Open AccessConsumption by needle‐eating insects on Scots pine in relation to season and stand age
Author(s) -
Tenow Olle,
Larsson Stig
Publication year - 1987
Publication title -
ecography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.973
H-Index - 128
eISSN - 1600-0587
pISSN - 0906-7590
DOI - 10.1111/j.1600-0587.1987.tb00766.x
Subject(s) - frass , scots pine , population density , guild , biology , zoology , ecology , biomass (ecology) , population , forestry , geography , horticulture , botany , pinus <genus> , demography , habitat , larva , sociology
Trapping of frass‐drop from needle‐eating insects in three Scots pine stands, 18‐, 55‐and 120‐yr‐old, respectively, in three years, revealed that the consumption rate in the two older stands on average displayed three peaks: in July (consumption by Panolis flammea and a first wave of diprionids), late August/early September (lasiocampid/sphingids, a second wave of diprionids), and September/October ( Bupalus piniarius ). Annual consumption was the same in these two stands, on average 7 kg dw ha −1 . In the young stand, there was no late season peak (due to the absence of B. piniarius ,) consumption ceasing one month earlier, at 0.2 kg dw ha −1 . Consumption intensity (consumption per needle biomass) corresponded to 0.05%, 0.5% and 1.2% of new needle production, respectively, in the three stands, and increased approximately linearly with the needle biomass of the tree. This increase with size (age) of the tree seems to be due to the multiplicative effect of a larger complexity of the grazer guild and a higher population density of single insect species.