Pre-Vashon fossil Coleoptera of Fraser age from the Fraser Lowland, British Columbia

1985 ◽  
Vol 22 (4) ◽  
pp. 498-505 ◽  
Author(s):  
R. F. Miller ◽  
A. V. Morgan ◽  
S. R. Hicock

Samples of organic silt from post-Coquitlam Quadra sand at Port Moody and Mary Hill, British Columbia (dated at 18 300 and 18 700 years BP, respectively) were examined for insect remains and yielded small assemblages of beetles.At Port Moody species of the family Staphylinidae, whose members are often associated with moss or leaf litter, are the most abundant fossils present. Other specimens included open-ground beetles of the family Carabidae, as well as weevils (Curculionidae) and bark beetles (Scolytidae), which inhabit conifers. The assemblage appears to represent an open forest-floor community. Some of the species in this site have distribution ranges that do not include the Port Moody area today, but do occur in the interior of British Columbia and at higher altitude near the coast. One of the most numerous species, Micropeplus laticollis Mäklin, occurs in duff of conifers including Picea engelmannii, Abies lasiocarpa, Pinus ponderosa, and Pinus contorta. These trees are characteristic of the subalpine forest. The insect assemblage suggests an in situ deposit, subalpine in nature, probably in a cool but dry environment that developed during the short episode when this part of the Fraser Lowland was ice free between the Coquitlam and Vashon ice advances.The beetle assemblage from Mary Hill Quadra sediments probably indicates that a bog environment existed at that time; however, the lack of specific identifications precludes detailed paleoclimatic interpretation.

2002 ◽  
Vol 32 (11) ◽  
pp. 1947-1960 ◽  
Author(s):  
Roberta Parish ◽  
Joseph A Antos

Tree-ring width chronologies of three species from a 330-year-old subalpine forest were used to reconstruct outbreaks of 2 year cycle spruce budworm (Choristoneura biennis Freeman). The growth of host species, Engelmann spruce (Picea engelmannii Parry ex Engelm.) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.), was compared with that of the nonhost, lodgepole pine (Pinus contorta Dougl. ex Loud.) with and without the removal of the effects of climate on growth. Seven periods, 1989–1991, 1943–1957, 1911–1927, 1869–1875, 1839–1861, 1823–1829, 1785–1801, were identified in which the growth of both host species was reduced relative to the non-host; this includes the single known outbreak from 1944 to 1956. Spectral analysis indicated a periodicity for growth reduction of the host relative to non-host species of ca. 45 years for both spruce and fir. For three periods, the known outbreak in the 1940–1950s, and two inferred outbreaks in the 1910–1920s and 1840–1850s, we calculated the four measures of radial growth first proposed by Brubaker and Greene (L.B. Brubaker and S.K. Greene. 1979. Can. J. For. Res. 9: 95–105): the maximum rate of growth loss, 1-year and 5-year losses, and the rate and time to recovery. Growth losses were greater for fir than for spruce during all three periods. During the 1940–1950s, growth losses were severe, but losses were less in the 1910–1920s. The impact of C. biennis has varied among outbreak periods but, overall, has made a pronounced contribution to present stand conditions. Our work suggests that budworms have been a frequent agent of disturbance with major effects on forest dynamics in southern British Columbia, especially in spruce–fir forests when long periods occur between fires.


1988 ◽  
Vol 66 (5) ◽  
pp. 963-969 ◽  
Author(s):  
Gregory A. Carter ◽  
William K. Smith

Differences in water and photosynthetic relations were compared for three codominant conifers (Engelmann spruce (Picea engelmaniï), subalpine fir (Abies lasiocarpa), and lodgepole pine (Pinus contorta) at microhabitats within a subalpine forest (central Rocky Mountains, U.S.A.) that were considered representative of different successional stages. Diumal measurements of photosynthesis, leaf conductance, and transpiration were taken at microhabitats considered early-successional (open), intermediate (forest gap), and late-successional (forest understory) environments to evaluate possible influences of gas-exchange physiology in observed distributional and successional patterns. Pine had greater water-use efficiency (photosynthesis/transpiration) in early- versus late-successional environments, primarily as a result of a lower leaf conductance and transpiration. Photosynthetic performance was similar among all three species at each respective microhabitat and increased as the openness of the microhabitat increased. Greater water-use efficiency may significantly improve the growth of pine over spruce and fir on more open, drier sites at lower elevation. Higher transpiration in spruce and fir may limit these species to higher elevation sites, to understory sites at middle elevations, and to moister open sites at lower elevations (e.g., riparian sites).


2011 ◽  
Vol 41 (2) ◽  
pp. 331-340 ◽  
Author(s):  
Christof Bigler ◽  
Thomas T. Veblen

Litter and dead wood affect important processes in forest ecosystems such as nutrient and carbon cycling and are key influences on biodiversity and fire behavior. Increased tree mortality rates in western North America associated with climate trends and increased bark beetle activity highlight the need to better understand the dynamics of litter and dead wood following tree death. For eight old-growth stands in a subalpine forest landscape in northern Colorado (USA), we compared litter and dead wood loads beneath more than 200 dead and live Engelmann spruce (Picea engelmannii Parry ex Engelm.), subalpine fir (Abies lasiocarpa (Hook.) Nutt.), and lodgepole pine (Pinus contorta Douglas ex Loudon). The dynamics of litter and dead wood were analyzed using chronosequences of tree death dates over >100 years that we determined from tree rings. Immediately following tree death, high loads of litter accumulated, particularly for the biggest spruces, which accumulated 10 times more litter than live spruces (five times more for fir, two times more for pine). We estimated a higher decay rate of litter for spruce (half-life of four years) than for pine (15 years) and fir (19 years). The accumulation rates for dead wood following tree death were highly variable among trees, but maximum accumulation was attained during the first 50–60 years.


Forests ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 656
Author(s):  
Javier E. Mercado

Research Highlights: Atypical and poorly understood attacks by Dendroctonus rufipennis (Kirby) to Pinus contorta Doug. ex Loudon were detected in the southern Rocky Mountains (SRM). The phenomenon is confirmed across all examined area. Its reproduction is described for the first time as well as the first attacks of D. adjunctus Blandf. in that host. Improved detection and diagnostics of D. rufipennis will allow a simpler, and efficient identification of the species. It will improve the detection capacity by pest detection specialists and entomologists, which will increase our understanding of the phenomena within and beyond the known range. Background and Objectives: In addition to D. ponderosae Hopk. other Dendroctonus species, sometimes together, attacked P. contorta that grew intermixed with Picea engelmannii in the SRM’ subalpine forest. The identification of these beetles was difficult. The goal was to improve the detection and identification of the species from similar Dendroctonus spp. attacking that host and to uncover biological facts about the phenomena. Materials and Methods: Dendroctonus attacking P. contorta were collected along the entire SRM, their attack signs and behavior were recorded. These characteristics were revised from those in the literature and new characters were introduced and tested. Results: The identification of Dendroctonus bark beetles attacking P. contorta in the SRM was improved using revised and new characters including attack signs, attack behavior, and adult beetle characters. An improved identification key couplet is presented to effectively distinguish D. murrayanae from D. rufipennis. Conclusions: Simplified insect identifications that are both accessible to users with different levels of expertise and are based on insect characters, their attack pattern, and signs, like the present, improve detection of insects of interest. Efficient insect detections allow a better understanding of the capabilities they have and the impact they cause to the woodland ecosystems we study, protect, and manage around the globe.


2003 ◽  
Vol 117 (3) ◽  
pp. 352 ◽  
Author(s):  
Trevor A. Kinley ◽  
John Bergenske ◽  
Julie-Anne Davies ◽  
David Quinn

Mountain Caribou are a rare ecotype of Woodland Caribou (Rangifer tarandus caribou) inhabiting the high-snowfall region of southeastern British Columbia, and are defined by their late-winter reliance on arboreal hair lichen of the genus Bryoria. During early winter, there is considerable variation in habitat use among populations. We snow-trailed Caribou in the southern Purcell Mountains during early winter to determine foraging patterns for the Purcell population. When snow was ≤51 cm deep, Caribou fed on Grouseberry (Vaccinium scoparium), the terrestrial lichen Cladonia, and arboreal lichens of the genus Bryoria. When snow was ≥62 cm deep, they ate exclusively arboreal lichens. In both periods, Caribou ate arboreal lichen from essentially every downed tree or branch encountered and fed with a higher intensity at downed trees than standing trees. During the low-snow period, Caribou fed at fewer trees but used those with greater lichen abundance, and fed more intensively at each, compared to the deep-snow period. In comparison to trees occurring on the foraging path but at which Caribou did not feed, those from which arboreal lichen was foraged intensively were of larger diameter, had greater lichen abundance, and were more likely to be Subalpine Fir (Abies lasiocarpa) or Engelmann Spruce (Picea engelmannii) and less likely to be Whitebark Pine (Pinus albicaulis), Lodgepole Pine (P. contorta) or Alpine Larch (Larix lyalli). The shift in diet between the low-snow and deep-snow periods reflected two modes of foraging within the early winter period, distinct from one another and apparently also distinct from the late-winter season. Management for early-winter habitat will require retention of some commercially significant forest across extensive areas, both near the subalpine forest – subalpine parkland ecotone and lower in the subalpine forest.


1998 ◽  
Vol 28 (2) ◽  
pp. 284-290 ◽  
Author(s):  
D F Clark ◽  
D D Kneeshaw ◽  
P J Burton ◽  
J A Antos

An evaluation of how coarse woody debris (CWD) changes in quantity and quality during stand development was conducted using a 426-year chronosequence of 71 stands in sub-boreal forests in British Columbia. Additional characteristics of CWD were determined in 14 of the stands. Most stands are fire initiated and input from the predisturbance stand is critical in controlling the amounts and characteristics of CWD within young stands. Log volume declines from over 100 m3/ha in young stands (0-50 years) to just over 60 m3/ha in stands from 51 to 200 years old, and then increases to greater than 140 m3/ha in the oldest (>= 400-year-old) stands. Mean snag basal area is highest (31.6 m2/ha) in young, postfire stands, decreases to a very low value (2.0 m2/ha) in stands 51-100 years old, and then reaches a second maximum (12.1 m2/ha) in stands that are 201-250 years old; it declines slightly in very old stands. The high snag basal area in stands 201-250 years old coincides with the successional transition from lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) to stands dominated by subalpine fir (Abies lasiocarpa (Hook.) Nutt.) and interior spruce (hybrids of Picea glauca (Moench) Voss and Picea engelmannii Parry). Stand age, characteristics of the predisturbance forest, and the disturbance history of stands subsequent to stand initiation all appear to be very important in determining variation in both the quality and quantity of CWD in these sub-boreal forests.


1999 ◽  
Vol 29 (9) ◽  
pp. 1347-1356 ◽  
Author(s):  
R Parish ◽  
J A Antos ◽  
M -J Fortin

The dynamics of an old-growth Engelmann spruce (Picea engelmannii Parry) - subalpine fir (Abies lasiocarpa (Hook.) Nutt.) forest were investigated using stand-history reconstruction. Age and size structures, tree location, and radial increment patterns were used to link establishment and growth to disturbances. The spatial distribution of trees was used to infer patterns of establishment and mortality. The forest originated in the 1650s, probably after fire. Initial establishment took almost 80 years, after which fir continued to recruit effectively, but spruce did not. The tree-ring record showed no evidence of widespread disturbance during the first 200 years, but from about 1855 to 1900 a major period of canopy mortality caused by bark beetles released suppressed trees and provided opportunities for establishment and rapid growth of seedlings of both species. Most current canopy trees established or released during this period of disturbance; thus, many canopy trees are fairly young in this old-growth forest and canopy turnover is high. A short period of disturbance (1927-1932) caused by the balsam bark beetle (Dryocoetes confusus Swaine) resulted in release of suppressed trees but did not promote seedling establishment. At the time of study (1994), the stand was undergoing another minor disturbance caused by this insect. Bark beetles appear to be of fundamental importance in controlling the dynamics of spruce-fir forests during the long intervals that often occur between fires in cool, wet climates.


2003 ◽  
Vol 81 (4) ◽  
pp. 383-397 ◽  
Author(s):  
Elizabeth M Campbell ◽  
Joseph A Antos

To examine postfire succession in forests where Pinus albicaulis Englem. is common, we conducted chronosequence studies in two areas of contrasting climate in southern British Columbia. Tree age and growth data indicated that Pinus albicaulis established rapidly following fire disturbance but that trees also continued to establish in late seral stands. Interactions with Pinus contorta Dougl. ex Loud., which grows faster, are pivotal in controlling the population dynamics of Pinus albicaulis. Where Pinus contorta established abundantly after fire, it dominated stands and limited the abundance of Pinus albicaulis, even after the postfire Pinus contorta had largely died. In contrast, where few or no Pinus contorta established, Pinus albicaulis dominated stands throughout most of the successional sequence. Although Pinus albicaulis decreases in abundance in late seral stands, we found no evidence that it would be completely replaced by more shade-tolerant species in our study areas. Thus, Pinus albicaulis is not only a pioneer species like Pinus contorta, even though it establishes in abundance after disturbance, but also a stress tolerator, with population dynamics molded by its ability to grow slowly and persist for long periods under adverse conditions and by bird dispersal of its seeds.Key words: Abies lasiocarpa, forest fire, Picea engelmannii, Pinus albicaulis, Pinus contorta, succession.


2002 ◽  
Vol 32 (11) ◽  
pp. 1935-1946 ◽  
Author(s):  
Joseph A Antos ◽  
Roberta Parish

We used dendrochronological analysis of over 2000 trees in four 50 × 50 m plots to reconstruct the history and dynamics of a 330-year-old, fire-initiated spruce-fir forest. All lodgepole pine (Pinus contorta Dougl. ex Loud.), half of the canopy Engelmann spruce (Picea engelmannii Parry ex Engelm.), but less than 10% of the canopy subalpine fir (Abies lasiocarpa (Hook.) Nutt.) dated from the first 50 years of stand development. Tree-ring patterns of individual surviving trees showed no evidence of disturbance during the first 200 years after stand initiation; subsequently, episodes of disturbance are indicated by periods of release in understory fir. Although many fir owe their canopy position to release after disturbance, few canopy fir in the current stand established in response to either the stand-initiating event or subsequent partial disturbances. A seedling bank of long-lived fir appears critical to the dynamics of this forest. In contrast, establishment of almost all canopy spruce can be related to disturbance. This stand, although fire initiated, was structured primarily by a combination of partial disturbances and autogenic processes. We suspect that most old, fire-initiated stands in many forest regions are similarly structured and emphasize that the contribution of partial disturbances and autogenic processes should be fully assessed when examining their dynamics or managing such forests.


2017 ◽  
Vol 47 (5) ◽  
pp. 615-627 ◽  
Author(s):  
Kendrick J. Brown ◽  
Nicholas J. Hebda ◽  
Nicholas Conder ◽  
Karen G. Golinski ◽  
Brad Hawkes ◽  
...  

Holocene climate, vegetation, and fire history were reconstructed using pollen, molluscs, and charcoal from two lake sediment records (Scum and Norma lakes) collected from the Chilcotin Plateau, British Columbia, Canada. In the late-glacial period, cold steppe prevailed and fire was limited. Artemisia steppe expanded in the earliest Holocene as climate warmed and conditions became dry, with shallow basins drying out. High-frequency surface fires maintained the steppe. An increase in Pinus after 10 200 cal BP signals moistening and the establishment of Pinus ponderosa P. & C. Lawson and Pinus contorta Dougl. ex Loud. stands, with surface fires in the former and higher severity fires in the latter. Cooling around 8500 cal BP favored P. contorta, and a crown fire regime likely prevailed, with intermittent surface fires. Shallow basins began to fill with water. In the mid-Holocene, basins filled further and Picea increased slightly in abundance. Fire frequency decreased, though severity increased. In the last three millennia, modern P. contorta dominated forests were established, with mixed-severity fire disturbance. Considering the future, the results of this study align well with ecosystem climate niche simulations, indicating that non-arboreal and open-forest communities may again prevail widely on the plateau, together with surface fires. Land managers need to develop strategies to manage the upcoming transformation.


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