Murray F. Buell

THE UPLAND FOREST CONTINUUM IN NORTHERN NEW JERSEY

Quantitative data on trees, saplings and tree seedlings were taken from 60 acceptably homogeneous upland stands on a wide variety of geological substrata and topographic positions throughout northern New Jersey, partly to test the applicability of a unidimensional continuum in a heterogeneous environment. The strong negative correlation between stand altitude and continuum index could not be ascribed to altitude alone because rich calcareous soils were found at low altitudes while poor, shallow soils from more resistant rocks were found at higher elevations. Species diversity was greatest in forests on limestone substrata. Although Quercus species were found as leading species in 54 of the 60 stands, sapling data showed that in these forests as a whole succession is leading from dominance by oaks to dominance by Tsuga canadensis or by Acer saccharum, the association between these two species being weak. Though useful as a tool for the study of vegetation, a linear continuum was not applicable to the forests of northern New Jersey; they appear to conform to a pluri- dimensional continuum. It is concluded that the Clementsian concept of climax, as a process, is in no way degraded by the concept of the continuum, either linear or pluridimensional.

A Study of Two Forest Stands in Minnesota with an Interpretation of the Prairie‐Forest Margin

The deciduous forest extends northwestward in the northern half of Minnesota as a narrowing band between the coniferous forests on the east and the prairies on the west. This is well illustrated by Uphams original map of the vegetation of Minnesota and the various reproductions of it (Upham 1884, Rosendahl and Butters 1928, Daubenmire 1936, Buell and \Wilbur 1948). As is characteristic of such major vegetational transitions, the contacts of the deciduous belt with adjacent formations are usually not sharp. There is evidence that they are not at present in a state of equilibrium. As Griggs (1946) infers, such contacts probably seldom are. East of the hardwood belt there is a broad transition zone between it and the coniferous forests where, in the pattern of distribution of the vegetation, the conifers form the continuous phase and the maple-basswood community the discontinuous l)llase. Continuing eastward in northern Minnesota there are increasingly greater distances between the stands of the hardwood forest. West of the hardwood belt the continuous phase gradually shifts from deciduous forest to prairie. Isolated stands of trees or clumps of shrubs occur along the easternmost margin of the prairie. The transition to prairie is sharper than that to

Surface Level Fluctuation in Cedar Creek Bog, Minnesota

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org. Ecological Society of America is collaborating with JSTOR to digitize, preserve and extend access to Ecology.

Radial Mat Growth on Cedar Creek Bog, Minnesota

A bog mat surveyed in 1934, and at irregular intervals since, was reexamined in 1967. After 33 years the position of the margin of the mat was essentially unchanged, but the width of the zones had changed. The Decodon on the aquatic margin had increased slightly, and the larch—shrub zone had expanded outward, greatly reducing the sedge mat. The indications are that the concentric zones surrounding open water expand and contract under changing conditions, principally fluctuating water levels. See full-text article at JSTOR

Natural Revegetation of a Plowed Field in the New Jersey Pine Barrens

The vegetation on a formerly cultivated field in the New Jersey Pine Barrens was surveyed 5 and 13 months after abandonment. Both surveys indicated that Panicum virgatum, P. capillare, and Cyperus filiculmis var. macilentus were the most important components of the vegetation. The second survey revealed 53 species not encountered in the first survey. The total vascular flora of the 1-acre field was found to consist of 113 species. This is an extremely diverse flora for an area of this size in the Pine Barrens.

The Reproducibility of Shrub Cover Sampling

To test the validity of making quantitative measurements of vegetation cover, replicate samples of the same stand of vegetation were made. The line intercept method was used to determine shrub cover values on eight 10—m lines. The results treated statistically indicate that the sampling procedure is reproducible and the results directly comparable. See full-text article at JSTOR