Search

Ecosystem structure and processes of coastal temperate rainforests of the Pacific Northwest are thought to be strongly influenced by herbivory primarily of Roosevelt elk (Cervus elaphus roosevelti) and secondarily of Columbian black‐tailed deer (Odocoileus hemionus columbianus). Two large (0.5‐ha) exclosures were built in old‐growth coniferous rainforest communities in Olympic National Park, Washington, during 1979 to study these effects. Cover of shrubs, ferns, herbs, and graminoids and numbers of tree seedlings were described over 36 yr. Results show a sequence following ungulate exclusion of early release of shrubs, ferns, and herbs followed by eventual dominance of shrubs as other vegetation layers become shaded. Short‐term responses of individual species reflected functional traits related to ability to avoid or tolerate herbivory. Over the longer term, effects reflected changing competitive relationships among vegetation layers and other ecosystem dynamics such as the provision of fallen trees in the appropriate decay class to serve as establishment substrate for tree seedlings. In aggregate, vegetation composition shifted after 36 yr from a system dominated by herbaceous cover with a major graminoid component to one dominated by shrubs (5‐ to 6‐fold absolute increase) and ferns (5–7% increase in absolute cover), less absolute herb cover (15–20% loss), and almost no graminoids (<1.5% cover remaining in any plot) after 36 yr. These changes represented a substantial loss in plant community diversity with a loss of 46 of 74 species. Elk abundance outside of the exclosures began to decline in the 1990s leading to parallel changes in plant community trajectories outside of exclosures to those initially seen inside. While this suggests plant community responses inside the exclosures were also driven by elk exclusion, the strength of this response depends on elk abundance. [ABSTRACT FROM AUTHOR]

Limited information is available about threshold lake nitrogen concentrations necessary to stimulate phytoplankton species and biomass responses in remote nitrogen-limited mountain lakes. We conducted in situ enrichment bioassays in mountain lakes within Mount Rainier, North Cascades, and Olympic National Parks in Washington State, USA to characterize phytoplankton species and biomass responses to nitrogen enrichment, and associated dissolved inorganic nitrogen (DIN) concentration thresholds. Based on biomass and growth measurements, phytoplankton were nitrogen-limited or co-limited by nitrogen and phosphorus in the nine bioassay lakes. We identified 20 taxa that responded to nitrogen enrichment, and estimated response thresholds using nitrogen Monod half-saturation constants ( K) for 18 of these taxa. DIN thresholds in nitrogen-limited lakes were 13 μg N l for any increase in chlorophyll a, and 25 μg N l, for an increase beyond typical inter-annual chlorophyll a variation. K values ranged from 0.02 to 77 μg N l across most N-responsive taxa, and diatom K values were higher than those previously quantified in U.S. Rocky Mountain lakes. Approximately, 75% of sampled mountain lakes in the parks have summer dissolved inorganic nitrogen concentrations below biomass response thresholds. This finding suggests that phytoplankton in park mountain lakes are likely sensitive to future deposition-induced lake nitrogen enrichment. [ABSTRACT FROM AUTHOR]

We investigated predation by nonnative coyotes (Canis latrans) on endemic Olympic marmots (Marmota olympus) in Olympic National Park, Washington, in 2005 and 2006. Although nearly the entire marmot range is protected within the park, declines and local extirpations of the species have been documented. Through analyses of carnivore scat across the range of the Olympic marmot we determined the distribution and relative density of coyotes and characterized the extent to which coyotes and native carnivores preyed on marmots. We used mitochondrial DNA analysis of scats to determine carnivore species, and microsatellite markers for individual coyote identification. Scat analysis indicated that invasive coyotes are widespread and the numerically dominant carnivore on sampled trails within the Olympic highlands-71% (301 of 426) of all scats verified to species arose from coyote. Out of all carnivore scats collected, 11.6% (111 of 958) contained marmot remains. For 85% of the samples with marmots, coyotes were confirmed as the predator. The remainder arose from bobcat (13%) and cougar (2%). Coyotes were the predominant marmot predator across all months and in most regions of the park. Twelve out of 13 coyote individuals identified with genetic markers preyed on marmots. Marmots ranked 5th in frequency of coyote diet items, after snowshoe hares (Lepus americanus), mountain beavers (Aplodontia rufa), voles, and cervids. Scat analysis indicated that in the Olympic Mountains, the coyote as an invasive generalist predator is subsidized by abundant multiple prey, and appears to be the primary terrestrial predator on the endemic Olympic marmot. We conclude that predation by coyotes on marmots is widespread and substantial across the marmot's species range, and therefore likely driving observed marmot declines and extinctions. [ABSTRACT FROM AUTHOR]

The Mahalanobis distance statistic (D2) has emerged as an effective tool to identify suitable habitat from presence data alone, but there has been no mechanism to select among potential habitat covariates. We propose that the best combination of explanatory variables for a D2 model can be identified by ranking potential models based on the proportion of the entire study area that is classified as potentially suitable habitat given that a predetermined proportion of occupied locations are correctly classified. In effect, our approach seeks to minimize errors of commission, or maximize specificity, while holding the omission error rate constant. We used this approach to identify potentially suitable habitat for the Olympic marmot (Marmota olympus), a declining species endemic to Olympic National Park, Washington, USA. We compared models built with all combinations of 11 habitat variables. A 7-variable model identified 21,143 ha within the park as potentially suitable for marmots, correctly classifying 80% of occupied locations. Additional refinements to the 7-variable model (e.g., eliminating small patches) further reduced the predicted area to 18,579 ha with little reduction in predictive power. Although we sought a model that would allow field workers to find 80% of Olympic marmot locations, in fact, <3% of 376 occupied locations and <9% of abandoned locations were >100 m from habitat predicted by the final model, suggesting that >90% of occupied marmot habitat could be found by observant workers surveying predicted habitat. The model comparison procedure allowed us to identify the suite of covariates that maximized specificity of our model and, thus, limited the amount of less favorable habitat included in the final prediction area. We expect that by maximizing specificity of models built from presence-only data, our model comparison procedure will be useful to conservation practitioners planning reintroductions, searching for rare species, or identifying habitat for protection. [ABSTRACT FROM AUTHOR]

1. Faecal surveys are used widely to study variations in abundance and distribution of forest-dwelling mammals when direct enumeration is not feasible. The utility of faecal indices of abundance is limited, however, by observational bias and variation in faecal disappearance rates that obscure their relationship to population size. We developed methods to reduce variability in faecal surveys and improve reliability of faecal indices. 2. We used double-observer transect sampling to estimate observational bias of faecal surveys of Roosevelt elk Cervus elaphus roosevelti and Columbian black-tailed deer Odocoileus hemionus columbianus in Olympic National Park, Washington, USA. We also modelled differences in counts of faecal groups obtained from paired cleared and uncleared transect segments as a means to adjust standing crop faecal counts for a standard accumulation interval and to reduce bias resulting from variable decay rates. 3. Estimated detection probabilities of faecal groups ranged from < 0·2–1·0 depending upon the observer, whether the faecal group was from elk or deer, faecal group size, distance of the faecal group from the sampling transect, ground vegetation cover, and the interaction between faecal group size and distance from the transect. 4. Models of plot-clearing effects indicated that standing crop counts of deer faecal groups required 34% reduction on flat terrain and 53% reduction on sloping terrain to represent faeces accumulated over a standard 100-day interval, whereas counts of elk faecal groups required 0% and 46% reductions on flat and sloping terrain, respectively. 5. Synthesis and applications. Double-observer transect sampling provides a cost-effective means of reducing observational bias and variation in faecal decay rates that obscure the interpretation of faecal indices of large mammal abundance. Given the variation we observed in observational bias of faecal surveys and persistence of faeces, we emphasize the need for future researchers to account for these comparatively manageable sources of bias before comparing faecal indices spatially or temporally. Double-observer sampling methods are readily adaptable to study variations in faecal indices of large mammals at the scale of the large forest reserve, natural area, or other forested regions when direct estimation of populations is problematic. [ABSTRACT FROM AUTHOR]

This article recounts the history of the creation of Olympic National Park in Washington. The park was established despite strong opposition from local timber interests and local photographer Asahel Curtis. Curtis developed a reputation as a proponent of logging but the author argues he has been misunderstood and was actually a conservationist.

A vegetation chronosequence spanning over 300 years was established in unconstrained reaches of the lower Queets River in Olympic National Park, Washington, USA, for an examination of riparian successional patterns. The Queets is an unconstrained, dynamic, mountain river located within a temperate rain forest environment. Ongoing channel movements create intricate patterns in the physical structure of the valley. Twenty-one plots containing a total of 4359 trees were mapped and measured for structural and crown characteristics. Snags, logs, and understory vegetation were also quantified. Recent alluvial deposits are colonized primarily by early-successional trees Salix sitchensis and Alnus rubra. Conifer seedlings, primarily Picea sitchensis, generally invade after the initial cohort of hardwood trees begins senescence: 20-30 years for Salix and 40-60 years for Alnus. Through accumulation of sediments from floods and channel downcutting, surfaces become perched above the reach of annual floods after 40-80 years and are then slowly colonized by late successional tree species Acer circinatum, Acer macrophyllum, and Tsuga heterophylla. Diverse, old-growth forests ultimately develop after 200-250 years, containing some of the largest known trees in the Pacific Northwest. However, canopy and stem densities remain lower than comparative Pseudotsuga menziesii forests from the nearby Cascade Mountains. Vast individual crowns can develop, with occasional Picea up to 25 m wide and 70 m deep. Individual stands may accumulate >200 000 m³/ha of canopy volume—among the highest recorded on earth. Mixed among the generalized successional sequence are variations created by uncommon channel movements. Avulsions followed by channel incision form cobblefields in abandoned channels or other surfaces which are isolated from subsequent inundation and sediment deposition. These cobblefields embark on a different successional trajectory, which often includes conifer seedlings present in the initial cohort. Ultimately, whatever the initial trajectory, soils become productive due to soil conditioning by Alnus and the decomposition of other plant material. These biophysical complexities, interconnected patterns, and system-scale resilience are summarized in a multiple-pathway successional model that may be applicable to floodplain riparian forests throughout much of the Pacific coastal ecoregion. [ABSTRACT FROM AUTHOR]

Focuses on the efforts of U.S. Supreme Court Justice William O. Douglas to secure wilderness protection in the Pacific Northwest region of the U.S. Utilization of his national standing and network of friends to promote an environmental agenda for the region; Overview of his book "Of Men and Mountains"; Background on the controversy in Olympic National Park in Washington.

Most old fields in the Queers Valley of Olympic National Park, USA, remain dominated by exotic herbs 60 y after abandonment although the fields are surrounded by temperate rain forest. However, areas of some fields have been invaded by Picea sitchensis, one of three dominant forest species (with Alnus rubra and Tsuga heterophylla). This provided an opportunity to examine local variation of factors (competition, facilitation, cervid herbivory, soils) that influence tree colonization within a set of old fields, an approach rare in previous studies. Picea sapling invasion of field edges was negatively correlated with percent cover of Agrostis gigantea and positively correlated with Anthoxanthum odoratum. Potential indicators of competition (sod thickness, thatch thickness, percent ground cover) were correlated with Agrostis cover, Picea edge invasion was also correlated with soil organic matter. In experiments, seedlings of Picea and Tsuga emerged as readily in Agrostis as in Anthoxanthum or Pteridium aquilinum, but suffered higher mortality in Agrostis. Experimental seedling establishment was low and required reduction of competing vegetation. In experiments with transplanted seedlings, cervid herbivory suppressed growth of Tsuga and Alnus, but not Picea. Growth of Picea seedlings was facilitated by Pteridium. Differential tree colonization of the fields resulted from: (1) differential competition by invaded cover types against seedling establishment, (2) selective herbivory on tree species of established seedlings and (3) facilitation by fern cover of seedlings of an unbrowsed species. [ABSTRACT FROM AUTHOR]

Although mountainous landscapes dominate large areas of the Earth, our understanding of how elevation and aspect influence soil respiration in complex mountainous terrain is very limited. Therefore, we measured soil respiration throughout the growing season in 1999 and 2000 at 11 forested sites in Olympic National Park, Washington, USA along elevation-climatic gradients. The study sites ranged from temperate rain forest to alpine forests near tree line. Soil temperature was a significant predictor of soil respiration at all sites, and soil moisture explained additional variability at three sites (R2 from 0.42 to 0.90, P ≤ 0.01). Soil temperatures at the highest-elevation sites were 4.5°C cooler than those at the lowest elevation, but there were no relationships between soil respiration rates at a given temperature and elevation or mean annual temperature that would indicate acclimation of soil respiration to the cooler temperatures at high-elevation sites. Experimental urea additions (1.0 and 2.0 g N m-2 y-1) made at seven of the sites had no consistent effect on soil respiration. Total soil carbon dioxide (CO2) efflux during the growing season (May–September) varied from 0.34 to 0.75 kg C/m2 and was greater at low-elevation site s wit h warmer soil temperatures and longer growing seasons. Elevation and the length of the frost-free season could both be used to predict growing season (r2 = 0.53) and annual (r2 = 0.81) soil CO2 efflux for the 10 sites located in sleep mountainous terrain. Significant correlations also existed with mean annual temperature. These results suggest that warmer soils and a longer snow-free season associated with climatic warming could cause the mountainous ecosystems of the Olympic peninsula to evolve increasing amounts of CO2 from all elevations and aspects. [ABSTRACT FROM AUTHOR]

The article discusses the "Partnering with Your Park" session presented by Noah Glaude of North Olympic Library System, Danielle Lepping of North Olympic Library System and Dean Butterworth of Olympic National Park during Washington Library Association conference on November 3, 2017. Topics include partnership of the North Olympic Library with Olympic National Park, Poetry Walks, an annual spring program featuring poems on signs along National Park trails and lessons through it.