Showing papers on "Undergrowth published in 1975"

Undergrowth vegetation effects on the nutrient content of litterfall and soils in red pine and birch stands in Northern Minnesota.

Abstract: The role of hazel shrub and herbaceous undergrowth layers in nutrient cycling was studied in two red pine (Pinus r esinosa Ait) and two paper birch (Betula papyrifera Marsh) stands on similar soil types in northern Minnesota The annual litterfall produced by these undergrowths and by the overstory was sampled at 15 points in each stand as was the forest floor; the top 3 cm of mineral soil was sampled at 7 of the points In the pine stands both undergrowth layers significantly added to the total dry weight of litterfall Under hazel there was significantly more N, Ca, and Mn, and under herbs there was more than twice the amount of K in the litterfall than where these undergrowth layers were absent In the birch stands the differences in the nutrient content of the litterfall beneath these undergrowth layers were not great, and undergrowth layers had less effect on the nutrient cycle Although greater amounts of nutrients occurred in the litterfall under hazel and herbaceous layers, the amounts of total nutrients in the forest floor under each undergrowth type were not significantly different nor were total N, available P, or exchangeable K, Ca, Mg, and Mn in the top 3 cm of mineral soil Turnover rates were different under each type of undergrowth and in red pine stands the forest floor under hazel and herbs appeared to decompose more rapidly than the forest floor of pure pine, but not as rapidly as the forest floor under either hazel or herbs in the birch stands

Effects of the herbicide 2, 4, 5 – T on Onychiurus quadriocellatus Gisin (Coll.)

Abstract: The herbicide 2,4,5 trichloro phenoxy acetic acid (2,4,5-T), a representative of the hormone herbicides, is used in coniferous forests in The Netherlands to control the black cherry Prunus serotina Ehrh. This species, which was imported from Nothern America and planted in our forests mainly because it was thought to improve soil conditions, gradually became a serious problem. Because of its vigorous growth and competitive powers, it became dominant in many coniferous forests and in addition a number of deciduous stands with value from the point of view of nature conservancy were also invaded, interesting undergrowth being replaced by a uniform black cherry vegetation.

Influence of brushwood and undergrowth upon distribution of litter beetles in poor pine forests

Abstract: The influence of environmental differentiation upon the occurrence of animals permanently attracts notice of biocenology, mainly in view of the economically important knowledge of this phenomenon. This is why the ameliorative role of deciduous undergrowth (mainly oak and beech) , introduced artifically to poor pine forests, should be studied comprehensively. Considering the role of undergrowth, we cannot overlook the influence of brushwood on the soil fauna, which can be restricted by the undergrowth.