Treesearch

This paper revises a previously published range map of South Florida slash pine (Pinus elliottii Engelm. var. densa Little & Dorman) (Jour. Forestry 50 :918-023) and shows that this species occurs inland in the south central part of Florida.

WETLAND HYDROLOG¥ is a new and unique field of study in watershed 111anagentent research. Watershed managPmc11t needs are generally assoeiated with dry soil couditions or mountain nn•as where water is either a limited re;;ource or a flood producer, rather than with level areas where soils are saturated mueh of the time. Yet new rP earch in wetland hydrology in the Lake States and in the outheast has shown the need for knowledge about water relationships in saturated areas too. The key to research needs in these area. is lack of 1.-nowledge-about the interrelationships between water...

A series of 47 uncut, ¼-acre plots of insect- and disease-free even-aged pure loblolly pine in Georgia, South Carolina, and Virginia were selected for use in assessing the effects of age, site index, and density on sawlog quality. Plot ages ranged from 25 to 93 years, site indices from 52 to 104 feet, and stand densities from 102 to 179 square feet of basal area per acre of stems 0.6 d.b.h. and larger. The index of sawlog quality was "K"/MBF where "K" equals the number of overgrown knots, plus the sum of diameters of sound exposed knots, plus twice the sum of diameters of unsound knots....

Past studies in loblolly pine mensuration have resulted in the development of numerous analytic models for growth and yield. Most have treated growth and yield as essentially independent phenomena with no attempt to develop models that possess the logical compatibility which must exist between growth and yield observations. The present study develops models intended to express realistically the relationships between growth and yield. As an initial step, previously-used basal area and cubic-foot yield models were examined and screened for use in the analysis. The yield models selected for...

Stream crossings are the most vulnerable points in a deer-proof fence. When an inadequately constructed crossing washes out, enclosed deer may escape and unwanted animals enter. Structures of the type described here have withstood 2 years of frequent, severe flooding in the pine-hardwood hills of central Louisiana.

Sycamore seedlings survive better and, when fertilized, outgrow cuttings. These findings were determined from a planting made in 1961 in the Oconee River bottoms in Greene County, Georgia.

Greenwood stem cuttings taken from root suckers of Populus tremuloides and P. grandidentata were rooted in coarse sand under both intermittent mist and polyethylene sheeting in a greenhouse and under mist in an outdoor propagation bed. Prerooting treatment of cuttings with aqueous solutions of lBA (20-100 p.p.m. ) stimulated rooting. P. grandidentata cuttings were more difficult to propagate than those of P. tremuloides. Fungal and bacterial infection accounted for high mortality of cuttings in some experiments.

As a prelude to tree improvement work in the genus Swietenia, a study was made of specific gravity variation within the bole of six plantation-grown trees of bigleaf mahogany. Variation was appreciable, from 0.36 to 0.65 , and several patterns were determined. Specific gravity of the tree increased with growth rate, as expressed in diameter at breast height, but not with relative length of radius at a given height in a particular tree. It increased outward from the pith; but it was high at the base dropped markedly to a minimum at eight feet, then increased to near the base of the crown....