Pathology of conifer seed and timing of germination in high-elevation subalpine fir and Engelmann spruce forests of the southern interior of British Columbia

1999 ◽  
Vol 29 (2) ◽  
pp. 187-193 ◽  
Author(s):  
Jianwen Zhong ◽  
Bart J van der Kamp

Unstratified seed of Engelmann spruce (Picea engelmannii Parry) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.) in nylon mesh bags was placed on various natural and disturbed forest floor seed beds in the Engelmann Spruce - Subalpine Fir Zone in the southern interior of British Columbia in September 1995 and recovered just before snow melt in June 1996. Fifty-two and 86% of the viable spruce and fir seed, respectively, had germinated before snowmelt. Germination under snow may be an adaptation of these high-elevation species to short cool growing seasons. Seed viability at recovery was significantly lower on undisturbed forest floor seed beds (spruce, 13%; fir, 12%) than on exposed mineral soil (spruce, 57%; fir, 42%). Viability of seed placed on nurse logs was 38 and 23% for spruce and fir, respectively. Isolation from ungerminated seed yielded a Rhizoctonia sp., an as yet unidentified black mold at high frequencies, and several other seed pathogens at low frequency. Multiple linear regression of the frequency of isolation of Rhizoctonia and black mold on seed viability was highly significant for both tree species. Seed pathogens appear to cause a major loss of seed and seedlings in these forests, and this may explain both the common occurrence of regeneration on nurse logs and the requirement of mineral soil seed beds for adequate regeneration.

2003 ◽  
Vol 33 (11) ◽  
pp. 2210-2220 ◽  
Author(s):  
Cindy E Prescott ◽  
Graeme D Hope ◽  
Leandra L Blevins

Possible mitigation of nitrate losses associated with clearcuts through harvesting smaller gaps was tested in a high-elevation forest of Engelmann spruce (Picea engelmannii Parry ex Engelm.) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.). We measured concentrations of ammonium and nitrate after 6-week buried bag incubations of forest floor and mineral soil samples in replicated plots of uncut forest and gaps of 10, 1.0, and 0.1 ha and single-tree removal for 7 years after harvest. Nitrate concentrations in forest floor and mineral soil were elevated 3–7 years after harvesting in gaps of 0.1 ha and larger. Removal of the same proportion of trees as single trees did not result in increased nitrate concentrations, suggesting that nitrate losses could be reduced by harvesting single trees rather than creating gaps. Greater N availability was not associated with faster rates of decomposition of litter and forest floor, which were similar in gaps of all sizes (0–10 ha). Reciprocal transplant of forest floor and soil from the 10-ha gaps and the uncut forests indicated that changes in the nature of the forest floor or soil following harvest had a greater influence on nitrate concentrations than the changes in environmental conditions in the gaps.


2014 ◽  
Vol 27 (3) ◽  
pp. 233-256 ◽  
Author(s):  
Andrea C. Voit ◽  
Richard J. Hebda ◽  
Julien M.J. Racca ◽  
Reinhard Pienitz ◽  
Ian R. Walker ◽  
...  

Diatom analyses of sediments from a high elevation lake situated in an Engelmann Spruce - Subalpine Fir (ESSF) forest of south-central British Columbia, Canada, reveal long-term climate and water chemistry change. During the transition from the late-glacial / Pleistocene to the xerothermic early Holocene, small, benthic Fragilaria diatoms species that grew under low light conditions in Sicamous Creek Lake gave way to planktonic Cyclotella species that require open-water conditions. Warm temperatures in the mesothermic Holocene are indicated by smaller Cyclotella species and large, benthic pennate diatoms. Diatom communities reflected Neoglacial cooling in the late Holocene, with abundant Nitzschia fonticola and Achnanthes minutissima. Small, benthic Fragilaria regained abundance, suggesting cooling and conditions similar to the late-glacial interval. Diatom community composition responded to the deposition of the Mt. Mazama and Mt. St. Helens tephras, though the Mazama eruption caused greater change in relative abundance of various taxa within the assemblage. Correspondence analysis shows distinct communities have occurred since the initiation of sedimentation, likely due to climate controlled landscape and vegetation changes; diatom-inferred pH values using various models and training sets show limited acidification change occurred through the lake’s history.


1999 ◽  
Vol 75 (3) ◽  
pp. 467-472 ◽  
Author(s):  
Alan Vyse

The Sicamous Creek Project was established as part of the British Columbia Provincial Silvicultural Systems program in 1990 to investigate the effects of clearcutting and other practices on a high elevation forested ecosystem. The objective is to provide the forestry community with information on the ecology of high elevation forests in the Southern Interior, and the probable responses to a wide range of disturbance. After a period of planning by a team of scientists and foresters from several agencies, a site in subalpine fir-Engelmann spruce forest at 1530 m to 1830 m elevation near the town of Sicamous in the south central interior of British Columbia was logged in the winter of 1994–95. A range of treatments was created by logging one third of the forest in 30 ha experimental units using a range of opening sizes (individual tree selection, 1/10 ha, 1 ha, and 10 ha) and a no-logging control. Within these experimental units, smaller areas (0.08 ha) have been treated to create a range of soil disturbance conditions (no disturbance, burning, complete organic soil removal, mounding). A wide range of studies has been conducted on the site by a team of scientists before and after treatment and those studies are continuing. The project is long-term, (at least 30 years), the main treatments are sufficiently large to have operational significance, and the supported studies are intended to be interdisciplinary in scientific method and scope. Support for the project is strong within the operational forestry community because information on logging costs, safety issues and snags, windthrow, bark beetle management, wildlife habitat and small streams has already been made available to them. Studies of stand structure and wildlife habitat suggest that in future much greater emphasis should be placed on the silviculture of fir than spruce. Key words: silviculture systems, clearcutting, opening size, Engelmann spruce, subalpine fir, long term research, interdisciplinary research


2000 ◽  
Vol 15 (2) ◽  
pp. 62-69 ◽  
Author(s):  
Han Y. H. Chen ◽  
Karel Klinka

Abstract To estimate potential productivity of the high-elevation Engelmann Spruce and Subalpine Fir (ESSF) zone of British Columbia forests, the height growth models developed from low-elevation forests are currently used to estimate site indices of subalpine fir (Abies lasiocarpa), Engelmann spruce (Picea engelmannii), and lodgepole pine (Pinus contorta). Whether these models are adequate to describe height growth of high-elevation forests is of concern. We sampled a total of 319 naturally established, even-aged, and undamaged stands with breast height age ≥50 yr (165 for subalpine fir, 87 for Engelmann spruce, and 67 for lodgepole pine) ranging widely in climate and available soil moisture and nutrients. In each sampled stand, three dominant trees were destructively sampled for stem analysis. Height growth models developed from fitting data to a conditioned logistic function explained > 97% variation in height for all three study species. Examined by residual analysis, no models showed lack of fit. These models provided more accurate estimates of site index than the currently used models developed from low-elevation stands or different species. It is recommended that the models developed in this study be applied to estimate site index of the three species in the ESSF zone in British Columbia. West. J. Appl. For. 15(2):62-69.


2001 ◽  
Vol 31 (12) ◽  
pp. 2183-2199 ◽  
Author(s):  
Markus L Heinrichs ◽  
Richard J Hebda ◽  
Ian R Walker

The vegetation and natural disturbance history of the Mount Kobau area, in the Engelmann spruce (Picea engelmannii Parry ex Engelm.) – subalpine fir (Abies lasiocarpa (Hook.) Nutt.) (ESSF) forest of southern British Columbia, was reconstructed using pollen, plant macrofossils, and microscopic charcoal. Late-glacial vegetation, occurring from about 11 000 14C years BP, consisted of an Artemisia steppe under a cold and dry climate. Rapid warming occurred at the start of the Holocene, approximately 10 000 to 9500 years BP, and grassland steppe vegetation prevailed. Moisture increased during the mid-Holocene, from approximately 7000 to 3800 years BP, and fires may have occurred more widely and burned more severely. Open lodgepole pine (Pinus contorta Dougl. ex Loud.) parkland occupied the mountain summit. Late-Holocene cooling at 4000 years BP resulted in the establishment of modern ESSF forest. The vegetation and inferred climate history confirm a broad three-stage (warm dry – moderate moist – cool moist) regional climatic pattern of the Holocene. Under future anticipated climate change, the high-elevation, dry ESSF forests in southern British Columbia may be replaced by grasslands.


2006 ◽  
Vol 82 (1) ◽  
pp. 84-94 ◽  
Author(s):  
C C Lajzerowicz ◽  
A. Vyse ◽  
M. Jull ◽  
T. Newsome

We compared survival and growth of planted seedlings of Engelmann spruce and subalpine fir across a range of harvest opening sizes (> 10 ha, 1 ha, 0.2 ha, 0.1 ha, 0.03 ha and individual tree selection) from three silvicultural systems trials in high-elevation spruce – subalpine fir forests in south-central British Columbia. Climatic patterns and growing season air and soil temperatures were similar across sites. Seedling survival decreased with opening size. Local site climates, influenced by aspect and moisture and air drainage, were more influential than elevation. Seedling growth was best in large openings and similar in opening sizes from 1 ha to 0.1 ha. Smaller openings created by group selection and individual tree selection methods were not favourable for successful planting at elevations close to timberline. The two species had similar absolute and relative growth rates but spruce responded more strongly to better growing environments. Key words: planted seedlings, Engelmann spruce, Picea engelmannii Parry ex Engelm., subalpine fir, Abies lasiocarpa (Hook.) Nutt., opening size, elevation effects, silvicultural systems, British Columbia, mountain forests


2003 ◽  
Vol 79 (2) ◽  
pp. 259-262 ◽  
Author(s):  
Craig DeLong ◽  
Del Meidinger

High-elevation, late-successional forests over much of British Columbia are dominated by Engelmann spruce (Picea engelmannii Parry ex. Engelm.) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.). Throughout the range of these forests, however, there is a wide variation in natural disturbance and successional dynamics as influenced by diverse climate and topography. We divided these high elevation forests into four groups arranged along a regional climatic gradient that affects forest composition, structure and disturbance regime. For each, we describe the climate, topography, major vegetation, and natural disturbance dynamics. We suggest that management practices reflect the ecological variability demonstrated for these high elevation forests. Key words: high elevation forests, ecological variability, natural disturbance dynamics, vegetation, Engelmann spruce, subalpine fir, British Columbia, climate, topography


2001 ◽  
Vol 31 (12) ◽  
pp. 2098-2106 ◽  
Author(s):  
Pál Varga ◽  
Karel Klinka

We described quantitatively the height distributions of three high-elevation, old-growth stands in the Engelmann Spruce – Subalpine Fir zone of west-central British Columbia. The stands were composed of subalpine fir (Abies lasiocarpa (Hook.) Nutt.), with very few Engelmann spruce (Picea engelmannii Parry ex Engelm.) trees; had a two-storied canopy; and were multiaged. The height distributions were quantified by fitting curves to the cumulative frequency distributions. The diameter distributions of the study stands were reverse-J shaped and similar to those of other old-growth Engelmann spruce – subalpine fir stands in the Pacific Northwest; however, the height distributions were different, indicating the presence of two canopy layers. We suggest that high-elevation, subalpine boreal, old-growth stands composed of shade-tolerant tree species may display a modal height distribution instead of a reverse-J shape. This structural pattern is suggestive of the transition between the gap-phase and tree-island regeneration models and of the cyclic mode of succession.


2003 ◽  
Vol 33 (5) ◽  
pp. 847-853 ◽  
Author(s):  
Sylvia E Welke ◽  
Graeme D Hope ◽  
Gary A Hunt

The effect of timber harvesting on the biomass, nutrient standing crop, and decomposition of fine roots (<2 mm) was studied in a high elevation, Engelmann spruce (Picea engelmannii Parry ex Engelm.) – subalpine fir (Abies lasiocarpa (Hook.) Nutt.) forest. Root dynamics were compared in openings of different sizes. The sequential core method was used to collect fine root samples over 4 years. Differences in fine root biomass between opening sizes were most significant for the active fine root portion and were most pronounced in the fall compared with the spring. Active fine root biomass was significantly lower in the 10-ha clearcuts (164 kg/ha) compared with control plots (275 kg/ha). Furthermore, active fine root biomass was often lower in the 1.0-ha opening than in the 0.1-ha and control plots. A similar trend was established for inactive fine root biomass, although this was not consistent over sampling years. Nutrient concentrations of K, but no other elements, were higher in control plots. Nutrient standing crops, however, followed trends observed in fine root biomass. In the 10-ha clearcuts, the largest changes in fine root biomass occurred at the edge of the opening. The findings suggest that small (<10 ha) cutblocks may maintain greater fine root longevity.


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