B. Stadler et T. Muller, Effects of aphids and moth caterpillars on epiphytic microorganisms in canopies of forest trees, CAN J FORES, 30(4), 2000, pp. 631-638
Citations number
36
Categorie Soggetti
Plant Sciences
Journal title
CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE
Different types of herbivores were investigated for their effects on microo
rganisms in the phyllosphere of forest trees during the growing season. Aph
ids on spruce, beech, and oak produced honeydew, which was readily consumed
by microorganisms and resulted in two to three orders of magnitude higher
densities (colony forming units) of bacteria, yeasts, and filamentous fungi
on leaves of infested trees. The amounts of honeydew excreted by different
aphid species and their mode of excretion (large droplets, tiny droplets s
cattered over leaves, production of wax wool) affected the degree to which
honeydew could be processed by epiphytic microorganisms. All groups of micr
oorganisms appeared to be energy limited. These results were consistent for
different growth media offered to the microorganisms. Leaf-feeding moth ca
terpillars also positively affected the growth of microorganisms on leaves
of beech and oak. The effects were more pronounced for bacteria and yeasts
especially on oak. Thus, different functional groups of herbivores positive
ly affected the growth of microorganisms in the phyllosphere of trees. It i
s suggested that the population dynamics of herbivores and their feeding ch
aracteristics are important features, which should be considered when the p
opulation dynamics of microorganisms in the canopies of trees is studied.