Effects of the amount and composition of the forest floor on emergence and early establishment of loblolly pine seedlings

1995 ◽  
Vol 25 (3) ◽  
pp. 480-486 ◽  
Author(s):  
Michael G. Shelton
Keyword(s):  
Loblolly Pine ◽  
Forest Floor ◽  
Soil Surface ◽  
Fit Indices ◽  
Exponential Relationship ◽  
Pine Seedlings ◽  
Exponential Trend ◽  
Seed Placement ◽  
Negative Exponential ◽  
Floor Material

Five forest floor weights (0, 10, 20, 30, and 40 Mg/ha), three forest floor compositions (pine, pine–hardwood, and hardwood), and two seed placements (forest floor and soil surface) were tested in a three-factorial, split-plot design with four incomplete, randomized blocks. The experiment was conducted in a nursery setting and used wooden frames to define 0.145-m2 subplots. Forest floor composition had no significant effect on emergence or establishment of loblolly pine (Pinustaeda L.) seedlings. Numbers of emerging and established seedlings displayed a negative exponential relationship with forest floor weight (fit indices of 0.62 and 0.62, respectively). Seed placement significantly affected the number of emerging seedlings (forest floor > soil surface) and their survival (forest floor < soil surface). However, seed placement had no overall significant effect on the number of established seedlings because effects on emergence and survival essentially canceled out. Germination of herbaceous seeds in the soil bank also displayed a negative exponential trend with forest floor weight (fit indices of 0.46 and 0.50 for the weight of grasses and forbs, respectively) and was not significantly affected by forest floor composition. Results indicate that forest floor composition is not a factor in the natural regeneration of the pine component of mixed pine–hardwood stands and suggest that when pine seed production is adequate, moderate amounts of forest floor material will improve pine seedling development because of suppression of herbaceous vegetation.

Loblolly pine regeneration and competing vegetation 5 years after implementing uneven-aged silviculture

1994 ◽  
Vol 24 (12) ◽  
pp. 2448-2458 ◽  
Author(s):  
Michael G. Shelton ◽  
Paul A. Murphy
Keyword(s):  
Loblolly Pine ◽  
Q Factor ◽  
Fit Indices ◽  
Competing Vegetation ◽  
Single Tree ◽  
Pine Seedlings ◽  
Treatment Models ◽  
Pine Regeneration ◽  
Single Tree Selection ◽  
North Louisiana

The effects of three basal areas (9.2, 13.8, and 18.4 m2/ha), maximum diameters (30.5, 40.6, and 50.8 cm), and site indices (≤24.6, 24.7–27.4, and ≥27.5 m at 50 years) on establishment and development of loblolly pine (Pinustaeda L.) regeneration and competing vegetation were determined on 81 permanent, 0.20-ha plots in south Arkansas and north Louisiana. Plots were harvested to the designated basal areas, maximum diameters, and a q-factor of 1.2 using the single-tree selection method during 1983 (a bumper seed year) and 1985 (a seed year failure); this necessitated including the year of harvest as a fourth variable. Pine regeneration and competing vegetation were evaluated 4 or 5 years after treatment. Models were developed to predict the number and percent stocking of pine seedlings and saplings and the percent coverage of competing vegetation. Fit indices ranged from 0.21 to 0.52 for pine regeneration and from 0.15 to 0.73 for coverage of competing vegetation. Pine regeneration was generally greatest for the 1983 harvest, the largest maximum diameters, and the poorest sites. Coverage for vines, hardwoods, and total vegetation was greatest on the good sites and generally for the lowest basal areas. Coverage of grasses, herbs, and shrubs did not vary significantly among treatments. Results suggest that seed production and competing vegetation influence the initial amounts of loblolly pine regeneration obtained with uneven-aged silviculture using single-tree selection.

Early growth of lodgepole pine after establishment of alsike clover–Rhizobium nitrogen-fixing symbiosis

1992 ◽  
Vol 22 (8) ◽  
pp. 1089-1093 ◽  
Author(s):  
R. Trowbridge ◽  
F.B. Holl
Keyword(s):  
Forest Floor ◽  
Lodgepole Pine ◽  
Nitrogen Concentration ◽  
Growing Season ◽  
Early Growth ◽  
Percent Cover ◽  
Foliar Nitrogen ◽  
Growing Seasons ◽  
Pine Seedlings ◽  
Needle Mass

An overdense lodgepole pine (Pinuscontorta Dougl. ex Loud.) stand was knocked down and the site was prepared by broadcast burn, windrow burn, or mechanical forest floor removal. Inoculated alsike clover (Trifoliumhybridum L.) was seeded at 0, 10, 20, and 30 kg/ha for the three different site preparation treatments to determine the effects of (i) site preparation on infection and effectiveness of the clover–Rhizobium symbiosis and clover percent cover and (ii) the clover–Rhizobium N2-fixing symbiosis on survival, early growth, and foliar nitrogen concentration of lodgepole pine seedlings. The N2-fixing symbiosis established well in all treatments. Clover percent cover increased with increasing rate of seeding, although by relatively few percent in the clover seeded plots. Broadcast burning, windrow burning, and mechanical forest floor removal did not affect the establishment of the N2-fixing symbiosis or clover percent cover. Lodgepole pine survival was not affected by the seeding treatments in any year, nor were height measurements during the first three growing seasons. Seedling height was slightly less in clover-seeded plots compared with controls in the fourth growing season. Lodgepole pine seedlings on clover-seeded plots had decreased diameter growth compared with controls during the first three growing seasons, but incremental diameter growth no longer showed this effect by the fourth growing season. Needle mass (g/100 needles) was less in clover-seeded plots at the end of the second growing season, but this effect was reversed by the fourth growing season, when both needle mass and foliar nitrogen concentration in lodgepole pine foliage were greater in clover-seeded plots.

EFFECTS OF HERBICIDES ON CARBON DIOXIDE UPTAKE BY PINE SEEDLINGS

1967 ◽  
Vol 45 (7) ◽  
pp. 961-971 ◽  
Author(s):  
S. Sasaki ◽  
T. T. Kozlowski
Keyword(s):  
Carbon Dioxide ◽  
Gas Exchange ◽  
Soil Surface ◽  
Pinus Resinosa ◽  
Spray Application ◽  
Leaf Color ◽  
Carbon Dioxide Uptake ◽  
Chlorophyll Breakdown ◽  
Pine Seedlings ◽  
Steady Rate

Experiments were conducted on effects of herbicides applied to soil or sprayed on shoots on CO2 uptake of 3-year-old Pinus resinosa Ait. seedlings. When applied to the soil, atrazine, monuron, EPTC, and 2,4-D at 20 lb/ac (soil surface basis) or at 4000 p.p.m. variously decreased absorption of CO2. Monuron checked gas exchange most rapidly, with no CO2 uptake measurable after 10 days. Atrazine and 2,4-D inhibited absorption of CO2 at a steady rate. EPTC caused a delayed inhibition of CO2 uptake. DCPA, CDAA, CDEC, and NPA did not affect gas exchange significantly. Monuron applied as a spray depressed CO2 uptake somewhat faster than the soil-applied herbicide. Very rapid inhibition of CO2 uptake was observed after spray application of 2,4-D or EPTC. Atrazine affected gas exchange similarly when applied as a spray or incorporated in the soil. DCPA, applied as a spray, did not affect absorption of CO2 significantly. Possible reasons for differences in CO2 uptake after spray and soil-application of certain herbicides are discussed. Inert ingredients of EPTC applied as sprays at a concentration of 4000 p.p.m. greatly reduced CO2 absorption 3 days after treatment. However, the rapid early depression of gas exchange was followed by recovery, with no obvious deleterious effects on growth up to 3 months after treatment. Some herbicides checked CO2 absorption without chlorophyll breakdown whereas others did not. Monuron completely inhibited CO2 uptake long before any changes in leaf color were evident. In contrast, depression of CO2 absorption by atrazine and 2,4-D rather closely paralleled development of toxicity symptoms, especially chlorosis. These observations suggested that some herbicides such as monuron affected the photosynthetic mechanism more directly than others such as atrazine, 2,4-D, and EPTC.

Growth and gas exchange of loblolly pine seedlings as influenced by drought and air pollutants

1990 ◽  
Vol 51 (1-2) ◽  
pp. 105-116 ◽  
Author(s):  
Woong S. Lee ◽  
Boris I. Chevone ◽  
John R. Seiler
Keyword(s):  
Gas Exchange ◽  
Loblolly Pine ◽  
Air Pollutants ◽  
Pine Seedlings

scholarly journals The Association of a Longidorus Species with Stunting and Root Damage of Loblolly Pine (Pinus taeda L.) Seedlings

Plant Disease ◽  
2002 ◽  
Vol 86 (7) ◽  
pp. 803-807 ◽  
Author(s):  
Stephen W. Fraedrich ◽  
Michelle M. Cram
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Dry Weight ◽  
Forest Tree ◽  
Root Weight ◽  
Extraction Techniques ◽  
Seedling Root ◽  
Pine Seedlings ◽  
Proper Diagnosis ◽  
Pinus Taeda L

A Longidorus species was consistently associated with patches of stunted and chlorotic loblolly pine seedlings at a forest-tree nursery in Georgia. Seedlings from affected areas had poorly developed root systems that lacked lateral and feeder roots. Longidorus population densities in composite soil samples from the margins of patches ranged from 9 to 67 nematodes per 100 cm3 of soil. In a growth chamber experiment, seedling root dry weight decreased with respect to the initial Longidorus dose as well as the final Longidorus populations in containers. The dry root weight of seedlings were 0.117, 0.090, 0.066, and 0.065 g in containers initially infested with 0, 50, 100, and 200 Longidorus, respectively. Lateral and fine roots were lacking on seedlings at the highest doses. Populations of Longidorus increased in all containers during the experiment. Damage to loblolly pine seedlings caused by Longidorus is a previously undescribed problem in southern pine nurseries. Proper diagnosis of the problem by nematode testing laboratories may require the use of extraction techniques specific for larger nematodes such as Longidorus.

Use of near- and mid-infrared spectroscopy to distinguish carbon and nitrogen originating from char and forest-floor material in soils

2008 ◽  
Vol 172 (1) ◽  
pp. 63-70 ◽  
Author(s):  
Kerstin Michel ◽  
Thomas Terhoeven-Urselmans ◽  
Renate Nitschke ◽  
Phillip Steffan ◽  
Bernard Ludwig
Keyword(s):  
Infrared Spectroscopy ◽  
Forest Floor ◽  
Mid Infrared ◽  
Mid Infrared Spectroscopy ◽  
Carbon And Nitrogen ◽  
Floor Material

Predicting Urea Hydrolysis in a Loblolly Pine Forest Floor

2014 ◽  
Vol 78 (6) ◽  
pp. 2071-2077
Author(s):  
David E. Kissel ◽  
Miguel L. Cabrera ◽  
Joseph Craig ◽  
Jiro Ariyama ◽  
Nicolas Vaio ◽  
...  
Keyword(s):  
Loblolly Pine ◽  
Forest Floor ◽  
Urea Hydrolysis ◽  
Pine Forest

Growth of Common Purslane as Influencing Control and Importance as a Weed

Weed Science ◽  
1972 ◽  
Vol 20 (1) ◽  
pp. 20-23 ◽  
Author(s):  
H. J. Hopen
Keyword(s):  
Soil Surface ◽  
Crop Species ◽  
Central United States ◽  
Seed Placement ◽  
The Common ◽  
Common Purslane ◽  
The Individual ◽  
Preemergence Herbicides ◽  
Postemergence Herbicides ◽  
High Soil Temperature

A higher population of common purslane(Portulaca oleraceaL.) developed on a smooth seedbed than a rough seedbed. Purslane germinated best when the seed were placed on the soil surface, and the percentage germination decreased progressively as depth of seed placement increased. Growth of common purslane was greater at elevated nutrient levels and was dependent on adequate phosphorus in the nutrient media. High soil temperature requirements for optimum germination make common purslane a middle to late-growing season weed in the central United States. Often preemergence herbicides which are effective on common purslane have become ineffective by the time the common purslane population has developed, and postemergence herbicides which do not injure the individual crop species must be relied on for common purslane control.

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