Premium
Insects and fungi on a C 3 sedge and a C 4 grass exposed to elevated atmospheric CO 2 concentrations in open‐top chambers in the field
Author(s) -
THOMPSON G. B.,
DRAKE B. G.
Publication year - 1994
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/j.1365-3040.1994.tb02014.x
Subject(s) - biology , botany , festuca rubra , scirpus , shoot , horticulture , ecology , wetland
The effects of elevated atmospheric CO 2 concentration on plant‐fungi and plant‐insect interactions were studied in an emergent marsh in the Chesapeake Bay. Stands of the C 3 sedge Scirpus olneyi Grey, and the C 4 grass Spartina patens (Ait.) Muhl. have been exposed to elevated atmospheric CO 2 concentrations during each growing season since 1987. In August 1991 the severities of fungal infections and insect infestations were quantified. Shoot nitrogen concentration ([N]) and water content (WC) were determined. In elevated concentrations of atmospheric CO 2 , 32% fewer S. olneyi plants were infested by insects, and there was a 37% reduction in the severity of a pathogenic fungal infection, compared with plants grown in ambient CO 2 concentrations. S. olneyi also had reduced [N], which correlated positively with the severities of fungal infections and insect infestations. Conversely, S. patens had increased WC but unchanged [N] in elevated concentrations of atmospheric CO 2 and the severity of fungal infection increased. Elevated atmospheric CO 2 concentration increased or decreased the severity of fungal infection depending on at least two interacting factors, [N] and WC; but it did not change the number of plants that were infected with fungi. In contrast, the major results for insects were that the number of plants infected with insects decreased, and that the amount of tissue that each insect ate also decreased.