Genetically Improved Ponderosa Pine Seedlings Outgrow Nursery-Run Seedlings with and without Competition—Early Findings

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.

1999 ◽  
Vol 29 (7) ◽  
pp. 940-946
Author(s):  
P M McDonald ◽  
S R Mori ◽  
G O Fiddler

In northern California, ponderosa pine (Pinus ponderosa Dougl. ex Laws. var. ponderosa) height and diameter growth were analyzed to determine if genetically improved seedlings were more competitive than other vegetation and if they outgrew nursery stock in the field. Analysis of growth during the third through sixth growing seasons (1992-1995), indicated no statistical differences for pine height or diameter among genetic classes (control pollinated, wind pollinated, nursery run) when grown with competing vegetation. In 1995, mean height of seedlings grown with competition was 2.4 m for control-pollinated seedlings, 2.3 m for wind-pollinated seedlings, and 2.2 m for nursery-run seedlings. For seedlings grown essentially without competition, control-pollinated seedlings significantly outgrew nursery-run seedlings in height each year for the first six growing seasons. In 1995, the values were 3.0 versus 2.6 m, respectively. The competition consisted of a vigorous stand of shrubs, hardwood sprouts, forbs, and grasses. Within each genetic class, mean height and diameter of pines were significantly larger without competition.


1994 ◽  
Vol 9 (1) ◽  
pp. 24-28
Author(s):  
Philip M. McDonald ◽  
Celeste S. Abbott ◽  
Gary O. Fiddler

Abstract One-year-old Sierra chinkapin (Castanopsis sempervirens) sprouts, greenleaf manzanita (Arctostaphylos patula var. platyphylla) seedlings, and new fronds of bracken fern (Pteridium aquilinum var. pubescens), present in a 1-yr-old ponderosa pine (Pinus ponderosa var. ponderosa) plantation in northern California, were treated once with one of three herbicides (Velpar L, Escort, and Garlon 4) in fall 1986 and spring 1987 and their density and development compared among treatments and to a control. After 6 growing seasons, chinkapin sprouts in the control averaged more than 16,000 per acre, manzanita seedlings over 19,000, and bracken ferns more than 13,000 per acre. After 6 growing seasons, mean ponderosa pine diameter ranged from 2.03 in. in the Velpar treatment to 1.28 in. in the control. Cover of combined shrubs, also after six seasons, was about 3% with Velpar, 7% with Garlon, 20% with Escort, and 51% in the control. Bracken fern cover was greatest (13%) where foliage-active Garlon reduced competing shrubs, and least in the soil-active Velpar treatment (2%) and the control (3%), where heavy competition from shrubs precluded establishment. West. J. Appl. For. 9(1):24-28.


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.


1999 ◽  
Vol 14 (1) ◽  
pp. 48-52
Author(s):  
Fabian C. C. Uzoh

Abstract The effects of competing herbaceous vegetation on the growth of ponderosa pine seedlings with and without the herbicide Pronone were characterized in this 1987-1990 study. Study areas were established in 36 plantations across western Montana on Champion International Corporation's timberland (currently owned by Plum Creek Timber Company). The study sites were divided into three precipitation classes: low, medium, and high. Mean percent stem volume growth was calculated for 3 yr by precipitation class. Split-plot analyses of variance for precipitation class, treatment, and interaction were conducted across sites between treated and untreated seedlings to test for significant (a = 0.05) differences in growth. A two-dimensional plot of precipitation class by treated versus untreated trees was constructed to show growth rate trends. After 3 growing seasons, the treated seedlings showed significantly higher stem volume growth than their untreated counterparts regardless of precipitation class. The difference between treated and untreated seedlings was statistically significant. West. J. Appl. For. 14(1):48-52.


1999 ◽  
Vol 14 (3) ◽  
pp. 164-168 ◽  
Author(s):  
Michael J. Pipas ◽  
Gary W. Witmer

Abstract A 2 yr study on the Rogue River and Mt. Hood National Forests in Oregon evaluated physical barriers for protection of Pinus ponderosa seedlings against damage by Thomomys talpoides. Seedlings protected with one of three weights of: (1) plastic mesh tubing (Vexar®) or (2) sandpapertubing (Durite®) were evaluated against control seedlings. On the Rogue River sites, Vexar® seedlings had the highest survival (62.6%), followed by the controls (59.1%), then Durite® seedlings (17.9%). Gophers were the primary cause of death for the Vexar® seedlings, versus desiccation for the Durite® seedlings. On the Mt. Hood sites, heavyweight Vexar® seedlings had the highest survival (35.4%), medium-weight Durite® seedlings the lowest (2.7%). Seedling mortality caused by gophers was highest for controls (70.2%), followed by light-weight (62.2%) and heavy-weight (53.9%) Vexar® treatments. Overall survival was low (Rogue River = 42%, Mt. Hood = 19.8%). Growth was greatest for the control seedlings but only significantly greater than growth of Durite® seedlings on the Rogue River sites. Growth of seedlings was not compromised by the Vexar® tubing. Although neither type of tubing was highly protective, Vexar® tubes performed better than Durite® tubes. West. J. Appl. For. 14(3):164-168.


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.


Forests ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1067
Author(s):  
Aalap Dixit ◽  
Thomas Kolb ◽  
Owen Burney

Ponderosa pine (Pinus ponderosa Lawson & C. Lawson var. scopulorum Engelm.) forests of the southwestern US are threatened by climate change and deforestation. Information about geographic patterns of provenance variation in budburst phenology is needed to make decisions about selecting seed sources for future planting. In this study, provenance variation in the budburst phenology of ponderosa pine seedlings was examined using common garden studies. Seedlings from 21 provenances, representing an elevational gradient in Arizona and New Mexico, were planted in July 2018 at a ponderosa pine-dominated field site in northern Arizona. Field budburst was monitored weekly on all seedlings in the spring of 2019. Field budburst was compared with budburst timing of the same provenances measured under greenhouse conditions. The hypotheses for this study were that (1) budburst varies among provenances, with earlier budburst in low-elevation provenances, and (2) differences in budburst timing among provenances are consistent for seedlings grown in greenhouse and field environments. Field results show that provenances vary in budburst date and that low- and middle-elevation provenances break bud sooner than high-elevation provenances. Field budburst date had a moderate, positive correlation with provenance mean annual precipitation (r = 0.522) and a moderate, negative trend with latitude (r = −0.413). Budburst date of provenances in the greenhouse had a moderate, positive trend with budburst date in the field (r = 0.554), suggesting application of greenhouse results to field plantings. Such information about provenance variation and environmental and geographic trends in budburst timing will be useful for developing species-specific seed transfer guidelines and effective assisted migration strategies in a changing climate.


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.


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.


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