scholarly journals Black Bear Damage to Forest Stands in Western Washington

1999 ◽  
Vol 14 (3) ◽  
pp. 128-131 ◽  
Author(s):  
William B. Stewart ◽  
Gary W. Witmer ◽  
Gary M. Koehler

Abstract Cambium-feeding behavior by black bears (Ursus americanus), or bear damage, is a major reforestation problem in the Pacific Northwest. Historically, studies have measured the cumulative effects of damage over time, but few have viewed damage in the frame of one season. Bear damage occurring in 1996 was surveyed in areas of radio-marked bears in western Washington. Fresh damage occurred on 48% of bear location plots (n = 96). Douglas-fir (Pseudotsuga menziesii) (69%), western hemlock (Tsuga heterophylla) (19%), and Pacific silver fir (Abies amabilis) (10%) with a mean dbh of 25.1, 29.5, and 30.7 cm, respectively, were most frequently damaged. Random plots were surveyed from mid-July to mid-August to measure habitat availability. Stand and site variables were measured on freshly damaged bear location plots, random plots, and nondamaged bear location plots. This study identified several variables that make forest stands vulnerable to bear damage: conifer dbh, conifer density, stand age, and canopy cover. Awareness of such stand characteristics can assist natural resource managers with animal damage prevention and control programs. West. J. Appl. For. 14(3):128-131.

2008 ◽  
Vol 140 (5) ◽  
pp. 539-556 ◽  
Author(s):  
Zoë Lindo ◽  
Marilyn Clayton ◽  
Valerie M. Behan-Pelletier

AbstractWe present the systematics and ecology of a new species of arboreal oribatid mite in the family Achipteriidae, Anachipteria geminussp. nov., a dominant arthropod in canopy lichens associated with western hemlock (Tsuga heterophylla (Raf.) Sarg. (Pinaceae)) and Pacific silver fir (Abies amabilis (Dougl. ex Loud.) Dougl. ex Forbes (Pinaceae)) in the coniferous temperate and montane forests of the Pacific Northwest of North America. The species is described on the basis of the morphology of all active instars plus molecular sequence data for the D3 region of the 28s rRNA (D3-28s) and mitochondrial cytochrome oxidase 1 (CO1) genes. Anachipteria geminus is the dominant oribatid mite in foliose lichens in the upper canopies of Pacific montane conifer trees. Specimens were found in 100% of canopy lichens sampled, and abundances can reach 1450 individuals / 100 g dry mass of lichen. Analysis of the population structure indicates that A. geminus has seasonally stable populations consistent with overlapping generations. Anachipteria geminus expresses morphological character states that require expanding the diagnoses of the genus Anachipteria and the family Achipteriidae. A revised diagnosis and morphological key to species of Anachipteria in Canada are given.


Zootaxa ◽  
2010 ◽  
Vol 2403 (1) ◽  
pp. 10 ◽  
Author(s):  
ZOE LINDO ◽  
MARILYN CLAYTON ◽  
VALERIE BEHAN-PELLETIER

We present the systematics and ecology of a new species of arboreal oribatid mite in the family Peloppiidae (Acari: Oribatida), Dendrozetes jordani n. sp., a dominant arthropod on branch tips and arboreal lichens associated with western hemlock (Tsuga heterophylla (Pinaceae)) and Pacific silver fir (Abies amabilis (Pinaceae)) in the coniferous temperate and montane forests of the Pacific Northwest of North America. Dendrozetes jordani represents the first record of the genus Dendrozetes in North America. The species is described on the basis of morphology of all active instars plus molecular sequence data for the mitochondrial cytochrome oxidase I (COI) gene. Dendrozetes jordani is compared with type specimens of D. caudatus Aoki from Japan, and a revised diagnosis of the genus Dendrozetes is given. Dendrozetes jordani has a stable, overlapping population structure through the year, and its association with trees in Pinaceae is an ecological characteristic shared with D. caudatus from Japan.


2005 ◽  
Vol 20 (2) ◽  
pp. 94-100 ◽  
Author(s):  
Robert L. Mathiasen ◽  
Carolyn M. Daugherty

Abstract A total of 24 mixed conifer stands in Washington and Oregon infested with western hemlock dwarf mistletoe (Arceuthobium tsugense subsp. tsugense) were sampled to compare host susceptibility to this parasitic plant. Temporary circular plots were established around dominant, severely infected western hemlocks (Tsuga heterophylla). Within plots, species, diameter at breast height, and dwarf mistletoe rating (6-class system) were determined for each live tree. More than 5,700 trees were sampled in 275 plots. Based on the incidence of infection, tree species were assigned to host susceptibility classes. Western hemlock is classified as the only principal host of western hemlock dwarf mistletoe. Pacific silver fir (Abies amabilis), noble fir (Abies procera), and mountain hemlock (Tsuga mertensiana) are classified as occasional hosts. Resource managers can use the host susceptibility classifications based on this study for decisions regarding which trees to retain when selectively harvesting mixed conifer stands infested with western hemlock dwarf mistletoe in the Pacific Northwest. West. J. Appl. For. 20(2):94–100.


2002 ◽  
Vol 32 (6) ◽  
pp. 1057-1070 ◽  
Author(s):  
Linda E Winter ◽  
Linda B Brubaker ◽  
Jerry F Franklin ◽  
Eric A Miller ◽  
Donald Q DeWitt

The history of canopy disturbances over the lifetime of an old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stand in the western Cascade Range of southern Washington was reconstructed using tree-ring records of cross-dated samples from a 3.3-ha mapped plot. The reconstruction detected pulses in which many western hemlock (Tsuga heterophylla (Raf.) Sarg.) synchronously experienced abrupt and sustained increases in ringwidth, i.e., "growth-increases", and focused on medium-sized or larger ([Formula: see text]0.8 ha) events. The results show that the stand experienced at least three canopy disturbances that each thinned, but did not clear, the canopy over areas [Formula: see text]0.8 ha, occurring approximately in the late 1500s, the 1760s, and the 1930s. None of these promoted regeneration of the shade-intolerant Douglas-fir, all of which established 1500–1521. The disturbances may have promoted regeneration of western hemlock, but their strongest effect on tree dynamics was to elicit western hemlock growth-increases. Canopy disturbances are known to create patchiness, or horizontal heterogeneity, an important characteristic of old-growth forests. This reconstructed history provides one model for restoration strategies to create horizontal heterogeneity in young Douglas-fir stands, for example, by suggesting sizes of areas to thin in variable-density thinnings.


2016 ◽  
Author(s):  
Huan Gu ◽  
Christopher A. Williams ◽  
Bardan Ghimire ◽  
Feng Zhao ◽  
Chengquan Huang

Abstract. Assessment of forest carbon storage and uptake is central to understanding the role forests play in the global carbon cycle and policy-making aimed at mitigating climate change. Current U.S. carbon stocks and fluxes are monitored and reported at fine-scale regionally, or coarse-scale nationally. We proposed a new methodology of quantifying carbon uptake and release across forested landscapes in the Pacific Northwest (PNW) at a fine scale (30 m) by combining remote-sensing based disturbance year, disturbance type, and aboveground biomass with forest inventory data in a carbon modelling framework. Time since disturbance is a key intermediate determinant that aided the assessment of disturbance-driven carbon emissions and removals legacies. When a recent disturbance was detected, time since disturbance can be directly determined by remote sensing-derived disturbance products; and if not, time since last stand-clearing was inferred from remote sensing-derived 30 m biomass map and field inventory-derived species-specific biomass regrowth curves. Net ecosystem productivity (NEP) was further mapped based on carbon stock and flux trajectories that described how NEP changes with time following harvest, fire, or bark beetle disturbances of varying severity. Uncertainties from biomass map and forest inventory data were propagated by probabilistic sampling to provide a probabilistic, statistical distribution of stand age and NEP for each forest pixel. We mapped mean, standard deviation and statistical distribution of stand age and NEP at 30 m in the PNW region. Our map indicated a net ecosystem productivity of 5.2 Tg C y−1 for forestlands circa 2010 in the study area, with net uptake in relatively mature (> 24 year old) forests (13.6 Tg C y−1) overwhelming net negative NEP from tracts that have seen recent harvest (−6.4 Tg C y−1), fires (−0.5 Tg C y−1), and bark beetle outbreaks (−1.4 Tg C y−1). The approach will be applied to forestlands in other regions of the conterminous U.S. to advance a more comprehensive monitoring, mapping and reporting the carbon consequences of forest change across the U.S.


2019 ◽  
Vol 12 (4) ◽  
pp. 223-228 ◽  
Author(s):  
Lindsay E. Koby ◽  
Timothy S. Prather ◽  
Harold Quicke ◽  
Jared Beuschlein ◽  
Ian C. Burke

AbstractVentenata [Ventenata dubia (Leers) Cross] is a winter annual grass relatively new to the inland Pacific Northwest that is capable of displacing desired vegetation. Indaziflam was evaluated for the management of V. dubia on two Conservation Reserve Program (CRP) sites near Moscow, ID, and Pullman, WA. While perennial grasses were dormant, applications of indaziflam in mixture with various herbicides were made in spring 2016. Treatment effects were evaluated for 2 yr by visual assessments of community composition and canopy cover of V. dubia and other non-weedy species (assessments occurred 3 to 6 mo after treatment, depending on location) and by representative cover class assessments. Biomass samples of all plant species were collected in the summer of 2017. Reduced V. dubia cover was observed in 2016, except when glyphosate was used alone. In 2017 indaziflam applied alone or in mixture with rimsulfuron effectively controlled V. dubia with minimal impact on desirable vegetation. Plant biomass from nontreated plots averaged 40 g m−2 for V. dubia and 100 to 179 g m−2 for perennial grasses. Plant biomass averaged <11 g m−2 for V. dubia and 371 to 490 g m−2 for perennial grasses when indaziflam at 102 g ai ha−1 plus glyphosate at 474 g ai ha−1 was applied. Smooth brome (Bromus inermis Leyss.) biomass was positively associated with the reduction of V. dubia, and there was a decrease in diversity associated with the removal of V. dubia through effective treatments. Indaziflam is an effective tool for the management of V. dubia in perennial grass stands, and spring applications of indaziflam should be in mixture with herbicides with POST activity.


1989 ◽  
Vol 4 (1) ◽  
pp. 10-13 ◽  
Author(s):  
Andrew C. Mason ◽  
David L. Adams

Abstract Bear damage was at least five times higher in thinned blocks than in adjacent unthinned blocks of western larch (Larix occidentalis), lodgepole pine (Pinus contorta), and Engelmann spruce (Picea engelmannii) on the Kootenai National Forest in northwest Montana. Western larch suffered the greatest damage (63% of all trees damaged and 92% of the trees killed). Damaged larch ranged from 4 to 13 in. dbh; the 4 to 8-in. dbh class accounted for 85% of the damage. Douglas-fir (Pseudotsuga menziesii), western redcedar (Thuja plicata), subalpine fir (Abies lasiocarpa), western white pine (Pinus monticola), and western hemlock (Tsuga heterophylla) were not damaged. Stand projections showed up to a 17% reduction in board-foot yield from bear damage, after 50 years, compared with hypothetical undamaged stands. West. J. Appl. For. 4(1):10-13, January 1989.


Radiocarbon ◽  
2015 ◽  
Vol 57 (5) ◽  
pp. 917-941 ◽  
Author(s):  
Ian Hutchinson

Surface-breaking ruptures on shallow crustal faults in the southern Puget Lowland in western Washington State about a millennium ago prompted abrupt changes in land level and triggered tsunamis in Puget Sound. The displacement on the Seattle fault most likely occurred in the 1050–1020 cal BP interval. Structures further south (the Tacoma and Olympia faults, and one or more faults in the southern Hood Canal zone) ruptured at about the same time, or slightly earlier. The low frequency of radiocarbon ages from archaeological sites in the region in the aftermath of the “millennial series” of earthquakes, when compared to bootstrapped samples from a database of 1255 ages from the Pacific Northwest as a whole, suggests that these very large earthquakes had significant socioeconomic consequences. The cultural record from coastal archaeological sites shows that although survivors camped on the shore in the aftermath, many coastal villages appear to have been abandoned, and were not reoccupied for several centuries. There is little evidence, however, to suggest that people migrated from southern Puget Sound to neighboring areas, and no evidence of social conflict in the adjacent areas that might have served as havens.


2020 ◽  
Vol 49 (4) ◽  
pp. 823-828
Author(s):  
Alex N Neidermeier ◽  
Darrell W Ross ◽  
Nathan P Havill ◽  
Kimberly F Wallin

Abstract Two species of silver fly, Leucopis argenticollis (Zetterstedt) and Leucopis piniperda (Malloch) (Diptera: Chamaemyiidae), from the Pacific Northwest region of North America have been identified as potential biological control agents of hemlock woolly adelgid (Hemiptera: Adelgidae: Adelges tsugae Annand) in eastern North America. The two predators are collectively synchronized with A. tsugae development. To determine whether adult emergence of the two species of silver fly are also synchronized with one another, we collected adult Leucopis which emerged from A. tsugae-infested western hemlock [Pinaceae: Tsuga heterophylla (Raf.) Sarg.] from four sites in the Pacific Northwest over a 29-d period. Specimens were collected twice daily in the laboratory and identified to species using DNA barcoding. The study found that more adult Leucopis were collected in the evening than the morning. Additionally, the daily emergences of adults over the 29-d sampling period exhibited sinusoidal-like fluctuations of peak abundance of each species, lending evidence to a pattern of temporal partitioning. This pattern could have logistical implications for their use as biological control agents in eastern North America, namely the need to release both species for maximum efficacy in decreasing A. tsugae populations.


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