Gl. Mills et al., Changes in fatty acid and hydrocarbon composition of leaves during decomposition in a southeastern blackwater stream, ARCH HYDROB, 152(2), 2001, pp. 315-328
Fatty acid and hydrocarbon composition were determined in decomposing leaf
packets of sweetgum (Liquidambar styraciflua) and water oak (Quercus nigra)
from a snag habitat in a southeastern blackwater stream. The initial total
fatty acid and hydrocarbon concentrations in sweetgum leaves were signific
antly greater than in the oak species. Higher concentrations of unsaturated
fatty acids and dicyclic diterpenoid hydrocarbons accounted for most of th
is difference. Both of these biochemical subgroups are preferentially degra
ded relative to the bulk leaf material and other corn pounds within their r
espective lipid classes. No significant differences remained after 70 days
of decomposition. Cuticular fatty acids are selectively preserved and thus,
increased relative to noncuticular components during decomposition. The ba
cterially derived iso- and anteiso-branched-chain fatty acids increased mar
kedly after 23 days. The results of this study suggest that qualitative dif
ferences in lipid composition may contribute to the observed difference in
overall decomposition rate of leaves between these species.