Hardwood Invasion in a Comparatively Old White Pine Afforested Area

Abstract

What will be the ultimate effect of biotic factors on developing forests is a problem of extreme importance in many of the eastern states where reforestation plans are rapidly being materialized. Especially is this true where areas or habitats not wholly adapted for certain desired conifer species are involved. At the present time we have attained a considerable knowledge relative to the effects of such biotic factors as plant succession, disease, insects and man upon forest production in natural habitats, but as yet little information is available relative to the r6le these factors play in afforested areas which have been allowed to revert to nature after years of careful forest management. With this problem in mind, the writer, in September, 1930, began a study of the effects of certain biotic factors in a small and comparatively old afforested area carrying a stand of white pines, Pinus strobus, which were in some cases approximately a century old. From general observations, it was apparent that hardwoods had invaded the stand with such rapidity and success that they threatened to become the dominant species in the near future. Furthermore, it was evident that the white pines were suffering a high mortality, due to biotic or edaphic disturbances. In the course of the investigation, a number of quadrats were laid out and photographs were taken of the vegetation in order to secure data relative to the effects of the plant invasion in the pine grove over a long period of time. It was necessary to discontinue this study in November, 1931, when the city of Syracuse (present owner of the grove) found it necessary to eradicate the invading vegetation in order to prevent the partial or complete destruction of the white pine. The invaders, with the exception of a few cherry and maple trees, Prunus serotina, P. avium and Acer saccharum were removed and the habitat was rejuvenated in many low places by the addition of several inches of fertile soil. Before this change was made, considerable data were obtained which may throw some light on the problem mentioned above. Historically, little is known of the original owner of the pine grove or of the date of the planting other than the annual ring history obtained from the trees. There are, however, two aged residents in the neighborhood who can recall several facts concerning the pine grove as it appeared and was managed 65 years ago. They state that there was at that time (i866) a