Kendra Spence Cheruvelil

Drawing on national survey data, this study is one of the first to explore Hispanic Serving Research Universities (HSRU) doctoral students’ organizational climate perceptions and career outcomes as compared to peers at non-Hispanic Serving Research Universities (non-HSRUs). Results indicate that doctoral students perceived academic climates similarly between HSRUs and non-HSRUs; some career outcomes are better at HSRUs than those at non-HSRUs. We update the servingness framework to align with the nuances of doctoral education.

Although authorship is central to the career advancement of many ecologists, the processes used to assign authorship credit on papers are not always clear, ethical, or equitable. We developed the concept of authorship climate (perceptions of fairness related to procedures, communication practices, and outcomes of authorship decisions) and measured it using a survey of early‐career scientists from four fields across U.S. Ph.D.‐granting institutions. The results pointed to important differences in authorship climate perceptions across fields, career stages, and demographics. This paper provides an overview of the results, especially for the field of biology that encompasses ecology, and provides recommendations for improving authorship climate for ecologists.

Quantifying and predicting precipitation and water flow and their influences is challenged by the dynamic relationships between and timing of precipitation and water fluxes. To help with these challenges, scientists use “water year” to examine and predict the impacts of precipitation and relevant extreme climatic and hydrological events on ecosystems. However, traditional water year definitions used in the US lack a consideration of areal variation in climate and hydrology, which is needed when studying ecosystems at regional or national scales. We developed local water year (LWY) values that consider spatial variation using existing definitions whereby the water year begins in the month with the lowest or highest average monthly streamflow. We employed spatial interpolation to assign LWY start and end months to 202 subregions across the conterminous United States that range from 4,384 to 134,755 km². This dataset can be linked with diverse climate, terrestrial, and aquatic data for broad‐scale studies.

Climate change is predicted to intensify lake algal blooms globally and result in regime shifts. However, observed increases in algal biomass do not consistently correlate with air temperature or precipitation, and evidence is lacking for a causal effect of climate or the nonlinear dynamics needed to demonstrate regime shifts. We modeled the causal effects of climate on annual lake chlorophyll (a measure of algal biomass) over 34 y for 24,452 lakes across broad ecoclimatic zones of the United States and evaluated the potential for regime shifts. We found that algal biomass was causally related to climate in 34% of lakes. In these cases, 71% exhibited abrupt but mostly temporary shifts as opposed to persistent changes, 13% had the potential for regime shifts. Climate was causally related to algal biomass in lakes experiencing all levels of human disturbance, but with different likelihood. Climate causality was most likely to be observed in lakes with minimal human disturbance and cooler summer temperatures that have increased over the 34 y studied. Climate causality was variable in lakes with low to moderate human disturbance, and least likely in lakes with high human disturbance, which may mask climate causality. Our results explain some of the previously observed heterogeneous climate responses of lake algal biomass globally and they can be used to predict future climate effects on lakes.

Local and regional‐scaled studies point to the important role of lake type (natural lakes vs. reservoirs), surface water connectivity, and ecological context (multi‐scaled natural settings and human factors) in mediating lake responses to disturbances like drought. However, we lack an understanding at the macroscale that incorporates multiple scales (lake, watershed, region) and a variety of ecological contexts. Therefore, we used data from the LAGOS‐US research platform and applied a local water year timeframe to 62,927 US natural lakes and reservoirs across 17 ecoregions to examine how chlorophyll a responds to drought across various ecological contexts. We evaluated chlorophyll a changes relative to each lake's baseline and drought year. Drought led to lower and higher chlorophyll a in 18% and 20%, respectively, of lakes (both natural lakes and reservoirs included). Natural lakes had higher magnitudes of change and probabilities of increasing chlorophyll a during droughts than reservoirs, and these differences were particularly pronounced in isolated and highly‐connected lakes. Drought responses were also related to long‐term average lake chlorophyll a in complex ways, with a positive correlation in less productive lakes and a negative correlation in more productive lakes, and more pronounced drought responses in higher‐productivity lakes than lower‐productivity lakes. Thus, lake chlorophyll responses to drought are related to interactions between lake type and surface connectivity, long‐term average chlorophyll a , and many other multi‐scaled ecological factors (e.g., soil erodibility, minimum air temperature). These results reinforce the importance of integrating multi‐scaled ecological context to determine and predict the impacts of global changes on lakes.

The LAGOS‐US RESERVOIR data module classifies all 137,465 lakes ≥ 4 ha in the conterminous U.S. into three categories using a machine learning predictive model based on visual interpretation of lake outlines and a lake shape classification rule. Natural Lakes (NLs) are defined as naturally formed, lacking large, flow‐altering structures; Reservoir Class A's (RSVR_A) are defined as lakes likely human‐made or human‐altered by a large water control structure; and Reservoir Class B's (RSVR_Bs) are lakes likely human‐made but are not connected to streams and have a shape rare in NLs. We trained machine learning models on 12,162 manually classified lakes to predict assignment as an NL or RSVR, then further classified RSVRs based on NHD Fcodes, isolation, and angularity. Our classification indicates that > 46% of lakes ≥ 4 ha in the conterminous U.S. are reservoir lakes. These data can be easily combined with other LAGOS‐US modules and U.S. national databases for the broad‐scale study of reservoir lakes and NLs.

Authorship of academic publications is central to scientists’ careers, but decisions about how to include and order authors on publications are often fraught with difficult ethical issues. To better understand scholars’ experiences with authorship, we developed a novel concept, authorship climate, which assesses perceptions of the procedural, informational, and distributive justice associated with authorship decisions. We conducted a representative survey of more than 3,000 doctoral students, postdoctoral researchers, and assistant professors from a stratified random sample of U.S. biology, economics, physics, and psychology departments. We found that individuals who tend to have more power on science teams (e.g., assistant professors and lead authors) perceived authorship climate to be more positive than those who tend to have less power (e.g., graduate students and non-lead authors). Alphabetical approaches for assigning authorship were associated with higher perceptions of procedural justice (i.e., perceptions of fairness and voice in processes and procedures) and informational justice (i.e., the extent to which individuals feel that information is justified and communicated honestly) but lower perceptions of distributive justice (i.e., perceptions of fairness in the outcomes of decisions). Individuals with more marginalized identities also tended to perceive authorship climate more negatively than those with no marginalized identities. These results illustrate how the concept of authorship climate can facilitate enhanced understanding of early-career scholars’ authorship experiences, and they highlight potential steps that can be taken to promote more positive authorship experiences for scholars of all identities.