Breeding systems and pollination requirements of two wild lowbush blueberries, Vaccinium angustifolium and V. myrtilloides, in the Canadian boreal forest in the Chapleau Crown Game Preserve, Ontario, were tested. Fruit production, size and seediness were significantly higher in samples exposed to natural pollination than in those cross-or self-pollinated by hand. There were no significant differences among artificial treatments (variously hand-pollinated and bagged) except when cross-pollination (xenogamy) was done by insect pins. In V. angustifolium, the density of flowering varied with forest age (canopy closure). It was most in open areas and least in the sites with the most mature forest. Although fruit-set and seediness varied among forest habitats of different ages, there were no significant differences between sites in forests of different ages. Thus, pollination seems to be similarly effective no matter the age of the forest. In both species, fruit-set in 1992, which had severe June frosts, was markedly poorer than that in 1993 when the flowers suffered little frost damage. The combined number of complete and incomplete seeds from the fruit among the breeding and pollination systems tested were similar; however, the ratio of complete seeds to total seeds was greater from cross-pollinated than from self-pollinated flowers. Our observations indicate that there is little natural fruit-set without insect-mediated cross-pollination and that cross-pollination provides much better fruit and seed-set than does self-pollination.

Pollination systems in the boreal zone range from generalist to specialist, both entomologically and botanically. The relative importance of wind pollination, insect pollination, sexual separation between and within plants, and between flowers, hermaphroditism of flowers, and various breeding systems are related to plant growth form and habitat. The diversity and specializations of anthophilous insects parallel those in other bioge0graphic zones, but seem less developed. We suggest that this reflects the combined effects of evolutionary youth, severity of climate, restriction of symbiont ranges within those of their hosts, and the naturally frequent perturbations by fire or insect outbreaks in the zone, requiring faunal and floral vagility and constraining specialization in mutualism. Modern perturbations by logging and pesticides seem to be well buffered because of the relative openness of the ecosystem (compared to others), although damage has been documented. Insect pollination is as much a keystone process in the boreal forest as elsewhere, despite the immediate counter-impression given by the dominance ofwind-pollinated conifers. Nevertheless, there are few studies, botanical or entomological in situ. The boreal system offers important opportunities in general and applied research in pollination ecology and synecology generally.

Usui,M.,Kakuda,Y.andKevan,P.G. lgg4.Compositionandenergyvaluesofwildfruitsfromtheborealforestofnorthern Ontario. Can. J. Plant Sci. 74: 581-587. Seventein wild fruit species from the Chapleau Crown Game Preserve in northern Ontario were investigated for composition and energy value. The mean moisture, fat, protein and carbohydrate levels were77.l., 0.84, 1.6 andT .6%,-respectively,iased on fresh fniit weight. Carbohydrates showed the greatest variations in composition.with values ranging from 1.8% for corn lLly to 16.4% for wild sirsaparilla. Total energy values were 9f9u]ateO !q. 4: compositional data. Wild sarsaparilla (73.4kcal ttjO g-t), pincherry (69.8-kcal 100 g-r). red elderberry (68'8 kcal 100 g-'), serviceberry (54.0 kcal 100 g^-t, and lowbush bluebeiry (52.5 kcal 100 g -r; were ranked in the top five. Two species of lowbush blueberries iV. angustifoliim 4nd V. myrtilloides) were studied for location and level of slope effects on composition and total energy values.