scholarly journals Interference interactions in experimental pine–hardwood stands

1993 ◽  
Vol 23 (10) ◽  
pp. 2032-2043 ◽  
Author(s):  
Todd S. Fredericksen ◽  
Shepard M. Zedaker ◽  
David W. Smith ◽  
John R. Seiler ◽  
Richard E. Kreh
Keyword(s):  
Leaf Area ◽  
Loblolly Pine ◽  
Black Locust ◽  
Light Availability ◽  
Relative Yield ◽  
Growth And Yield ◽  
Red Maple ◽  
Replacement Series ◽  
Herbaceous Vegetation ◽  
Hardwood Species

A replacement series field experiment was established in 1989 in the Piedmont physiographic province of Virginia with loblolly pine (Pinustaeda L.), red maple (Acerrubrum L.), and black locust (Robiniapseudoacacia L.) to quantify the effects of interference and elucidate its mechanisms. Stands were planted with and without herbaceous vegetation. After three growing seasons, interference among pine, hardwood species, and herbaceous vegetation significantly affected growth and yield. While herbaceous vegetation significantly affected all stands, it reduced the yield of hardwood species more than of loblolly pine. Loblolly pine appeared to ameliorate the effect of herbaceous vegetation on hardwoods in some stands. Based on relative yield totals, interference relationships between pine and hardwood species were neutral in all replacement series except for the loblolly pine–black locust series with herbaceous vegetation, where a mutualistic relationship was evident on poorer sites of the study. Pine appeared to compete effectively with hardwoods through efficient use of soil moisture and nitrogen, although pines had lower root/shoot ratios. Pine also had the greatest amount of leaf area of all species. Black locust reduced light availability to pine in some stands, but may have provided some nutritional benefits. Black locust and red maple appeared to increase allocation to roots in herbaceous vegetation, especially in pure stands. Root/shoot ratio, water-use efficiency, and leaf area were the measured variables most closely correlated with tree yield.

Directed Foliar Sprays of Forestry Herbicides for Loblolly Pine Release

1990 ◽  
Vol 14 (4) ◽  
pp. 199-206 ◽  
Author(s):  
James H. Miller
Keyword(s):  
Loblolly Pine ◽  
Growing Season ◽  
Red Oak ◽  
Red Maple ◽  
Yellow Poplar ◽  
Foliar Sprays ◽  
Crown Volume ◽  
Hardwood Species ◽  
Water Oak ◽  
Potential Use

Abstract Six herbicides were compared as directed foliar sprays applied in May, July, and September on seven hardwood species and on loblolly pine. Equal-cost mixtures that met or exceeded minimum labeled rates were tested for Weedone 2,4- DP, Gadon 4, Garlon 3A, Arsenal Applicator Concentrate, Roundup, Escort, and Roundup + Escort. Test hardwoods were sweetgum, southern red oak, water oak, red maple, pignut hickory, dogwood, and yellow poplar. Crown volume reduction and rootstock reduction after one growing season were the main indicators of efficacy. Using directed sprays, yellow poplar was the easiest species to control, and pignut hickory was the most difficult. Control of sweetgum was most effective with Weedone, Arsenal, and Roundup. For control of oaks, the most effective applications were in July with Arsenal, Garlon 4 and 3A, and Roundup; but these and other hardwood species tended to refoliate 2 years after Arsenal treatment. Herbicide safety to loblolly pine was best with Arsenal and Escort, while injury was greatest with Roundup and Garlon 3A, which might have potential use in precommercial thinnings. South. J. Appl. For 14(4):199-206.

Hardwood Eradication Improves Productivity of Thinned Loblolly Pine Stands

1984 ◽  
Vol 8 (4) ◽  
pp. 194-197 ◽  
Author(s):  
T. R. Clason
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Volume Growth ◽  
Growth And Yield ◽  
Detectable Effect ◽  
Herbaceous Vegetation ◽  
Vegetation Control ◽  
Pine Stands ◽  
Pinus Taeda L

Abstract A single hardwood eradication treatment in a 7-year-old loblolly pine (Pinus taeda L.) stand along with pine stocking control increased growth and yield over a 10-year period. Herbaceous vegetation control had no detectable effect at ages 12 and 17. Treated plots had smaller stems, which could be controlled more readily by fire, although the number of understory stems was similar for all treatments. Mean annual radial and merchantable volume growth on treated plots surpassed controls by 30%. Future stand values were enhanced by removing hardwood competition. Residual stand sawtimber volumes on the treated plots were twice that of the control.

scholarly journals Drought and Ozone Stress Effects on Competition among Selected Prairie Grass Species and Giant Foxtail

1999 ◽  
Vol 9 (2) ◽  
pp. 227-234 ◽  
Author(s):  
Gregory A. Endress ◽  
Anton G. Endress ◽  
Louis R. Iverson
Keyword(s):  
Leaf Area ◽  
Water Availability ◽  
Relative Yield ◽  
Leaf Number ◽  
Grass Species ◽  
Big Bluestem ◽  
Weed Species ◽  
Replacement Series ◽  
Giant Foxtail ◽  
The Impact

Differential responses of species to environmental stress may interfere with restoration of prairie ecosystems or change community structure. The impact of increasing atmospheric ozone (O3) concentrations and/or low water on the growth of Andropogon gerardii Vitm. (big bluestem) and Sorghastrum nutans (L.) Nash (indian grass), two common warm-season native grasses, and Setaria faberi Herrm. (giant foxtail), a vigorous annual weed species, were studied in replacement series. Giant foxtail grew better than either big bluestem or indian grass under all tested conditions. The leaf areas of all three species were primarily controlled by water availability. Big bluestem and indian grass accumulated biomass equally well under high water availability, but with low water, indian grass accumulated more biomass than did bluestem. Three-way analysis of variance showed biomass, leaf area, and leaf number differed among species; low water was significant in all cases except for indian grass leaf area; and the O3 effect was significant only in the case of foxtail biomass. The interaction of O3 concentration and low water was significant only for indian grass biomass and leaf number; the interaction of species combination and low water was significant only for big bluestem leaf area and biomass. Relative yield calculations indicated that under conditions of elevated O3 and low water, big bluestem was the least competitive, while indian grass was most competitive. Intraspecific competition was common, each species apparently utilizing the environment in different ways. The results also suggest that giant foxtail at a low relative density may be used as a nurse species in prairie restorations as growth of big bluestem and indian grass were improved when in mixtures with foxtail.

Removal of Hardwood Vegetation Increases Growth and Yield of A Young Loblolly Pine Stand

1978 ◽  
Vol 2 (3) ◽  
pp. 96-97 ◽  
Author(s):  
T. R. Clason
Keyword(s):  
Loblolly Pine ◽  
Growth Rates ◽  
Radial Growth ◽  
Volume Growth ◽  
Growth And Yield ◽  
Additive Effects ◽  
Herbaceous Vegetation ◽  
Precommercial Thinning ◽  
Vegetation Removal ◽  
Growth Increase

Abstract In five years, growth and yield of a pre-commercially thinned, natural, seven-year-old loblolly pine stand were significantly increased by removing hardwood vegetation. Compared to thinned-only plots, the additive effects of removing hardwood and herbaceous vegetation increased radial growth rates 36 percent and cubic volume growth 63 percent. Removing hardwoods alone accounted for a 23-percent radial growth increase and a 45-percent volume growth increase. Thinning and herbaceous vegetation removal offered no advantage above thinning alone. Optimal increases in growth were obtained when the precommercial thinning included the eradication of hardwood vegetation.

scholarly journals A Dynamic Stand Growth Model System for Loblolly Pine Responding to Mid-Rotation Treatments

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 556
Author(s):  
Mauricio Zapata-Cuartas ◽  
Bronson P. Bullock ◽  
Cristian R. Montes ◽  
Michael B. Kane
Keyword(s):  
Growth Model ◽  
Loblolly Pine ◽  
Basal Area ◽  
Model System ◽  
Growth And Yield ◽  
Site Quality ◽  
Response To Treatment ◽  
Plantation Management ◽  
Vegetation Control ◽  
Dominant Height

Intensive loblolly pine (Pinus taeda L.) plantation management in the southeastern United States includes mid-rotation silvicultural practices (MRSP) like thinning, fertilization, competitive vegetation control, and their combinations. Consistent and well-designed long-term studies considering interactions of MRSP are required to produce accurate projections and evaluate management decisions. Here we use longitudinal data from the regional Mid-Rotation Treatment study established by the Plantation Management Research Cooperative (PMRC) at the University of Georgia across the southeast U.S. to fit and validate a new dynamic model system rooted in theoretical and biological principles. A Weibull pdf was used as a modifier function coupled with the basal area growth model. The growth model system and error projection functions were estimated simultaneously. The new formulation results in a compatible and consistent growth and yield system and provides temporal responses to treatment. The results indicated that the model projections reproduce the observed behavior of stand characteristics. The model has high predictive accuracy (the cross-validation variance explained was 96.2%, 99.7%, and 98.6%; and the prediction root mean square distance was 0.704 m, 19.1 trees ha−1, and 1.03 m2ha−1 for dominant height (DH), trees per hectare (N), and basal area (BA), respectively), and can be used to project the current stand attributes following combinations of MRSP and with different thinning intensities. Simulations across southern physiographic regions allow us to conclude that the most overall ranking of MRSP after thinning is fertilization + competitive vegetation control (Fert + CVC) > fertilization only (Fert) > competitive vegetation control only (CVC), and Fert + CVC show less than additive effect. Because of the model structure, the response to treatment changes with location, age of application, and dominant height growth as indicators of site quality. Therefore, the proposed model adequately represents regional growth conditions.

Estimating individual tree leaf area in loblolly pine plantations using LiDAR-derived measurements of height and crown dimensions

2005 ◽  
Vol 213 (1-3) ◽  
pp. 54-70 ◽  
Author(s):  
Scott D. Roberts ◽  
Thomas J. Dean ◽  
David L. Evans ◽  
John W. McCombs ◽  
Richard L. Harrington ◽  
...  
Keyword(s):  
Leaf Area ◽  
Loblolly Pine ◽  
Pine Plantations ◽  
Individual Tree ◽  
Tree Leaf ◽  
Crown Dimensions

Development patterns in two hemlock–hardwood stands in southern New England

1986 ◽  
Vol 16 (5) ◽  
pp. 885-891 ◽  
Author(s):  
Matthew J. Kelty
Keyword(s):  
New England ◽  
Canopy Structure ◽  
Basal Area ◽  
Height Growth ◽  
Northern Red Oak ◽  
Red Maple ◽  
Clear Cutting ◽  
Southern New England ◽  
Hardwood Species ◽  
Constant Rate

Two forest stands, composed primarily of northern red oak (Quercusrubra L.), red maple (Acerrubrum L.), and eastern hemlock (Tsugacanadensis (L.) Carr.), were studied by stand-reconstruction techniques to determine the pattern of development of canopy structure. One stand had originated following clear-cutting 87 years ago; the other, following catastrophic windthrow 44 years ago. Juvenile height growth of the hardwood species was much greater than that of hemlock and a stratified canopy developed by age 30 years, with hardwoods forming an overstory canopy above hemlock. Hemlocks maintained overstory positions only if they were 3 m or more in height immediately following canopy disturbance. In the older stand, hardwood height growth was about twice that of the tallest understory hemlocks during the first 30 years. The hardwood overstory slowed after that and grew at the same rate as the tallest understory hemlocks, which maintained a constant rate of height growth, and a constant to accelerating rate of basal area growth for much of the 87-year measurement period. The height growth of the tallest understory hemlocks was apparently limited in part by breakage of terminal shoots, caused by abrasion against branches of overstory hardwood crowns.

Leaf Area Index (LAI) of Loblolly Pine and Emergent Vegetation Following a Harvest

2011 ◽  
Vol 54 (6) ◽  
pp. 2057-2066 ◽  
Author(s):  
D. A. Sampson ◽  
D. M. Amatya ◽  
C. D. Blanton Lawson ◽  
R. W. Skaggs
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Loblolly Pine ◽  
Emergent Vegetation ◽  
Area Index

Effects of Plant Density and Thinning on High-Yielding Dry Beans (Phaseolus vulgaris) in Mexíco

1977 ◽  
Vol 13 (4) ◽  
pp. 325-335 ◽  
Author(s):  
Aguilar M. Immer ◽  
R. A. Fischer ◽  
Joshue Kohashi S.
Keyword(s):  
Phaseolus Vulgaris ◽  
Leaf Area ◽  
Seed Weight ◽  
Plant Density ◽  
Plant Competition ◽  
Growth And Yield ◽  
Positive Relation ◽  
Dry Beans ◽  
Leaf Area Duration ◽  
Pod Number

SUMMARYThe influence of leaf area and inter-plant competition on the growth and yield of a crop of high-yielding dry beans (Phaseolus vulgaris L.) in central Mexico was studied, using density and thinning treatments. The highest seed yield (4210 kg/ha at 14% moisture) was obtained with the highest density (28·8 plants/m2). Thinning showed that pods/plant was sensitive to inter-plant competition between 36 and 78 days after seeding (first flower at 50 days), but seeds/pod, and especially seed weight, were not sensitive. It is suggested that the close positive relation between yield and leaf area duration derives from the influence of photosynthate supply upon pod number.

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