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Leslie A. Jones

Publications and source records attributed to Leslie A. Jones.

11 recordsLinked to original sources

Projected warming portends seasonal shifts of stream temperatures in the Crown of the Continent Ecosystem, USA and Canada

Climate warming is expected to increase stream temperatures in mountainous regions of western North America, yet the degree to which future climate change may influence seasonal patterns of stream temperature is uncertain. In this study, a spatially explicit statistical model framework was integrated with empirical stream temperature data (approximately four million bi-hourly recordings) and high-resolution climate and land surface data to estimate monthly stream temperatures and potential change under future climate scenarios in the Crown of the Continent Ecosystem, USA and Canada (72,000 km2). Moderate and extreme warming scenarios forecast increasing stream temperatures during spring, summer, and fall, with the largest increases predicted during summer (July, August, and September). Additionally, thermal regimes characteristic of current August temperatures, the warmest month of the year, may be exceeded during July and September, suggesting an earlier and extended duration of warm summer stream temperatures. Models estimate that the largest magnitude of temperature warming relative to current conditions may be observed during the shoulder months of winter (April and November). Summer stream temperature warming is likely to be most pronounced in glacial-fed streams where models predict the largest magnitude (> 50%) of change due to the loss of alpine glaciers. We provide the first broad-scale analysis of seasonal climate effects on spatiotemporal patterns of stream temperature in the Crown of the Continent Ecosystem for better understanding climate change impacts on freshwater habitats and guiding conservation and climate adaptation strategies.

Climatic Change

Temperature

Stream temperature has direct and indirect effects on stream ecology and is critical in determining both abiotic and biotic system responses across a hierarchy of spatial and temporal scales. Temperature variation is primarily driven by solar radiation, while landscape topography, geology, and stream reach scale ecosystem processes contribute to local variability. Spatiotemporal heterogeneity in freshwater ecosystems influences habitat distributions, physiological functions, and phenology of all aquatic organisms. In this chapter we provide an overview of methods for monitoring stream temperature, characterization of thermal profiles, and modeling approaches to stream temperature prediction. Recent advances in temperature monitoring allow for more comprehensive studies of the underlying processes influencing annual variation of temperatures and how thermal variability may impact aquatic organisms at individual, population, and community based scales. Likewise, the development of spatially explicit predictive models provide a framework for simulating natural and anthropogenic effects on thermal regimes which is integral for sustainable management of freshwater systems.

Book chapter

Climate-induced glacier and snow loss imperils alpine stream insects

Climate warming is causing rapid loss of glaciers and snowpack in mountainous regions worldwide. These changes are predicted to negatively impact the habitats of many range-restricted species, particularly endemic, mountaintop species dependent on the unique thermal and hydrologic conditions found only in glacier-fed and snowmelt-driven alpine streams. Though progress has been made, existing understanding of the status, distribution, and ecology of alpine aquatic species, particularly in North America, is lacking, thereby hindering conservation and management programs. Two aquatic insects – the meltwater stonefly Lednia tumana and the glacier stonefly Zapada glacier – were recently proposed for listing under the U.S. Endangered Species Act due to climate-change-induced habitat loss. Using a large dataset (272 streams, 482 total sites) with high-resolution climate and habitat information, we describe the distribution, status, and key environmental features that limit L. tumana and Z. glacier across the northern Rocky Mountains. Lednia tumana was detected in 113 streams (175 sites) within Glacier National Park (GNP) and surrounding areas. The probability of L. tumana occurrence increased with cold stream temperatures and close proximity to glaciers and permanent snowfields. Similarly, densities of L. tumana declined with increasing distance from stream source. Zapada glacier was only detected in 10 streams (20 sites), six in GNP and four in mountain ranges up to ~600 km southwest. Our results show that both L. tumana and Z. glacier inhabit an extremely narrow distribution, restricted to short sections of cold, alpine streams often below glaciers predicted to disappear over the next two decades. Climate warming-induced glacier and snow loss clearly imperils the persistence of L. tumana and Z. glacier throughout their ranges, highlighting the role of mountaintop aquatic invertebrates as sentinels of climate change in mid-latitude regions.

Global Change Biology

Long term changes in trout numbers following channel reconstruction, instream wood placement, and livestock removal from a spring creek in the Blackfoot Basin, Montana

To restore habitat for wild trout, Kleinschmidt Creek, a low-gradient, groundwater-dominated stream in the Blackfoot Basin, Montana, was reconstructed using natural channel design principles. Reconstruction increased stream sinuosity from a ratio of 1.1 to 1.6, decreased mean channel width from 14.5 to 2.8 m, and increased sediment transport capacity to reduce accumulations of fine instream sediment. To further improve trout habitat, coarse woody debris (CWD) was variably placed within the new channel and livestock were excluded to promote the vegetative recovery of the riparian area. To evaluate the response of wild trout (92% Brown Trout Salmo trutta ) to channel restoration, the abundance (number of trout per linear meter) and biomass (g/linear m) of age 1+ trout were monitored for 15 years (1998–2012) in a reach with low density CWD (1.3 stems/100 m) and compared with regional (reference) trends. Posttreatment (2002–2012) trout numbers in the low-density CWD reach were also compared with those in a reach with high-density CWD (18.2 stems/100 m). Long-term trends for the reference reaches showed a significant negative trend in trout abundance and no significant trend for biomass. Long-term trends for the low-density CWD reach showed a significant positive trend in abundance, as well as a significant trend in biomass. Trout abundance and biomass increased over the posttreatment period in the low-density CWD reach. However, in the high density CWD reach, while posttreatment abundance increased significantly, there was no significant trend in biomass. These results demonstrated that channel restoration increased wild trout populations in a deep, narrow, vegetated stream and that instream wood provided primarily short-term benefits during the early phase of habitat recovery.

Montana

Climate-induced range contraction of a rare alpine aquatic invertebrate

Climate warming poses a serious threat to alpine-restricted species worldwide, yet few studies have empirically documented climate-induced changes in distributions. The rare stonefly, Zapada glacier (Baumann and Gaufin), endemic to alpine streams of Glacier National Park (GNP), Montana, was recently petitioned for listing under the US Endangered Species Act because of climate-change-induced glacier loss, yet little was known about its current status and distribution. We resampled streams throughout the historical distribution of Z. glacier to investigate trends in occurrence associated with changes in temperature and glacial extent. The current geographic distribution of the species was assessed using morphological characteristics of adults and DNA barcoding of nymphs. Bayesian phylogenetic analysis of mtDNA data revealed 8 distinct clades of the genus corresponding with 7 known species from GNP, and one potentially cryptic species. Climate model simulations indicate that average summer air temperature increased (0.67–1.00°C) during the study period (1960–2012), and glacial surface area decreased by ∼35% from 1966 to 2005. We detected Z. glacier in only 1 of the 6 historically occupied streams and at 2 new locations in GNP. These results suggest that an extremely restricted historical distribution of Z. glacier in GNP has been further reduced over the past several decades by an upstream retreat to higher, cooler sites as water temperatures increased and glacial masses decreased. More research is urgently needed to determine the status, distribution, and vulnerability of Z. glacier and other alpine stream invertebrates threatened by climate change in mountainous ecosystems.

Montana

Instream habitat restoration and stream temperature reduction in a whirling disease-positive Spring Creek in the Blackfoot River Basin, Montana

Anthropogenic warming of stream temperature and the presence of exotic diseases such as whirling disease are both contemporary threats to coldwater salmonids across western North America. We examined stream temperature reduction over a 15-year prerestoration and postrestoration period and the severity of Myxobolus cerebralis infection (agent of whirling disease) over a 7-year prerestoration and postrestoration period in Kleinschmidt Creek, a fully reconstructed spring creek in the Blackfoot River basin of western Montana. Stream restoration increased channel length by 36% and reduced the wetted surface area by 69% by narrowing and renaturalizing the channel. Following channel restoration, average maximum daily summer stream temperatures decreased from 15.7°C to 12.5°C, average daily temperature decreased from 11.2°C to 10.0°C, and the range of daily temperatures narrowed by 3.3°C. Despite large changes in channel morphology and reductions in summer stream temperature, the prevalence and severity of M. cerebralis infection for hatchery Rainbow Trout Oncorhynchus mykiss remained high (98–100% test fish with grade > 3 infection) versus minimal for hatchery Brown Trout Salmo trutta (2% of test fish with grade-1 infection). This study shows channel renaturalization can reduce summer stream temperatures in small low-elevation, groundwater-dominated streams in the Blackfoot basin to levels more suitable to native trout. However, because of continuous high infections associated with groundwater-dominated systems , the restoration of Kleinschmidt Creek favors brown trout Salmo trutta given their innate resistance to the parasite and the higher relative susceptibility of other salmonids.

Montana

Invasive hybridization in a threatened species is accelerated by climate change

Climate change will decrease worldwide biodiversity through a number of potential pathways 1 , including invasive hybridization 2 (cross-breeding between invasive and native species). How climate warming influences the spread of hybridization and loss of native genomes poses difficult ecological and evolutionary questions with little empirical information to guide conservation management decisions 3 . Here we combine long-term genetic monitoring data with high-resolution climate and stream temperature predictions to evaluate how recent climate warming has influenced the spatio-temporal spread of human-mediated hybridization between threatened native westslope cutthroat trout ( Oncorhynchus clarkii lewisi ) and non-native rainbow trout ( Oncorhynchus mykiss ), the world’s most widely introduced invasive fish 4 . Despite widespread release of millions of rainbow trout over the past century within the Flathead River system 5 , a large relatively pristine watershed in western North America, historical samples revealed that hybridization was prevalent only in one (source) population. During a subsequent 30-year period of accelerated warming, hybridization spread rapidly and was strongly linked to interactions between climatic drivers—precipitation and temperature—and distance to the source population. Specifically, decreases in spring precipitation and increases in summer stream temperature probably promoted upstream expansion of hybridization throughout the system. This study shows that rapid climate warming can exacerbate interactions between native and non-native species through invasive hybridization, which could spell genomic extinction for many species.

Alberta, Idaho, Montana

Quantifying the effectiveness of conservation measures to control the spread of anthropogenic hybridization in stream salmonids: A climate adaptation case study

Quantifying the effectiveness of management actions to mitigate the effects of changing climatic conditions (i.e., climate adaptation) can be difficult, yet critical for conservation. We used population genetic data from 1984 to 2011 to assess the degree to which ambient climatic conditions and targeted suppression of sources of nonnative Rainbow Trout Oncorhynchus mykiss have influenced the spread of introgressive hybridization in native populations of Westslope Cutthroat Trout O. clarkii lewisi . We found rapid expansion in the spatial distribution and proportion of nonnative genetic admixture in hybridized populations from 1984 to 2004, but minimal change since 2004. The spread of hybridization was negatively correlated with the number of streamflow events in May that exceeded the 75th percentile of historic flows ( r = −0.98) and positively correlated with August stream temperatures ( r = 0.89). Concomitantly, suppression data showed a 60% decline in catch per unit effort for fish with a high proportion of Rainbow Trout admixture, rendering some uncertainty as to the relative strength of factors controlling the spread of hybridization. Our results illustrate the importance of initiating management actions to mitigate the potential effects of climate change, even where data describing the effectiveness of such actions are initially limited but the risks are severe.

Montana

Estimating thermal regimes of bull trout and assessing the potential effects of climate warming on critical habitats

Understanding the vulnerability of aquatic species and habitats under climate change is critical for conservation and management of freshwater systems. Climate warming is predicted to increase water temperatures in freshwater ecosystems worldwide, yet few studies have developed spatially explicit modelling tools for understanding the potential impacts. We parameterized a nonspatial model, a spatial flow-routed model, and a spatial hierarchical model to predict August stream temperatures (22-m resolution) throughout the Flathead River Basin, USA and Canada. Model comparisons showed that the spatial models performed significantly better than the nonspatial model, explaining the spatial autocorrelation found between sites. The spatial hierarchical model explained 82% of the variation in summer mean (August) stream temperatures and was used to estimate thermal regimes for threatened bull trout (Salvelinus confluentus) habitats, one of the most thermally sensitive coldwater species in western North America. The model estimated summer thermal regimes of spawning and rearing habitats at <13 C&deg; and foraging, migrating, and overwintering habitats at <14 C&deg;. To illustrate the useful application of such a model, we simulated climate warming scenarios to quantify potential loss of critical habitats under forecasted climatic conditions. As air and water temperatures continue to increase, our model simulations show that lower portions of the Flathead River Basin drainage (foraging, migrating, and overwintering habitat) may become thermally unsuitable and headwater streams (spawning and rearing) may become isolated because of increasing thermal fragmentation during summer. Model results can be used to focus conservation and management efforts on populations of concern, by identifying critical habitats and assessing thermal changes at a local scale.

River Research and Applications

Assessing the impacts of river regulation on native bull trout ( Salvelinus confluentus ) and westslope cutthroat trout ( Oncorhynchus clarkii lewisi ) habitats in the upper Flathead River, Montana, USA

Hungry Horse Dam on the South Fork Flathead River, Montana, USA, has modified the natural flow regimen for power generation, flood risk management and flow augmentation for anadromous fish recovery in the Columbia River. Concern over the detrimental effects of dam operations on native resident fishes prompted research to quantify the impacts of alternative flow management strategies on threatened bull trout (Salvelinus confluentus) and westslope cutthroat trout (Oncorhynchus clarkii lewisi) habitats. Seasonal and life‐stage specific habitat suitability criteria were combined with a two‐dimensional hydrodynamic habitat model to assess discharge effects on usable habitats. Telemetry data used to construct seasonal habitat suitability curves revealed that subadult (fish that emigrated from natal streams to the river system) bull trout move to shallow, low‐velocity shoreline areas at night, which are most sensitive to flow fluctuations. Habitat time series analyses comparing the natural flow regimen (predam, 1929&ndash;1952) with five postdam flow management strategies (1953&ndash;2008) show that the natural flow conditions optimize the critical bull trout habitats and that the current strategy best resembles the natural flow conditions of all postdam periods. Late summer flow augmentation for anadromous fish recovery, however, produces higher discharges than predam conditions, which reduces the availability of usable habitat during this critical growing season. Our results suggest that past flow management policies that created sporadic streamflow fluctuations were likely detrimental to resident salmonids and that natural flow management strategies will likely improve the chances of protecting key ecosystem processes and help to maintain and restore threatened bull trout and westslope cutthroat trout populations in the upper Columbia River Basin.

Montana

The distribution and abundance ofa nuisance native alga, Didymosphenia geminata,in streams of Glacier National Park: Climate drivers and management implications

Didymosphenia geminata (didymo) is a freshwater alga native to North America, including Glacier National Park, Montana. It has long been considered a cold-water species, but has recently spread to lower latitudes and warmer waters, and increasingly forms large blooms that cover streambeds. We used a comprehensive monitoring data set from the National Park Service (NPS) and USGS models of stream temperatures to explore the drivers of didymo abundance in Glacier National Park. We estimate that approximately 64% of the stream length in the park contains didymo, with around 5% in a bloom state. Results suggest that didymo abundance likely increased over the study period (2007–2009), with blooms becoming more common. Our models suggest that didymo abundance is positively related to summer stream temperatures and negatively related to total nitrogen and the distance downstream from lakes. Regional climate model simulations indicate that stream temperatures in the park will likely continue to increase over the coming decades, which may increase the extent and severity of didymo blooms. As a result, didymo may be a useful indicator of thermal and hydrological modification associated with climate warming, especially in a relatively pristine system like Glacier where proximate human-related disturbances are absent or reduced. Glacier National Park plays an important role as a sentinel for climate change and associated education across the Rocky Mountain region.

Montana