The Influence of Woody and Herbaceous Competition on Early Growth of Naturally Regenerated Loblolly and Shortleaf Pines

1991 ◽  
Vol 15 (4) ◽  
pp. 179-185 ◽  
Author(s):  
M. D. Cain

Abstract Four levels of competition control were used to study the response of naturally regenerated loblolly and shortleaf pines (Pinus taeda L. and P. echinata Mill.) in southern Arkansas. Treatments included: (1) Check (no competition control), (2) woody competition control, (3) herbaceous competition control, and (4) total control of nonpine vegetation. Herbaceous plants were controlled for 4 consecutive years, and woody plants were controlled for 5 years. Control of herbaceous vegetation resulted in significant increases in pine height, groundline diameter (GLD), and volume per tree. Control of only woody competition did not improve pine growth compared to untreated checks. After 5 years, pines on total control plots had significantly larger GLDs and significantly more volume per tree compared to pines on any other treatment. Pine growth gains were achieved with herbaceous competition control and total control of nonpine vegetation although these two treatments averaged 4,000 more pines/ac, in trees taller than 5 ft, than the other two treatments. Results of this investigation represent a unique standard of pine growth to which operational treatments might be compared. South. J. Appl. For. 15(4):179-185.

1999 ◽  
Vol 29 (7) ◽  
pp. 947-959 ◽  
Author(s):  
Michael D Cain

Stand dynamics of naturally regenerated, even-aged, loblolly pines (Pinus taeda L.) and shortleaf pines (P. echinata Mill.) were examined on the Upper Coastal Plain of southeastern Arkansas, U.S.A., following four levels of competition control. Treatments included a check (Ck) with no competition control, woody control (WC), herbaceous control (HC), and total control (TC) of nonpine vegetation. After pines became established from natural seeding, herbicides were used to control herbaceous plants for four consecutive years and woody plants for five consecutive years. At age five, 1235 crop pines/ha were retained and all noncrop pines >1.5 m tall were precommercially hand thinned. Although 93% of crop pines on Ck plots were judged free-to-grow 13 years after establishment, crop pines on vegetation control plots were larger (P [Formula: see text] 0.001) in mean diameter at breast height, total height, and volume per tree. From age 5 through 13 years, crop pine diameter growth increased on WC plots and decreased on HC plots because of hardwood competition in the latter treatment. At age 13, mean pine volume production was 48% greater (P < 0.01) on plots that received competition control than on Ck plots (160 m3·ha-1); TC resulted in 31% more (P < 0.01) volume (282 m3·ha-1) than the mean of WC and HC plots; and there was no difference (P = 0.15) between the latter two treatments.


1989 ◽  
Vol 13 (1) ◽  
pp. 8-12 ◽  
Author(s):  
M. D. Cain

Abstract A simple competition assessment system was evaluated as part of an intensive competition control study in a natural, even-aged stand of loblolly-short-leaf pine (Pinus taeda L.- P. echinata Mill.) seedlings in southern Arkansas. Four levels of competition control were maintained annuallyfor 3 years as follows: (1) no competition control, (2) woody competition control, (3) herbaceous competition control, and (4) total control of nonpine vegetation. The competition assessment system is based on a correlation of total height to groundline diameter (gld) for loblolly pine seedlingsthat are less than 6 ft tall. The correlation indicated that if seedling gld's are not within + 10 mm of total seedling height (in feet) multiplied by 10, then the seedlings would most likely show a positive growth response to competition control. South. J. Appl. For. 13(1):8-12.


1980 ◽  
Vol 4 (2) ◽  
pp. 67-70 ◽  
Author(s):  
M. D. Cain ◽  
W. F. Mann

Abstract Hardwoods and herbaceous vegetation quickly invaded a north Louisiana loblolly (Pinus taeda L.) site following chopping and planting. In the sixth year, more than 20,000 stems per acre were competing with the pines. Where hardwoods were cut down annually, loblolly volume at age 6 was 49 percent higher than on untreated areas. Annually cutting and grubbing-out hardwood roots resulted in a larger increase in volume, but not significantly greater than topping alone.


1995 ◽  
Vol 19 (2) ◽  
pp. 60-64 ◽  
Author(s):  
Charles H. Walkinshaw ◽  
James P. Barnett

Abstract Loblolly pines (Pinus taeda L.) that were 8 to 17 yr old tolerated one to three fusiform rust (Cronartium quercuum [Berk.] Miyabe ex Shiraif sp. fusiforme) galls in their stems. Families with four or more galls in their stems lost 25% or more of the trees by age 17. In living trees with less than four stem galls, diameter growth was comparable to that of trees with no galls. Tolerance was indicated by the ability of loblolly pines to maintain the rust fungus in stems that had dbh's similarto asymptomatic trees on the same site. In plantations, the number of galls in the stem was generally one to two per infected tree. This was also true for mature trees (12 to 38 in. dbh) along the Natchez Trace Parkway. These trees have been infected with fusiform rust for nearly 100 yr. On the other hand, the presence of four or more stem galls seems to be a reliable indicator of mortality rather than tolerance. South. J. Applied For. 19 (2): 60-64.


2002 ◽  
Vol 32 (7) ◽  
pp. 1171-1179 ◽  
Author(s):  
David B South ◽  
D GM Donald

Four seedling conditioning treatments and four fall fertilization treatments were applied to loblolly pine (Pinus taeda L.) seedlings in a bare-root nursery in Alabama. Three conditioning treatments involved undercutting plus root wrenching (two, four, and six times), and a fourth treatment included top-pruning (three times) and no undercutting. Fertilizer treatments consisted of (i) control, (ii) 150 kg/ha of N, (iii) 150 kg/ha of N plus 150 kg/ha of P, and (iv) 150 kg/ha of K. On two sites, seedlings were planted in November, and an equal number were placed in cool storage and planted 6 weeks later in mid-December. Results 5 years after outplanting were generally similar for both sites; however, experimental error terms were higher on the sandy site. As a result, conditioning and fertilizer treatments had a statistically significant effect on volume per hectare at the loamy site but not at the sandy site. Volume per hectare was enhanced by undercutting in August followed by two root wrenchings and fall fertilization with N plus P. Storing seedlings reduced height, groundline diameter, and volume per hectare at both sites and reduced survival at the loamy site. Survival of both freshly planted and stored seedlings was greater than 71% at both sites.


2003 ◽  
Vol 33 (6) ◽  
pp. 1076-1083 ◽  
Author(s):  
Gregory T Munger ◽  
Rodney E Will ◽  
Bruce E Borders

To determine the importance of competition control and annual fertilization on leaf gas exchange, light-saturated net photosynthesis (Asat), stomatal conductance (gs), and internal CO2 concentration (Ci) were measured multiple times in different-aged loblolly pine (Pinus taeda L.) stands growing at a Piedmont (BF Grant) and Coastal Plain (Waycross) location in Georgia, U.S.A. At both locations, competition control decreased Asat and gs (Asat from 4.53 to 4.12 µmol·m–2·s–1, gs from 0.058 to 0.050 mol·m–2·s–1 at BF Grant; Asat from 4.22 to 4.01 µmol·m–2·s–1, gs from 0.054 to 0.049 mol·m–2·s–1 at Waycross). Overall, fertilization did not have a positive impact on Asat, even though fertilization significantly increased foliar nitrogen concentration. At BF Grant, fertilization significantly decreased gs from 0.057 to 0.051 mol·m–2·s–1 and Ci from 217 to 205 µmol·mol–1. In addition, the decrease in Ci associated with fertilization became larger with stand age. At Waycross, fertilization decreased Ci from 211 to 203 µmol·mol–1 and the interaction between fertilization and stand age was significant for gs and Ci. These results indicate that silivcultural practices that increase resource availability and stand growth did not enhance leaf gas exchange.


1977 ◽  
Vol 1 (4) ◽  
pp. 8-10
Author(s):  
D. H. Van Lear ◽  
N. B. Goebel ◽  
J. G. Williams

Abstract The performance of adjacent unthinned plantations of loblolly (Pinus taeda L.) and slash pine (P. elliottii Engelm.) on three sites in South Carolina was evaluated after 16 growing seasons. Sites ranged from a noneroded Piedmont soil to an excessively drained sandy soil of the Sandhills physiographic region. Growth and survival varied widely among sites, with greatest productivity occurring in the Piedmont and the lowest in the Congaree Sandhills. Despite the droughty nature of the latter site, survival after 16 growing seasons was over 80 percent for both species. On a volume basis, loblolly pine outperformed slash pine at the upper Pidemont and Aiken Plateau sites, while slash pine was superior on the dry Sandhills site. Incidence of fusiform rust was much higher for both species at the Aiken Plateau than at the other sites.


2002 ◽  
Vol 26 (4) ◽  
pp. 173-180 ◽  
Author(s):  
Michael D. Cain ◽  
James P. Barnett

Abstract Genetically improved, container loblolly pine (Pinus taeda L.) seedlings were compared to naturally established loblolly seedlings on a cutover pine site. Crop pines on 6 of 12 plots were released from woody and herbaceous competition within a 2 ft radius of each stem. On release plots, woody competition was controlled by hand-cutting for 5 consecutive yr and herbaceous competition was controlled with herbicides for 4 consecutive yr after pine establishment. Competition control increased 12 yr survival by 68 percentage points for natural pines and by 47 percentage points for planted pines. Twelve years after field establishment, mean-tree volume of planted pines was no different than that of naturally established pines. Nevertheless, volume gains of 150% to 200% were achieved within regeneration techniques as a result of release. South. J. Appl. For. 26(4):173–180.


1984 ◽  
Vol 8 (4) ◽  
pp. 194-197 ◽  
Author(s):  
T. R. Clason

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.


2004 ◽  
Vol 34 (9) ◽  
pp. 1802-1818 ◽  
Author(s):  
Dean F Meason ◽  
Daniel Markewitz ◽  
Rodney E Will

Forest floor organic matter in managed pine forests can accumulate large quantities of N during early stand development. The conversion of the forest floor from a net accumulator to a net source of N as stands age, however, is not well quantified, nor is the effect of management activities on this conversion process. Nitrogen flux from the forest floor of different-aged Pinus taeda L. stands (8, 12, and 14 years old) was measured to understand the impact of annual fertilization (~70 kg N·ha–1·year–1) and complete interspecific competition control on forest floor N cycling. Throughfall and forest floor leachate solutions were collected for 1 year and N mineralization assays conducted. Volume-weighted mean concentrations were used in conjunction with hydrologic fluxes to estimate the net nitrate (NO3–-N), ammonium (NH4+-N), and dissolved organic N flux from the forest floor. Complete competition control had no effect on the inorganic N flux. Changes in inorganic or organic N flux also were not discernable with stand age. Fertilization treatments, excluding fertilizer pulses, significantly increased the forest floor release of N in the fertilized stands compared with the nonfertilized stands (p < 0.05). Overall fluxes of NO3–-N and NH4+-N from the forest floor were, respectively, 2.8 and 6.2 kg N·ha–1·year–1 for fertilized stands and –1.1 and 0.9 kg N·ha–1·year–1 for nonfertilized stands. Unlike inorganic N, organic N was retained in fertilized stands as a result of large organic throughfall inputs. Nitrogen cycling through the forest floor was ~4 kg·ha–1·year–1 greater in fertilized stands. This increased N release may account for as much as 6% of average annual pine demand and thus may well enhance productivity in future years.


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