Research
Our Big Questions
Leveraging agricultural land’s natural ability to recapture and store previously lost soil organic carbon (SOC) is one of the most efficient, feasible, and scalable “natural climate solutions” at humanity’s disposal. While croplands keep expanding globally, cropland abandonment is a global phenomenon that naturally recaptures part of the more than 100 Pg of soil carbon historically lost through traditional agriculture.
Yet the extent and duration of agricultural land abandonment and the potential of soils to store carbon following abandonment have not been quantified, and there is no consensus about the best strategies to maximize SOC recovery after abandonment.
This project will resolve this uncertainty by:
- Mapping cropland abandonment,
- Modeling and mapping SOC sequestration potentials in abandoned croplands.
This project leverages Earth Observation and ground-based data with machine-learning to inform policy and guide sustainable land management.
We will identify hotspots for carbon sequestration, best practices, and provide farmers, corporations and governments a scientific tool to economically incentivize the protection of ecosystems undergoing land use changes that promote carbon sequestration.
Forest restoration holds major potential to capture carbon from the atmosphere. But nature-based solutions related to forest restoration also have major pitfalls when the “how, where, and who” aspects of implementation are inappropriate.
Our lab is studying a potential win-win for both the climate and biodiversity crisis: natural forest regrowth. Under this approach, forests are allowed to regrow through the natural dispersal of seeds, rather than through tree planting by people.
In this research project, we are targeting a feedback between biodiversity and carbon storage involving seed dispersal by animals. About half of plant species – and over 90% of tree species in many tropical forests – rely on animals for seed dispersal. Allowing forests to regenerate naturally following deforestation and other disturbances holds potential to increase the biodiversity of plants in a forest and their resilience to climate change.
Yet the success of natural forest regrowth may also depend on the biodiversity and movement patterns of seed-dispersing animals in an area. Our ongoing research seeks to model seed dispersal by animals and its influence on the carbon trajectory of tropical forests. This work aims to increase the predictability of natural forest regrowth trajectories and identify regions where this restoration approach can be most effective.
Previous research determined that nutrients such as nitrogen are an important co-factor of plant growth, and therefore, plant carbon sequestration. Substantial efforts have been devoted to introduce nitrogen as a co-factor in the most used carbon cycle (CMIP) and vegetation models (TRENDY). Despite of it, the amount of nitrogen plants are taking from the soil to be part of its tissue remains unquantified.
Most of the nitrogen on earth can be found in the atmosphere in gas form (N2), comprising more than 70% of the atmosphere. Even if abundant, N2 is not available to be absorbed by plants, and biotic soil processes led by microorganisms are necessary to transform this nitrogen in plant-friendly forms such as ammonium or nitrate. Aside from these nitrogen-fixing microorganisms, we can also find other microorganisms that compete for organically bound nitrogen of which only part of it is going to available for plants to be absorbed.
We are aiming to leverage published field data accounting for plant biomass increase in roots, wood (if woody plant) and leaves as well as for the nitrogen contained in these tissues to train a machine-learning model.
There we will be determining the drivers that affect this relation, creating an upscaled map of nitrogen uptake worldwide and comparing the differences these results suppose to global change calculations.
If you are interested in collaborating or discussing with us feel free to reach out at helenavp@mit.edu
Related papers:
Fernández-Martínez M, Vicca S, Janssens IA, Sardans J, Luyssaert S, Campioli M, Chapin FS III, Ciais P, Malhi Y, Obersteiner M et al. 2014. Nutrient availability as the key regulator of global forest carbon balance. Nature Climate Change 4: 471–476.
Hungate, B.A., Dukes, J.S., Shaw, M.R., Luo, Y., Field, C.B. Nitrogen and Climate change. Science 302, 1512-1513, (2003)
Terrer, C., Jackson, R.B., Prentice, I.C. et al. Nitrogen and phosphorus constrain the CO2 fertilization of global plant biomass. Nat. Clim. Chang. 9, 684–689 (2019). https://doi.org/10.1038/s41558-019-0545-2
The terrestrial system is considered a net carbon sink in the global carbon cycle, referred to as “the missing link”. However, whether the global soil carbon pool is a net sink or source is still not clear. Our lack of understanding in the fate of plant biomass after plant lifetime and its transformation into soil organic matter makes this challenge more difficult. We explore the temporal change of SOC in response to climate. Knowing the change of SOC storage in the past few decades can help us understand the potential amount of soil carbon sequestration in the next decades and provide benchmarking information to current SOC Earth System Models.
This research initiative aims to quantify the impact of vegetation dynamics and cover alterations on biophysical and biogeochemical properties in terrestrial ecosystems. Utilizing advanced computational models, the project focuses on understanding the interactions among energy, water, and carbon fluxes.
Specific attention is devoted to assessing the efficacy of terrestrial carbon sinks in various scenarios, including deforestation, reforestation, and natural greening processes.
Additionally, the project investigates internal forest feedback mechanisms, such as alterations in resilience thresholds that may exacerbate vulnerability to wildfires and extreme climatic events. The overarching objective is to resolve extant uncertainties in terrestrial carbon sink dynamics, thereby enhancing our understanding of their implications for global climate change and informing evidence-based strategies.
The increase in extreme weather events caused by climate change has become more observable in recent years and can have profound impacts on the forest ecosystem. As climate change fosters more intense storms, we are expecting the cycle of forest damage and regrowth, referred to as the disturbance regime, to occur more frequently, altering forest dynamics and potentially reducing carbon storage. Therefore, it is critical to understand the impacts of these severe storms on carbon dynamics.
Identifying vulnerable regions can significantly aid in swift disaster management following storms, helping preserve our forest resources and the crucial role they play in mitigating climate change through informed and timely interventions.
This project leverages multi-sensor land and atmosphere remote sensing observations, climate reanalysis data, and earth system models combined with statistical methods and machine learning to understand the spatial patterns of ecosystem carbon dynamics affected by extreme storms from local to global scale. This research will improve the coupling of the land and atmosphere carbon dynamics in Earth System Models and is crucial for understanding the weakening of forest carbon sink.
The role that nutrient limitation plays in constraining biomass is a major source of uncertainty in projections of the terrestrial carbon sink, and therefore our understanding of future climate change. An ecosystem level approach, incorporating above and below ground biomass in addition to soil carbon stocks, is vital to understanding the net impact of nutrient limitation across various carbon pools.
Almost all terrestrial ecosystems experience nutrient limitation by nitrogen, phosphorus, or both. To attempt to alleviate nutrient limitations, plants can increase their fine root biomass, stimulate the liberation of nutrients from soil organic matter through mycorrhizal fungi or bacteria, increase the fixation of atmospheric nitrogen to plant-available forms, increase the production of relevant enzymes, and decrease the concentration of nutrients in their tissues. These responses to nutrient limitation vary by plant functional type and can impact plant biomass, microbial biomass, and soil carbon differently.
Our objective is to understand the impacts that nutrient limitation alleviation strategies have on terrestrial carbon stocks. By understanding the costs and benefits that would make certain strategies more advantageous to others in different ecological conditions, we hope to explain seemingly contradictory responses to elevated carbon dioxide experiments. Ultimately, we aim to provide a better understanding of how, where, and why nutrients may limit the terrestrial carbon sink.
Please reach out to tcambron@mit.edu if you are interested in discussing this topic or potential collaborations.
Peatlands store an estimated one-third of the world’s soil organic carbon. However, land-use change and wildfires have induced and will continue to induce large greenhouse gas emissions from this dense carbon sink.
This project uses field data, remote sensing data, and modeling to understand the past and future of the global peatland carbon sink.