Stand density, drought, and herbivory constrain ponderosa pine regeneration pulse

2020 ◽  
Vol 50 (9) ◽  
pp. 862-871 ◽  
Author(s):  
Thomas E. Kolb ◽  
Kelsey Flathers ◽  
John B. Bradford ◽  
Caitlin Andrews ◽  
Lance A. Asherin ◽  
...  

Trees in dry forests often regenerate in episodic pulses when wet periods coincide with ample seed production. Factors leading to success or failure of regeneration pulses are poorly understood. We investigated the impacts of stand thinning on survival and growth of the 2013 cohort of ponderosa pine (Pinus ponderosa Douglas ex P. Lawson & C. Lawson) seedlings in northern Arizona, United States. We measured seedling survival and growth over the first five growing seasons after germination in six stand basal areas (BAs; 0, 7, 14, 23, 34, and 66 (unthinned) m2·ha−1) produced by long-term experimental thinnings. Five-year survival averaged 2.5% and varied among BAs. Mean survival duration was longer in intermediate BAs (11 to 16 months) than in clearings and high BAs (5 months). The BAs of 7, 14, and 23 m2·ha−1 had >2600 5-year-old seedlings·ha−1. In contrast, regeneration was lower in the clearing (666 seedlings·ha−1) and failed completely in the 34 m2·ha−1 and unthinned treatments. Seedling survival was highest during wet years and lowest during drought years. Many surviving seedlings had no net height growth between years 4 and 5 because of stem browsing. Results indicate that natural regeneration of ponderosa pine is influenced by stand BA, drought, herbivory, and interactions between extreme climatic events.

1991 ◽  
Vol 6 (1) ◽  
pp. 11-15 ◽  
Author(s):  
Robin Rose ◽  
John Gleason ◽  
Mary Atkinson ◽  
Tom Sabin

Abstract In probably one of the first studies of its kind, three different seed sources of 2 + 0 ponderosa pine (Pinus ponderosa) seedlings were graded on the basis of three root-volume categories (< 4.5, 4.5-7, and > 7 cm³) and out-planted to determine differences in survival and growth over 1 and 2 growing seasons, examine the relationship of seedling field height to nursery root volume, total fresh weight, diameter, and height over the same period, and observe differences in nutrient uptake by seedlings among the three categories over 174 days in the field. Seedling survival was good over the two growing seasons. Seedlings graded to the largest root-volume category were significantly taller and grew significantly more than those in the two smaller categories over the 2 years. Nitrogen and potassium contents decreased over the growing season, those seedlings with larger root volumes showing the greatest decrease. The results suggest that root volume has potential as a useful criterion for grading seedlings. West. J. Appl. For. 6(1):11-15.


2005 ◽  
Vol 35 (1) ◽  
pp. 37-47 ◽  
Author(s):  
V H Bonnet ◽  
A W Schoettle ◽  
W D Shepperd

Regeneration of ponderosa pine after fire depends on the patterns of seed availability and the environmental conditions that define safe sites for seedling establishment. A transect approach was applied in 2002 to determine the spatial distribution of regeneration from unburned to burned areas within the landscape impacted by the Jasper Fire of 2000 in the Black Hills of South Dakota (USA). Canopy conditions alone, reflecting seed availability, at the stand level were not correlated with regeneration success. However, canopy conditions in combination with ground conditions explained patterns of regeneration success at the plot level (2 m × 6 m scale), and ground conditions explained these patterns at the quadrat level (0.2 m × 0.2 m scale). Only at the finer level of the quadrat could environmental factors explain seedling survival. Safe sites were characterized, in part, by the presence of scorched needle litter on blackened mineral soil. Areas with high understory cover restricted regeneration in the undisturbed forest and reduced seedling survival in the burned areas. The description of environmental conditions that favor and discourage ponderosa pine regeneration success will improve our understanding of how environmental heterogeneity within burned areas will contribute to the future forested landscape.


1989 ◽  
Vol 4 (4) ◽  
pp. 124-128 ◽  
Author(s):  
Ole T. Helgerson ◽  
Steven D. Tesch ◽  
Stephen D. Hobbs ◽  
D. H. McNabb

Abstract Two stocktypes (1 + 0 container-grown plugs and 2 + 0 nursery grown bareroots) of ponderosa pine (Pinus ponderosa) and of Douglas-Fir (Pseudotsuga menziesii) were planted on a hot, droughty, low-elevation site in southwest Oregon (Interior Valley Zone) to assess the potential for reforesting this type of site. After five growing seasons, bareroots survived (98%) significantly (P < 0.05) better than plugs (89%); survival did not differ significantly by species. Douglas-fir was taller than pine, pine was larger in diameter, and the two species had approximately equal stem volumes. Bareroots were consistently larger than plugs. These species and stocktypes can provide good reforestation after 5 years on an Interior Valley Zone site when seedlings are of good quality, are planted properly, and are given good weed control. West. J. Appl. For. 4(4):124-128, October 1989.


2003 ◽  
Vol 18 (2) ◽  
pp. 109-114 ◽  
Author(s):  
Steven J. Stein ◽  
Diana N. Kimberling

Abstract Information on the mortality factors affecting naturally seeded conifer seedlings is becoming increasingly important to forest managers for both economic and ecological reasons. Mortality factors affecting ponderosa pine (Pinus ponderosa) seedlings immediately following natural germination and through the following year were monitored in Northern Arizona. The four major mortality factors in temporal order included the failure of roots to establish in the soil (27%), herbivory by lepidopteran larvae (28%), desiccation (30%), and winterkill (10%). These mortality factors were compared among seedlings germinating in three different overstory densities and an experimental water treatment. Seedlings that were experimentally watered experienced greater mortality than natural seedlings due to herbivory (40%), nearly as much mortality due to the failure of roots to establish in the soil (20%), less mortality due to winterkill (5%), and no mortality due to desiccation. The seedling mortality data through time were summarized using survivorship curves and life tables. Our results suggest that managers should consider using prescribed burns to decrease the percentage of seedlings that die from failure of their roots to reach mineral soil and from attack by lepidopteran larvae. West. J. Appl. For. 18(2):109–114.


Weed Science ◽  
1982 ◽  
Vol 30 (1) ◽  
pp. 98-101 ◽  
Author(s):  
John C. Tappeiner ◽  
Steven R. Radosevich

An experiment was established in 1961 to determine the influence of bearmat (Chamaebatia foliolosa Benth.) competition on ponderosa pine (Pinus ponderosa Laws.) survival and growth. Ponderosa pine seedlings were planted in bearmat which was: (A) untreated, (B) sprayed with a mixture of 2,4-D [(2,4-dichlorophenoxy)acetic acid] and 2,4,5-T [(2,4,5-trichlorophenoxy)acetic acid], and (C) eliminated by a combination of herbicide, clipping sprouts, and trenching to prevent root and rhizome invasion. Ponderosa pine survival after 19 yr averaged 9%, 66%, and 90%, respectively, for the three treatments. Tree height after 19 yr averaged 1.6, 1.9, and 5.7 m for treatments A, B, and C, respectively. Soil moisture use was initially less on the herbicide-treated than on the untreated plots, but bearmat quickly sprouted after application to compete with the pine seedlings for moisture. After 19 yr the bearmat was more dense and appeared to be more vigorous on the sprayed plots than on those receiving no treatment. We estimate that 75% reduction in net wood production could result after 50 yr on this site from bearmat competition.


2020 ◽  
Vol 113 (6) ◽  
pp. 3017-3020
Author(s):  
Monica L Gaylord ◽  
Stephen R McKelvey ◽  
Christopher J Fettig ◽  
Joel D McMillin

Abstract Recent outbreaks of engraver beetles, Ips spp. De Geer (Coleoptera: Curculionidae; Scolytinae), in ponderosa pine, Pinus ponderosa var. scopulorum Engelm. (Pinales: Pinaceae), forests of northern Arizona have resulted in widespread tree mortality. Current treatment options, such as spraying individual P. ponderosa with insecticides or deep watering of P. ponderosa in urban and periurban settings, are limited in applicability and scale. Thinning stands to increase tree vigor is also recommended, but appropriate timing is crucial. Antiaggregation pheromones, widely used to protect high-value trees or areas against attacks by several species of Dendroctonus Erichson (Coleoptera: Curculionidae; Scolytinae), would provide a feasible alternative with less environmental impacts than current treatments. We evaluated the efficacy of the antiaggregation pheromone verbenone (4,6,6-trimethylbicyclo[3.1.1]hept-3-en-2-one) in reducing attraction of pine engraver, I. pini (Say), to funnel traps baited with their aggregation pheromone in two trapping assays. Treatments included 1) unbaited control, 2) aggregation pheromone (bait), 3) bait with verbenone deployed from a pouch, and 4) bait with verbenone deployed from a flowable and biodegradable formulation (SPLAT Verb, ISCA Technologies Inc., Riverside, CA). Unbaited traps caught no beetles. In both assays, baited traps caught significantly more I. pini than traps with either formulation of verbenone, and no significant difference was observed between the verbenone pouch and SPLAT Verb. In the second assay, we also examined responses of Temnochila chlorodia (Mannerheim) (Coleoptera: Trogositidae), a common bark beetle predator. Traps containing verbenone pouches caught significantly fewer T. chlorodia than the baited control and SPLAT Verb treatments. We conclude that verbenone shows promise for reducing tree mortality from I. pini.


1994 ◽  
Vol 9 (2) ◽  
pp. 57-61 ◽  
Author(s):  
Philip M. McDonald ◽  
Gary O. Fiddler ◽  
Jay H. Kitzmiller

Abstract Three classes of ponderosa pine (Pinus ponderosa) seedlings (nursery-run, wind-pollinated, control-pollinated) were evaluated for stem height and diameter at the USDA Forest Service's Placerville Nursery and the Georgetown Ranger District in northern California. Pines in all three classes were grown with competing vegetation or maintained in a free-to-grow condition. Control-pollinated seedlings were statistically taller (P < 0.05) than nursery-run counterparts when outplanted, and after 1 and 2 growing seasons in the field with and without competition. They also had significantly larger diameters when outplanted and after 2 growing seasons in the field when free to grow. Wind-pollinated seedlings grew taller than nursery-run seedlings when free to grow. A large amount of competing vegetation [bearclover (Chamaebatia foliolosa)—29,490 plants per acre; herbaceous vegetation—11,500; hardwood sprouts—233; and whiteleaf manzanita (Arctostaphylos viscida) seedlings—100] ensure that future pine development will be tested rigorously. West. J. Appl. For. 9(2):00-00.


1997 ◽  
Vol 12 (3) ◽  
pp. 69-73 ◽  
Author(s):  
R. Rose ◽  
D. L. Haase ◽  
F. Kroiher ◽  
T. Sabin

Abstract This is the final summary of two studies on the relationship between root volume and seedling growth; early results were published previously. Survival, growth, and stem volume were determined for 2+0 ponderosa pine (Pinus ponderosa) and Douglas-fir (Pseudotsuga menziesii) seedlings after 8 growing seasons. For each species, seedlings from three seedlots were assigned to one of three root-volume categories [<4.5 cm3 (RV1), 4.5-7 cm3 (RV2), and >7 cm3 (RV3) for ponderosa pine; <9 cm3 (RV1), 9-13 cm3 (RV2), and >13 cm3 (RV3) for Douglas-fir]. On a dry harsh ponderosa pine site on the eastern slopes of Mt. Hood in Oregon, where gopher and cattle damage decreased the number of seedlings, more seedlings in the highest root-volume category survived (70%) than in the smaller root-volume categories (62% and 50%). Douglas-fir on a good site in the Coast Range of Oregon showed significantly greater height and stem volume for the largest root-volume category, whereas annual shoot growth and survival did not differ. Root volume is one of several potentially useful criteria for predicting long-term growth and survival after outplanting. West. J. Appl. For. 12(3):69-73.


1991 ◽  
Vol 67 (3) ◽  
pp. 245-248 ◽  
Author(s):  
J. L. Kingery ◽  
R. T. Graham

During the summer and fall of 1982, a study was established on the Nez Percé National Forest in central Idaho to assess the effects of cattle grazing on the performance of a new ponderosa pine (Pinus ponderosa Laws.) plantation. Three study sites were located in a Douglas-fir/ninebark (Pseudotsuga menziesii/Physocarpus malvaceus) habitat type. Results after six years showed that livestock use can influence tree seedling establishment. Mortality and damage to tree seedlings from cattle resulted primarily from trampling rather than from browsing. Five and one-half percent of the seedlings were damaged by cattle, of which 3.6% died. Browsing by deer and elk caused the most growth loss. Overall damage was greatest from non-animal causes. Seedling quality at the time of planting, handling of the seedling, and droughty conditions during the first two years of the study contributed to this type of damage. Overall performance of the tree seedlings were relatively poor. Total mortality to tree seedlings resulting from all sources of damage was 43.6% for the grazed treatment and 25.3% for the non-grazed treatment.


1995 ◽  
Vol 12 (2) ◽  
pp. 80-85
Author(s):  
Phillip E. Reynolds ◽  
Micheal J. Roden

Abstract Metsulfuron (ALLY or ESCORT), 36 and 72 g ai/ha (~ 0.5 and 1.0 oz ai/ac), and sulfometuron (OUST), 150, 300, and 450 g ai/ha (~ 2.1, 4.2, and 6.3 oz ai/ac), were applied to a northern New Brunswick clearcut (silty clay loam and silty clay soils) to reduce raspberry competition. Treatment, using skidder-mounted herbicide application equipment, occurred in May and August 1986, with planting of 2+2, bareroot, black spruce seedlings in June 1986 and in June 1987. Seedling survival and growth were measured yearly for 5 growing seasons after planting. By August 1991, raspberry cover was less in some treatments than in controls. Survival of seedlings planted 1 month after spring treatments was less than controls, and no significant stem volume increases were observed. Survival of seedlings planted approximately 1 yr after spring treatments was greater than that of control seedlings. Survival of seedlings planted after some summer treatments also was poor, and no significant stem volume increases were noted for seedlings planted after site preparation with sulfometuron. Optimal stem volume increases over control seedlings were observed for seedlings planted 1 yr after spring sulfometuron treatment. These increases occurred sooner than for seedlings planted 1 yr after spring metsulfuron treatment or after summer metsulfuron treatment. Fifth-year stem volume for these seedlings was correlated with raspberry cover (r² = 0.44), decreasing as raspberry cover increased. We conclude that the use of other less expensive silvicultural herbicides may provide equally effective raspberry control and better black spruce seedling survival and growth. North. J. Appl. For. 12(2):80-85.


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