Holocene vegetation, climate, and lake-level changes in the Interior Douglas-fir Biogeoclimatic Zone, British Columbia

1989 ◽  
Vol 26 (9) ◽  
pp. 1811-1825 ◽  
Author(s):  
Rolf W. Mathewes ◽  
Miriam King
Keyword(s):  
British Columbia ◽  
Tsuga Heterophylla ◽  
Climatic Conditions ◽  
Douglas Fir ◽  
Sediment Type ◽  
Stratigraphic Correlation ◽  
Study Region ◽  
Radiocarbon Dates ◽  
The Holocene ◽  
Pollen Influx

Chilhil, Phair, Fishblue, and Horseshoe lakes in the southern interior of British Columbia were cored and analyzed for pollen. Phair Lake was also examined for plant macrofossils and aquatic molluscs. Two dated volcanic tephras (Mazama and Bridge River) are present in three of the four lakes and, together with radiocarbon dates, provide an absolute chronology for pollen-influx calculations and stratigraphic correlation. Abrupt changes in sediment type at Phair Lake about 5650 and 2000 years ago correlate with Neoglacial advances near the coast–interior transition. Pollen changes suggestive of moister conditions and the presence of an aquatic mollusc (Valvata sincera helicoidea) at Phair and Chilhil lakes are consistent with the Neoglacial evidence of cooler and wetter conditions after about 2400 years ago. The driest part of the Holocene was the early, pre-Mazama (ca. 6600–6800 years ago) interval, when the vegetation was more open and herb rich and the lake levels were lower than at present. Wetter climatic conditions appear in post-Mazama time, indicated by regional increases in the pollen of Tsuga heterophylla and other coastal and subalpine trees. Pollen-influx values for the Interior Douglas-fir Zone are broadly consistent at all sites, with values of < 2000 –8000 grains cm−2 year−1. Douglas-fir (Pseudotsuga menziesii) has been an important forest species in the study region throughout the Holocene.

Regional and ecological patterns in interior Douglas-fir climate–growth relationships in British Columbia, Canada

2010 ◽  
Vol 40 (2) ◽  
pp. 308-321 ◽  
Author(s):  
Hardy P. Griesbauer ◽  
D. Scott Green
Keyword(s):  
Climate Change ◽  
British Columbia ◽  
High Elevation ◽  
Climatic Conditions ◽  
Douglas Fir ◽  
Growth Patterns ◽  
Growth Responses ◽  
Study Region ◽  
Tree Ring Data ◽  
Dry Climates

How climate change will affect tree growth across species’ geographic and climatic ranges remains a critical knowledge gap. Tree-ring data were analyzed from 33 interior Douglas-fir ( Pseudotsuga menziesii var. glauca (Beissn.) Franco) stands spanning wide geographic and climatic conditions in the interior of British Columbia to gain insights into how within-species growth responses to climate can vary based on local environmental conditions over a broad climatic and geographic range, including populations growing at the species’ range and climatic margins. Populations growing in relatively warm and dry climates had growth patterns correlated mostly with annual precipitation, whereas populations growing in high-elevation wet and cold climates had growth patterns correlated with snowfall, winter and annual temperatures, and ocean–atmosphere climate systems. Populations growing at climatic extremes (e.g., coldest, driest, warmest) in each study region had the strongest responses to climate. Projected climate change may negatively influence Douglas-fir productivity across most of its range, and populations growing near the species’ climatic limits may provide early and strong indications of future responses.

Palynology and Paleoecology of Postglacial Sediments from the Lower Fraser River Canyon of British Columbia

1975 ◽  
Vol 12 (5) ◽  
pp. 745-756 ◽  
Author(s):  
R. W. Mathewes ◽  
G. E. Rouse
Keyword(s):  
Tsuga Heterophylla ◽  
Climatic Conditions ◽  
Douglas Fir ◽  
Fraser River ◽  
Pollen Assemblage ◽  
Glacial Ice ◽  
Transitional Area ◽  
Postglacial History ◽  
History Of Vegetation ◽  
History Of

The postglacial history of vegetation in the Yale area of the lower Fraser River Canyon is described from sediments of two lakes using percentage pollen analysis supplemented with macrofossil evidence and radiocarbon dating. Deposition of postglacial sediments, ranging from basal clays to gyttjas, began about 11 500 y B.P. Three distinct pollen assemblage zones are distinguished, reflecting in part the main climatic conditions for the intervals. The oldest zone, with high percentages of pine (Pinus) and alder (Alnus) pollen, suggests cool and moist conditions following withdrawal of glacial ice. This is followed by marked increases in Douglas-fir (Pseudotsuga), grasses and other nonarboreal pollen, suggesting in part, warmer and drier conditions. The third zone, ranging from about the Mt. Mazama ash at 6600 y B.P. to the present, is marked by high alder and Douglas-fir, and increasing cedar (Thuja-Chamaecyparis type), western hemlock (Tsuga heterophylla), fir (Abies) and birch; an assemblage indicating a return to wetter conditions. This sequence contrasts with previously described successions that recognized the classical Hypsithermal in adjacent areas. The sequence of inferred vegetational changes, although similar to those described for the Haney area to the west, suggests that the Yale area has been a biogeoclimatically transitional area for much of postglacial time.

Palynology and paleoecology of postglacial sediments in an anoxic basin, Saanich Inlet, British Columbia

1983 ◽  
Vol 20 (5) ◽  
pp. 873-885 ◽  
Author(s):  
Linda E. Heusser
Keyword(s):  
British Columbia ◽  
Pinus Contorta ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Thuja Plicata ◽  
Alnus Rubra ◽  
Red Cedar ◽  
Saanich Inlet ◽  
Anoxic Basin

Varved, black clayey silts deposited in the marine waters of Saanich Inlet yield unusually abundant and diverse pollen assemblages derived from the coastal Douglas-fir (Pseudotsuga) and western hemlock (Tsuga heterophylla) forests of southwestern British Columbia. The 12 000 year palynological record chronicles the development of vegetation since ice left Saanich Inlet: the succession of pine (Pinus contorta) and alder (Alnus rubra) woodlands by forests characterized by Douglas-fir and oak (Quercus) and later by western hemlock and red cedar (Thuja plicata). Rapid deposition of annual layers of pollen, charcoal, and other terrigenous particles provides detailed evidence of changes in land use during the past few hundred years: settlement, logging, farming, and urbanization. Vegetational and climatic changes inferred from pollen spectra in the marine sediments of Saanich Inlet compare favorably with changes inferred from correlative pollen assemblages previously described from adjacent parts of Vancouver Island and the Fraser River valley.

scholarly journals Dating rice remains through phytolith carbon-14 study reveals domestication at the beginning of the Holocene

2017 ◽  
Vol 114 (25) ◽  
pp. 6486-6491 ◽  
Author(s):  
Xinxin Zuo ◽  
Houyuan Lu ◽  
Leping Jiang ◽  
Jianping Zhang ◽  
Xiaoyan Yang ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Wild Species ◽  
Study Region ◽  
Radiocarbon Dates ◽  
The Holocene ◽  
Carbon 14 ◽  
The Poor ◽  
Pottery Sherds ◽  
Lower Yangtze ◽  
Rice Domestication

Phytolith remains of rice (Oryza sativa L.) recovered from the Shangshan site in the Lower Yangtze of China have previously been recognized as the earliest examples of rice cultivation. However, because of the poor preservation of macroplant fossils, many radiocarbon dates were derived from undifferentiated organic materials in pottery sherds. These materials remain a source of debate because of potential contamination by old carbon. Direct dating of the rice remains might serve to clarify their age. Here, we first validate the reliability of phytolith dating in the study region through a comparison with dates obtained from other material from the same layer or context. Our phytolith data indicate that rice remains retrieved from early stages of the Shangshan and Hehuashan sites have ages of approximately 9,400 and 9,000 calibrated years before the present, respectively. The morphology of rice bulliform phytoliths indicates they are closer to modern domesticated species than to wild species, suggesting that rice domestication may have begun at Shangshan during the beginning of the Holocene.

Quaternary Palynology of the Pacific Slope of Washington

1977 ◽  
Vol 8 (3) ◽  
pp. 282-306 ◽  
Author(s):  
Calvin J. Heusser
Keyword(s):  
Pinus Contorta ◽  
Meteorological Data ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Olympic Peninsula ◽  
The Holocene ◽  
Pollen Stratigraphy ◽  
The Pacific ◽  
Pacific Slope

Quaternary deposits on the Pacific slope of Washington range in age from the earliest known interglaciation, the Alderton, through the Holocene. Pollen stratigraphy of these deposits is represented by 12 major pollen zones and is ostensibly continuous through Zone 8 over more than 47,000 radiocarbon yr. Before this, the stratigraphy is discontinuous and the chronology less certain. Environments over the time span of the deposits are reconstructed by the comparison of fossil and modern pollen assemblages and the use of relevant meteorological data. The Alderton Interglaciation is characterized by forests of Douglas fir (Pseudotsuga menziesii), alder (Alnus), and fir (Abies). During the next younger interglaciation, the Puyallup, forests were mostly of pine, apparently lodgepole (Pinus contorta), except midway in the interval when fir, western hemlock (Tsuga heterophylla), and Douglas fir temporarily replaced much of the pine. Vegetation outside the limits of Salmon Springs ice (>47,00034,000 yr BP) varied chiefly between park tundra and forests of western hemlock, spruce (Picea), and pine. The Salmon Springs nonglacial interval at the type locality records early park tundra followed by forests of pine and of fir. During the Olympia Interglaciation (34,000–28,000 yr BP), pine invaded the Puget Lowland, whereas western hemlock and spruce became manifest on the Olympic Peninsula. Park tundra was widespread during the Fraser Glaciation (28,000–10,000 yr BP) with pine becoming more important from about 15,000 to 10,000 yr BP. Holocene vegetation consisted first of open communities of Douglas fir and alder; later, closed forests succeeded, formed principally of western hemlock on the Olympic Peninsula and of western hemlock and Douglas fir in the Puget Lowland. Over the length of the reconstructed environmental record, climate shifted between cool and humid or relatively warm, semihumid forest types and cold, relatively dry tundra or park tundra types. During times of glaciation, average July temperatures are estimated to have been at least 7°C lower than today. Only during the Alderton Interglaciation and during the Holocene were temperatures higher for protracted periods than at present.

scholarly journals Paleoecological Investigation of Vegetation, Climate and Fire History in, and Adjacent to, Kootenay National Park, Southeastern British Columbia, Canada

2022 ◽  
Vol 9 ◽  
Author(s):  
Thomas J. Rodengen ◽  
Marlow G. Pellatt ◽  
Karen E. Kohfeld
Keyword(s):  
British Columbia ◽  
National Park ◽  
Fire History ◽  
Accumulation Rate ◽  
Fire Frequency ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Carbon Accumulation ◽  
Early Holocene ◽  
In Fire

Paleoecological investigation of two montane lakes in the Kootenay region of southeast British Columbia, Canada, reveal changes in vegetation in response to climate and fire throughout the Holocene. Pollen, charcoal, and lake sediment carbon accumulation rate analyses show seven distinct zones at Marion Lake, presently in the subalpine Engelmann Spruce-Subalpine Fir (ESSF) biogeoclimatic (BEC) zone of Kootenay Valley, British Columbia. Comparison of these records to nearby Dog Lake of Kootenay National Park of Canada in the Montane Spruce (MS) BEC zone of Kootenay Valley, British Columbia reveals unique responses of ecosystems in topographically complex regions. The two most dramatic shifts in vegetation at Marion Lake occur firstly in the early Holocene/late Pleistocene in ML Zone 3 (11,010–10,180 cal. yr. B.P.) possibly reflecting Younger Dryas Chronozone cooling followed by early Holocene xerothermic warming noted by the increased presence of the dry adapted conifer, Douglas-fir (Pseudotsuga menziesii) and increasing fire frequency. The second most prominent change occurred at the transition from ML Zone 5 through 6a (∼2,500 cal. yr. B.P.). This zone transitions from a warmer to a cooler/wetter climate as indicated by the increase in western hemlock (Tsuga heterophylla) and subsequent drop in fire frequency. The overall cooling trend and reduction in fire frequency appears to have occurred ∼700 years later than at Dog Lake (∼43 km to the south and 80 m lower in elevation), resulting in a closed montane spruce forest, whereas Marion Lake developed into a subalpine ecosystem. The temporal and ecological differences between the two study sites likely reflects the particular climate threshold needed to move these ecosystems from developed forests to subalpine conditions, as well as local site climate and fire conditions. These paleoecological records indicate future warming may result in the MS transitioning into an Interior Douglas Fir (IDF) dominated landscape, while the ESSF may become more forested, similar to the modern MS, or develop into a grassland-like landscape dependent on fire frequency. These results indicate that climate and disturbance over a regional area can dictate very different localized vegetative states. Local management implications of these dynamic landscapes will need to understand how ecosystems respond to climate and disturbance at the local or ecosystem/habitat scale.

Life History and Habits of Pseudohylesinus nebulosus (Leconte) (Coleoptera: Scolytidae) in the Interior of British Columbia

1956 ◽  
Vol 88 (5) ◽  
pp. 197-202 ◽  
Author(s):  
J. Walters ◽  
L. H. McMullen
Keyword(s):  
British Columbia ◽  
Pinus Ponderosa ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Thuja Plicata ◽  
Western North America ◽  
The West ◽  
Red Cedar ◽  
Yellow Pine

The Douglas-fir hylesinus, Pseudohylesinus nebulosus (Leconte), is a common bark beetle in western North America from British Columbia to Mexico. Although Douglas fir, Pseudotsuga menziesii (Mirb.) Franco, is the preferred host, the beetle has been collected also from western red cedar, Thuja plicata Donn, grand fir, Abies grandis (Dougl.) Lindl., amabilis fir, Abies amabilis (Dougl.) Forb., and western hemlock, Tsuga heterophylla (Raf.) Sarg., on the west coast of British Columbia, and from western hemlock and western yellow pine, Pinus ponderosa Laws., in the interior of the Province. Swaine (1918) describes Pseudohylesinus nebulosus (Lec.) as “a slender species, with strong colour-markings in dark and light reddish-brown; the male very densely clothed with stout scales; the epistomal lobe strongly developed; length, 2.8 mm.; width, 1.2 mm. The supposed female has interspace 9 on the declivity less strongly serrate, and the elytral scales decidedly elongate and becoming plumose towards the base.”

Modem pollen spectra from west central British Columbia

1993 ◽  
Vol 71 (11) ◽  
pp. 1486-1495 ◽  
Author(s):  
Richard J. Hebda ◽  
Gregory B. Allen
Keyword(s):  
British Columbia ◽  
Tsuga Heterophylla ◽  
Douglas Fir ◽  
Dominant Type ◽  
Subalpine Fir ◽  
Engelmann Spruce ◽  
Regional Background ◽  
Pollen Surface ◽  
Pollen Rain ◽  
Pollen And Spores

Sixty-four moss and organic litter samples were collected from five biogeoclimatic zones distributed from sea level on the central coast of British Columbia onto the western edge of the Interior Plateau at 1000 – 1900 m and analyzed for pollen and spores. Four of the five biogeoclimatic zones produced characteristic pollen and spore spectra. The coastal western hemlock biogeoclimatic zone is characterized by Tsuga heterophylla, Alnus, and Cupressaceae. Significant levels of nonarboreal pollen (NAP), mainly Lysichiton and fern spores, occur in some sites. Interior Douglas-fir zone samples are dominated by Pseudotsuga and Tsuga heterophylla with notable Betula, Cupressaceae, and Alnus. Pinus pollen becomes the dominant type at the eastern margins of the interior Douglas-fir zone and dominates the Engelmann spruce – subalpine fir, montane spruce, and sub-boreal pine–spruce biogeoclimatic zones at high and intermediate elevations to the east. In the Engelmann spruce – subalpine fir zone, Abies pollen is characteristically more abundant than Picea, and notable percentages of NAP, especially Artemisia, occur. In the transition from Engelmann spruce – subalpine fir zone to montane spruce zone, Abies and Picea percentages are about equal or Picea predominates slightly, whereas in the montane spruce zone and sub-boreal pine spruce zones, Picea values exceed Abies values often four to five times. Percent pollen and spore versus percent taxon cover diagrams, despite widely spread values, reveal general relationships and background pollen rain values for major taxa valuable to the interpretation of fossil pollen assemblages. Pinus is greatly overrepresented with a regional background of 10–15%. At low to intermediate cover values, Tsuga heterophylla, Pseudotsuga, and Cupressaceae are represented more or less as they occur in the vegetation, with regional backgrounds up to 5%. Picea and Abies are underrepresented, with regional background value of 0–3%. Key words: pollen, surface spectra, biogeoclimatic zones, species cover, British Columbia.

Deglacial landforms and Holocene vegetation trajectories in the northern interior cedar-hemlock forests of British Columbia

2020 ◽  
Author(s):  
Daniel Girard Gavin ◽  
Ariana White ◽  
Paul Sanborn ◽  
Richard Hebda
Keyword(s):  
British Columbia ◽  
Fire History ◽  
Vegetation History ◽  
Sediment Cores ◽  
Rocky Mountain ◽  
Tsuga Heterophylla ◽  
Thuja Plicata ◽  
Radiocarbon Dates ◽  
Lower Terrace ◽  
Closed Canopy

The northern Rocky Mountain Trench of eastern British Columbia is a broad valley mantled by glaciolacustrine terraces supporting a complex mix of mesic-temperate (“interior wetbelt”) forests that are strongly affected by terrain and substrate. Neither the geomorphic history during early-Holocene deglaciation nor the vegetation history of the origin of the Tsuga heterophylla and Thuja plicata populations in the interior wetbelt forest is well understood. Sediment cores were obtained from two lakes, 10 km apart and occupying different terraces (83 m elevational difference) and compared to existing fire-history and paleoclimate reconstructions. Radiocarbon dates and a mapped terrain classification indicate the upper terrace formed as a lacustrine and glaciofluvial kame terrace hundreds of years prior to a lower terrace formed by glaciolacustrine sediments of a proglacial lake. The minimum limiting ages of these terraces correlate with dated jökulhlaup deposits of the Fraser River. The upper site’s first detectable pollen at &gt; 11.0 ka was dominated by light-seeded pioneer taxa (Poaceae, Artemisia, and Populus) followed by a peak in Pinus and finally dominance by Betula at 10.2 ka. Pollen data suggest an earlier invasion of T. heterophylla than previously understood. Wetlands on extensive poorly drained glaciolacustrine soils promoted the persistence of boreal taxa and open forests (e.g., Picea mariana) while the better-drained upper kame terrace promoted development of closed-canopy shade-tolerant taxa. Invasion and expansion of mesic cedar-hemlock taxa progressed since at least the middle Holocene but was highly constrained by edaphic controls.

Quaternary Paleoecology and Stratigraphy of the Sea Cliffs, Western Olympic Peninsula, Washington

1972 ◽  
Vol 2 (02) ◽  
pp. 202-216 ◽  
Author(s):  
Linda E. Florer
Keyword(s):  
Tsuga Heterophylla ◽  
Stratigraphic Correlation ◽  
Olympic Peninsula ◽  
Radiocarbon Dates ◽  
Constituent Species ◽  
Alpine Plant Communities ◽  
Western Washington ◽  
Sea Cliff ◽  
Quaternary Paleoecology ◽  
Sea Cliffs

The sea cliffs of the western Olympic Peninsula are composed chiefly of discontinuous beds of unconsolidated gravel, sand, silt, and peat of Pleistocene age. Two lower stratigraphic units, the “Steamboat Creek gravel” and “Joe Creek silt”, were deposited probably during the Puyallup Interglaciation; the upper unit, the “Kalaloch silt”, was deposited during an interval that extends from Salmon Springs Glaciation through Fraser Glaciation. Radiocarbon dates of the Kalaloch silt range from about 17,000 to &gt; 48,000 BP. Pollen analysis and stratigraphic correlation of the sea cliff sediments indicate that the present vegetation of the Olympic Peninsula has existed in this part of western Washington since the Puyallup Interglacial. During the Puyallup, the low elevation Tsuga heterophylla-Picea forest or its seral stages were predominant. During subsequent glaciations the low elevation forest was replaced by montane or alpine plant communities in areas near the ice front. At sites farther removed from glacial termini, low elevation forest apparently persisted, thriving in centers from which constituent species spread during interstadials.

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