Strip Cut Research Articles

Evaluation of site impacts associated with three silvicultural prescriptions in an upland hardwood stand in northern Alabama, USA

Soil disturbance patterns and associated changes in soil physical status were measured in a study that evaluated the implementation of three alternative management prescriptions in an upland hardwood stand in northern Alabama, USA. Management prescriptions applied in this study consisted of a clear-cut, strip cut, and deferment cut that were compared to a non-harvested control. Final tabulations of disturbance types indicated disturbance to be similar in clear-cut and deferment cut treatments with less disturbance in strip cut sites. Soil physical response varied by soil property but, in general, as disturbance intensity increased, soil physical properties responded accordingly. Bulk densities were elevated to the highest degree in the clear-cut sites while soil strength as indicated by cone index measurements attained its highest levels in the deferment cut. These differences were thought to be due to differences in trafficking patterns related to the implementation of each management prescription.

Modelling the temporal variation in the seed production of North American trees

Many aspects of temporal variation in tree seed production (e.g., the proability distribution, periodicity, uni modality) are poorly understood. In this paper, we used 32 annual seed production records from 22 species to show that there are no discernible endogenous cycles, and there is a modest (but seldom significant) tendency for a high seed production year to be followed by an unusually low production year. Finally, we found that all of the records conformed to a single lognormal probability distribution, although our ability to discriminate among species, given short and extremely variable records, is admittedly very limited. We used the lognormal to develop the distribution of the sums of local seed production events (summed across 4 years) as an aid in predicting postharvest or postfire tree regeneration success. Our conclusion is that reliable (defined as 90% of the time) adequate stocking at the edge of an area source requires that the species of interest must comprise a very large fraction of the total basal area per area. Indeed, if the species constitutes less than about 50% of the source, neither burns nor even very narrow strip cuts will be reliably stocked.

215 Estimation of Longitudinal Tensile Strength in Filament Wound Pipe using Notched Specimen

For the longitudinal tensile strength of filament wound pipes of glass fiber reinforced plastics (GFRP), Japan Industrial Standard K 7033 (JIS K 7033) was established in 1998,where three kinds of test methods (method A, B and C) were recommended for determining the tensile strengths. The objectives of this study were to compare the tensile strengths measured by each test method and to check whether each test results were acceptable or not for the modified test methods. The longitudinal tensile tests were conducted based on the JIS K 7033. For specimen geometry, a strip cut in the longitudinal direction of the pipe was used in method A, method B used a full section of the pipe and method C used a notched rectangular plate cut from a pipe wall section, so that two of the sides were parallel and the other two sides were at right angles to the longitudinal axis of the pipe. It was found that the three tensile strengths often did not agreed with each other within lower winding angles, and method C agreed with method B within higher winding angle. We discussed the accuracy of each test method, which was proposed as the simplified method to obtain the longitudinal tensile strength of the filament wound pipes.

Sexual recruitment of trees in strip cuts in eastern Canada

I tested a sexual recruitment model that couples equations for seed production, dispersal, and juvenile survivorship using 10 sets of recent strip cuts in Quebec and New Brunswick. The model states that seed production is dependent on basal area and inversely proportional to seed mass, while juvenile survival is directly proportional to seed mass. In consequence, the seed mass effects should (roughly) cancel out, and fecundity should be primarily a function of basal area. Further, the model predicts that species evenness should be more or less the same following strip-cutting. As expected from the model, the single best predictor (r2 = 0.53) of recruitment density was the basal area density (area/area) of the source trees, and all cuts were well stocked. There was a stronger tendency toward a post-harvest increase in species evenness than was expected. Ninety percent of all stems were recruited by the fourth growing season.

Sexual recruitment of trees in strip cuts in eastern Canada

I tested a sexual recruitment model that couples equations for seed production, dispersal, and juvenile survivorship using 10 sets of recent strip cuts in Quebec and New Brunswick. The model states that seed production is dependent on basal area and inversely proportional to seed mass, while juvenile survival is directly proportional to seed mass. In consequence, the seed mass effects should (roughly) cancel out, and fecundity should be primarily a function of basal area. Further, the model predicts that species evenness should be more or less the same following strip-cutting. As expected from the model, the single best predictor (r2 = 0.53) of recruitment density was the basal area density (area/area) of the source trees, and all cuts were well stocked. There was a stronger tendency toward a post-harvest increase in species evenness than was expected. Ninety percent of all stems were recruited by the fourth growing season.

A silvicultural experiment to mitigate pest damage

An optimal impact design experiment was established in 1997 to investigate silvicultural alternatives for reducing vulnerability of white spruce (Picea glauca (Moench) Voss) stands to spruce budworm (Choristoneura fumiferana (Clem.)) damage. Ecosystem and insect population responses are being assessed in stands, thinned using a cut-to-length harvest system that removed 25% or 50% of standing volume in three patterns: uniform shelterwood cuts, standard strip cuts, and strips with "feathered" edges. Clear-cuts and untreated checks support comparisons among the undisturbed state, conventional practice, and thinning regimes. Subplots in the uniform shelterwood cuts and untreated checks were fertilized with 200 kg N/ha in early spring of 1998. The experimental approach permits strong inferences to be made about treatment effects but requires several years to obtain the final results from the research program. Keywords: spruce budworm, thinning, project design

CFIRP: What we learned in the first ten years

In response to public dissatisfaction with forest management methods, we initiated the College of Forestry Integrated Research Project (CFIRP) to test alternative silvicultural systems in Douglas-fir (Pseudotsuga menziesii) stands in western Oregon. We compared costs and biological and human responses among a control and three replicated silvicultural alternatives to clearcutting that retained structural features found in old Douglas-fir forests. Treatments were applied within 8- to 15-ha stands and attempted to mimic crown fires (modified clearcut), windthrow (green tree retention), and small-scale impacts such as root rot diseases (small patch group selection). We also compared costs in three unreplicated treatments (large patch group selection, wedge cut, and strip cut). Each treatment included differences in the pattern of retained dead trees (snags), as either scattered individuals or as clumps. Good communication among researchers and managers, a long-term commitment to the project, and careful documentation of research sites and data are important to the success of long-term silvicultural research projects. To date, over 30 publications have resulted from the project. Key words: alternative silviculture, data management, Douglas-fir, green tree retention, harvesting costs, human dimensions, Oregon, Pseudotsuga menziesii, recreation, wildlife

Effets de la coupe à blanc et de la coupe par bandes sur la régénération obtenue après 5 ans dans des pessières noires du Québec

An experiment was conducted to compare the effects of traditional clear-cutting with those of strip cutting on regeneration of black spruce, Piceamariana (Mill.) B.S.P., stands on scarified and unscarified uplands and on lowlands. To that effect, regeneration surveys were done before cutting, in the following year, and 3 and 5 years after cutting. Five years after harvesting, strip cutting led to higher coniferous stocking than clear-cutting on scarified uplands and on lowlands. On unscarified uplands, the gain attributable to strip cutting was not significant. The coniferous stocking of strip cuts on scarified uplands was not greater than on unscarified uplands. So the efficiency of scarification could not be proved in that study. Stocking obtained after 5 years remained closely related to the one observed immediately after harvesting in the strip cufs as in the clear-cuttings. This is particularly true for balsam fir, Abiesbalsamea (L.) Mill. In the strip cuts, the balsam fir stocking was constant while the one of black spruce increased. This could have an impact on the evolution of the composition of the new stands and, consequently, on their vulnerability to spruce budworm, Choristoneurafumiferana (Clem.). The majority of the clear-cuttings were well regenerated 5 years after harvesting. Their average coniferous stocking was slightly above 60%. However, 48% of the clear-cuttings did not reach this level when only unscarified plots on uplands were considered. Advance growth was abundant in those plots but suffered high losses during harvesting. Consequently, reducing the losses during harvesting would result in a lower proportion of clear-cuttings with insufficient coniferous stocking 5 years after cutting. On the other hand, almost all the strip cuts with insufficient regeneration after harvesting were well regenerated 5 years later. Thus, strip cutting could be an interesting option on sites with insufficient advance growth and on sites well regenerated before cutting but where important losses during harvesting are anticipated.

A spatial problem for an elastic wedge with a strip cut

Integral equations are obtained for problems of the elastic equilibrium of a spatial wedge, weakened by a planar strip cut located in the median half-plane of the wedge, for different boundary conditions on the faces of the wedge. A known normal load, which is symmetrical about the plane of the cut is applied to the edges of the cut. In the case when the cut reaches the edge of the wedge, the solution of the problem using the method of paired integral equations reduces to Fredholm integral equations of the second kind with symmetric kernels. The possibility of the cleavage of the wedge along an edge [1] is shown. A simple formula which is convenient for applications is found for the normal stress intensity factor at one end of the cut. Calculations for various wedge aperture angles are carried out using this formula.

Plant species diversity on even-aged harvests at the Hubbard Brook Experimental Forest: 10-year results

Comparisons of plant species diversity were made on two separate watersheds treated by a block clearcut and progressive strip cut in the Hubbard Brook Experimental Forest in New Hampshire. Intrinsic diversity profiles were used to make diversity comparisons. A jackknifing technique was used on the diversity profiles for bias correction and to test for intrinsic diversity orderings. Comparisons were made within treatments over time and between treatments at 1 and 10 years after cutting. The results suggest that plant species diversity was lowest the year following treatment on both watersheds, and that it was at its highest 10 years after cutting on the progressive strip cut; however, diversity was found to be decreasing after 10 years on the block clearcut. In addition, the data suggest that the overall diversity of the progressive strip cut was higher than that of the block clearcut both immediately and 10 years after treatment.

Évolution de la régénération, dans deux vieilles coupes par bandes, dans des peuplements d'épinette noire au Québec

The distribution and growth in height of two black spruce populations were studied in two areas that had been strip cut, one in 1968–1969 in the Nicauba Experimental Forest and the other in 1954 around Lake Massie. By careful sampling of trees, advance growth could be differentiated from post-established regeneration; to a certain extent, spruce originating from seed could also be distinguished from trees that grew by layering. Stem analysis was used to compare the juvenile growth of advanced and post-established regenerated black spruce to that of trees in the residual strips. The stocking and the density are high for black spruce 18–20 years after logging, regardless of their origin (seed, layering, advance growth, or post-established regeneration): more than 80% and over 18 000 stems/ha, respectively. The yield for seedlings is not uniform from strip to strip; it is significant in some and negligible in others. Thirty-four years after strip-cutting the area around Lake Massie, the stocking of black spruce is also over 80% and the density is greater than 22 000 stems/ha, but these trees originated almost exclusively by layering. In the Nicauba Experimental Forest, seedlings established themselves very rapidly after strip-cutting. Overall, over a 20-year period, the juvenile rate of growth in height of the dominant advance growth (mainly layers) in the two areas is comparable to that of the dominant trees in the residual strips of Nicauba; it is almost double the rate observed in dominant post-established regenerated black spruce in the Nicauba area.

Modeling of diffusion and electric current flow through disordered thin layers (membranes)

Numerical calculations in the framework of a percolation model are performed to study stationary diffusion and conduction in thin layers of disordered materials. It is shown that when the fraction of unbroken bonds on a square lattice in two dimensions is less than 0.25 the diffusion coefficient (conductivity) of a strip cut out of the lattice depends exponentially on the strip width.

The function of autonomic receptors in canine ureteral smooth muscle

I have investigated the effects of autonomic drugs and prostaglandins on in vitro smooth muscle spontaneous contractions and made the quantitative analysis of autonomic receptors in the canine ureter. Ureteral muscle strip cut helically usually generated spontaneous contractions whereas those cut circularly or longitudinally did not generate spontaneous contractions. These results suggest the importance of knowing which direction to cut the ureteral smooth muscle in order to generate spontaneous contractions. Norepinephrine (alpha), phenylephrine (alpha 1), carbachol (muscarinic) and PGF2 alpha caused significant increase in contractile force. Terbutaline (beta 2) and PGE2 caused significant decreases in contractile force, while dobutamine (beta 1) and clonidine (alpha) caused no effect. Autonomic receptor densities were determined using radiology and binding techniques. The number of maximum binding sites (Bmax) of 3H-prazosin (PZ), 3H-yohimbine (YOH), 3H-dihydroaloprenolol (DHA) and 3H-quinuclidinylbenzilate (QNB) were 53.8, 16.9, 11.2 and 5.28 fmol/ml protein, respectively. These data suggest that the contractile responses to adrenergic and cholinergic agonists in the canine ureter are mediated through functional adrenergic (alpha 1, beta 2) and muscarinic cholinergic receptors and that the prostaglandins have a role in the contraction of the canine ureter.

Regeneration after Strip Cutting and Block Clearcutting in Northern Hardwoods

Abstract Regeneration was studied during the first 10 years after clearcutting on two sites in the northern hardwood forest of New Hampshire. One site was a 12-ha block clearcut; the other was a 36-ha progressive strip cut harvested in three phases using 25-m wide strips which approximated one tree height. Permanent plots on each site were measured at intervals of 1 to 4 years. Changes in the density and biomass of the major commercial species and their primary noncommercial competitors are presented. At 10 years after clearcutting, yellow birch was the most common tree on the block clearcut; sugar maple was most numerous on the strip cut. Pin cherry dominated the biomass on the block clearcut and the strips first cut (1970), but yellow birch and sugar maple biomass was greater on the strips cut later (1972 and 1974). North. J. Appl. For. 7:65-68, June 1990.

Effects of Forest Clearcutting in New England on Stream Chemistry

AbstractDifferences in stream chemistry between recently clearcut and nearby uncut watersheds were generally small in a wide variety of soil and forest types throughout New England. Water samples were collected during six periods of the year in 1978 and 1979 from 6 entirely clearcut, 32 partially clearcut, and 18 uncut watersheds. The largest differences that could be attributed to harvesting occurred in entirely clearcut watersheds, especially in the White Mountains of New Hampshire. In one area of the White Mountains, inorganic N was 4 times higher (2 mg/L), and Ca was 2 times higher (4 mg/L) in streams from a clearcut watershed than in a nearby uncut watershed. Elsewhere, only minor changes in stream chemistry resulted from cutting; the amount of the cutting response was of the same magnitude as natural variations among streams draining similar watersheds. Clearcutting less than entire watersheds, patch and strip cuts, and buffer strips along streams all appear to reduce the magnitude of changes in stream chemistry.

Development of canopy stratification during early succession in northern hardwoods

Canopy development on a 6-year-old strip cut was analyzed by measuring the heights to terminal buds and bud scale scars of the tallest individuals of each species present on 50 plots of radius 6 m. Phenology of height growth was monitored during the following growing season. Pin cherry ( Prunus pensylvania L.), an intolerant short-lived tree, had the fastest growth rate and was on the average the tallest species from the second to the sixth year of regrowth. Although advance regeneration of sugar maple ( Acer saccharum Marsh.) and beech ( Fagus grandifoloa Ehrh.) were the tallest trees during the first growing season, their slower growth rate insured that they would not keep up with the pin cherry. Trembling aspen ( Populus tremuloides Michx.), striped maple ( Acer pensylvanicum L.) and yellow birch ( Betula alleghaniensis Britt.) occupied an intermediate position in the canopy by the end of the sixth growing season, and showed relatively greater annual height increment than beech or sugar maple. Height growth phenology differed slightly for each species. Beech, ash ( Fraxinus americana L.) and sugar maple commenced growth early, grew rapidly and set buds all by 1 August (beech by 15 June). Yellow birch, pin cherry and trembling aspen started growing as early as the others, grew more slowly at first but then grew for a longer period of time. Striped maple seemed to be somewhat intermediate. Growth phenology and growth rate are related to the tolerance and growth form type (e.g. determinate or indeterminate) of the species. The most tolerant species tend to be determinate in growth form, have slower growth rates and complete height growth earlier. The intolerant species tend to be indeterminate, have a faster growth rate and continue to grow for a longer period. These may be mechanisms by which many species can grow together and avoid adverse effects such as suppression.

White Spruce Seed Dispersal in Central British Columbia

Seed dispersal of white spruce (Picea glauca) (Moench) Voss) from stands bordering a large clearcut and a strip cut was studied. Seedfall fell sharply with distance from the clearcut edge to 100 m, but even at 300 m the average dispersed seed density exceeded 740 000 seeds/ha or 3% of that recorded within the stand. Dispersed seed density in the middle of the 200-metre-wide strip cut exceeded 1 300 000 seeds/ha or 20% of that recorded within the bordering stands. About one-third of the seeds was disseminated by the end of September.

Temperature and Moisture Conditions on a Plowed Jack Pine Strip Cut in Southeastern Manitoba

Soil moisture, maximum surface temperatures, and duration of critical temperatures for jack pine (Pinusbanksiana Lamb.) seedlings were measured across a scarified east–west strip cut on a dry site in southeastern Manitoba. Temperature conditions were significantly less severe on the southern third of the strip and usually more favorable on the south side and in the trough of plowed furrows. Soil moisture remained within the available range [Formula: see text] at 3.8- and 7.6-cm depths under undisturbed and trough seedbeds throughout the growing season. Results indicate that moisture and temperature conditions lethal to germinants exist on all seedbeds of this site under weather conditons normally expected in the area. The more uniform moisture conditions under the trough seedbed suggest that it is most favorable for planting.

55] The synthesis of [32P]adenosine 3′,5′-cyclic phosphate and other ribo- and deoxyribonucleoside 3′,5′-cyclic phosphates

Publisher Summary The general procedure described in this chapter allows the two-step chemical synthesis from [ 32 P] orthophosphoric acid of the eight common ribo- and deoxyribonucleoside 3', 5'-cyclic monophosphates. The method is simple and reliable and provides any of the cyclic nucleotides with equal facility in yields of 30–60% relative to starting 32 P i and with a specific activity of greater than 1 mCi/μmole. The procedure given in this chapter has been modified but the basic chemical steps are the same. The chapter is supported between two glass rods held together at each end with rubber bands and is handled with these rods. Spotting is done with a Pasteur pipette, and the solvent is removed by a stream of warm air from one or two hair dryers. Nucleotide bands located under ultraviolet light are cut out with a large guillotine and one end of the strip cut to a point for elution; the marker nucleotide is not included.