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At least 613 records · Page 34Linked to original sources

Double agents: Invasive Burmese pythons (Python bivittatus) and Argentine black and white tegus (Salvator merianae) as potential seed dispersers in south Florida

Invasive species can reshape ecological processes, including seed dispersal, through both direct and indirect pathways. In this study, we explore how invasive reptiles influence seed dispersal dynamics in the Greater Everglades ecosystem using two case studies: the Burmese python ( Python bivittatus ) and the Argentine black and white tegu ( Salvator merianae ). Guided by a conceptual framework, we investigate three primary mechanisms through which invasive species may alter seed outcomes: direct seed consumption, predation on seed dispersers before seed ingestion, and secondary seed dispersal via predation on animals that have already consumed seeds. Burmese pythons, as apex predators, may contribute to seed dispersal through diploendozoochory while simultaneously driving trophic cascades that restructure the seed disperser community. Tegus, as omnivorous frugivores, directly consume and disperse a wide diversity of plant seeds. We documented 25 seed morphotypes in python diets and 73 in tegu diets, spanning a broad 38 families and including native, endangered, and invasive plant species. Using a binary interaction network, we found that these reptiles exhibit high generalization, nestedness, and connectance—suggesting they are becoming functionally integrated into Everglades seed dispersal networks. These findings reveal that invasive reptiles not only disrupt native plant–animal interactions but may also reshape them, with implications for ecosystem stability, restoration, and management.

Florida↗

Vulnerability of gulf ribbed mussels to marsh surface maximum temperatures

Gulf ribbed mussels ( Geukensia granosissima ) act as ecosystem engineers and reside within the marsh platform of saltmarshes across the northern Gulf of Mexico. With climate models projecting increasing temperatures, and more frequent and extreme heat events, these mussels face increasing temperature-related risks. Marsh surface and subsurface (5-cm depth) temperature was measured continuously in the summer of 2022 in south Louisiana Gulf ribbed mussel habitat at nine stations. Marsh surface maximum temperatures were 5°C higher and more variable than recorded water temperatures, exceeding 38°C for periods of up to 3 h which generally coincided with low tides and peak solar radiation. Marsh subsurface temperatures were cooler with a lower mean and maximum temperature compared with the marsh surface, but higher than adjacent water. In two laboratory experiments the acclimated and acute thermal tolerance of wild mussels collected from the saltmarsh where temperatures were recorded, were explored. G. granosissima survived more than 40 days of continuous exposure in the laboratory to mean daily temperature values recorded for the marsh and subsurface microhabitats (28°C–34°C) but their calculated median lethal time (LT 50 ) ranged from 35 to 56 days (36°C), to less than 3 days (40°C). Mussels acclimated to temperatures similar to long-term average water temperatures (28°C–32°C) and then exposed to maximum daily temperatures acutely experienced LT 50 of less than 6 days (38°C), <1 day (40°C), and of less than 5 h (42°C). For G. granosissima both their thermal tolerance and behavioral response likely contribute to their survival in the face of extreme heat events, and their resulting distribution across the marsh surface and subsurface. Overall, results indicate that ribbed mussels in coastal Louisiana may rely on their ability to migrate vertically and bury in the marsh to avoid extreme heat exposure (temperature, duration) that may be lethal. The ability of Gulf ribbed mussels to endure short-term thermal extremes may ultimately determine the mussels' use as a tool in marsh stabilization and coastal restoration.

Louisiana↗

Recognition of oxidized sulfide minerals as an exploration guide for uranium

The difference in color between tan to red oxidized sandstone and gray reduced sandstone on either side of the reduction-oxidation (redox) interface, which is- the locus of uranium concentration in roll-type deposits, has been noted and used locally as an exploration guide within known uranium districts. Reduced sandstone is characterized in many deposits by the presence of iron sulflde minerals (particularly marcasite and pyrite) that occur as replacements of and overgrowths on iron-titanium oxide minerals and plant debris and as cement of detrital grains. Oxidation of the sulfldes by oxygenated ground water forms yellow to red ferric oxide and ferric hydroxide phases ("limonite") that replace the FeS 2 minerals. Processes other than the oxidation of sulfldes, however, can cause reddening of clastic sediments without the creation of a redox boundary, and so color alone is not a sufficient condition by which to judge the potential for uranium ore in frontier areas. Ferric oxides that form by the oxidation of iron sulflde minerals can be distinguished from other forms of ferric oxide by reflection microscopic examination of polished grain mounts- and polished thin sections'. Diagnostic features of oxidized sulfldes are limonite pseudomorphs of sulfldes and limonite containing internal textures that mimic characteristic textures of previously sulfldized detrital phases. Recognition of oxidized sulfides by reflection microscopy, then, can distinguish oxidized sandstones, which might have a redox boundary downdip and which would therefore be favorable hosts for uranium concentration, from those without such potential.

Journal of Research of the U.S. Geological Survey↗

Does fecundity of cisco vary in the Upper Great Lakes?

Fecundity of fish is influenced by several factors, including body length, condition, population density, and environmental conditions. It follows that fecundity of fish populations can exhibit spatiotemporal variability; thus, periodic quantification of length–fecundity relationships is important for management. We hypothesized that average fecundity of Cisco Coregonus artedi in the upper Laurentian Great Lakes would be lower in Lake Superior than in Lakes Huron and Michigan. The trophic status of these lakes recently converged, but Lakes Huron and Michigan currently support lower Cisco densities; thus, we expected that they would reach larger sizes and have greater fecundity owing to lower intraspecific competition. Ovaries were collected from prespawn Cisco during 2008–2010 to test this hypothesis. We also compared length–fecundity relationships for 2008–2010 to those of precollapse (1930s–1950s) populations to explore how relationships have changed. Average fecundity of Cisco during 2008–2010 was lower in Lake Superior compared to Lakes Huron and Michigan; length–fecundity relationships in the latter two lakes did not vary significantly, so they were combined. Body condition was highest in Lakes Huron and Michigan. We used otoliths to determine age and found that body condition was domed shaped with respect to age in Lakes Huron and Superior. There were no females older than age 5 in our samples from Lake Michigan because that population was just beginning to recover from very low levels. Females of intermediate age had the highest fecundities in both Lake Huron (ages 7–13) and Lake Superior (ages 8–18). We hypothesize that differences in body morphometry may also influence fecundity, with deeper‐bodied C. artedi albus , the predominant form in Lakes Michigan and Huron, having greater fecundity than shallower‐bodied C. artedi artedi in Lake Superior. Moreover, varying Cisco diets and seasonal movement patterns across lakes may have also contributed to differences. Females in Lakes Superior and Michigan are currently more fecund than their precollapse counterparts.

Great Lakes↗

Demographic factors affecting population growth in giant gartersnakes

Demographic models provide insight into which vital rates and life stages contribute most to population growth. Integral projection models (IPMs) offer flexibility in matching model structure to a species’ demography. For many rare species, data are lacking for key vital rates, and uncertainty might dissuade researchers from attempting to build a demographic model. We present work that highlights how the implications of uncertainties and unknowns can be explored by building and analyzing alternative models. We constructed IPMs for the threatened giant gartersnake ( Thamnophis gigas ) based on published studies to determine where management efforts could be targeted to have the greatest effect on population persistence and what unknowns remain for future research. Given uncertainty in the survival of snakes during their first year, and in the form of the size‐survival relationship, we modeled a range of scenarios and evaluated where models agree about factors influencing population growth and where discrepancies exist. For most scenarios, the survival of large adult females had the greatest influence on population growth, but the relative importance of juvenile versus adult somatic growth for population growth was dependent on the recruitment probability and the shape of the size‐survival function. More data on temporal variation and covariance among vital rates would improve stochastic models for the giant gartersnake. This paper demonstrates the effectiveness of IPMs for studying the demography of reptiles and the value of the model‐building process for formalizing what is known and unknown about the demography of rare species. Published 2019. This article is a U.S. Government work and is in the public domain in the USA.

California↗

Constraining fault constitutive behavior with slip and stress heterogeneity

We study how enforcing self-consistency in the statistical properties of the preshear and postshear stress on a fault can be used to constrain fault constitutive behavior beyond that required to produce a desired spatial and temporal evolution of slip in a single event. We explore features of rupture dynamics that (1) lead to slip heterogeneity in earthquake ruptures and (2) maintain these conditions following rupture, so that the stress field is compatible with the generation of aftershocks and facilitates heterogeneous slip in subsequent events. Our three-dimensional fmite element simulations of magnitude 7 events on a vertical, planar strike-slip fault show that the conditions that lead to slip heterogeneity remain in place after large events when the dynamic stress drop (initial shear stress) and breakdown work (fracture energy) are spatially heterogeneous. In these models the breakdown work is on the order of MJ/m2, which is comparable to the radiated energy. These conditions producing slip heterogeneity also tend to produce narrower slip pulses independent of a slip rate dependence in the fault constitutive model. An alternative mechanism for generating these confined slip pulses appears to be fault constitutive models that have a stronger rate dependence, which also makes them difficult to implement in numerical models. We hypothesize that self-consistent ruptures could also be produced by very narrow slip pulses propagating in a self-sustaining heterogeneous stress field with breakdown work comparable to fracture energy estimates of kJ/M2. Copyright 2008 by the American Geophysical Union.

Journal of Geophysical Research B: Solid Earth↗

Mineralogy and chemistry of cobbles at Meridiani Planum, Mars, investigated by the Mars Exploration Rover Opportunity

Numerous loose rocks with dimensions of a few centimeters to tens of centimeters and with no obvious physical relationship to outcrop rocks have been observed along the traverse of the Mars Exploration Rover Opportunity. To date, about a dozen of these rocks have been analyzed with Opportunity's contact instruments, providing information about elemental chemistry (Alpha Particle X‐ray Spectrometer), iron mineralogy and oxidation states (Mössbauer Spectrometer) and texture (Microscopic Imager). These “cobbles” appear to be impact related, and three distinct groups can be identified on the basis of chemistry and mineralogy. The first group comprises bright fragments of the sulfate‐rich bedrock that are compositionally and texturally indistinguishable from outcrop rocks. All other cobbles are dark and are divided into two groups, referred to as the “Barberton group” and the “Arkansas group,” after the first specimen of each that was encountered by Opportunity. Barberton group cobbles are interpreted as meteorites with an overall chemistry and mineralogy consistent with a mesosiderite silicate clast composition. Arkansas group cobbles appear to be related to Meridiani outcrop and contain an additional basaltic component. They have brecciated textures, pointing to an impact‐related origin during which local bedrock and basaltic material were mixed.

Journal of Geophysical Research E: Planets↗

Using near-real-time monitoring data from Pu'u 'Ō'ō vent at Kīlauea Volcano for training and educational purposes

Training non-scientists in the use of volcano-monitoring data is critical preparation in advance of a volcanic crisis, but it is currently unclear which methods are most effective for improving the content-knowledge of non-scientists to help bridge communications between volcano experts and non-experts. We measured knowledge gains for beginning-(introductory-level students) and novice-level learners (students with a basic understanding of geologic concepts) engaged in the Volcanoes Exploration Program: Pu&lsquo;u &lsquo;Ō&lsquo;ō (VEPP) &ldquo;Monday Morning Meeting at the Hawaiian Volcano Observatory&rdquo; classroom activity that incorporates authentic Global Positioning System (GPS), tilt, seismic, and webcam data from the Pu&lsquo;u &lsquo;Ō&lsquo;ō eruptive vent on Kīlauea Volcano, Hawai&lsquo;i (NAGT website, 2010), as a means of exploring methods for effectively advancing non-expert understanding of volcano monitoring. Learner groups consisted of students in introductory and upper-division college geology courses at two different institutions. Changes in their content knowledge and confidence in the use of data were assessed before and after the activity using multiple-choice and open-ended questions. Learning assessments demonstrated that students who took part in the exercise increased their understanding of volcano-monitoring practices and implications, with beginners reaching a novice stage, and novices reaching an advanced level (akin to students who have completed an upper-division university volcanology class). Additionally, participants gained stronger confidence in their ability to understand the data. These findings indicate that training modules like the VEPP: Monday Morning Meeting classroom activity that are designed to prepare non-experts for responding to volcanic activity and interacting with volcano scientists should introduce real monitoring data prior to proceeding with role-paying scenarios that are commonly used in such courses. The learning gains from the combined approach will help improve effective communications between volcano experts and non-experts during times of crisis, thereby reducing the potential for confusion and misinterpretation of data.

Hawaii↗

Examining the role of unusually warm Indo‐Pacific sea‐surface temperatures in recent African droughts

Southern Africa (SA) and eastern Africa (EA) experienced a sequence of severe droughts in December–February (SA DJF) 2015–2016, October–December (EA OND) 2016 and March–April–May 2017 (EA MAM). This sequence contributed to severe food insecurity. While climate variability in these regions is very complex, the goal of this study is to analyse the role played by unusually warm Indo–Pacific SSTs, where unusual is defined as a 1‐in‐6 year event. We use observed sea‐surface temperatures (SST) and satellite–gauge rainfall observations, a 20‐member ensemble of Community Atmospheric Model version 5.1 simulations (CAM5), and a 40‐member ensemble of climate change simulations from the Community Earth Systems Model version 1 (CESM1) Large Ensemble Community Project (LENS) to explore climate conditions associated with warm events identified based on eastern and western Pacific SSTs. Our analysis suggests that strong El Niño's may be followed by warm western Pacific SST conditions, which can lead to conditions conducive to successive and potentially predictable droughts in SA DJF, EA OND and EA MAM. We show that different regions of warm SST are related to recent droughts—SA DJF: Niño 3.4; EA OND: western equatorial Pacific (WEP); and EA MAM: western North Pacific (WNP). For DJF and MAM, respectively, the CAM5 model driven with observed SST and the same model driven within a climate change experiment indicate that warmer El Niño's and WNP events produce more intense atmospheric responses, potentially associated with more severe droughts. OND climate seems to be strongly influenced by the Indian Ocean Dipole, which corresponds with some WEP events. Given global warming, we suggest that the extreme Niño 3.4 and west Pacific SST events responsible for 2015–2017 droughts are likely to reoccur, thus humanitarian agencies should prepare to predict and respond to multi‐year drought and substantial food insecurity in SA and EA.

Journal of the Royal Meteorological Society↗

The landfall and inland penetration of a flood-producing atmospheric river in Arizona. Part I: observed synoptic-scale, orographic, and hydrometeorological characteristics

Atmospheric rivers (ARs) are a dominant mechanism for generating intense wintertime precipitation along the U.S. West Coast. While studies over the past 10 years have explored the impact of ARs in, and west of, California’s Sierra Nevada and the Pacific Northwest’s Cascade Mountains, their influence on the weather across the intermountain west remains an open question. This study utilizes gridded atmospheric datasets, satellite imagery, rawinsonde soundings, a 449-MHz wind profiler and global positioning system (GPS) receiver, and operational hydrometeorological observing networks to explore the dynamics and inland impacts of a landfalling, flood-producing AR across Arizona in January 2010. Plan-view, cross-section, and back-trajectory analyses quantify the synoptic and mesoscale forcing that led to widespread precipitation across the state. The analyses show that a strong AR formed in the lower midlatitudes over the northeastern Pacific Ocean via frontogenetic processes and sea surface latent-heat fluxes but without tapping into the adjacent tropical water vapor reservoir to the south. The wind profiler, GPS, and rawinsonde observations document strong orographic forcing in a moist neutral environment within the AR that led to extreme, orographically enhanced precipitation. The AR was oriented nearly orthogonal to the Mogollon Rim, a major escarpment crossing much of central Arizona, and was positioned between the high mountain ranges of northern Mexico. High melting levels during the heaviest precipitation contributed to region-wide flooding, while the high-altitude snowpack increased substantially. The characteristics of the AR that impacted Arizona in January 2010, and the resulting heavy orographic precipitation, are comparable to those of landfalling ARs and their impacts along the west coasts of midlatitude continents.

Arizona↗

A decade of induced slip on the causative fault of the 2015 Mw 4.0 Venus earthquake, northeast Johnson County, Texas

On 7 May 2015, a M w 4.0 earthquake occurred near Venus, northeast Johnson County, Texas, in an area of the Bend Arch-Fort Worth Basin that reports long-term, high-volume wastewater disposal and that has hosted felt earthquakes since 2009. In the weeks following the M w 4.0 earthquake, we deployed a local seismic network and purchased nearby active-source seismic reflection data to capture additional events, characterize the causative fault, and explore potential links between ongoing industry activity and seismicity. Hypocenter relocations of the resulting local earthquake catalog span ~4–6 km depth and indicate a fault striking ~230 ° , dipping to the west, consistent with a nodal plane of the M w 4.0 regional moment tensor. Fault plane solutions indicate normal faulting, with B axes striking parallel to maximum horizontal compressive stress. Seismic reflection data image the reactivated basement fault penetrating the Ordovician disposal layer and Mississippian production layer, but not displacing post-Lower Pennsylvanian units. Template matching at regional seismic stations indicates that low-magnitude earthquakes with similar waveforms began in April 2008, with increasing magnitude over time. Pressure data from five saltwater disposal wells within 5 km of the active fault indicate a disposal formation that is 0.9–4.8 MPa above hydrostatic. We suggest that the injection of 28,000,000 m 3 of wastewater between 2006 and 2015 at these wells led to an increase in subsurface pore fluid pressure that contributed to inducing this long-lived earthquake sequence. The 2015 M w 4.0 event represents the largest event in the continuing evolution of slip on the causative fault.

Texas↗

Setting and tracking suppression targets for sea lampreys in the Great Lakes

In response to invasive species, the course of action taken by management agencies often evolves over a range of options from a do-nothing approach to suppression to complete eradication. As a case study of suppression targets, we explore the history of approaches used by the Great Lakes Fishery Commission in response to the invasion of the Laurentian Great Lakes by sea lampreys ( Petromyzon marinus ). With the early realization that eradication was not possible using available techniques, focus shifted to suppression of sea lampreys to support fish community objectives for the lakes. As a surrogate for damage to the fishery, a suppression target was defined for the maximum acceptable marking rate, indicated by the average number of sea lamprey wounds observed on every 100 large lake trout ( Salvelinus namaycush ) surveyed. Historic marking rates were used to delineate time periods of acceptable sea lamprey predation levels as an approximate measure of sea lamprey-induced mortality. A second target, independent of lake trout population status, was based on the average sea lamprey abundance estimated during the specified time periods. These intuitive targets have served as suppression benchmarks for the Sea Lamprey Control Program in the Great Lakes, allowing decision makers to gauge progress towards targets, refine control strategies and prioritize geographic areas for increased control effort. Here we document the development and subsequent changes to targets, summarize the methods used to implement these changes, and provide considerations for the future.

Great Lakes↗

A statistical framework to track temporal dependence of chlorophyll–nutrient relationships with implications for lake eutrophication management

A reliable chlorophyll–nutrient relationship (CNR) is essential for lake eutrophication management. Although the spatial variability of CNRs has been extensively explored, temporal variations of CNRs at the individual lake scale has rarely been discussed. The paucity of information about temporal dependence in CNRs may in part be due to the lack of a suitable statistical framework that helps guide such investigations. In order to reveal temporal dependence of CNR, this study develop a novel statistical framework. In the framework, we employ quantile regression to generate overall (the entire dataset), annual (subsets for each year), and accumulative (subsets collected before a certain year) CNRs. We aim to 1) show biases of annual relationships by comparing the overall and annual relationships and 2) determine whether or not data accumulation is enough to develop a reliable CNR. We use Lake Champlain and Lake Kasumigaura as case studies to illustrate the necessary steps needed to utilize this novel framework. Results show that large interannual variations exist for CNRs. Accumulative relationships tend to converge to the overall relationship, indicating that overall relationships are reliable for informing lake-specific eutrophication management in the two case study lakes. The novel statistical framework that we propose for a procedure to estimate reliable CNRs is important for informing lake-specific eutrophication control decision-making processes.

Ibaraki Prefecture, Lake Champlain, Lake Kasumigau↗

A statistical framework to track temporal dependence of chlorophyll–nutrient relationships with implications for lake eutrophication management

A reliable chlorophyll–nutrient relationship (CNR) is essential for lake eutrophication management. Although the spatial variability of CNRs has been extensively explored, temporal variations of CNRs at the individual lake scale has rarely been discussed. The paucity of information about temporal dependence in CNRs may in part be due to the lack of a suitable statistical framework that helps guide such investigations. In order to reveal temporal dependence of CNR, this study develop a novel statistical framework. In the framework, we employ quantile regression to generate overall (the entire dataset), annual (subsets for each year), and accumulative (subsets collected before a certain year) CNRs. We aim to 1) show biases of annual relationships by comparing the overall and annual relationships and 2) determine whether or not data accumulation is enough to develop a reliable CNR. We use Lake Champlain and Lake Kasumigaura as case studies to illustrate the necessary steps needed to utilize this novel framework. Results show that large interannual variations exist for CNRs. Accumulative relationships tend to converge to the overall relationship, indicating that overall relationships are reliable for informing lake-specific eutrophication management in the two case study lakes. The novel statistical framework that we propose for a procedure to estimate reliable CNRs is important for informing lake-specific eutrophication control decision-making processes.

Journal of Hydrology↗

Landscape-scale processes influence riparian plant composition along a regulated river

Hierarchical frameworks are useful constructs when exploring landscape- and local-scale factors affecting patterns of vegetation in riparian areas. In drylands, which have steep environmental gradients and high habitat heterogeneity, landscape-scale variables, such as climate, can change rapidly along a river's course, affecting the relative influence of environmental variables at different scales. To assess how landscape-scale factors change the structure of riparian vegetation, we measured riparian vegetation composition along the Colorado River through Grand Canyon, determined which factors best explain observed changes, identified how richness and functional diversity vary, and described the implications of our results for river management. Cluster analysis identified three divergent floristic groups that are distributed longitudinally along the river. These groups were distributed along gradients of elevation, temperature and seasonal precipitation, but were not associated with annual precipitation or local-scale factors. Species richness and functional diversity decreased as a function of distance downstream showing that changing landscape-scale factors result in changes to ecosystem characteristics. Species composition and distribution remain closely linked to seasonal precipitation and temperature. These patterns in floristic composition in a semiarid system inform management and provide insights into potential future changes as a result of shifts in climate and changes in flow management.

Arizona↗

Geodetic constraints on a 25-year magmatic inflation episode near Three Sisters, central Oregon

Crustal inflation near the Three Sisters volcanic center documented since the mid-1990s has persisted for more than two decades. We update past analyses of the event through 2020 by simultaneously inverting InSAR interferograms, GPS time series, and leveling data for time-dependent volcanic deformation source parameters. We explore several source models to estimate how the deformation rate varied through time and to identify parameters that can reproduce measured deformation. Our preferred model is a Mogi source 4.1 km below sea level (5.9 km below the surface) about 5 km west of the summit of South Sister. Inflation started in late 1995 or 1996; the rate increased rapidly during 1998–1999, and peaked in late 1999, resulting in maximum surface uplift of about 30 cm by mid-2020. Since 2000, the inflation rate generally declined exponentially with a time constant of about 6 years. Two source inflation scenarios fit the data equally well. In the first, the crust surrounding the source is elastic and the net source-volume increase, which we attribute to persistent magma input, has been about 49 × 10 6 m 3 . The second scenario adds a viscoelastic shell surrounding the Mogi source. In that case, an injection of about 21 × 10 6 m 3 of magma prior to 2000, followed by continuing relaxation of the viscoelastic shell, can account for most of the observed surface deformation. In both scenarios, modeling reveals quasiperiodic increases in the inflation rate (pulses) with a recurrence interval of 3–4 years, both before and after 2000.

Oregon↗

Exploring the exploitation of migratory moths by radio-marked grizzly bears in Wyoming

Grizzly bear ( Ursus arctos ) feeding on migratory army cutworm moths ( Euxoa auxiliaris ) was first documented by the Interagency Grizzly Bear Study Team (IGBST) during the early 1980s in the southeastern portion of the Greater Yellowstone Ecosystem (GYE). Since those initial observations, use of this seasonally available food resource by grizzly bears has grown substantially. As of 2023, we have documented 4,754 observations of grizzly bears feeding or digging at high-elevation talus slopes. We used those records to identify 36 unique moth sites in the GYE, assessed geographic characteristics of these sites, and documented chronology and frequency of use by grizzly bears. We used occurrences of radio-collared grizzly bears to identify a sample of bears that foraged at moth sites and investigated characteristics of fidelity, duration, diel activity, and movement patterns. Grizzly bears exhibited high fidelity to specific moth sites within and across years. Bears showed approximately 50% reductions in movement metrics while using sites, albeit with increased activity patterns. Estimates of feeding metrics by females exceeded those of males in intensity and duration of both use and daily activity. Given increasing human impacts and interest in observing this feeding interaction, quantifying metrics that describe the spatial and temporal patterns of moth site use by grizzly bears could be beneficial for future management. Further analyses are needed to fully examine the relationship between caloric influences of moth use on grizzly bear demographic rates.

Idaho, Montana, Wyoming↗

Diversification of forest management can mitigate wind damage risk and maintain biodiversity

Mitigating future forest risks, safeguarding timber revenues and improving biodiversity are key considerations for current boreal forest management. Alternatives to rotation forestry likely have an important role, but how they will perform under a changing climate remains unclear. We used a boreal forest growth simulator to explore how variations on traditional clear-cutting, in rotation length, thinning intensity, and increasing number of remaining trees after final harvest (green tree retention), and on extent of continuous cover forestry will affect stand-level probability of wind damage, timber production, deadwood volume, and habitats for forest species. We used business-as-usual rotation forestry as a baseline and compared alternative management adaptations under the reference and two climate change scenarios. Climate change increased overall timber production and had lower impacts on biodiversity compared to management adaptations. Shortening the rotation length reduced the probability of wind damage compared to business-as-usual, but also decreased both deadwood volume and suitable habitats for our focal species. Continuous cover forestry, and management with refraining from thinnings, and extension of rotation length represent complementary approaches benefiting biodiversity, with respective effects of improving timber revenues, reducing wind damage risk, and benefiting old-growth forest structures. However, extensive application of rotation length shortening to mitigate wind damage risk may be detrimental for forest biodiversity. To safeguard forest biodiversity over the landscape, shortening of the rotation length could be complemented with widespread application of regimes promoting old-growth forest structures.

European Journal of Forest Research↗