Winter Climate and Lake Morphology Control Ice Phenology and Under‐Ice Temperature and Oxygen Regimes in Mountain Lakes

Smits, Adrianne P.; Gomez, Nicholas W.; Dozier, Jeff; Sadro, Steven

doi:10.1029/2021jg006277

Cited by 15 publications

(19 citation statements)

References 64 publications

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“…The high elevation lakes that R. sierrae inhabit are under ice and snow cover from approximately November to June. More severe winters lead to longer ice and snow cover, shorter ice‐free durations during summer months and cooler summer water temperatures (Smits et al, 2021). A well‐supported measure/proxy of winter severity is the snow water equivalent (SWE) on April 1st of the current year (extracted from the California Data Exchange Center for snow survey locations across the Sierra Nevada).…”

Section: Methodsmentioning

confidence: 99%

Host density has limited effects on pathogen invasion, disease‐induced declines and within‐host infection dynamics across a landscape of disease

Wilber

Knapp

Smith

et al. 2022

Journal of Animal Ecology

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1. Host density is hypothesized to be a major driver of variability in the responses and outcomes of wildlife populations following pathogen invasion. While the effects of host density on pathogen transmission have been extensively studied, these studies are dominated by theoretical analyses and small‐scale experiments. This focus leads to an incomplete picture regarding how host density drives observed variability in disease outcomes in the field. 2. Here, we leveraged a dataset of hundreds of replicate amphibian populations that varied by orders of magnitude in host density. We used these data to test the effects of host density on three outcomes following the arrival of the amphibian‐killing fungal pathogen Batrachochytrium dendrobatidis (Bd): the probability that Bd successfully invaded a host population and led to a pathogen outbreak, the magnitude of the host population‐level decline following an outbreak and within‐host infection dynamics that drive population‐level outcomes in amphibian–pathogen systems. 3. Based on previous small‐scale transmission experiments, we expected that populations with higher densities would be more likely to experience Bd outbreaks and would suffer larger proportional declines following outbreaks. To test these predictions, we developed and fitted a Hidden Markov Model that accounted for imperfectly observed disease outbreak states in the amphibian populations we surveyed. 4. Contrary to our predictions, we found minimal effects of host density on the probability of successful Bd invasion, the magnitude of population decline following Bd invasion and the dynamics of within‐host infection intensity. Environmental conditions, such as summer temperature, winter severity and the presence of pathogen reservoirs, were more predictive of variability in disease outcomes. 5. Our results highlight the limitations of extrapolating findings from small‐scale transmission experiments to observed disease trajectories in the field and provide strong evidence that variability in host density does not necessarily drive variability in host population responses following pathogen arrival. In an applied context, we show that feedbacks between host density and disease will not necessarily affect the success of reintroduction efforts in amphibian‐Bd systems of conservation concern.

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Section: Methodsmentioning

confidence: 99%

Host density has limited effects on pathogen invasion, disease‐induced declines and within‐host infection dynamics across a landscape of disease

Wilber

Knapp

Smith

et al. 2022

Journal of Animal Ecology

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“…Using temperature and DO probes in lakes of the Sierra Nevada and the Klamath mountains, Smits et al. (2021) concluded that air temperature and precipitation (snowfall) were the most important drivers of the timing of ice formation and ice‐off, while lake morphometry was the most important factor determining DO depletion rates under ice. They found that seasonal and interannual variability were higher in small, shallow lakes than larger, deeper lakes.…”

Section: Physical and Biogeochemical Dynamicsmentioning

confidence: 99%

“…Cross-lake variation in the ice-off date involved relationships between lake size, snow thickness, and ice thickness. Smits et al (2021) used a set of 15 lakes spanning a large elevation gradient in the Sierra Nevada of California to highlight the considerable among-year variability in duration of ice cover, with about a 40 day difference in duration of ice-cover resulting from variation in winter snowpack and temperature. Very high snowpack on high elevation mountain lakes was identified as a more important driver of ice-off and ice-phenology than in low elevation lakes.…”

Section: Changes In Lake and River Icementioning

confidence: 99%

Whither Winter: The Altered Role of Winter for Freshwaters as the Climate Changes

et al. 2022

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Our changing climate is having effects on freshwater ecosystems in all seasons, especially winter. High latitude lakes, wetlands, and rivers are experiencing shorter periods of ice cover, and lower latitudes systems that used to freeze are experiencing open water conditions throughout the winter. A 2019 AGU Chapman conference convened aquatic scientists to examine these changes and address the implications of changing winters to aquatic life, chemistry, and physics. Several studies demonstrate decreased ice cover duration than in the past. The removal of an ice “lid” from lakes and rivers impacts the exchange of gases with the atmosphere and the predominant types of metabolism occurring in the waters below, with the potential for more photosynthesis and an increase in oxic versus anoxic metabolism when the lid is removed. Multiple studies indicated an increase in the interannual variability of winters, especially in terms of ice‐cover duration and ice quality. Increased variability may simply be an outcome of a more variable winter climate or small differences in environmental conditions such as temperature that can have strong effects on gas exchange, light transmission, and turbulence when ice forms. A question that merits further consideration is whether and how winters of shorter duration and severity will change the dynamics of freshwater systems. Are there memory or legacy effects that carry over to the next season or year? There is much work to be done to understand how changing winters will impact the biogeochemical behavior of lakes and rivers in the coming decades.

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“…Functioning indicators present some advantages over structural ecosystem components since change in ecosystem process rates can be immediately linked to certain levels of environmental change (Palmer and Ruhi, 2019). For instance, the proliferation of reliable and relatively inexpensive sensors for monitoring dissolved oxygen, and easy-to-use software for the calculation of gross primary production (GPP) and Ecosystem Respiration (ER; Engel et al 2019) is underpinning a revolution in the use of this kind of indicator (Bernhardt et al 2018;Smits et al 2021). These two factors enable scientists to estimate ecosystem metabolism more frequently and in greater detail.…”

Section: The Spanish Mountain National Parksmentioning

confidence: 99%

An evaluation of freshwater monitoring programs in ILTER nodes and mountain national parks: identifying key variables to monitor global change effects

et al. 2022

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Identifying and quantifying global change impacts on biotic and abiotic components of ecosystems is critical to promote an effective adaptation that increases the success of conservation strategies. To achieve this goal, global and regional assessment efforts require certain degree of harmonization on local monitoring programs to establish relevant comparisons at different spatio-temporal scales. Otherwise, the lack of harmonization might hinder the detection and assessment on the effects of human impacts. In this work we have compiled information on freshwater monitoring programs located in areas of intensive research and conservation interest: International Long Term Ecological Research (ILTER) nodes and mountain National Parks. We aimed at evaluating the quality and robustness of these programs to assess the impact of global change, addressing from the worldwide to the European and Spanish national scale. Results highlighted that freshwater monitoring programs lack a common strategy to monitor these ecosystems. Even at the continental and national scales, contrasting strategies and level of detail have been historically applied. Water quality, habitat and biodiversity are more commonly monitored than community structure and ecosystem functioning. Monitoring efforts on the Spanish Mountain National parks indicated differences on the targeted aquatic ecosystems. Rivers and lakes received a higher attention, while mires were rarely considered. Our results provide evidence that greater efforts should be directed towards constructing a coordinated strategy to monitor freshwater ecosystems at national, continental, and global scales. This strategy should involve a shared backbone of biophysical and biogeochemical variables for each habitat type on agreed protocols that are implemented across regions and administrative borders. Achieving this will support a substantial advance on the ecological research to further delineate proper conservation strategies to face the challenges imposed by global change.

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Winter Climate and Lake Morphology Control Ice Phenology and Under‐Ice Temperature and Oxygen Regimes in Mountain Lakes

Cited by 15 publications

References 64 publications

Host density has limited effects on pathogen invasion, disease‐induced declines and within‐host infection dynamics across a landscape of disease

Host density has limited effects on pathogen invasion, disease‐induced declines and within‐host infection dynamics across a landscape of disease

Whither Winter: The Altered Role of Winter for Freshwaters as the Climate Changes

An evaluation of freshwater monitoring programs in ILTER nodes and mountain national parks: identifying key variables to monitor global change effects

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