Changing the culture of ecology from the ground up

We are two early career soil ecologists in academia who entered the field of soil ecology with the goal of studying soil-climate feedbacks to make meaningful contributions to climate change mitigation. Although our training and research extensively focused on the effects of climate change on soil ecosystems, we were not trained during our PhD nor incentivized as postdocs to work on solutions for climate change mitigation. So the question we ask here is: Given the consensus among ecologists about the urgency of the climate crisis, why is our field not promoting more solutions-oriented research in training and practice? In this commentary, we provide our perspective on (1) the way forward shown by individual soil ecologists doing solutions-oriented research, (2) some specific cultural barriers to academic institutional support, and (3) three examples promoting solutions-oriented science that improve support for early career researchers and reduce barriers to entry

The world of underground ecology in a changing environment

This special feature presents state-of-the-art soil ecological science and was sparked following the 2-day long online live event entitled “Ecology Underground” during the Ecological Society of America annual meeting of 2020. Here, we, the co-guest-editors of this special feature, present this body of research in context of the current state of the field. This issue highlights that we are currently in a hot time for microbial research in soil science. Specifically, we find that two themes emerge from this corpus as key next questions to answer to move the field forward. How do microbial processes scale up in space and time? And how do they respond to multiple interacting global change factors

Promoting and maintaining changes in smoking behaviour for patients following discharge from a smokefree mental health inpatient stay: Development of a complex intervention using the Behaviour Change Wheel.

Evidence suggests that smokers can successfully quit, remain abstinent or reduce smoking during a smokefree mental health inpatient stay, provided behavioural/pharmacological support are offered. However, few evidence-based strategies to prevent the return to pre-hospital smoking behaviours post-discharge exist. We report the development of an intervention designed to support smoking-related behaviour change following discharge from a smokefree mental health stay. We followed the Behaviour Change Wheel (BCW) intervention development process. The target behaviour was supporting patients to change their smoking behaviours following discharge from a smokefree mental health stay. Using systematic reviews, we identified the barriers/enablers, classified according to the Theoretical Domains Framework (TDF). Potential intervention functions to address key influences were identified by consulting the BCW and Behaviour Change Technique (BCT) taxonomy. Another systematic review identified effectiveness of BCTs in this context. Stakeholder consultations were conducted to prioritise/refine intervention content. Barriers/enablers to supporting smoking cessation were identified within the domains of environmental context and resources (lack of staff time); knowledge (ill-informed interactions about smoking); social influences, and intentions (lack of intention to deliver support). Potential strategies to address these influences included goal setting, problem solving, feedback, social support, and information on health consequences. A strategy for operationalising these techniques into intervention components was agreed: pre-discharge evaluation sessions, personalised resource folder, tailored behavioural and text message support post-discharge, and a peer interaction group, delivered by a trained mental health worker. The intervention includes targeted resources to support smoking-related behaviour change in patients following discharge from a smokefree mental health setting. Using the BCW and TDF supported a theoretically and empirically informed process to define and develop a tailored intervention that acknowledges barriers and enablers to supporting smoking cessation in mental health settings. The result is a novel complex theory- and evidence-based intervention that will be formally tested in a randomised controlled feasibility study

Tracing the New Carbon Cycle From Plant Inputs to Microbial Outputs Across an Arctic Permafrost Thaw Gradient

Arctic systems are experiencing some of the most rapid warming due to climate change, causing permafrost C stocks to thaw and become available for decomposition. Since these systems store approximately 1.7 times the amount of C currently in the atmosphere, its decomposition and release as CO2 and CH4 could have profound effects as a positive feedback to climate change. However, the net effect of permafrost thaw depends not just on decomposition of the old C, but also on the changes taking place in the “new C-cycle” controlled by plant C-uptake and decomposition of their inputs to the soil. In many places, plant communities are expected to become more productive as temperatures warm which may increase C uptake from the atmosphere. Changes in plant community composition may also alter microbial community composition and the decomposability and input rates of litter, resulting changes to C storage versus production of CO2 and CH4. Here we investigate these processes in a thawing permafrost peatland. We found that plant community composition plays an important role in shaping phyllosphere microbial communities but environmental conditions are more important to shaping rhizosphere communities. Plant communities were especially important in shaping methanogenic and methanotrophic communities, which may have important implications for CH4 production. Plant community change also resulted in increased rates of C and nutrient inputs to the soil due to a transition from perennial to annual communities. These litter inputs are decomposed most rapidly in post-thaw areas and drive an increased rate of CH4 production from both the litter itself and the soil organic material already present. Overall, we found that permafrost thaw in peat-dominated systems leads to an increasing rate of C-cycling (larger inputs as well as outputs) driven in large part by changes in plant community composition and their impacts on microbial community and decomposition. Plant community characteristics may be especially important in determining the pathways to CH4 production as well as the timing and total quantities produced. We suggest that shifts in the plant community after permafrost thaw in peat-dominated systems result in major changes to the “new C cycle” which may have as important an impact on climate change feedbacks as decomposition of thawed permafrost itself

Connecting plant traits and social perceptions in riparian systems: Ecosystem services as indicators of thresholds in social-ecohydrological systems

A major challenge in predicting the response of both social-hydrological and social-ecological systems to environmental change is the lack of a causal framework for predicting thresholds of change between the linked social and natural components. Here we propose a social-ecohydrological thresholds (SEHT) framework that integrates social-hydrological, trait-based ecological, and ecosystem services concepts. This approach facilitates the identification of thresholds by treating ecosystem services as indicators of the coupling of social and natural components of the system. Using the San Pedro riparian corridor in Arizona as a case study, we implemented the SEHT framework using ecological research and stakeholder perspectives to identify key drivers and thresholds in the social-ecohydrological system. In this way, we were able to describe expected outcomes of different hydrological change scenarios on the system. Stakeholders provided input on the utility of this information to inform management decisions aimed at mitigating the impacts of environmental change. The SEHT framework provides insight on dynamics of ecosystem services. This paper demonstrates that application of the framework enables the identification of several critical drivers of potential thresholds in ecosystem services that derive from either natural or social components of the overall system. These potential thresholds can guide ecosystem service assessment and monitoring and provide a roadmap for environmental management and the development of management scenarios.USA National Science Foundation (NSF) [DEB-1010495]; Inter-American Institute for Global Change Research (IAI) [CRN3056, GEO-1128040]; Morris K. and Stewart L. Udall Foundation; USDA NIFA Hatch project through the Maryland Agricultural Experimentation Station24 month embargo; published online: 12 August 2018This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Biotic and Environmental Drivers of Plant Microbiomes Across a Permafrost Thaw Gradient

Plant-associated microbiomes are structured by environmental conditions and plant associates, both of which are being altered by climate change. The future structure of plant microbiomes will depend on the, largely unknown, relative importance of each. This uncertainty is particularly relevant for arctic peatlands, which are undergoing large shifts in plant communities and soil microbiomes as permafrost thaws, and are potentially appreciable sources of climate change feedbacks due to their soil carbon (C) storage. We characterized phyllosphere and rhizosphere microbiomes of six plant species, and bulk peat, across a permafrost thaw progression (from intact permafrost, to partially- and fully-thawed stages) via 16S rRNA gene amplicon sequencing. We tested the hypothesis that the relative influence of biotic versus environmental filtering (the role of plant species versus thaw-defined habitat) in structuring microbial communities would differ among phyllosphere, rhizosphere, and bulk peat. Using both abundance- and phylogenetic-based approaches, we found that phyllosphere microbial composition was more strongly explained by plant associate, with little influence of habitat, whereas in the rhizosphere, plant and habitat had similar influence. Network-based community analyses showed that keystone taxa exhibited similar patterns with stronger responses to drivers. However, plant associates appeared to have a larger influence on organisms belonging to families associated with methane-cycling than the bulk community. Putative methanogens were more strongly influenced by plant than habitat in the rhizosphere, and in the phyllosphere putative methanotrophs were more strongly influenced by plant than was the community at large. We conclude that biotic effects can be stronger than environmental filtering, but their relative importance varies among microbial groups. For most microbes in this system, biotic filtering was stronger aboveground than belowground. However, for putative methane-cyclers, plant associations have a stronger influence on community composition than environment despite major hydrological changes with thaw. This suggests that plant successional dynamics may be as important as hydrological changes in determining microbial relevance to C-cycling climate feedbacks. By partitioning the degree that plant versus environmental filtering drives microbiome composition and function we can improve our ability to predict the consequences of warming for C-cycling in other arctic areas undergoing similar permafrost thaw transitions

Plant organic matter inputs exert a strong control on soil organic matter decomposition in a thawing permafrost peatland.

Peatlands are climate critical carbon (C) reservoirs that could become a C source under continued warming. A strong relationship between plant tissue chemistry and the soil organic matter (SOM) that fuels C gas emissions is inferred, but rarely examined at the molecular level. Here we compared Fourier transform infrared (FT-IR) spectroscopy measurements of solid phase functionalities in plants and SOM to ultra-high-resolution mass spectrometric analyses of plant and SOM water extracts across a palsa-bog-fen thaw and moisture gradient in an Arctic peatland. From these analyses we calculated the C oxidation state (NOSC), a measure which can be used to assess organic matter quality. Palsa plant extracts had the highest NOSC, indicating high quality, whereas extracts of Sphagnum, which dominated the bog, had the lowest NOSC. The percentage of plant compounds that are less bioavailable and accumulate in the peat, increases from palsa (25%) to fen (41%) to bog (47%), reflecting the pattern of percent Sphagnum cover. The pattern of NOSC in the plant extracts was consistent with the high number of consumed compounds in the palsa and low number of consumed compounds in the bog. However, in the FT-IR analysis of the solid phase bog peat, carbohydrate content was high implying high quality SOM. We explain this discrepancy as the result of low solubilization of bog SOM facilitated by the low pH in the bog which makes the solid phase carbohydrates less available to microbial decomposition. Plant-associated condensed aromatics, tannins, and lignin-like compounds declined in the unsaturated palsa peat indicating decomposition, but lignin-like compounds accumulated in the bog and fen peat where decomposition was presumably inhibited by the anaerobic conditions. A molecular-level comparison of the aboveground C sources and peat SOM demonstrates that climate-associated vegetation shifts in peatlands are important controls on the mechanisms underlying changing C gas emissions

Coupling plant litter quantity to a novel metric for litter quality explains C storage changes in a thawing permafrost peatland

Permafrost thaw is a major potential feedback source to climate change as it can drive the increased release of greenhouse gases carbon dioxide (CO2 ) and methane (CH4 ). This carbon release from the decomposition of thawing soil organic material can be mitigated by increased net primary productivity (NPP) caused by warming, increasing atmospheric CO2 , and plant community transition. However, the net effect on C storage also depends on how these plant community changes alter plant litter quantity, quality, and decomposition rates. Predicting decomposition rates based on litter quality remains challenging, but a promising new way forward is to incorporate measures of the energetic favorability to soil microbes of plant biomass decomposition. We asked how the variation in one such measure, the nominal oxidation state of carbon (NOSC), interacts with changing quantities of plant material inputs to influence the net C balance of a thawing permafrost peatland. We found: (1) Plant productivity (NPP) increased post-thaw, but instead of contributing to increased standing biomass, it increased plant biomass turnover via increased litter inputs to soil; (2) Plant litter thermodynamic favorability (NOSC) and decomposition rate both increased post-thaw, despite limited changes in bulk C:N ratios; (3) these increases caused the higher NPP to cycle more rapidly through both plants and soil, contributing to higher CO2 and CH4  fluxes from decomposition. Thus, the increased C-storage expected from higher productivity was limited and the high global warming potential of CH4 contributed a net positive warming effect. Although post-thaw peatlands are currently C sinks due to high NPP offsetting high CO2 release, this status is very sensitive to the plant community's litter input rate and quality. Integration of novel bioavailability metrics based on litter chemistry, including NOSC, into studies of ecosystem dynamics, is needed to improve the understanding of controls on arctic C stocks under continued ecosystem transition.Open access articleThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Coupling plant litter quantity to a novel metric for litter quality explains C storage changes in a thawing permafrost peatland.

Permafrost thaw is a major potential feedback source to climate change as it can drive the increased release of greenhouse gases carbon dioxide (CO2 ) and methane (CH4 ). This carbon release from the decomposition of thawing soil organic material can be mitigated by increased net primary productivity (NPP) caused by warming, increasing atmospheric CO2 , and plant community transition. However, the net effect on C storage also depends on how these plant community changes alter plant litter quantity, quality, and decomposition rates. Predicting decomposition rates based on litter quality remains challenging, but a promising new way forward is to incorporate measures of the energetic favorability to soil microbes of plant biomass decomposition. We asked how the variation in one such measure, the nominal oxidation state of carbon (NOSC), interacts with changing quantities of plant material inputs to influence the net C balance of a thawing permafrost peatland. We found: (1) Plant productivity (NPP) increased post-thaw, but instead of contributing to increased standing biomass, it increased plant biomass turnover via increased litter inputs to soil; (2) Plant litter thermodynamic favorability (NOSC) and decomposition rate both increased post-thaw, despite limited changes in bulk C:N ratios; (3) these increases caused the higher NPP to cycle more rapidly through both plants and soil, contributing to higher CO2 and CH4  fluxes from decomposition. Thus, the increased C-storage expected from higher productivity was limited and the high global warming potential of CH4 contributed a net positive warming effect. Although post-thaw peatlands are currently C sinks due to high NPP offsetting high CO2 release, this status is very sensitive to the plant community's litter input rate and quality. Integration of novel bioavailability metrics based on litter chemistry, including NOSC, into studies of ecosystem dynamics, is needed to improve the understanding of controls on arctic C stocks under continued ecosystem transition