The Insect Ecology of Red Pine Plantations in Central Ontario: IV. The Crown Fauna

Abstract

The faunal changes in the crown stratum of a newly established red pine plantation were observed during the first five years of growth. The crown faunae of three older stands planted in 1950, 1939, and 1929 were sampled throughout the growing seasons of four consecutive years by a technique employing pyrethrum insecticide. The stands represent four stages in the development of a red pine community over a period of 35 years, and the presence, distribution, density, annual and seasonal fluctuations, species succession, and food relations of arthropod taxa are discussed. Species colonizing trees in the establishment stage are largely replaced in the transition stage by a species-complex that persists throughout the succeeding monoculture and young-forest stages. Arthropod density in relation to crown size increases rapidly until the trees are about 15 years of age, and then declines. The pattern of seasonal abundance is dominated by a few species. The ratio between parasite–predator and prey species remains remarkably stable throughout the three older stages of the community.