Ponderosa Pine Habitat Types as an Indicator of Site Quality in the Dixie National Forest, Utah

1989 ◽  
Vol 4 (2) ◽  
pp. 52-54 ◽  
Author(s):  
David L. Verbyla ◽  
Richard F. Fisher

Abstract Forest habitat types have been purported to be useful indicators of site quality. This is generally true for habitat types with different dominant tree species. However, few have studied the site indicator value of habitat types with the same dominant tree species. We measured site index (base age 25) from 172 randomly selected plots within the ponderosa pine (Pinus ponderosa) zone of the Dixie National Forest, Utah. The range of site index within any one habitat type was broad. Poor sites occurred on all five habitat types. However, the best sites occurred only on the Pinus ponderosa/Symphoricarpos oreophilus and Pinus ponderosa/Quercus gambelii habitat types. Therefore, habitat type may be useful in predicting the best sites, but only if other site information is used in addition to habitat type. West. J. Appl. For. 4(2):52-54, April 1989.

1991 ◽  
Vol 21 (5) ◽  
pp. 606-611 ◽  
Author(s):  
W. F. Stansfield ◽  
J. P. McTague ◽  
R. Lacapa

A dominant-height equation for ponderosa pine (Pinusponderosa Laws.) was constructed utilizing a parameter prediction method and a model by J.E. King. The site-index equation was obtained by inverting the dominant-height equation. A method was examined for indirectly obtaining parameter prediction equations. It proved superior to two direct parameter prediction approaches. Other site-quality variables, such as habitat type groups and elevation, were included in the dominant-height and site-index equations and were successful in refining predictive capability.


2013 ◽  
Vol 43 (10) ◽  
pp. 963-971 ◽  
Author(s):  
Jianwei Zhang ◽  
William W. Oliver ◽  
Robert F. Powers

The self-thinning rule has been used extensively to predict population dynamics under intraspecific and interspecific competition. In forestry, it is an important silvicultural concept for maintaining stand health in the face of climate change and biotic stress, but uncertainty exists because traditional self-thinning limits were set subjectively without regard to site quality. We addressed this by analyzing ponderosa pine (Pinus ponderosa Lawson & C. Lawson) data from 109 research plots measured repeatedly and 59 inventory plots measured once across California. Self-thinning boundaries were fitted to the data with quantile regression and stochastic frontier function (SFF) techniques with and without site index (SI) as a covariate. The models from both methods fitted the data well with either research plots or all plots. Slopes for size-density trajectories were –0.45 with the 0.99 quantile and –0.47 for SFF. Maximum stand density indices (SDI) were 1250 trees per hectare (TPH) with the 0.99 quantile and 1050–1060 TPH with SFF. Mortality occurred when site occupancy from SFF reached 0.75, suggesting a zone of imminent mortality. Curvilinear trends in maximum SDI across SI for both methods indicate that self-thinning varies with site quality. Any management regimes that increase site quality and productivity will increase the self-thinning boundary.


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.


1978 ◽  
Vol 8 (2) ◽  
pp. 214-219 ◽  
Author(s):  
Ralph E. Williams ◽  
C. D. Leaphart

The area of root disease centers on the Coeur d'Alene National Forest in northern Idaho was effectively estimated from large-scale color infrared aerial photographs. An estimated 5.1% (12 160.7 ha) of the commercial forest land was occupied by infection centers. Root disease centers were identified in 113 of 364 stands actually surveyed. Although most of these 113 stands were of the Tsugaheterophylla – Pachistimamyrsinites habitat type, the highest percentage of stands with root disease was found in the Abiesgrandis – Pachistimamyrsinites habitat type.Observations made during these studies suggest that occurrence of Pseudotsugamenziesii (Mirb.) Franco, Abiesgrandis (Dougl.) Lindl., or both in a stand is the most important factor in the expression of root disease centers. Accuracy of interpretation of photographs was 92%; incorrect interpretations were consistently associated with stands in the Abieslasiocarpa series of habitat types or with stands stocked with conifers tolerant of root pathogens.


2011 ◽  
Vol 41 (8) ◽  
pp. 1698-1709 ◽  
Author(s):  
Chengcai Ni ◽  
Gordon Nigh

Stand age is often hard to measure accurately. Measurement error in age affects height estimates when height is projected from one age to another age. In this study, our objective was to derive an estimator for the variance of the component of projection error associated with the error in age. To evaluate the estimator, a simulation approach was employed and the results showed that the estimator worked well in most cases. When the variance of the error in age increases and the projection is forward, however, the estimator might not work as well as in other cases. Another objective was to examine how the error in age behaved under different height–age models and to what extent it affected height and site index estimates. The effect of the error in age depended on its magnitude, the height–age model, initial value of dominant height and age, and projection length. It was also shown that the effect was sometimes negligible, but it could be considerable in other cases. Data from 80 ponderosa pine ( Pinus ponderosa Dougl. ex Laws.) trees in British Columbia, Canada, were used in an illustrative example.


1998 ◽  
Vol 15 (3) ◽  
pp. 116-123 ◽  
Author(s):  
Peter N. Bakken ◽  
James E. Cook

Abstract The arboreal regeneration of 24 mature, fully stocked forests distributed among 6 common habitat types (Kotar et al. 1988) in north-central Wisconsin were studied. Nineteen of the stands were inventoried in 1992 and 1993; in 1993 an additional 5 stands were included. The density and composition of small (<25 cm) and large (25-150 cm) seedlings were determined, and the relationships of the understory and overstory were investigated. No significant (P < 0.05) differences were found for seedling densities of either size class among habitat types. This was due, in part, to the large variation within most habitat types; this in turn is primarily a function of the temporally variable nature of seedlings. The average densities per habitat type ranged from 3,125-20,200/ha for large seedlings and from 20,208-152,083/ha for the small seedlings. Red and sugar maple strongly dominated the regeneration. Red maple was the most common (88-96%) species in the small seedling size class on the three driest habitat types, and sugar maple (88-99%) on the two most mesic habitat types. In the middle of the site quality gradient, the two maples shared dominance with northern red oak. The level of maple dominance was lower in the large seedling class, ranging from 53-93%. The small seedling size class was significantly related to the amount of maple basal area each year, but the strength of this relationship weakened from 1992 to 1993. The widespread domination by red and sugar maple is a function of their regeneration ecology, shade tolerance, fire suppression, and deer browsing. The seedling composition and densities have important implications for the management of these forests. The regeneration and overstory characteristics suggest that it would be easiest to direct the composition one of several ways on the PMV and AVVib habitat types. Fairly heavy overstory treatments, in conjunction with seedbed preparation, are probably necessary to regenerate significant amounts of species other than sugar maple on the two most mesic habitat types. North. J. Appl. For. 15(3):116-123.


1980 ◽  
Vol 112 (8) ◽  
pp. 797-809 ◽  
Author(s):  
J. S. Elkinton ◽  
D. L. Wood

AbstractMale Ips paraconfusus selected a host, ponderosa pine (Pinus ponderosa), over a non-host, white fir (Abies concolor), only after the beetles had bored through the outer bark and into the phloem. Males, when given a choice between bark discs of these tree species in petri dishes, bored readily through the outer bark of either species. However, the beetles penetrated no more than 1 mm into the phloem of white fir, but they bored extensively in the phloem of ponderosa pine. The beetle’s preference for the pine over fir phloem was apparent with intact samples of phloem with the outer bark removed and with ground phloem. No preferences were apparent for the ground or intact pine or fir outer bark, with the phloem removed. The beetles bored preferentially in fissured as opposed to smooth outer bark of either tree. Beetles did not feed in the outer bark but did feed in the phloem of either species. In field experiments beetles attracted to logs of pine and fir bored through the outer bark of each species in nearly equal numbers. In white fir they re-emerged and departed soon after penetration of the phloem, whereas in ponderosa pine they continued excavation of tunnels in the phloem. In contrast, few beetles penetrated even the outer back of incense cedar (Calocedrus decurrens), another non-host species.


1990 ◽  
Vol 122 (2) ◽  
pp. 343-347 ◽  
Author(s):  
R.W. Thier ◽  
M.A. Marsden

AbstractIncidence of the western pine shoot borer, Eucosma sonomana Kearfott, and tree growth measurements from 5687 ponderosa pines, Pinus ponderosa Dougl. ex Laws., were recorded in the Calf Pen plantation Payette National Forest, ID. The percentage of trees infested by shoot borer generally increased as tree height increased.Infestation of the tree’s leader usually resulted in reduced height growth especially where needle length was shortened in the leader. Height growth of infested leaders was less than uninfested leaders. This difference in height growth increased with the total height of the tree as measured in the previous year.


1999 ◽  
Vol 29 (7) ◽  
pp. 1027-1038 ◽  
Author(s):  
Robert F Powers ◽  
Phillip E Reynolds

Factorial combinations of vegetation, nutrient, and insect control treatments were applied repeatedly to three contrasting California plantations of Pinus ponderosa var. ponderosa Dougl. ex Laws. Ten-year findings show that potential productivity is far greater than previously believed. Stem volume gains were linked directly with increases in crown volume. Insect problems were negligible. Vegetation control increased tree growth profoundly on xeric sites but less so on the most mesic. Where soil was both droughty and infertile, growth responses traced primarily to improved soil moisture availability and secondarily to better nutrition. The most fertile site also was droughty, and trees responded only to improved moisture availability. Water was less limiting on the most productive site. There, both fertilizers and herbicides triggered similar, substantive growth increases. Drought from both plant competition and climate reduced stomatal conductance, xylem water potential, and net assimilation rates. Assimilation rates increased linearly with site index, but treatment differences were not apparent once drought had peaked. Fertilization improved water-use efficiency where water stress was not extreme. Advantages in water availability to pines from vegetation control will dissipate as tree crowns close and transpiration rises.


1986 ◽  
Vol 1 (4) ◽  
pp. 121-124 ◽  
Author(s):  
John A. Helms ◽  
C. Hipkin

Abstract Soil bulk density was measured around 423 trees (0.48 ha) in a 16-year-old ponderosa pine (Pinus ponderosa) plantation in the Sierra Nevada of California. A landing, skid trail, and areas adjacent to skid trails had soil bulk density increased by 43, 30, and 18% compared to areas with lowest bulk density. Due to differences in mean tree volume and initial survival, volume per unit area in these three locations was reduced by 69, 55, and 13%. Areas between skid trails were relatively unaffected. Assuming full stocking, reduction in productivity by age 40 yr in the most heavily compacted areas is equivalent to about one site index class. Further reduction in projected volume on highly compacted areas could occur due to lower initial survival. Alternative approaches to skid trail management are suggested. West. J. Appl. For. 1:121:124, Oct. 1986.


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