Search for: All records

Abstract Disturbances cause rapid changes to forests, with different disturbance types and severities creating unique ecosystem trajectories that can impact the underlying soil microbiome. Pile burning—the combustion of logging residue on the forest floor—is a common fuel reduction practice that can have impacts on forest soils analogous to those following high-severity wildfire. Further, pile burning following clear-cut harvesting can create persistent openings dominated by nonwoody plants surrounded by dense regenerating conifer forest. A paired 60-year chronosequence of burn scar openings and surrounding regenerating forest after clear-cut harvesting provides a unique opportunity to assess whether belowground microbial processes mirror aboveground vegetation during disturbance-induced ecosystem shifts. Soil ectomycorrhizal fungal diversity was reduced the first decade after pile burning, which could explain poor tree seedling establishment and subsequent persistence of herbaceous species within the openings. Fine-scale changes in the soil microbiome mirrored aboveground shifts in vegetation, with short-term changes to microbial carbon cycling functions resembling a postfire microbiome (e.g. enrichment of aromatic degradation genes) and respiration in burn scars decoupled from substrate quantity and quality. Broadly, however, soil microbiome composition and function within burn scar soils converged with that of the surrounding regenerating forest six decades after the disturbances, indicating potential microbial resilience that was disconnected from aboveground vegetation shifts. This work begins to unravel the belowground microbial processes that underlie disturbance-induced ecosystem changes, which are increasing in frequency tied to climate change. 

Mentorship can be part of the solution to developing a more diverse global scientific workforce, but robust longitudinal evidence is limited. Developmental mentor network theory can advance our understanding of the impact of a wide range of mentors across social contexts by distinguishing between the content of mentorship support (eg career support) and the structural characteristics of an individual's mentor network (eg density of connections among mentors). We tested the influence of mentor network characteristics on longitudinal social integration into the Earth and environmental sciences, as indicated by science identity development (a key indicator of social integration) and graduate‐school applications in STEM (science, technology, engineering, and mathematics)‐related fields of study, based on a sample of 233 undergraduate women at nine universities in the US. Our findings indicated that belonging to close‐knit, larger, and skill‐focused mentorship networks creates a “sticky web” of social connections, providing information and resources that increase retention of college women in the Earth and environmental sciences. 

Rampant gender-based harassment and discrimination are recognized problems that negatively impact efforts to diversify science, technology, engineering and mathematics (STEM) fields. We explored the particularities of this phenomenon in the geosciences, via focus groups conducted at STEM professional society meetings, with the goal of informing interventions specific to the discipline. Using grounded theory analysis, two primary drivers for the persistence and perpetuation of gender-based harassment in the geosciences were identified: a particular history of power dynamics and maintenance of dominant stereotypes, and a pattern of ineffective responses to incidents of harassment and discrimination. Informed by intersectional feminist scholarship by women of color that illustrates how efforts to address the underrepresentation of women in STEM without attending to the overlapping impacts of racism, colonialism, ableism, and classism will not succeed, we view harassment and discrimination as structural problems that require collective solutions. Continuing to recruit individuals into a discipline without changing its fundamental nature can tokenize and isolate them or encourage assimilation and acceptance of deep-seated traditions no matter how damaging. It is the responsibility of those in power, and especially those who hold more privileged status due to their social identities, to contribute to the dismantling of current structures that reinforce inequity. By providing explanatory illustrative examples drawn from first-person accounts we aim to humanize the numbers reported in workplace climate surveys, address gaps in knowledge specific to the geosciences, and identify interventions aligned with an intersectional framework that aim to disrupt discriminatory practices endemic to the geosciences and larger STEM community. 

Abstract An abundance of literature has examined barriers to women’s equitable representation in science, technology, engineering, and math (STEM) fields, with many studies demonstrating that STEM fields are not perceived to afford communal goals, a key component of women’s interest in future careers. Using Goal Congruity Theory as a framework, we tested the longitudinal impact of perceptions of STEM career goal affordances, personal communal and agentic goal endorsements, and their congruity on persistence in science from the second through fourth years of college among women in STEM majors in the United States. We found that women’s intent to persist in science were highest in the fall of their second year, that persistence intentions exhibited a sharp decline, and eventually leveled off by their fourth year of college. This pattern was moderated by perceptions of agentic affordances in STEM, such that women who believe that STEM careers afford the opportunity for achievement and individualism experienced smaller declines. We found that higher perceptions of communal goal affordances in STEM consistently predicted higher persistence intentions indicating women may benefit from perceptions that STEM affords communal goals. Finally, we found women with higher agentic affordances in STEM also had greater intentions to persist, and this relationship was stronger for women with higher agentic goals. We conclude that because STEM fields are stereotyped as affording agentic goals, women who identify interest in a STEM major during their first years of college may be drawn to these fields for this reason and may benefit from perceptions that STEM affords agentic goals. 

Abstract Dissolved organic matter (DOM) is recognized for its importance in freshwater ecosystems, but historical reliance on DOM quantity rather than indicators of DOM composition has led to an incomplete understanding of DOM and an underestimation of its role and importance in biogeochemical processes. A single sample of DOM can be composed of tens of thousands of distinct molecules. Each of these unique DOM molecules has their own chemical properties and reactivity or role in the environment. Human activities can modify DOM composition and recent research has uncovered distinct DOM pools laced with human markers and footprints. Here we review how land use change, climate change, nutrient pollution, browning, wildfires, and dams can change DOM composition which in turn will affect internal processing of freshwater DOM. We then describe how human-modified DOM can affect biogeochemical processes. Drought, wildfires, cultivated land use, eutrophication, climate change driven permafrost thaw, and other human stressors can shift the composition of DOM in freshwater ecosystems increasing the relative contribution of microbial-like and aliphatic components. In contrast, increases in precipitation may shift DOM towards more relatively humic-rich, allochthonous forms of DOM. These shifts in DOM pools will likely have highly contrasting effects on carbon outgassing and burial, nutrient cycles, ecosystem metabolism, metal toxicity, and the treatments needed to produce clean drinking water. A deeper understanding of the links between the chemical properties of DOM and biogeochemical dynamics can help to address important future environmental issues, such as the transfer of organic contaminants through food webs, alterations to nitrogen cycling, impacts on drinking water quality, and biogeochemical effects of global climate change. 

Abstract Geosciences remain one of the least diverse fields. Efforts to diversify the discipline need to address the role of hostile and exclusionary work and learning environments. A workplace climate survey distributed to five professional organizations illustrates varied experiences of earth and space scientists over a 12‐month period (pre‐COVID). A majority experienced positive interactions in the workplace. However, scientists of color, women and non‐binary individuals, scientists with disabilities, and lesbian, gay, bisexual, queer, pansexual, and asexual (LGBQPA+) scientists more frequently experienced negative interactions, including interpersonal mistreatment, discriminatory language, and sexual harassment. Geoscientists of color were more likely to experience devaluation of their work than white scientists. More than half of women and non‐binary respondents, as well as those who identify as LGBQPA+ experienced identity‐based discriminatory remarks. Disabled geoscientists were more likely to hear negative identity‐based language than those who did not disclose a disability. Overall, 14% of all respondents experienced sexual harassment in the previous year. Rates were greatest for historically excluded groups: non‐binary (51%), LGBQPA+ (33%), disabled (26%), women (20%), and geoscientists of color (17%). A majority of geoscientists reported avoiding their colleagues and almost a third considered leaving their institution or a career change. Historically excluded groups were more likely to report opting out of professional activities with potential career consequences. To address continued exclusion and low retention in the earth and space sciences, recruitment is not enough. We need to create environments that ensure opportunities for all to thrive.