nondefoliated diets, but the patterns were host species‐specific. Overall, CO 2 and defoliation appeared to exert independent effects on foliar chemistry and forest tent caterpillar performance.