Multiple indirect effects of plant litter affect the establishment of woody seedlings in old fields

• Published in: Ecology (Durham) 1994-09, Vol.75 (6), p.1727-1735
• Main Author: Facelli, J.M
• Format: Article
• Language: English
• Subjects: AILANTHUS; AILANTHUS ALTISSIMA; Animal and plant ecology; Animal, plant and microbial ecology; Arthropods; Biological and medical sciences; BIOLOGICAL COMPETITION; Biomass; COMMUNITY ECOLOGY; COMPETENCIA BIOLOGICA; COMPETITION BIOLOGIQUE; DEPREDACION; ECOLOGIA VEGETAL; Ecological competition; Ecology; EMERGENCE; EMERGENCIA; ESTABLECIMIENTO DE PLANTAS; ETABLISSEMENT DE LA PLANTE; FOREST LITTER; Fundamental and applied biological sciences. Psychology; GRAINE; GROWTH RATE; herb; Herbivores; Herbs; HOJARASCA FORESTAL; INDICE DE CRECIMIENTO; INSECTA; INSECTICIDAS; INSECTICIDE; INSECTICIDES; Insects; LEVEE; LITIERE FORESTIERE; NEW JERSEY; PHYTOECOLOGIE; PLANT COMPETITION; PLANT ECOLOGY; PLANT ESTABLISHMENT; PLANT INTERACTION; Plant litter; PLANTAS SILVESTRES; PLANTE SAUVAGE; PLANTULAS; PLANTULE; Poultry litter; PREDATION; SEEDLING EMERGENCE; SEEDLINGS; SEEDS; SEMILLA; Synecology; TAUX DE CROISSANCE; Terrestrial ecosystems; Trees; WILD PLANTS
• ISSN: 0012-9658; 1939-9170
• DOI: 10.2307/1939632

I studied the effects of oak leaf litter, herb competition, and insect herbivory on the establishment of seedlings of Ailanthus altissima in New Jersey, USA. I performed two experiments in an early-successional site in two consecutive years. In the first experiment I tested the effects of litter and competition, and their interaction, on establishment and growth of tree seedlings. In the second experiment I studied the effect of insecticide application in combination with litter and herb competition on seedling establishment and growth, and on arthropod abundance. In the absence of competition, litter had no significant effect on the biomass of woody seedlings, though it delayed seedling emergence. Herb competition reduced the growth of the woody seedlings, but the addition of leaf litter reduced the density and biomass of the herbs, indirectly improving the growth of the woody seedlings. Litter increased both invertebrate damage to seedling cotyledons and seedling mortality. The application of insecticide increased seedling emergence and reduced seedling mortality, and more so in the presence of litter. The total number of arthropods and the number of plant-chewing arthropods were increased by the addition of litter and reduced by application of insecticide. Thus, litter had, simultaneously, a positive indirect effect on individual biomass through reduced competition, and a negative indirect effect on the number of individuals through increased seed/or seedling predation, and a negative direct effect on seedling mortality.