Modern pollen rain of Washington

1978 ◽  
Vol 56 (13) ◽  
pp. 1510-1517 ◽  
Author(s):  
Calvin J. Heusser
Keyword(s):  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
Alpine Tundra ◽  
Subalpine Forest ◽  
Western Coast ◽  
Coast Range ◽  
Columbia Plateau ◽  
Modern Pollen ◽  
The Pacific ◽  
Pollen Rain

Modern pollen rain was studied at 98 sites distributed in a belt transect some 250 km wide running a distance of 425 km between La Push on the Pacific coast and Grand Coulee on the Columbia Plateau. Sites are located in a variety of plant communities from the Picea sitchensis Zone near sea level to the Alpine Tundra Zone at 2285 m in the Cascades. The purposes of the study are (1) to establish the nature of the pollen rain and its relation to vegetation sources and (2) to develop further the pool of potential analogs of fossil pollen spectra for use in the reconstruction of Quaternary environments.Relative frequencies are shown for the pollen of Pinus, Picea, Abies, Tsuga, Pseudotsuga, Cupressaceae, Alnus, Gramineae, Cyperaceae, Chenopodiaceae, Artemisia, and Compositae. Results indicate the pollen rain to be related to source vegetation at the collection sites except for certain instances of infiltration by extraneous types, of which Pinus is most conspicuous. Alnus is the dominant pollen in the Puget Lowland and the western Coast and Cascade Ranges; Tsuga heterophylla is most prominent in the Coast Range; and Pinus ranks foremost in the eastern Cascades and on the Columbia Plateau. On the Columbia Plateau, the Gramineae, Artemisia, Compositae, and Chenopodiaceae are also distinctive. Subalpine forest types and nonarboreals are generally characteristic of the Timberline and Alpine Tundra Zones.

Modern Pollen Rain and Vegetational History of the Malaspina Glacier District, Alaska

1986 ◽  
Vol 25 (1) ◽  
pp. 100-120 ◽  
Author(s):  
Dorothy M. Peteet
Keyword(s):  
Gulf Of Alaska ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
Plant Succession ◽  
Coastal Forest ◽  
Modern Pollen ◽  
Pollen Rain ◽  
History Of ◽  
Climatic Cooling ◽  
Coastal Meadow

Seventy surface pollen samples from coastal forest, coastal meadow, muskeg, tree line, and alpine tundra communities form a basis for interpreting fossil pollen assemblages in the Malaspina Glacier district, Alaska. Poflen and macrofossil analyses of three radiocarbon-dated fossil sections from Icy Cape indicate that vegetational changes resulting from plant succession can be distinguished from those of migrational and climatic origin. Vegetation of the early Holocene xerothermic interval (10,000–7600 yr B.P.) was dominated by Alnus communities. Wetter conditions ensued, enabling generative muskeg surfaces to develop and first Picea sitchensis, then Tsuga heterophylla to expand from areas southeastward. Climatic cooling in more recent millennia (3500 yr B.P. to the present) is indicated by the appearance and persistent growth of Tsuga mertensiana and Selaginella selaginoides along this portion of the Gulf of Alaska coastline.

A late Quaternary vegetation history from Lily Lake, Chilkat Peninsula, southeast Alaska

1990 ◽  
Vol 68 (5) ◽  
pp. 1106-1112 ◽  
Author(s):  
Les C. Cwynar
Keyword(s):  
Pinus Contorta ◽  
Vegetation History ◽  
Late Quaternary ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
Coastal Forest ◽  
Southeast Alaska ◽  
Plant Migration ◽  
Arrival Times ◽  
The Pacific

Pollen and plant macrofossil analyses of a radiocarbon-dated core from Lily Lake on the Chilkat Peninsula, southeast Alaska, provide evidence for the history of the Pacific Coastal Forest. A Pinus contorta woodland with an abundance of herbs and ferns initially became established after deglaciation (10 870 years BP). By 10 330 years BP, Alnus viridis had become a significant component of the pine woodland while herbs and other shrubs declined. At 9480 years BP, Picea sitchensis and Populus were locally present and P. contorta populations declined. Tsuga heterophylla, which dominates the modern vegetation, became locally established at 7880 years BP. The last major component, Tsuga mertensiana, joined the vegetation about 6710 years BP. The modern closed forest, dominated by T. heterophylla and P. sitchensis, became established about 2870 years BP. The arrival times for the dominant species are compatible with dates from other studies that suggest a northward migration along the coast. Key words: fossil pollen, Alaska, Quaternary, plant migration, coastal forest.

Late-Glacial Vegetation and Climate Change in Western Oregon

1998 ◽  
Vol 49 (3) ◽  
pp. 287-298 ◽  
Author(s):  
Laurie D. Grigg ◽  
Cathy Whitlock
Keyword(s):  
Pacific Northwest ◽  
Younger Dryas ◽  
Late Glacial ◽  
Warming Trend ◽  
Cascade Range ◽  
Subalpine Forest ◽  
Coast Range ◽  
The Pacific ◽  
Dry Conditions ◽  
Vegetation And Climate

Pollen records from two sites in western Oregon provide information on late-glacial variations in vegetation and climate and on the extent and character of Younger Dryas cooling in the Pacific Northwest. A subalpine forest was present at Little Lake, central Coast Range, between 15,700 and 14,850 cal yr B.P. A warm period between 14,850 and 14,500 cal yr B.P. is suggested by an increase in Pseudotsuga pollen and charcoal. The recurrence of subalpine forest at 14,500 cal yr B.P. implies a return to cool conditions. Another warming trend is evidenced by the reestablishment of Pseudotsuga forest at 14,250 cal yr B.P. Increased haploxylon Pinus pollen between 12,400 and 11,000 cal yr B.P. indicates cooler winters than before. After 11,000 cal yr B.P. warm dry conditions are implied by the expansion of Pseudotsuga. A subalpine parkland occupied Gordon Lake, western Cascade Range, until 14,500 cal yr B.P., when it was replaced during a warming trend by a montane forest. A rise in Pinuspollen from 12,800 to 11,000 cal yr B.P. suggests increased summer aridity. Pseudotsuga dominated the vegetation after 11,000 cal yr B.P. Other records from the Pacific Northwest show an expansion of Pinus from ca. 13,000 to 11,000 cal yr B.P. This expansion may be a response either to submillennial climate changes of Younger Dryas age or to millennial-scale climatic variations.

Fire and Vegetation History from the Coastal Rain Forest of the Western Oregon Coast Range

2002 ◽  
Vol 58 (3) ◽  
pp. 215-225 ◽  
Author(s):  
Colin J. Long ◽  
Cathy Whitlock
Keyword(s):  
Vegetation History ◽  
Fire Frequency ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
Eastern Coast ◽  
Summer Drought ◽  
Coast Range ◽  
Episode Frequency ◽  
History Of ◽  
In Fire

AbstractHigh-resolution charcoal and pollen analyses were used to reconstruct a 4600-yr-long history of fire and vegetation near Taylor Lake in the wettest forests of coastal Oregon. Today, fires in these forests are rare because the season of ignition does not coincide with months of dry fuels. From ca. 4600 to 2700 cal yr B.P. fire episodes occurred at intervals of 140±30 yr while forest vegetation was dominated by disturbance-adapted taxa such as Alnus rubra. From ca. 2700 cal yr B.P. to the present, fire episodes have become less common, occurring at intervals of 240±30 yr, and fire-sensitive forest taxa, such as Tsuga heterophylla and Picea sitchensis, have become more prominent. Fire occurrence during the mid-Holocene was similar to that of the more xeric forests in the eastern Coast Range and suggests that summer drought was widespread. After ca. 2700 cal yr B.P., a decrease in fire episode frequency suggests that cooler conditions and possibly increased summer fog allowed the establishment of present-day Picea sitchensis forests within the watershed. These results provide evidence that fire has been an important disturbance agent in the Coast Range of Oregon, and variations in fire frequency and climate have led to the establishment of present-day forests.

Interaction of vegetation control and fertilization on conifer species across the Pacific Northwest

2002 ◽  
Vol 32 (1) ◽  
pp. 136-152 ◽  
Author(s):  
Robin Rose ◽  
J Scott Ketchum
Keyword(s):  
Weed Control ◽  
Pacific Northwest ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Tsuga Heterophylla ◽  
Stem Volume ◽  
Coast Range ◽  
Basal Diameter ◽  
Vegetation Control ◽  
The Pacific

An experiment evaluating three levels of vegetation competition control (no control, 1.5 m2 of vegetation control, and 3.3 m2 of vegetation control), each with two fertilization treatments (fertilization at the time of planting with complete slow-release fertilizer (Woodace® IBDU), or no fertilization), was installed at five sites. Two of these sites were planted with Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in the Oregon Coast Range, one with ponderosa pine (Pinus ponderosa Dougl. ex P. Laws. & C. Laws.) in eastern Washington, one with western hemlock (Tsuga heterophylla (Raf.) Sarg.) in the coastal hemlock zone in Oregon, and one with coastal redwood (Sequoia sempervirens (D. Don) Endl.) in northern California. At four of the five sites, mean stem volume, basal diameter, and height of seedlings increased significantly with increasing area of weed control, and the magnitude of difference between treatments increased with time. Fertilization significantly increased seedling size only at the two sites with adequate soil moisture; increases were marginally significant at a third. Response to fertilization was less than from weed control and impacted growth for only the first year, whereas the influence of weed control continued to influence growth the entire length of the study (4 years). Area of vegetation control and fertilization did not interact significantly at any site.

Vegetation and Modern Pollen Rain From the Barrington Tops and Upper Hunter River Regions of New South Wales

1986 ◽  
Vol 34 (3) ◽  
pp. 293 ◽  
Author(s):  
JR Dodson ◽  
CA Myers
Keyword(s):  
Rain Forest ◽  
New South ◽  
Subalpine Forest ◽  
Modern Pollen ◽  
Eucalypt Forest ◽  
South Wales ◽  
Wide Range ◽  
Temperate Rain Forest ◽  
Pollen Rain ◽  
Eucalypt Forests

Vegetation was mapped using existing maps, Landsat interpretation, aerial photograph interpretation and some verification by ground surveys. Twenty-five moss cushions were collected to identify pollen rain and pollen indicators of vegetation for use in fossil pollen interpretation. Eucalyptus (10%), Poaceae (4-10%), Casuarina (4-5%), Asteraceae (Tubuliflorae) (0-4%) and Cyperaceae (0-2%) were the general components in the pollen rain of the region. Subtropical rain forest was characterized by Backhousia and low values of a wide range of taxa. Cool temperate rain forest had Nothofagus values above 40% and Eucalyptus values below 20%. Subalpine grasslands had Poaceae values above 45%, Eucalyptus values below 15% and small quantities of Epacridaceae and Goodeniaceae pollen. Subalpine forest and wet eucalypt forest formations had very similar pollen representation and could be confused in pollen spectra. However, Monotoca, Banksia, Leptospermum pollen and fern spores were more common in the wet eucalypt forests. Dry eucalypt formations were characterized by 2-20% values of Bursaria, Callitris and Dodonaea as well as eucalypt values.

scholarly journals Analysis of Intense Poleward Water Vapor Transports into High Latitudes of Western North America

2009 ◽  
Vol 24 (6) ◽  
pp. 1732-1747 ◽  
Author(s):  
Alain Roberge ◽  
John R. Gyakum ◽  
Eyad H. Atallah
Keyword(s):  
Water Vapor ◽  
North America ◽  
Vapor Transport ◽  
Water Vapor Transport ◽  
Western Coast ◽  
Synoptic Scale ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Subtropical Oceans ◽  
Pineapple Express

Abstract Significant cool season precipitation along the western coast of North America is often associated with intense water vapor transport (IWVT) from the Pacific Ocean during favorable synoptic-scale flow regimes. These relatively narrow and intense regions of water vapor transport can originate in either the tropical or subtropical oceans, and sometimes have been referred to as Pineapple Express events in previous literature when originating near Hawaii. However, the focus of this paper will be on diagnosing the synoptic-scale signatures of all significant water vapor transport events associated with poleward moisture transport impacting the western coast of Canada, regardless of the exact points of origin of the associated atmospheric river. A trajectory analysis is used to partition the events as a means of creating coherent and meaningful synoptic-scale composites. The results indicate that these IWVT events can be clustered by the general area of origin of the majority of the saturated parcels impacting British Columbia and the Yukon Territories. IWVT events associated with more zonal trajectories are characterized by a strong and mature Aleutian low, whereas IWVT events associated with more meridional trajectories are often characterized by an anticyclone situated along the California or Oregon coastline, and a relatively mature poleward-traveling cyclone, commonly originating in the central North Pacific.

Pollen Taphonomy in a Canyon Stream

1987 ◽  
Vol 28 (3) ◽  
pp. 393-406 ◽  
Author(s):  
Patricia L. Fall
Keyword(s):  
Surface Soil ◽  
Pollen Grains ◽  
Close Correlation ◽  
Soil Samples ◽  
Alluvial Deposits ◽  
Modern Pollen ◽  
Pollen Types ◽  
Pollen Rain ◽  
Arid Steppe ◽  
Turbulent Water

AbstractSurface soil samples from the forested Chuska Mountains to the arid steppe of the Chinle Valley, Northeastern Arizona, show close correlation between modern pollen rain and vegetation. In contrast, modern alluvium is dominated by Pinus pollen throughout the canyon; it reflects neither the surrounding floodplain nor plateau vegetation. Pollen in surface soils is deposited by wind; pollen grains in alluvium are deposited by a stream as sedimentary particles. Clay-size particles correlate significantly with Pinus, Quercus, and Populus pollen. These pollen types settle, as clay does, in slack water. Chenopodiaceae-Amaranthus, Artemisia, other Tubuliflorae, and indeterminate pollen types correlate with sand-size particles, and are deposited by more turbulent water. Fluctuating pollen frequencies in alluvial deposits are related to sedimentology and do not reflect the local or regional vegetation where the sediments were deposited. Alluvial pollen is unreliable for reconstruction of paleoenvironments.

Distribution of leaf orientations in six conifer species

2001 ◽  
Vol 79 (4) ◽  
pp. 389-397 ◽  
Author(s):  
Hugh J Barclay
Keyword(s):  
Pseudotsuga Menziesii ◽  
Pinus Contorta ◽  
Goodness Of Fit ◽  
Tsuga Heterophylla ◽  
Picea Sitchensis ◽  
The Other ◽  
Thuja Plicata ◽  
Leaf Angle ◽  
Conifer Species ◽  
Abies Grandis

Leaf angle distributions are important in assessing both the flexibility of a plant's response to differing daily and seasonal sun angles and also the variability in the proportion of total leaf area visible in remotely sensed images. Leaf angle distributions are presented for six conifer species, Abies grandis (Dougl. ex D. Don) Lindl., Thuja plicata Donn. ex D. Don, Tsuga heterophylla (Raf.) Sarg., Pseudotsuga menziesii (Mirb.) Franco, Picea sitchensis (Bong.) Carr. and Pinus contorta Dougl. ex Loud. var. latifolia. The leaf angles were calculated by measuring four foliar quantities, and then the distributions of leaf angles are cast in three forms: distributions of (i) the angle of the long axis of the leaf from the vertical for the range 0–180°; (ii) the angle of the long axis of the leaf for the range 0–90°; and (iii) the angle of the plane of the leaf for the range 0–90°. Each of these are fit to the ellipsoidal distribution to test the hypothesis that leaf angles in conifers are sufficiently random to fit the ellipsoidal distribution. The fit was generally better for planar angles and for longitudinal angles between 0° and 90° than for longitudinal angles between 0° and 180°. The fit was also better for Tsuga heterophylla, Pseudotsuga menziesii, Picea sitchensis, and Pinus contorta than for Abies grandis and Thuja plicata. This is probably because Abies and Thuja are more shade tolerant than the other species, and so the leaves in Abies and Thuja are preferentially oriented near the horizontal and are much less random than for the other species. Comparisons of distributions on individual twigs, whole branches, entire trees, and groups of trees were done to test the hypothesis that angle distributions will depend on scale, and these comparisons indicated that the apparent randomness and goodness-of-fit increased on passing to each larger unit (twigs up to groups of trees).Key words: conifer, leaf angles, ellipsoidal distribution.

MODERN POLLEN RAIN STUDIES IN EASTERN ONTARIO

1963 ◽  
Vol 41 (2) ◽  
pp. 243-252 ◽  
Author(s):  
James E. King ◽  
Ronald O. Kapp
Keyword(s):  
United States ◽  
Long Range ◽  
Southwestern United States ◽  
Pollen Trap ◽  
Modern Pollen ◽  
Pollen Rain ◽  
Moss Polsters ◽  
Eastern Ontario

Moss polsters were collected at 15 sites between Toronto and Lake Timagami, Ontario, and at 4 localities in the Lake Timagami area for the purpose of determining the regional pollen rain and its local variations. Pollen percentages of Acer, Quercus, Ambrosia, Chenopodiaceae, Compositae, and Gramineae decrease northward and Picea, Pinus, and Betula increase at the more northerly sites. From the three most northern sites a regional pollen rain was calculated by averaging the percentages from nine pollen spectra. In this area the regional pollen rain is dominated by Picea (15%), Pinus (38%), and Betula (22%). At one site a grain of Ephedra was recovered, apparently carried in by long range drift. The nearest place that it grows naturally is in the southwestern United States. Various pollen trap types were investigated and it was found that all types of moss polsters and some types of decaying stumps (depending on their moisture-holding capacity) were effective in preserving the modern pollen rain.

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