Factors Affecting Red Spruce Regeneration in Delining Areas of Camels Hump Mountain, Vermont

Abstract

Scarcity of red spruce (Picea rubens Sarg.) seedlings in declining spruce-fir forests of Camels Hump mountain, Vermont, prompted a study on some contributing factors involved in failure of spruce regeneration. Cones were shorter than those from low elevation red spruce trees from unaffected sites. Seed number in cones collected in declining areas of Camels Hump was low as were seed sizes and weights. Seed germination was at control levels only in good seed years. Capacity of seeds to form seedlings was reduced relative to that of controls, although seedling growth was normal. Coniferous litter contains presumed allelopathic substances leachable by contemporary precipitations that affect seed germination and seedling root development in red spruce, but not in balsam fir. Shield fern contains leachable substances that reduce seed germination and seedling root development in red spruce, but not balsam fir. Roots of red spruce germlings have lower capacity to penetrate through the increased forest duff depths of declining forests than do balsam fir roots. It is anticipated that substantial reproduction of red spruce will not occur in declining montane conifer forests under present conditions.