Lowland tundra plant stoichiometry is somewhat resilient decades following fire despite substantial and sustained shifts in community structure

The Arctic is experiencing the greatest increase in average surface temperature globally, which is projected to amplify wildfire frequency and severity. Wildfire alters the biogeochemical characteristics of arctic ecosystems. However, the extent of these changes over time-particularly with regard to plant stoichiometries relative to community structure-is not well documented. Four years after the Yukon-Kuskokwim Delta, Alaska, experienced its largest fire season, aboveground plant and lichen biomass was harvested across a gradient of burn history: unburned ("reference"), 2015 burn ("recent burn"), and 1972 burn ("historic burn") to assess the resilience of tundra plant communities to fire disturbance. Fire reduced aboveground biomass in the recent burn; early recovery was characterized by evergreen shrub and graminoid dominance. In the historic burn, aboveground biomass approached reference conditions despite a sustained reduction of lichen biomass. Although total plant and lichen carbon (C) and nitrogen (N) were reduced immediately following fire, N stocks recovered to a greater degree-reducing community-level C:N. Notably, at the species level, N enrichment was observed only in the recent burn. Yet, community restructuring persisted for decades following fire, reflecting a sustained reduction in N-poor lichens relative to more N-rich vascular plant species

Investigating the Feasibility of Agrivoltaics in Massachusetts

In order to mitigate global climate change, we need to decarbonize the electric grid. Utility-scale solar energy (USSE) is one of the fastest growing renewable energy sources. Currently, a lot of Massachusetts’ farmland is being lost to development, including solar development. As part of a solution, in 2018 the Massachusetts Department of Energy Resources (DOER) created the Solar Massachusetts Renewable Target (SMART) Program, which has an Agricultural Solar Tariff Generation Unit (ASTGU) provision. This provides an additional financial incentive on top of the base compensation rate for agrivoltaics (co-location of agriculture and photovoltaic arrays). In this project, we wanted to assess the initial feasibility and success of agrivoltaics in Massachusetts; particularly, we wanted to investigate whether this could be a way to successfully assist in the Commonwealth’s energy needs while mitigating the loss of farmland. We conducted a literature review, semi-structured stakeholder interviews, and an economic analysis. From this work, we found that while most stakeholders agree that more renewable energy is needed in the Commonwealth, there are disagreements about solar siting and the related regulations. Initial agrivoltaics research found that many factors play a role in agricultural yields, and more research is needed. Many stakeholders agree that the financial incentive will help fill this knowledge gap. As this process continues, we need to critically weigh the risks, benefits, and uncertainties of agrivoltaics. While we acknowledge that agrivoltaics likely reduces agricultural yields to some degree, we recommend the financial incentive remains. Agrivoltaics have the potential to help decarbonize the grid while allowing farmers to diversify their revenue streams. We have five recommendations to improve agrivoltaics in Massachusetts: the Massachusetts Department of Energy Resources (DOER) should maintain the agrivoltaic financial incentive; all relevant stakeholders should continue and increase research on agrivoltaics; DOER, with input from the Massachusetts Department of Agricultural Resources (MDAR) and relevant stakeholders, should provide flexibility in the requirements for the agrivoltaic incentive (shading, storage, etc.); DOER make annual reports from the approved projects publicly available to increase transparency and promote research; the Commonwealth should increase their involvement in solar siting. Since the start of the SMART Program, 17 ASTGU projects have been approved. Most of these projects are still under construction since COVID-19 has slowed the process. All the farmers and solar developers we spoke to with approved projects are very excited to start experimenting with agrivoltaics. In addition, a team of researchers at the University of Massachusetts, Amherst, recently received a $1.8 million grant from the Department of Energy to study agrivoltaics in the Commonwealth. Through these agrivoltaic projects and research, Massachusetts will continue to be a leader in this new technology

Warming effects on arctic tundra biogeochemistry are limited but habitat-dependent: a meta-analysis

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Pold, G., Baillargeon, N., Lepe, A., Rastetter, E. B., & Sistla, S. A. Warming effects on arctic tundra biogeochemistry are limited but habitat-dependent: a meta-analysis. Ecosphere, 12(10), (2021): e03777, https://doi.org/10.1002/ecs2.3777.Arctic tundra consists of diverse habitats that differ in dominant vegetation, soil moisture regimes, and relative importance of organic vs. inorganic nutrient cycling. The Arctic is also the most rapidly warming global area, with winter warming dominating. This warming is expected to have dramatic effects on tundra carbon and nutrient dynamics. We completed a meta-analysis of 166 experimental warming study papers to evaluate the hypotheses that warming changes tundra biogeochemical cycles in a habitat- and seasonally specific manner and that the carbon (C), nitrogen (N), and phosphorus (P) cycles will be differentially accelerated, leading to decoupling of elemental cycles. We found that nutrient availability and plant leaf stoichiometry responses to experimental warming were variable and overall weak, but that both gross primary productivity and the plant C pool tended to increase with growing season warming. The effects of winter warming on C fluxes did not extend into the growing season. Overall, although warming led to more consistent increases in C fluxes compared to N or P fluxes, evidence for decoupling of biogeochemical cycles is weak and any effect appears limited to heath habitats. However, data on many habitats are too sparse to be able to generalize how warming might decouple biogeochemical cycles, and too few year-round warming studies exist to ascertain whether the season under which warming occurs alters how ecosystems respond to warming. Coordinated field campaigns are necessary to more robustly document tundra habitat-specific responses to realistic climate warming scenarios in order to better understand the mechanisms driving this heterogeneity and identify the tundra habitats, communities, and soil pools most susceptible to warming.Funding for this project was provided by NSF Signals in the Soil grant number 1841610 to SAS and ER. SAS and ER conceived of and acquired funding for the project. NB completed the literature search

Facilitators of HIV Medical Care Engagement Among Former Prisoners

Linkage to and retention in medical care is a concern for HIV-positive individuals leaving custody settings in the United States. The minimal existing research points to low rates of entry into care in the months following release and lapsed viral control among releasees who are subsequently reincarcerated. We conducted seven small focus group discussions with 27 HIV-positive individuals who were recently incarceration in a California State prison to understand those factors that facilitated linkage to and retention in HIV care following their release. We used a consensual approach to code and analyze the focus group transcripts. Four main themes emerged from the analysis: 1) interpersonal relationships, 2) professional relationships, 3) coping strategies and resources, and 4) individual attitudes. Improving HIV-related outcomes among individuals after their release from prison requires strengthening supportive relationships, fostering the appropriate attitudes and skills, and ensuring access to resources that stabilize daily living and facilitate the process of accessing care

Defining key concepts for mental state attribution

The terminology used in discussions on mental state attribution is extensive and lacks consistency. In the current paper, experts from various disciplines collaborate to introduce a shared set of concepts and make recommendations regarding future use

Defining key concepts for mental state attribution

The terminology used in discussions on mental state attribution is extensive and lacks consistency. In the current paper, experts from various disciplines collaborate to introduce a shared set of concepts and make recommendations regarding future use