The Upland Forest Continuum in Northern New Jersey

Abstract

Quantitative data on trees, saplings and tree seedlings were taken from 60 acc~~tably homogeneous upland stands on a wide variety of geological substrata and topographic pos1~1ons th=oughout northern New Jersey, partly to test the applicability of a unidimensional co~tmuum m a ~eterog~neous environment. The strong negative correlation between stand al~ttude and contmuum mdex could not be ascribed to altitude alone because rich calcareous smls were _found at low altitudes while poor, shallow soils from more resistant rocks were found at htgher elevati~:ms. Species diversity was greatest in forests on limestone substrata. Although Qu~rcus spectes were found as Ieading species in 54 of the 60 stands, sapling data sho~ed that m these forests ~s a whole succession is leading from dominance by oaks to dom~nance. by Tsuga canadensts or by Acer saccharum, the association between these two spectes bemg. weak. Though useful as a tool for the study of vegetation, a linear continuum ~as no_t apphcab!e to the fo:ests of northern New Jersey; they appear to conform to a pluri-?u~enstonal contmuum. It 1s concluded that the Clementsian concept of climax, as a process, 1s m no way degraded by the concept of the continuum, either linear or pluridimensional.

The effects of environment and life stage on Quercus abundance in the eastern deciduous forest, USA: are sapling densities most responsive to environmental gradients?

“…White oak adult and sapling densities were highest on southern and southwestern slopes, as also reported by Keever (1953) and McCarthy et al (1984). Likewise, chestnut oak adult and sapling densities were greater on upper slopes and ridge tops, which is in agreement with the findings of Whittaker (1956), Buell et al (1966) and Lorimer (1980). Management strategies that consider aspect for white oak and slope position for chestnut oak will likely be more fruitful than strategies that focus on other site characteristics.…”

“…a Importance value = (relative dominance + relative density)/2. b Buell et al (1966) considered n. red oak, white oak and chestnut oak combined, sometimes and confounds (1) soil moisture with slope position; and (2) slope position with successional stage. c Greller et al (1979) does not describe whether these ''flats'' are ridge top, bottom lands, or not associated with slope position.…”

Late Holocene Pollen Stratigraphy in Four Northeastern United States Lakes

“…Castanea and Quercus were consistently present in the region, especially during the time represented by Zone III. In southeastern Pennsylvania and New Jersey, Quercus species, in combination with Carya (and Castanea prior to this century), are found on drier sites, while Tsuga and the northern hardwoods are found on more mesic sites (KEEVER, 1973;ROBICHAUD and BUELL, 1973;BUELL et al, 1966;OHMAN and BUELL, 1968). Tsuga is sensitive to drought and disturbance (ROGERS, 1978).…”

Catenation: Quantitative methods for the definition of coenoclines

“…The main limitation of the method is that the subjective ordering of dominants becomes difficult when there are more than about five of them, or when a single overriding gradient cannot account for most of the variation (Gimingham et al, 1966;Buell et al, 1966). In any case only one such catena can be extracted.…”

“…2). Tsuga canadiensis was assigned the extreme position at the upper end, rather than Acer saccharum (see also Buell et al 1966). Transposing Table 1 Average importance values of trees in stands with given species as leading dominant-Wisconsin B (from Brown & Curtis 1952) (species abbreviations: Bt = Betula lutea, Ar = Acer rubrum, others as in fig.…”