scholarly journals Ecology and Management ofMindarus kinseyiVoegtlin (Aphidoidea: Mindaridae) on White-Fir Seedlings at a California Forest Nursery

Hilgardia ◽  
1995 ◽  
Vol 62 (1) ◽  
pp. 1-62 ◽  
Author(s):  
L. E. Ehler ◽  
M. G. Kinsey
Keyword(s):  
Forest Nursery ◽  
White Fir

Soil microbial community response to nitrogen and phosphorous fertilization in a temperate forest nursery

2018 ◽  
Vol 51 (2) ◽  
Author(s):  
Muhammad Razaq ◽  
Muhammad Sajjad Haider ◽  
Salah Uddin ◽  
Liu Chunping ◽  
Hai-Long Shen ◽  
...  
Keyword(s):  
Microbial Community ◽  
Soil Microbial Community ◽  
Temperate Forest ◽  
Community Response ◽  
Forest Nursery ◽  
Soil Microbial

scholarly journals Pathogenicity and Virulence of Pythium Species Obtained from Forest Nursery Soils on Douglas-Fir Seedlings

Plant Disease ◽  
2013 ◽  
Vol 97 (6) ◽  
pp. 744-748 ◽  
Author(s):  
Jerry E. Weiland ◽  
Bryan R. Beck ◽  
Anne Davis
Keyword(s):  
Pseudotsuga Menziesii ◽  
Seedling Survival ◽  
The United States ◽  
Douglas Fir ◽  
Tree Seedlings ◽  
Pythium Species ◽  
Forest Nursery ◽  
Damping Off ◽  
Greenhouse Study ◽  
Forest Nurseries

Pythium species are common soilborne oomycetes that occur in forest nursery soils throughout the United States. Numerous species have been described from nursery soils. However, with the exception of P. aphanidermatum, P. irregulare, P. sylvaticum, and P. ultimum, little is known about the potential for other Pythium species found in nursery soils to cause damping-off of tree seedlings. A greenhouse study was conducted to evaluate the pathogenicity and virulence of 44 Pythium isolates representing 16 species that were originally recovered from soil at three forest nurseries in Washington and Oregon. Seeds of Douglas-fir (Pseudotsuga menziesii) were planted into soil infested with each of the isolates. Seedling survival, the number of surviving seedlings with necrotic root lesions, and taproot length were evaluated 4 weeks later. Responses of Douglas-fir to inoculation varied significantly depending on Pythium species and isolate. Eight species (P. dissotocum, P. irregulare, P. aff. macrosporum, P. mamillatum, P. aff. oopapillum, P. rostratifingens, P. sylvaticum, and P. ultimum var. ultimum) significantly reduced the number of surviving seedlings compared to the noninoculated treatment. However, all Pythium species caused a greater percentage of seedlings to develop root lesions (total mean 40%) than was observed from noninoculated seedlings (17%). Taproot length varied little among Pythium treatments and was not a useful character for evaluating pathogenicity. Results confirm the ability of P. irregulare, P. mamillatum, and P. ultimum var. ultimum to cause damping-off of Douglas-fir seedlings, and are indicative that other species such as P. dissotocum, P. aff. macrosporum, P. aff. oopapillum, P. rostratifingens, and P. sylvaticum may also be responsible for seedling loss.

Pathogens and insects in a pristine forest ecosystem: the Sierra San Pedro Martir, Baja, Mexico

2002 ◽  
Vol 32 (3) ◽  
pp. 448-457 ◽  
Author(s):  
Patricia E Maloney ◽  
David M Rizzo
Keyword(s):  
Forest Ecosystem ◽  
Bark Beetles ◽  
Stand Structure ◽  
Linear Regression Analysis ◽  
Mixed Conifer ◽  
San Pedro ◽  
White Fir ◽  
Sugar Pine ◽  
Sierra San Pedro Martir ◽  
Pristine Forest

We determined the incidence of pathogens and insects across mixed-conifer stands in the Sierra San Pedro Martir (SSPM) of northern Baja, Mexico, to assess the role of pests in a pristine forest ecosystem. We also determined the spatial distribution of the two most common pests, mistletoe, Phoradendron pauciflorum Torrey, and the fir engraver, Scolytus ventralis LeConte, of white fir (Abies concolor (Gord. & Glend.) Lindl.) across a 25-ha grid to assess spread and what host and pest variables were related. In these open parklike stands the mean tree density was 160 trees/ha, of which 58% were trees >20 cm diameter at breast height (DBH). In these low-density, mixed-aged stands we found that mixed-conifer species were well represented with no one species being completely dominant. Percent cumulative mortality for the SSPM was 12.7%, ranging from 2 to 24%, with the greatest amount of mortality occurring in the larger size classes, trees [Formula: see text]50 cm DBH. Multiple linear regression analysis showed that 78% of the mortality we observed was explained by pathogens and bark beetles (r2 = 0.78, P = 0.0001, F = 84). Mean pest incidence for Jeffrey pine (Pinus jeffreyi Grev. & Balf. in A. Murray), white fir, and sugar pine (Pinus lambertiana Dougl.) was 21, 88, and 2%, respectively. We found a number of relationships among host and pest variables, as well as a pathogen– insect interaction, and across the SSPM we found that nonhost species may be interfering in certain host–pest interactions. Spatial patterns from the 25-ha grid survey revealed that both P. pauciflorum and S. ventralis incidence were widespread. Phoradendron pauciflorum showed no spatial structure across the 25 ha but S. ventralis showed some degree of spatial structuring across the survey area. We also found that mistletoe severity was negatively correlated with regeneration of white fir. In pristine forests, pathogens and insects influence mortality and regeneration success, affecting stand structure and composition.

MOISTURE STRESS AND FIR ENGRAVER (COLEOPTERA: SCOLYTIDAE) ATTACK IN WHITE FIR INFECTED BY TRUE MISTLETOE

1974 ◽  
Vol 106 (3) ◽  
pp. 315-318 ◽  
Author(s):  
George T. Ferrell
Keyword(s):  
Xylem Sap ◽  
Moisture Stress ◽  
Paired Comparisons ◽  
White Fir

AbstractXylem sap tension, an indication of moisture stress, was compared in foliated twigs of white fir infected by the mistletoe, Phoradendron bolleanum subspecies pauciflorum, and in paired, uninfected fir at the lower, mid-, and upper crown level. The upper boles were examined for fir engraver attacks. Reproductively successful attacks containing little or no host oleoresin were found in the infected fir, while only a single unsuccessful attack filled with oleoresin was found in the uninfected trees. Mean moisture stress in the upper crowns of most of the infected fir exceeded that in uninfected trees in all paired comparisons except one with a light infection. No differences in mean moisture stress between infected and uninfected trees were found at the lower and mid-crown levels.

ESTIMATION OF GROWTH – TIME TEMPERATURE CHARACTERISTICS FOR ISOLATES OF FOMES PINI, A HEART ROT FUNGUS

1964 ◽  
Vol 42 (12) ◽  
pp. 1635-1652 ◽  
Author(s):  
Lee A. Paine ◽  
Gideon Schwarzbart ◽  
William G. O'Regan
Keyword(s):  
Regression Analysis ◽  
Cross Section ◽  
Growth Pattern ◽  
Storage Temperature ◽  
Three Dimensional ◽  
Douglas Fir ◽  
Growth Time ◽  
Optimum Temperature ◽  
Analysis Techniques ◽  
White Fir

Regression analysis techniques were applied to an estimation of three-dimensional surfaces representing the growth of Fomes pini as a function of time and temperature. These methods were judged to be valuable in their economy of data and in their provision of readily available plotting points for any desired cross section of the surface.The growth pattern of F. pini taken from Douglas fir was distinct from that of the form of F. pini found on nearby white fir. Growth of isolates from Douglas fir was more than twice that of white fir isolates after 18 days at near-optimum temperatures on malt agar. Estimates of growth trends and optimum temperatures were examined both for individual isolates of F. pini and for averages of isolates from the two host species, Douglas fir and white fir. Results suggest that chronological changes in the optimum temperature may be affected by the relation between the storage temperature preceding initial measurements and the terminal optimum temperature.

Mixed Forests of Red Fir and White Fir in Yosemite National Park, California

1984 ◽  
Vol 112 (1) ◽  
pp. 15 ◽  
Author(s):  
Albert J. Parker
Keyword(s):  
National Park ◽  
Yosemite National Park ◽  
Mixed Forests ◽  
White Fir

The effects of summer shoot production on height growth components of seedlings of California red and white fir

1992 ◽  
Vol 22 (5) ◽  
pp. 690-698 ◽  
Author(s):  
Stephen W. Hallgren ◽  
John A. Helms
Keyword(s):  
Soil Moisture ◽  
Growing Season ◽  
Shoot Elongation ◽  
Height Growth ◽  
Shoot Morphology ◽  
Apical Dome ◽  
White Fir ◽  
Shoot Production ◽  
Terminal Shoot ◽  
Needle Primordia

Morphogenesis of the terminal shoot was studied in 2-year-old seedlings of California red fir (Abiesmagnifica A. Murr.) and two elevational sources of white fir (Abiesconcolor (Gord. & Glend.) Lindl.). Seedlings were either watered or left unwatered during the growing season in order to produce different shoot morphologies and seedlings with and without a summer shoot. Under favorable soil moisture, the frequency of summer shoot production was 32, 53, and 82% for red fir and high- and low-elevation white fir, respectively. Drought from mid-May to mid-September reduced summer shoot production to less than 1% in both species. Spring shoot morphology was not an indicator of capacity to produce a summer shoot. Rate of primordium production was directly related to apical dome diameter. However, when the normal spring increase in apical dome diameter was arrested by summer shoot elongation, the rate of primordium production appeared to be unaffected. Although the apical and subapical meristems were active at the same time, they did not appear to be antagonistic. The major effects of producing a summer shoot were as follows: (i) elongation of 60–120% more intemodes in the current growing season, (ii) production of 15–40% more needle primordia in the overwintering bud, (iii) production of 30–60% more primordia annually, and (iv) increase in the percentage of total primordium production that developed into needles from 60% to 75–80%.

Forest Nursery Course, Muguga, 1952

1953 ◽  
Vol 18 (3) ◽  
pp. 118-118
Author(s):  
A. L. Griffith
Keyword(s):  
Forest Nursery

The Nonconventional Bonding of White Fir Flakeboard Using Nitric Acid

Holzforschung ◽  
1978 ◽  
Vol 32 (5) ◽  
pp. 162-166 ◽  
Author(s):  
W. E. Johns ◽  
H. D. Layton ◽  
T. Nguyen ◽  
J. K. Woo
Keyword(s):  
Nitric Acid ◽  
White Fir
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