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Abstract Lake trophic state is a key ecosystem property that integrates a lake’s physical, chemical, and biological processes. Despite the importance of trophic state as a gauge of lake water quality, standardized and machine-readable observations are uncommon. Remote sensing presents an opportunity to detect and analyze lake trophic state with reproducible, robust methods across time and space. We used Landsat surface reflectance data to create the first compendium of annual lake trophic state for 55,662 lakes of at least 10 ha in area throughout the contiguous United States from 1984 through 2020. The dataset was constructed with FAIR data principles (Findable, Accessible, Interoperable, and Reproducible) in mind, where data are publicly available, relational keys from parent datasets are retained, and all data wrangling and modeling routines are scripted for future reuse. Together, this resource offers critical data to address basic and applied research questions about lake water quality at a suite of spatial and temporal scales.

Abstract Postdoctoral positions provide critical opportunities for early‐career ecologists to build transferable skills, knowledge, and networks that will prepare them for professional success. However, these positions often come with personal and professional challenges such as stress, isolation, and lack of agency. Here, we describe a peer‐led postdoc program we created to maximize benefits and minimize challenges while preparing ourselves for a wide range of possible future careers using our training and expertise in ecology. We also give recommendations for other postdocs and early‐career scientists in ecology and across science, technology, engineering, and mathematics fields seeking to build a similar program.

Roughly 10% of the Earth's surface is permanently covered by glaciers and ice sheets and in mountain ecosystems, this proportion of ice cover is often even higher. From an ecological perspective, ice-dominated ecosystems place harsh controls on life including cold temperature, limited nutrient availability, and often prolonged darkness due to snow cover for much of the year. Despite these limitations, glaciers, and perennial snowfields support diverse, primarily microbial communities, though macroinvertebrates and vertebrates are also present. The availability and mass balance of key elements [(carbon (C), nitrogen (N), phosphorous (P)] are known to influence the population dynamics of organisms, and ultimately shape the structure and function of ecosystems worldwide. While considerable attention has been devoted to patterns of biodiversity in mountain cryosphere-influenced ecosystems, the ecological stoichiometry of these habitats has received much less attention. Understanding this emerging research arena is particularly pressing in light of the rapid recession of glaciers and perennial snowfields worldwide. In this review, we synthesize existing knowledge of ecological stoichiometry, nutrient availability, and food webs in the mountain cryosphere (specifically glaciers and perennial snowfields). We use this synthesis to develop more general understanding of nutrient origins, distributions, and trophic interactions in these imperiled ecosystems. We focus our efforts on three major habitats: glacier surfaces (supraglacial), the area beneath glaciers (subglacial), and adjacent downstream habitats (i.e., glacier-fed streams and lakes). We compare nutrient availability in these habitats to comparable habitats on continental ice sheets (e.g., Greenland and Antarctica) and show that, in general, nutrient levels are substantially different between the two. We also discuss how ongoing climate warming will alter nutrient and trophic dynamics in mountain glacier-influenced ecosystems. We conclude by highlighting the pressing need for studies to understand spatial and temporal stoichiometric variation in the mountain cryosphere, ideally with direct comparisons to continental ice sheets, before these imperiled habitats vanish completely.

Lakes are sentinels of environmental change. In cold climates, lake ice phenology—the timing and duration of ice cover during winter—is a key control on ecosystem function. Ice phenology is likely driven by a complex interplay between physical characteristics and climatic conditions. Under climate change, lakes are generally freezing later, melting out earlier, and experiencing a shorter duration of ice cover; however, few long-term records exist for large, high-elevation lakes which may be particularly vulnerable to climate impacts. Here, we quantified ice phenology over the last century (1927–2022) for North America’s largest high-elevation lake—Yellowstone Lake—and compared it to seven similar lakes in northern Europe. We show that contrary to expectation, the ice phenology of Yellowstone Lake has been uniquely resistant to climate change. Indeed, despite warming temperatures in the region, no change in the timing nor duration of ice cover has occurred at Yellowstone Lake due to buffering by increased snowfall. However, with projections of continued warming and shifting precipitation regimes in the high Rocky Mountains, it is unclear how long this buffering will last.

Global change may contribute to ecological changes in high-elevation lakes and reservoirs, but a lack of data makes it difficult to evaluate spatiotemporal patterns. Remote sensing imagery can provide more complete records to evaluate whether consistent changes across a broad geographic region are occurring. We used Landsat surface reflectance data to evaluate spatial patterns of contemporary lake color (2010–2020) in 940 lakes in the U.S. Rocky Mountains, a historically understudied area for lake water quality. Intuitively, we found that most of the lakes in the region are blue (66%) and were found in steep-sided watersheds (>22.5°) or alternatively were relatively deep (>4.5 m) with mean annual air temperature (MAAT)