scholarly journals The Effect of Microbial Endophyte Consortia on Pseudotsuga menziesii and Thuja plicata Survival, Growth, and Physiology Across Edaphic Gradients

2019 ◽  
Vol 10 ◽  
Author(s):  
Matthew M. Aghai ◽  
Zareen Khan ◽  
Matthew R. Joseph ◽  
Aubrey M. Stoda ◽  
Andrew W. Sher ◽  
...  
2001 ◽  
Vol 79 (4) ◽  
pp. 389-397 ◽  
Author(s):  
Hugh J Barclay

Leaf angle distributions are important in assessing both the flexibility of a plant's response to differing daily and seasonal sun angles and also the variability in the proportion of total leaf area visible in remotely sensed images. Leaf angle distributions are presented for six conifer species, Abies grandis (Dougl. ex D. Don) Lindl., Thuja plicata Donn. ex D. Don, Tsuga heterophylla (Raf.) Sarg., Pseudotsuga menziesii (Mirb.) Franco, Picea sitchensis (Bong.) Carr. and Pinus contorta Dougl. ex Loud. var. latifolia. The leaf angles were calculated by measuring four foliar quantities, and then the distributions of leaf angles are cast in three forms: distributions of (i) the angle of the long axis of the leaf from the vertical for the range 0–180°; (ii) the angle of the long axis of the leaf for the range 0–90°; and (iii) the angle of the plane of the leaf for the range 0–90°. Each of these are fit to the ellipsoidal distribution to test the hypothesis that leaf angles in conifers are sufficiently random to fit the ellipsoidal distribution. The fit was generally better for planar angles and for longitudinal angles between 0° and 90° than for longitudinal angles between 0° and 180°. The fit was also better for Tsuga heterophylla, Pseudotsuga menziesii, Picea sitchensis, and Pinus contorta than for Abies grandis and Thuja plicata. This is probably because Abies and Thuja are more shade tolerant than the other species, and so the leaves in Abies and Thuja are preferentially oriented near the horizontal and are much less random than for the other species. Comparisons of distributions on individual twigs, whole branches, entire trees, and groups of trees were done to test the hypothesis that angle distributions will depend on scale, and these comparisons indicated that the apparent randomness and goodness-of-fit increased on passing to each larger unit (twigs up to groups of trees).Key words: conifer, leaf angles, ellipsoidal distribution.


1991 ◽  
Vol 37 (1) ◽  
pp. 34-41 ◽  
Author(s):  
C. R. Bell ◽  
W. D. Ramey

A total of 377 heterotrophic bacteria were isolated on nonselective medium from the rhizoplanes of five species of conifer. The species were western hemlock (Tsuga heterophylla), Douglas-fir (Pseudotsuga menziesii), lodgepole pine (Pinus contorta), white spruce (Picea glauca), and western red cedar (Thuja plicata). Twenty-eight strains from this population were identified as presumptive agrobacteria. All proved nontumourigenic. Principal-component analysis indicated that the strains, which had clustered into two discrete groups, had intermediate biovar characteristics. Cluster 1 was predominately biovar 3/2 in character, cluster 2 was predominately biovar 2/3. All the presumptive agrobacteria were distributed randomly with respect to the tree species. This study demonstrates that agrobacteria, although atypical, do occur in forest soils and attests to the ubiquity of the genus in soil. Key words: Agrobacterium, biovars, crown gall, conifers.


1994 ◽  
Vol 72 (11) ◽  
pp. 1635-1646 ◽  
Author(s):  
X. J. Li ◽  
P. J. Burton ◽  
C. L. Leadem

Pregermination stratification treatment was generally more important than the effects of light on seed germination by 14 conifer species and varieties native to British Columbia. Nevertheless, there were some strong species differences in the response of germination to light. Final germination percentage after 21 days (28 days for Abies spp.) for both stratified and unstratified seeds of Picea glauca, Picea sitchensis, and Tsuga heterophylla showed no response to light during germination. Seed germination by Abies grandis, Pinus contorta var. contorta, Pinus contorta var. latifolia, Pinus ponderosa, Pseudotsuga menziesii var. glauca, and Pseudotsuga menziesii var. menziesii responded positively to light if unstratified but was not significantly affected by light when stratified. For Thuja plicata seeds, germination responded positively to light regardless of stratification pretreatment. Light appeared to reduce germination of stratified seeds of Abies amabilis, Abies lasiocarpa, Larix occidentalis, and Pinus monticola, although stratification conditions for these species were suboptimal. The germination rate of stratified seeds of all species and unstratified seeds of most species was increased by light. Results showed no significant relationship between germination response to light and shade-tolerance ranking or mean seed weight of the species. In six seed lots of Pinus contorta var. latifolia, however, we detected a weak negative correlation between mean seed weight and unstratified light responsivity measured after 1 week but a significant positive correlation when measured after 3 weeks. Very low light levels in closed-canopy forests or in the forest floor may prolong tree seed germination but are unlikely to constrain final germination levels after most seeds have been naturally stratified by moist, cool winter conditions. The importance of differences in the rate and timing of tree seed germination under natural conditions remains to be demonstrated. Key words: conifer biology, forest regeneration, light response, lodgepole pine, Pinus contorta, seed germination, stratification.


1998 ◽  
Vol 88 (6) ◽  
pp. 633-640 ◽  
Author(s):  
T.D. Schowalter ◽  
L.M. Ganio

AbstractVariation in canopy arthropod abundances and community structure were evaluated in an old-growth (500-year-old) forest at the Wind River Canopy Crane Research Facility in southwestern Washington, USA. Arthropods were sampled at three canopy levels and two seasons in each of four tree species (Pseudotsuga menziesii, Tsuga heterophylla, Abies grandis, and Thuja plicata). The four tree species had distinguishable arthropod species compositions and community organization. Thuja plicata (Cupressaceae) had a particularly distinctive canopy fauna dominated by several mite taxa which did not occur on the other tree species (all Pinaceae). Pseudotsuga menziesii hosted a relatively diverse arthropod fauna with greatest richness of taxa and functional groups. Distinct arthropod assemblages were not observed among canopy levels and sampling dates, but these factors significantly influenced abundances of 63% of the arthropod taxa, either individually or interactively with other factors. These data indicate that forests managed for fewer tree species eliminate important components of arthropod diversity in Pacific Northwest forests and that sampling for biodiversity assessment also should represent season and canopy level.


1959 ◽  
Vol 91 (11) ◽  
pp. 719-723 ◽  
Author(s):  
A. F. Hedlin

Gall midges have been reported from cones of western red cedar, Thuja plicata Donn., but none have been described. Keen (1958) reported the occurrence in Washington and Oregon of a cone midge which was credited with destroying 90 per cent of the seed. In 1940 Prebble and Graham reported a midge in cones of western red cedar at Cowichan Lake, B.C. These reports almost certainly refer to the midge described here. The only other species taken from red cedar cones was Lestodiplosis taxiconis Foote, but it occurred in verysmall numbers; previously it has been reported only from cones of Douglas fir, Pseudotsuga menziesii (Mirb.) Franco (Foote, 1956).


1997 ◽  
Vol 12 (3) ◽  
pp. 74-80 ◽  
Author(s):  
William I. Stein

Abstract Western redcedar (Thuja plicata) and Douglas-fir (Pseudotsuga menziesii) were planted together after applying seven site-preparation methods at one site in the Oregon Coast Ranges. Survival and growth of cedar were markedly less than Douglas-fir on this favorable site where both species were components of the original stand. Repeated browsing severely impeded the cedar. Site preparation by broadcast burning generally yielded the best results, but sowing grass after broadcast burning produced Douglas-fir responses similar to those for no site preparation. Where grass was sown, herbaceous cover was more abundant and taller, salmonberry differed little in density but was slightly taller, and development of red alder (Alnus rubra) was delayed. Red alder is currently overtopping conifers in all treatments, and release is needed to ensure sufficient conifer survival. This single example illustrates that much more effort than just planting a mix of species is required to establish a desired mixed stand. West. J. Appl. For. 12(3):74-80.


Author(s):  
Руслан Бесланович Хупов ◽  
Римма Шамсудиновна Заремук

Представлены результаты изучения сортов туи (Thuja L.) в условиях прикубанской зоны садоводства Краснодарского края по основным адаптивным признакам: зимостойкость (морозоустойчивость), засухоустойчивость (жаростойкость), устойчивость к доминирующим болезням (Lophodermium seditiosum), вредителям (Aphidoidea latreille и Carulaspis caruelii). Оценены декоративные признаки сортов. Целью исследований являлись комплексная оценка и выделение наиболее адаптивных и проявляющих максимально высокую декоративность сортов Thuja occidentalis и Thuja plicata в условиях участившихся абиотических и биотических стрессов, а также расширения современного сортимента вечнозелёных хвойных растений при создании живых изгородей и топиарных форм в условиях юга России. Представлены итоги комплексной оценки интродуцированных сортов туи Brabant, Degroots Spire, Malonyana, Mini Smaragd, Atrovirens, Can-Can и Dura. Установлено, что декоративные показатели сортов туи определяются сортовой спецификой, прежде всего относительной устойчивостью к болезням, вредителям в конкретных условиях произрастания. Из 7 сортов выделены наиболее адаптивные, сочетающие устойчивость к температурным стрессам (засухоустойчивые, зимостойкие), основным болезням и вредителям в сочетании с высокими декоративными показателями (архитектоника кроны, цвет и аромат хвои, период декоративности и др.). Сорта туи Degroots Spire, Mini Smaragd, Atrovirens и Dura по комплексу признаков отнесены к хорошо адаптированным к погодно-климатическим условиям региона и высоко декоративным группам растений и рекомендуются для расширения адаптивного регионального сортимента туи (Thuja L.) и широкого использования в озеленении на юге России.


Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3410
Author(s):  
Bozena Debska ◽  
Ewa Spychaj-Fabisiak ◽  
Wiesław Szulc ◽  
Renata Gaj ◽  
Magdalena Banach-Szott

The major indicator of soil fertility and productivity are humic acids (HAs) arising from decomposition of organic matter. The structure and properties of HAs depend, among others climate factors, on soil and anthropogenic factors, i.e., methods of soil management. The purpose of the research undertaken in this paper is to study humic acids resulting from the decomposition of crop residues of wheat (Triticum aestivum L.) and plant material of thuja (Thuja plicata D.Don.ex. Lamb) using electron paramagnetic resonance (EPR) spectroscopy. In the present paper, we report EPR studies carried out on two types of HAs extracted from forest soil and incubated samples of plant material (mixture of wheat straw and roots), both without soil and mixed with soil. EPR signals obtained from these samples were subjected to numerical analysis, which showed that the EPR spectra of each sample could be deconvoluted into Lorentzian and Gaussian components. It can be shown that the origin of HAs has a significant impact on the parameters of their EPR spectra. The parameters of EPR spectra of humic acids depend strongly on their origin. The HA samples isolated from forest soils are characterized by higher spin concentration and lower peak-to-peak width of EPR spectra in comparison to those of HAs incubated from plant material.


Plant Disease ◽  
2013 ◽  
Vol 97 (6) ◽  
pp. 744-748 ◽  
Author(s):  
Jerry E. Weiland ◽  
Bryan R. Beck ◽  
Anne Davis

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.


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