Welcome to the Bradford Lab!

Understanding carbon in ecosystems: biology, ecology, management, and environmental change 

Why focus on carbon and ecosystems? Soils and plants store huge quantities of carbon. Disturbances that degrade ecosystems release this into the atmosphere – in forms such as carbon dioxide – contributing to our changing climate. But soils and ecosystems are much more than reservoirs for carbon – their health is directly tied to water purification, flood prevention, maintenance of biodiversity, and agricultural production. Understanding how and why plants, animals, microbes and soils respond to environmental change will therefore help us understand the consequences for human well-being, and how we might manage them.

We use experimental and observational approaches to investigate these effects of global change, both in the field and laboratory. We primarily work across forests, agricultural lands, and grasslands in the United States.

The overall goal of our research is to provide the necessary mechanistic understanding required for reliable prediction of global change impacts on ecosystems, and their likely feedbacks to the climate system.

In addition, a number of us are involved in related research efforts to facilitate the development of a set of open tools that advance the application of soil science to inform policy and practice.  One such program is Quick Carbon, an approach designed to facilitate rapid measurement and verification of soil carbon in working landscapes.

POSTDOC OPPORTUNITY: We recently received an NSF Macrosystems grant and are looking to hire a postdoc for a start date around April 2020. If you’re interested, please check out the following job description. We hope to hear from you!

Postdoctoral position: local controls on decomposition and macrosystem biogeochemical patterns

The Bradford Lab at Yale (https://bradfordlab.yale.edu) is seeking a highly motivated postdoctoral scholar to study how local-scale controls on litter decomposition shape emergent macrosystem biogeochemical patterns. The postdoc will lead the establishment and execution of the field work at 18 NEON sites (and hence the position will involve periods of intensive travel), as well as the controlled laboratory research. In addition, the postdoc is expected to have an interest in working with the full collaborative group to develop the integration of the observations into statistical and process-based models to simulate macrosystem patterns in carbon and nitrogen cycling. The postdoctoral researcher will be expected to both lead and contribute to peer-reviewed publications from the empirical and modeling work, and there is funding to present the work at scientific meetings. The position is based in the Bradford Lab at Yale University, with opportunities to travel to the collaborating lab in Boulder, Colorado. This NSF-funded macrosystem grant is a collaborative effort among Mark Bradford (Yale), Will Wieder (CU Boulder and NCAR), and Steve Wood (The Nature Conservancy). All three PIs are committed to structured mentoring activities to prepare the postdoc to succeed in their career path in the ecological and biogeochemical sciences, and to work with those under-represented in these sciences to overcome and dismantle barriers. Starting salary for the position is 50K USD with a start date of April 1, 2019. Interested candidates should have a PhD in a related field and a demonstrated record of publication. Candidates with experience with litter decomposition, functional characterization of microbial communities, and/or biogeochemistry are encouraged to apply.

To apply, send a single PDF that includes a 1-page cover letter explaining research interests and experience, a CV, and listing three potential references. Applications or inquiries should be directed to mark.bradford@yale.edu with the subject line “Macrosystems decomp postdoc”.

Overview of the project:

Belowground organisms cycle carbon and nutrients and hence may influence how biogeochemical processes respond to environmental change. Whether this influence extends to shaping macrosystem biogeochemical behavior is unknown. Ecosystem theory and biogeochemical models are based on the assumption that it does not, with different belowground communities functioning similarly under the same environmental conditions. As such, the impact of disturbances such as climate change on macrosystem biogeochemical patterns should be predictable without understanding site-specific differences in these communities. Emerging evidence challenges the validity of this assumption of scale invariance and suggests instead that the activities of decomposer communities are uniquely shaped by regional climate. Our porject tests these competing hypotheses of scale invariance versus scale dependence for litter decomposition, a representative biogeochemical process. These competing hypotheses have not been evaluated because the design of previous broad scale decomposition experiments, which aggregate local-scale responses, does not permit falsification of the hypothesis of scale invariance. This information gap is addressed throughfield experiments, extensively replicated within 18 NEON sites in seven domains. The field research is being combined with controlled laboratory studies to quantify site-specific relationships between temperature, moisture, litter quality and decomposition rates, and to evaluate whether the relationships arise through selection by the domain-level climate for particular microbial functional traits. The mechanistic insights and data generated through this empirical work will inform the structure, and be used to directly estimate the parameters, of a biogeochemical model. The model will be used to forecast the sensitivity of macrosystem behavior to the possibility that it emerges from scale-dependent relationships generated by trade-offs which dictate the activities of belowground communities.