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  • 1
    In: Ecosphere, Wiley, Vol. 13, No. 6 ( 2022-06)
    Abstract: Wildfires devastated communities in Oregon and Washington in September 2020, burning almost as much forest west of the Cascade Mountain crest (“the westside”) in 2 weeks (~340,000 ha) as in the previous five decades (~406,00 ha). Unlike dry forests of the interior western United States, temperate rain forests of the Pacific Northwest have experienced limited recent fire activity, and debates surrounding what drove the 2020 fires, and management strategies to adapt to similar future events, necessitate a scientific evaluation of the fires. We evaluate five questions regarding the 2020 Labor Day fires: (1) How do the 2020 fires compare with historical fires? (2) How did the roles of weather and antecedent climate differ geographically and from the recent past (1979–2019)? (3) How do fire size and severity compare to other recent fires (1985–2019), and how did forest management and prefire forest structure influence burn severity? (4) What impact will these fires have on westside landscapes? and (5) How can we adapt to similar fires in the future? Although 5 of the 2020 fires were much larger than any others in the recent past and burned ~10 times the area in high‐severity patches 〉 10,000 ha, the 2020 fires were remarkably consistent with historical fires. Reports from the early 1900s, along with paleo‐ and dendro‐ecological records, indicate similar and potentially even larger wildfires over the past millennium, many of which shared similar seasonality (late August/early September), weather conditions, and even geographic locations. Consistent with the largest historical fires, strong east winds and anomalously dry conditions drove the rapid spread of high‐severity wildfire in 2020. We found minimal difference in burn severity among stand structural types related to previous management in the 2020 fires. Adaptation strategies for similar fires in the future could benefit by focusing on ignition prevention, fire suppression, and community preparedness, as opposed to fuel treatments that are unlikely to mitigate fire severity during extreme weather. While scientific uncertainties remain regarding the nature of infrequent, high‐severity fires in westside forests, particularly under climate change, adapting to their future occurrence will require different strategies than those in interior, dry forests.
    Type of Medium: Online Resource
    ISSN: 2150-8925 , 2150-8925
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2022
    detail.hit.zdb_id: 2572257-8
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  • 2
    In: Ecosphere, Wiley, Vol. 11, No. 12 ( 2020-12)
    Type of Medium: Online Resource
    ISSN: 2150-8925 , 2150-8925
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2020
    detail.hit.zdb_id: 2572257-8
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  • 3
    In: Ecological Applications, Wiley, Vol. 33, No. 1 ( 2023-01)
    Abstract: We conducted a range‐wide investigation of the dynamics of site‐level reproductive rate of northern spotted owls using survey data from 11 study areas across the subspecies geographic range collected during 1993–2018. Our analytical approach accounted for imperfect detection of owl pairs and misclassification of successful reproduction (i.e., at least one young fledged) and contributed further insights into northern spotted owl population ecology and dynamics. Both nondetection and state misclassification were important, especially because factors affecting these sources of error also affected focal ecological parameters. Annual probabilities of site occupancy were greatest at sites with successful reproduction in the previous year and lowest for sites not occupied by a pair in the previous year. Site‐specific occupancy transition probabilities declined over time and were negatively affected by barred owl presence. Overall, the site‐specific probability of successful reproduction showed substantial year‐to‐year fluctuations and was similar for occupied sites that did or did not experience successful reproduction the previous year. Site‐specific probabilities for successful reproduction were very small for sites that were unoccupied the previous year. Barred owl presence negatively affected the probability of successful reproduction by northern spotted owls in Washington and California, as predicted, but the effect in Oregon was mixed. The proportions of sites occupied by northern spotted owl pairs showed steep, near‐monotonic declines over the study period, with all study areas showing the lowest observed levels of occupancy to date. If trends continue it is likely that northern spotted owls will become extirpated throughout large portions of their range in the coming decades.
    Type of Medium: Online Resource
    ISSN: 1051-0761 , 1939-5582
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2023
    detail.hit.zdb_id: 2010123-5
    SSG: 12
    SSG: 23
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  • 4
    In: Ecosphere, Wiley, Vol. 10, No. 4 ( 2019-04)
    Abstract: The frequency, extent, and severity of wildfire strongly influence the structure and function of ecosystems. Mixed‐severity fire regimes are the most complex and least understood fire regimes, and variability of fire severity can occur at fine spatial and temporal scales, depending on previous disturbance history, topography, fuel continuity, vegetation type, and weather. During high fire weather in 2013, a complex of mixed‐severity wildfires burned across multiple ownerships within the Klamath‐Siskiyou ecoregion of southwestern Oregon where northern spotted owl ( Strix occidentalis caurina ) demographics were studied since 1990. A year prior to these wildfires, high‐resolution, remotely sensed forest structural information derived from light detection and ranging (lidar) data was acquired for an area that fully covered the extent of these fires. To quantify wildfire impact on northern spotted owl nesting/roosting habitat, we fit a relative habitat suitability model based on pre‐fire locations used for nesting and roosting, and forest structure variables developed from 2012 lidar data. Our pre‐fire habitat suitability model predicted nesting/roosting locations well, and variable response functions followed known resource selection patterns. These forests had typical characteristics of old‐growth forest, with high density of large live trees, high canopy cover, and complex structure in canopy height. We projected the pre‐fire model onto lidar data collected two months post‐fire to produce a post‐fire suitability map, which indicated that 〉 93% of pre‐fire habitat that burned at high severity was no longer suitable forest for nesting and roosting. We also quantified the probability that pre‐fire nesting/roosting habitat would burn at each severity class (unburned/low, low, moderate, high). Pre‐fire nesting/roosting habitat had lower probability of burning at moderate or high severity compared to other forest types under high burning conditions. Our results indicate that northern spotted owl habitat can buffer the negative effects of climate change by enhancing biodiversity and resistance to high‐severity fires, which are predicted to increase in frequency and extent with climate change. Within this region, protecting large blocks of old forests could be an integral component of management plans that successfully maintain variability of forests in this mixed‐ownership and mixed‐severity fire regime landscape and enhance conservation of many species.
    Type of Medium: Online Resource
    ISSN: 2150-8925 , 2150-8925
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2019
    detail.hit.zdb_id: 2572257-8
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  • 5
    In: Ecological Applications, Wiley, Vol. 29, No. 3 ( 2019-04)
    Abstract: Slow ecological processes challenge conservation. Short‐term variability can obscure the importance of slower processes that may ultimately determine the state of a system. Furthermore, management actions with slow responses can be hard to justify. One response to slow processes is to explicitly concentrate analysis on state dynamics. Here, we focus on identifying drivers of Northern Spotted Owl ( Strix occidentalis caurina ) territorial occupancy dynamics across 11 study areas spanning their geographic range and forecasting response to potential management actions. Competition with Barred Owls ( Strix varia ) has increased Spotted Owl territory extinction probabilities across all study areas and driven recent declines in Spotted Owl populations. Without management intervention, the Northern Spotted Owl subspecies will be extirpated from parts of its current range within decades. In the short term, Barred Owl removal can be effective. Over longer time spans, however, maintaining or improving habitat conditions can help promote the persistence of northern spotted owl populations. In most study areas, habitat effects on expected Northern Spotted Owl territorial occupancy are actually greater than the effects of competition from Barred Owls. This study suggests how intensive management actions (removal of a competitor) with rapid results can complement a slower management action (i.e., promoting forest succession).
    Type of Medium: Online Resource
    ISSN: 1051-0761 , 1939-5582
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2019
    detail.hit.zdb_id: 2010123-5
    SSG: 12
    SSG: 23
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  • 6
    In: Ecology, Wiley, Vol. 98, No. 6 ( 2017-06), p. 1640-1650
    Abstract: There is increasing need for methods that integrate multiple data types into a single analytical framework as the spatial and temporal scale of ecological research expands. Current work on this topic primarily focuses on combining capture–recapture data from marked individuals with other data types into integrated population models. Yet, studies of species distributions and trends often rely on data from unmarked individuals across broad scales where local abundance and environmental variables may vary. We present a modeling framework for integrating detection–nondetection and count data into a single analysis to estimate population dynamics, abundance, and individual detection probabilities during sampling. Our dynamic population model assumes that site‐specific abundance can change over time according to survival of individuals and gains through reproduction and immigration. The observation process for each data type is modeled by assuming that every individual present at a site has an equal probability of being detected during sampling processes. We examine our modeling approach through a series of simulations illustrating the relative value of count vs. detection–nondetection data under a variety of parameter values and survey configurations. We also provide an empirical example of the model by combining long‐term detection–nondetection data (1995–2014) with newly collected count data (2015–2016) from a growing population of Barred Owl ( Strix varia ) in the Pacific Northwest to examine the factors influencing population abundance over time. Our model provides a foundation for incorporating unmarked data within a single framework, even in cases where sampling processes yield different detection probabilities. This approach will be useful for survey design and to researchers interested in incorporating historical or citizen science data into analyses focused on understanding how demographic rates drive population abundance.
    Type of Medium: Online Resource
    ISSN: 0012-9658 , 1939-9170
    URL: Issue
    RVK:
    Language: English
    Publisher: Wiley
    Publication Date: 2017
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    detail.hit.zdb_id: 2010140-5
    SSG: 12
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  • 7
    In: Physiological Reports, Wiley, Vol. 3, No. 5 ( 2015-05), p. e12386-
    Type of Medium: Online Resource
    ISSN: 2051-817X
    Language: English
    Publisher: Wiley
    Publication Date: 2015
    detail.hit.zdb_id: 2724325-4
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  • 8
    In: Ecosphere, Wiley, Vol. 14, No. 2 ( 2023-02)
    Abstract: Managing forests for biodiversity conservation while maintaining economic output is a major challenge globally and requires accurate and timely monitoring of imperiled species. In the Pacific Northwest, USA, forest management is heavily influenced by the status of northern spotted owls ( Strix occidentalis caurina ), which have been in continued population decline for the past four decades. The monitoring program for northern spotted owls is transitioning from mark–resight surveys to a passive acoustic framework, requiring development of alternative analysis approaches. To maintain relevance for conservation and management, these analyses must accurately track underlying population changes, identify responses to disturbance, and estimate occupancy of owl pairs. We randomly selected and surveyed 5‐km 2 hexagons for 6 weeks using passive acoustic monitoring in the Olympic Peninsula of Washington and the Oregon Coast Range during the 2018 spotted owl breeding season. We used a convolutional neural network to identify spotted owl calls, followed by logistic regression to determine the sex of vocalizing owls to assign pair status. We implemented multistate occupancy models to estimate probabilities of detection, species‐level landscape use, and pair occupancy of spotted owls. We also quantified detections of barred owls ( Strix varia ), a congeneric competitor and important driver of spotted owl population declines. The overall rate of hexagon use by spotted owls was estimated at 0.21 (SD 0.04) after adjusting for imperfect detection, and pair occupancy was 0.07 (SD 0.02). The probability of detecting a pair (i.e., both female and male) during a weekly occasion was relatively low (0.03, SD 0.01), indicating that true pair occupancy was between 1.3 and 4.1 times greater than the proportion of hexagons with observed pair detections. Barred owls were ubiquitous, with a naïve occupancy rate of 0.97. The intensity of calling by barred owls had a weak, negative effect on the probability of spotted owls being paired when present but had little measurable effect on their detectability. This work establishes a framework that may be effective for spotted owl population monitoring and illustrates that pairs have very low detection probability, which—combined with increasingly low numbers of spotted owl pairs—is an important consideration for conservation and management.
    Type of Medium: Online Resource
    ISSN: 2150-8925 , 2150-8925
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2023
    detail.hit.zdb_id: 2572257-8
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  • 9
    In: Ecosphere, Wiley, Vol. 7, No. 12 ( 2016-12)
    Abstract: Environmental regulations often require wildlife surveys prior to habitat disturbance to avoid impacts or as the basis for planning mitigation, yet project‐level surveys may not provide the insights needed to guide long‐term management. Management of the red tree vole ( Arborimus longicaudus ) has largely been based on such surveys. As an alternative approach, we evaluated distribution patterns using frequency of red tree vole occurrence and habitat suitability models to guide conservation planning. We developed a suite of models based on subsets of covariates from two previously developed models and evaluated the extent to which spatial covariates improved the models. We used presence–absence data that were collected from 364 randomly selected 1‐ha Current Vegetation Survey and Forest Inventory and Analysis plots to develop models and describe occurrence patterns. The best models included a spatial covariate, maximum tree diameter, distance from suitable habitat, forest age class, and the interaction between maximum tree diameter and forest age class. We compared performance of the previously published models, our best model, and an ensemble model that used predictions from all three models. Under the ensemble model, correct classification rates were relatively high and considerably improved, suggesting that the application of all three models provided greater accuracy than any individual model. We argue that habitat models, coupled with spatial patterns of the frequency of occurrence, can provide useful tools for addressing species management and may provide more insight than project‐level surveys. The use of habitat suitability models can therefore be closely tied to red tree vole management decisions and conservation strategies, as well as reducing survey costs that otherwise often make projects infeasible.
    Type of Medium: Online Resource
    ISSN: 2150-8925 , 2150-8925
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2016
    detail.hit.zdb_id: 2572257-8
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  • 10
    Online Resource
    Online Resource
    Wiley ; 1986
    In:  Annals of the New York Academy of Sciences Vol. 478, No. 1 ( 1986-10), p. 131-146
    In: Annals of the New York Academy of Sciences, Wiley, Vol. 478, No. 1 ( 1986-10), p. 131-146
    Type of Medium: Online Resource
    ISSN: 0077-8923 , 1749-6632
    URL: Issue
    RVK:
    Language: English
    Publisher: Wiley
    Publication Date: 1986
    detail.hit.zdb_id: 2834079-6
    detail.hit.zdb_id: 211003-9
    detail.hit.zdb_id: 2071584-5
    SSG: 11
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