Soil nitrogen and lodgepole pine seedling responses to five years of legume cover

1998 ◽  
Vol 74 (4) ◽  
pp. 578-582 ◽  
Author(s):  
J. M. Kranabetter ◽  
R. Trowbridge

Legumes were tested for their ability to increase soil N content and improve growth of lodgepole pine (Pinus contorta Dougl. ex Loud.) seedlings in west-central British Columbia. A trial with alsike clover at varying densities were tested at one site, while three legume species (alsike clover, birdsfoot trefoil, and white clover) were tested on a second site. After five years of legume cover, mineralizable N mass of the forest floor were 0.5 to 4.5 times those of controls. Total N of the forest floor more than doubled in the seeding density study compared with controls, but was insignificant in the multiple species study. Despite observed increases in soil nitrogen, lodgepole pine growth was not enhanced by the legume treatments. Factors such as N immobilization, root distribution, low S levels, and competition for B may have limited the response of lodgepole pine seedlings to additions of biologically fixed-N. Key words: nitrogen-fixation, legumes, lodgepole pine, soil nitrogen

1992 ◽  
Vol 22 (8) ◽  
pp. 1089-1093 ◽  
Author(s):  
R. Trowbridge ◽  
F.B. Holl

An overdense lodgepole pine (Pinuscontorta Dougl. ex Loud.) stand was knocked down and the site was prepared by broadcast burn, windrow burn, or mechanical forest floor removal. Inoculated alsike clover (Trifoliumhybridum L.) was seeded at 0, 10, 20, and 30 kg/ha for the three different site preparation treatments to determine the effects of (i) site preparation on infection and effectiveness of the clover–Rhizobium symbiosis and clover percent cover and (ii) the clover–Rhizobium N2-fixing symbiosis on survival, early growth, and foliar nitrogen concentration of lodgepole pine seedlings. The N2-fixing symbiosis established well in all treatments. Clover percent cover increased with increasing rate of seeding, although by relatively few percent in the clover seeded plots. Broadcast burning, windrow burning, and mechanical forest floor removal did not affect the establishment of the N2-fixing symbiosis or clover percent cover. Lodgepole pine survival was not affected by the seeding treatments in any year, nor were height measurements during the first three growing seasons. Seedling height was slightly less in clover-seeded plots compared with controls in the fourth growing season. Lodgepole pine seedlings on clover-seeded plots had decreased diameter growth compared with controls during the first three growing seasons, but incremental diameter growth no longer showed this effect by the fourth growing season. Needle mass (g/100 needles) was less in clover-seeded plots at the end of the second growing season, but this effect was reversed by the fourth growing season, when both needle mass and foliar nitrogen concentration in lodgepole pine foliage were greater in clover-seeded plots.


1986 ◽  
Vol 64 (11) ◽  
pp. 2719-2725 ◽  
Author(s):  
Keith N. Egger ◽  
J. W. Paden

Twenty-two species of postfire ascomycetes belonging to the order Pezizales were screened for biotrophic interactions with roots of lodgepole pine (Pinus contorta Dougl.). Biotrophic associations ranged from pathogenicity to mycorrhizal symbiosis, but most species tested did not show any affinity for roots. Pyropyxis rubra (Peck) Egger and Rhizina undulata Fr. were aggressive pathogens that infected the vascular cylinder and killed the seedlings. Tricharina praecox (Karst.) Dennis var. intermedia Egger, Yang & Korf also had some ability to infect the vascular cylinder, but usually did not kill the seedlings. Geopyxis carbonaria (A. & S.) Sacc. and Trichophaea hemisphaerioides (Mont.) Graddon invaded the cortex, forming complex intracellular structures, but did not penetrate the vascular cylinder. They may form mutualistic associations under certain conditions. The only confirmed mutualistic species was Sphaerosporella brunnea (A. & S.) Svrcek & Kubicka, which formed ectendomycorrhizae. Anthracobia maurilabra (Cooke) Boud. and A. tristis (Bomm., Rouss. & Sacc.) Boud. appear to be primarily root-surface inhabitants with limited capacity to infect cortical tissues through breaks in the epidermis. Gyromitra infula (Schaef.) Quél. penetrated the epidermis but was unable to overcome host defences against pathogenic infection.


2012 ◽  
Vol 92 (6) ◽  
pp. 1207-1212 ◽  
Author(s):  
Joanne E. MacDonald ◽  
Jen Hacking ◽  
Yuhui Weng ◽  
Jeff Norrie

MacDonald, J. E., Hacking, J., Weng, Y. and Norrie, J. 2012. Root growth of containerized lodgepole pine seedlings in response to Ascophyllum nodosum extract application during nursery culture. Can. J. Plant Sci. 92: 1207–1212. Vigorous root growth immediately after spring planting is crucial to ensure a well-developed root system before the occurrence of drought events associated with climate change. The objective of this study was to enhance spring root growth of containerized lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) seedlings. Seedling culture began in April. In September, seedlings were root drenched with an extract of the brown marine alga Ascophyllum nodosum (L.) Le Jolis in finisher fertilizer at rates of 1:750, 1:500, and 1:250. Finisher fertilizer alone served as control. Applications were made three or six times. Seedling culture continued until lifting in December, and then seedlings were freezer stored. Frequency of application had no effect on root growth, whereas rate of application had a significant effect. Compared with control, the 1:750, 1:500, and 1:250 rates significantly reduced total length of the root system in mid October. After overwintering and growing under favorable environmental conditions for 21 d, the 1:500 rate significantly increased the total number of white roots, as well as the number of both short and long white roots. These results suggest that application of Ascophyllum nodosum extract may be a valuable nursery practice to increase spring root growth, thereby enhancing drought resistance.


1979 ◽  
Vol 55 (3) ◽  
pp. 102-105 ◽  
Author(s):  
D. G. Blackmore ◽  
Wm. G. Corns

Perennial herbaceous vegetation, mainly marsh reed grass, (Calamagrostis canadensis (Michx) Beauv.), was sprayed with glyphosate on the day before planting one-year-old plugs of lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) and white spruce (Picea glauca (Moench) Voss) on cutover forest land north of Edson, Alberta. Spraying at 4.5 kg ai/ha, included spot and strip applications in June 1976, compared with unsprayed scalps and controls. At the same time, all treatments were repeated plus a 9 g, 22-8-2 fertilizer tablet for each seedling. Another experiment at the same site, begun on August 1, 1976, compared scalp, unfertilized control and glyphosate strip treatments, followed by planting of pine seedlings the day after spraying 4.5 kg ai/ha glyphosate. An adjacent experiment, also commenced on August 1, included dosages of 1.1 to 5.6 kg ai/ha with planting of pine seedlings in 4.5 kg/ha and in control plots in May 1977. August application of 2.2 kg/ha provided excellent initial vegetation control, as effective as the larger amounts applied at that time, and was superior during the first 12 months to 4.5 kg/ha applied in June. Twenty-six months after the spring planting new shoot growth of fertilized pine in the glyphosate strips was statistically significantly greater than that for all other treatments and growth in fertilized scalps was also very good. At the same time leader growth of spruce in fertilized scalps was significantly greater than that for other treatments but growth in glyphosate strips did not exceed that of unfertilized controls. Contrary to results of spring planting, there was marked injury and mortality of pine planted in August in glyphosate plots which had been sprayed on the preceding day. Seedlings planted in glyphosate-treated strips nine months after the August spraying exceeded the growth of control plants but not until the year after they were planted.


2001 ◽  
Vol 79 (12) ◽  
pp. 1449-1464 ◽  
Author(s):  
Darwyn S Coxson ◽  
Janet Marsh

Lichen community development was examined in a postfire chronosequence from lodgepole pine (Pinus contorta Dougl. ex Loud var. latifolia Engelm.) forests in the Omineca region of north-central British Columbia and in stands originating from logging in the early 1980s. Fire-origin stands showed dense regeneration of pine and widespread growth of acrocarpous mosses such as Polytrichum spp. As canopy thinning progressed, Cladonia spp. lichens initiated development at the forest floor surface. By 50–100 years after stand origin, Cladina mitis and Cladina rangiferina dominated at the forest floor surface, remaining at high cover values well into the second century of stand development. Late seral stages of stand development (approximately 150+ years) showed increasing basal area and canopy cover of lodgepole pine, with feathermoss mats (e.g., Pleurozium schreberi) replacing terrestrial lichens at the forest floor surface. Stand ordinations confirmed these groupings of species. Stand structural factors that correlate best with lichen mat development include tree density, basal area, and canopy cover. Changes in the leaf area index and associated litterfall loading appear to precipitate the replacement of terrestrial lichen mats in "old-growth" stands. Interestingly, this trend was reversed in mature stands where winter harvesting of trees removed canopy cover without disturbing the forest floor surface. Lichen cover in these sites, 15 years after harvest, exceeded that of comparably aged fire-origin stands. Summer harvesting (with a presumed greater disturbance of soils) did not trigger a similar rebound of lichen communities. Instead, vascular plants appeared to invade these sites, following a seral sequence different from that occurring in fire-origin stands.Key words: terrestrial lichens, pine woodlands, caribou habitat.


1966 ◽  
Vol 12 (3) ◽  
pp. 531-537 ◽  
Author(s):  
M. I. Timonin

Comparative studies of the rhizosphere of healthy and diseased lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) seedlings revealed a definite rhizosphere effect. Higher counts of bacteria and fungi were found in the rhizosphere of diseased seedlings whereas the incidence of sporeforming bacteria antagonistic to Fusarium culmorum (W.G. Sm.) Sacc. and Rhizoctonia solani Kühn was nearly six times greater in the rhizosphere of healthy seedlings than in that of diseased seedlings. Species of Aspergillus, Phoma, Pythium, Rhizoctonia, and Rhizopus were isolated only from the rhizosphere of diseased seedlings; Alternaria, Cephalosporium, Metarrhizium, Spicaria, and Tilachlidium were isolated only from the rhizosphere of healthy seedlings. Aspergillus restrictus, A. fumigatus, Cylindrocarpon olidum, and Botryosporium sp. proved to be pathogenic to lodgepole pine seedlings. These results are discussed in relation to the microbial population in the rhizosphere of a variety of cultivated plants resistant and susceptible to soil-borne pathogens.


Plant Disease ◽  
1997 ◽  
Vol 81 (3) ◽  
pp. 311-311 ◽  
Author(s):  
G. R. Stanosz ◽  
D. L. Kimbler

Shoot blight was observed on lodgepole pine (Pinus contorta Douglas ex Loud.) seedlings in fall 1994 at the USDA Forest Service Bessey Tree Nursery, Halsey, NE. Shoots were stunted, cankered, and sometimes curled at the tips, and bore brown needles that often had been killed before full elongation. Pycnidia were present on necrotic needles and stems. Conidia from these pycnidia produced pure cultures of Sphaeropsis sapinea (Fr.:Fr.) Dyko & Sutton in Sutton. The fungus was identified based on cultural, pycnidial, and conidial characteristics and comparison with known isolates. Also, random amplified polymorphic DNA markers of isolates were consistent with those of the A morphotype of S. sapinea (1). The ability of each of the two recognized morphotypes of S. sapinea to cause shoot blight of lodgepole pine was tested by inoculation of potted, 2-year-old seedlings in a greenhouse. Elongating terminal shoots were wounded by removing a needle pair approximately 1 cm below the shoot apex. A plug cut from an actively growing culture on water agar (WA) was placed fungus-side-down on the wound. The two isolates used (128, A morphotype; and 124, B morphotype) are representative of larger collections of these two morphotypes for which aggressiveness has been compared (2). Noncolonized WA plugs were placed on similarly wounded control seedlings. Nonwounded control seedlings also were used. Parafilm was wrapped around the shoots to hold the agar plugs in place and was removed 1 week later. Each treatment was applied to 10 seedlings in each of five completely randomized replicates. After 4 weeks, the condition (living or dead) of shoot tips was recorded, and the length of necrotic stem (canker) below the point of inoculation was measured to the nearest 0.25 cm. Segments of shoots were harvested, surface sterilized, and incubated to determine the presence of the pathogen. Analyses of variance were performed with Minitab for Windows version 10.1 software (Minitab Inc., State College, PA). Seedlings inoculated with either morphotype developed symptoms resembling those observed in the nursery. Neither incidence of shoot tip death nor severity (as indicated by canker length) differed greatly according to isolate morphotype. The means for number of shoot tips killed by the A and B isolates were 8.8 and 6.4 (out of 10), respectively (P = 0.07). The means for lengths of cankers produced by the A and B isolates were 4.9 and 3.8 cm, respectively (P = 0.10). Among controls, only one wounded seedling developed any symptoms. The pathogen was identified on incubated shoot segments from inoculated seedlings, but not those of control seedlings. This is the first report of S. sapinea as a cause of shoot blight of lodgepole pine in the U.S., and it associates the A morphotype with damage observed in the Bessey nursery. Further, the ability of the B morphotype to cause disease of lodgepole pine is established. Results of inoculations contrast with those obtained with red pine (Pinus resinosa Aiton) seedlings, on which the B morphotype was not aggressive (2). Susceptibility of lodgepole pine seedlings to both A and B morphotypes of S. sapinea, however, is similar to that exhibited by the related species, jack pine (P. banksiana Lamb.) (2). These species are classified in subsection “contortae” of the genus Pinus. Both morphotypes of S. sapinea should be considered as potential causes of shoot blight encountered on lodgepole pine. References: (1) G. R. Stanosz et al. Plant Dis. 80:1175, 1996. (2) J. T. Blodgett and G. R. Stanosz. Plant Dis. 81:143, 1997.


1973 ◽  
Vol 53 (2) ◽  
pp. 395-399 ◽  
Author(s):  
HAROLD M. ETTER ◽  
L. W. CARLSON

Dormant 3-yr-old lodgepole pine seedlings (Pinus contorta var. latifolia) were stored for 3–4 mo in air-tight plastic bags at 2 ± 1 C in the dark. Groups of 40–50 seedlings were removed from storage and grown in a greenhouse for 5 wk. Needle and root samples were taken at the time of planting and 5 wk later to determine their relative water content (RWC) and sugar contents. The upper needles had a 3–10% higher RWC than the lower needles. Comparisons between actively growing versus nonactive classes of seedlings demonstrated that new root growth after planting was not related to the hydration of the needles at the time of planting. Contents of free sugars (glucose, fructose, sucrose, stachyose, raffinose, galactose, and xylose), starch, and pectic sugars (arabinose, galactose, xylose, and mannose) were all reduced during the 5-wk growth period. Differences in subsequent root activity were not related to differences in root sugar contents at planting; however, sucrose content in actively growing root systems was significantly higher than in roots with no new growth 5 wk after planting. The supply of sucrose from the shoot after planting appeared to be associated with the occurrence of new root growth in stored lodgepole pine seedlings. Damage during storage to photosynthetic or sugar transport systems in the shoot may have caused inadequate export of sucrose to the root system after planting, which in turn reduced the root regeneration capacity.


1998 ◽  
Vol 76 (2) ◽  
pp. 213-217 ◽  
Author(s):  
S M Bradbury

Lodgepole pine (Pinus contorta Dougl. ex Loud.) seedlings, originating from seed in three southwestern Alberta cut blocks, were sampled to identify their ectomycorrhizal associates. Fourteen ectomycorrhizal taxa were identified, 10 were common to all three cut blocks, and 12 to two cut blocks. Individual seedlings were colonized by two fungal associates on average and never had more than six fungal associates at one sampling time. Total percent colonization of seedling roots was greater than 50% one year after seed germination and greater than 90% two years after seed germination. Species richness increased throughout the course of the study; however, all but two ectomycorrhizal taxa were found in mature forests nearby. Typical late-stage ectomycorrhizal fungi colonized regenerating lodgepole pine seedlings in the absence of refuge host plants; therefore, either these fungi remained viable in situ between harvesting and regeneration or they migrated back into the cut block once revegetation was initiated.Key words: lodgepole pine seedlings, ectomycorrhiza, percent relative abundance, Alberta cut blocks.


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