B. Stadler et B. Michalzik, Linking aphid honeydew, throughfall, and forest floor solution chemistry of Norway spruce, ECOL LETT, 1(1), 1998, pp. 13-16
In a seminatural manipulation experiment with artificial irrigation we foll
owed throughfall and forest floor solution chemistry collected underneath a
phid infested and uninfested Norway spruce. Solutions underneath infested t
rees showed significantly higher concentrations of dissolved organic carbon
(DOC) but lower concentrations of dissolved organic nitrogen (DON), NO3-N,
and NH4-N in throughfall solutions and of NH4-N in forest floor solutions.
Average concentrations were 40.5% (DON), 27.5% (NO3-N), and 46.2% lower (N
H4-N) underneath infested trees in throughfall solutions, and 19.5% (DON),
9.4% (NO3-N), and 42.0% (NH4-N) lower in forest floor solutions. Difference
s in throughfall were more pronounced than in forest floor leachates. It is
likely that honeydew is fuelling the metabolism of micro-organisms and thu
s critically affects above and below ground nutrient cycles. We emphasize t
he importance of linking the biology of herbivores and micro-organisms with
geochemical processes.