Diameter Distribution of Some Subalpine Fir Stands in Central British Columbia

Author(s):  
Pal Varga ◽  
Karel Klinka
2005 ◽  
Vol 35 (12) ◽  
pp. 2841-2850 ◽  
Author(s):  
S Craig DeLong ◽  
Lori D Daniels ◽  
Ben Heemskerk ◽  
Ken Olaf Storaunet

Time since death and time since fall were estimated for hybrid spruce (Picea glauca (Moench) Voss × Picea engelmannii Parry ex Engelm.) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.) logs to quantify temporal changes in log decay and habitat quality in east-central British Columbia. We sampled 136 logs (72 spruce and 64 fir) for species, size, and morphological attributes and used dendroecological techniques to estimate year of death (n = 97) and fall (n =  22). Time since death and time since fall of spruce and fir were similar in decay classes 1 and 2; fir was older than spruce in more advanced stages of decay. Discriminant analysis based on time since fall correctly classified logs into four decay classes for 67% and 80% of spruce and fir, respectively. Function as wildlife habitat changed significantly as logs decayed. Logs served as elevated runways for approximately 15 years and then increased in value as habitat for invertebrates and insectivores as wood softened and vegetation established. Concealed spaces increased as the wood decomposed but decreased when logs collapsed. We conclude that decay classes represent biologically and statistically significant stages of log decomposition that are relevant to wildlife habitat and therefore provide a useful construct for model development and field interpretation..


1996 ◽  
Vol 72 (2) ◽  
pp. 193-198 ◽  
Author(s):  
K. Klinka ◽  
H. Y. H. Chen ◽  
Q. Wang ◽  
R. E. Carter

Stem analysis data from even-aged Engelmann spruce (Picea engelmannii Parry ex Engelm.) and subalpine fir [Abies lasiocarpa (Hook.) Nutt.] stands on zonal sites in the Engelmann Spruce—Subalpine Fir biogeoclimatic zone of British Columbia were used to examine the relationships of site index and height growth and elevation, latitude, and longitude. Elevation and latitude were found to be strongly negatively correlated with site index of both study species. Spruce site index (bh age 50) was predicted to decrease 2.9 m and fir site index 2.5 m with every 100 m and 1° increase in elevation and latitude, respectively; however, (i) site index of both species appeared to decline faster with increasing latitude than elevation, and (ii) decrease appeared to be faster for spruce than for fir. Comparison of height growth curves for stands on zonal and azonal sites with similar site index from different elevations and latitudes suggested that there are probably inconsequential differences between the shape of curves for either species. These findings imply that (i) subalpine fir is better adapted to subalpine boreal climates than Engelmann spruce and (ii) development of polymorphic site index curves for estimating site index of both species may be appropriate. Key words: elevation, latitude, longitude, site index, height growth, Abies lasiocarpa, Picea engelmannii, Engelmann Spruce—Subalpine Fir zone


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.


2006 ◽  
Vol 58 (1) ◽  
pp. 123-139 ◽  
Author(s):  
Markus L. Heinrichs ◽  
Martin G. Evans ◽  
Richard J. Hebda ◽  
Ian R. Walker ◽  
Samantha L. Palmer ◽  
...  

Abstract Environmental sensitivity to temperature change was established by comparing pollen, plant macrofossils, macroscopic charcoal, and sediment yield data from Lake of the Woods, Cathedral Provincial Park in the Cascade Mountains of southern British Columbia, Canada, to an independent record of midge-inferred paleotemperature. Steppe vegetation with some spruce and fir occurred initially, developing into pine forests in the warm early Holocene. These forests burned often, preventing spruce and fir succession. Once established, the forests retained an Engelmann Spruce-Subalpine Fir character. After 8000 cal BP, in warm but wetter conditions, the forest contained less pine and fires burned less frequently. About 4000 cal BP, cooler temperatures resulted in closure of the Engelmann Spruce-Subalpine Fir forests and a further reduction in fire frequency. Sediment yield results suggest a stable environment throughout the Holocene, likely due to sediment trapping in two upstream lakes. Midge-inferred temperatures correspond closely with a consensus reconstruction of temperatures from southern British Columbia, however Cathedral Provincial Park terrestrial ecosystems were not as sensitive to past climate change when compared to other nearby Engelmann Spruce-Subalpine Fir sites.


Rangifer ◽  
1998 ◽  
Vol 18 (5) ◽  
pp. 117 ◽  
Author(s):  
Douglas C. Heard ◽  
Kathryn L. Vagt

Caribou (Rangifer tarandus) in British Columbia are classified into mountain, northern and boreal ecotypes based on behavioural and ecological characteristics. We recognized 12 mountain caribou herds, 27 northern caribou herds, and an area occupied by low density boreal caribou dispersed in the boreal forests of the northeast portion of the province. Abundance estimates were usually based on attempts at total counts made from the air. Trends were based on repeated population estimates or the difference between recruitment and mortality rates for each herd. In 1996 there were approximately 18 000 caribou in British Columbia; 2300 mountain and 15 600 northern and boreal. These estimates suggest a slight increase in the numbers of both ecotypes over the last 18 years. Fifteen percent of the herds were reportedly increasing, 10% were decreasing, 31% were stable, but for 44% of the herds the trend was unknown. Historically caribou were found throughout 8 of the 14 biogeoclimatic zones in B.C. Caribou are now rarely found in the Sub-Boreal Spruce zone, likely due to increased predation from wolves that increased in response to increasing moose numbers. Ranges of several herds in the Engelmann Spruce — Subalpine Fir and Alpine Tundra zones of south-eastern British Columbia are also reduced relative to historic conditions, probably because of habitat loss, habitat fragmentation, predation and hunting. Forest harvesting represents the greatest threat to caribou habitat and current research focuses on the mitigation of forest harvesting impacts.


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.


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