Quantifying rates of biome shifts under climate change in arctic and boreal ecosystems
Quantifying rates of biome shifts under climate change in arctic and boreal ecosystems
The global carbon stockpile is largely concentrated in boreal forests, with estimates ranging from 30-50%. Multiple threats to these forests that will force a transition from a global carbon sink to source include wildfire, insects, permafrost melt and timber harvesting. Yet predictions of how climate change will impact boreal forests have not included each of these disturbance agents that may lead to a runaway climate scenario, and so uncertainty is high regarding the capacity of these forests to maintain their status as carbon sinks. Central to the uncertainty is in how climate change may cause ecosystem conversions from tundra to forest, and forest to grassland, and how these may feedback to accelerate climate change. Our research goal is to evaluate the ability of arctic and boreal ecosystems to keep pace with climate change, quantifying temporal and spatial variation in biome shifts and vegetation-climate feedbacks across a large latitudinal gradient in central Siberia.
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Project website: https://melissalucash.com/projects/siberia
Functional paleoecology
I specialize in biodiversity dynamics of the past by linking plant functional traits to paleoecological records. The strength of my research lies in the breadth and depth of big-data, being ecological and paleoecological, and statistical approaches I use to understand macroecological phenomena and biodiversity dynamics. The big-data methods I am developing quantify key aspects of biodiversity that are both novel to and principal for understanding how future-global scenarios may unravel.
My interests lie in biodiversity in terrestrial settings and ecosystem services and resilience. The nexus of these have led me to develop novel studies on past ecosystems, wherein I quantify plant functional diversity and examine individual trait variations through time.
I continue to strive for improvement in how we understand how our world works.
Recent Research
Proof of concept: Transforming pollen data to ecological function
Temperature 12k Project
My work has led me to large international collaborations. Recently, I was invited to participate in the Temperature 12k Project.
Previous efforts to reconstruct Holocene temperature variations were based on a small dataset, and results varied significantly from models. This international project is reconstructing global temperatures by developing a new database housing a variety of proxy-based temperature reconstructions from individual sites, marine and terrestrial.
As the Lead Coordinator for pollen-based reconstructions globally, I am playing a large role by directing a team in quality-controlling datasets, so that the global synthesis will be accurate and future users of the data will be assured of their quality.
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This work was recently published in Nature Scientific Data
Functional paleoecology is a growing field that provides new perspectives on ecosystem processes and function that are not typically available from traditional paleoecological methods. However, there has yet to be an assessment for how well the transformation represents ecological function.
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As a proof of concept, surface pollen samples in North America were linked to three plant functional traits (plant heigh, leaf area, seed mass) corresponding to the fitness function and comparisons were made to the datasets that were used to make the transformation. Results show that indeed, transforming pollen to ecological function captures the niche space of plant species in North America, and from these estimates, the latitudinal gradient of functional diversity was reconstructed.
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This work was recently accepted for a Special Issue in Frontiers in Ecology & Evolution
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Development of the latitudinal functional diversity and trait space gradients from pollen data and plant traits in North America and Europe
The latitudinal biodiversity gradient (LBG) is represented by a decrease of net biodiversity with increasing absolute latitude. Deep-time studies suggest that some form of the LBG has been present over the past ~500 million years, but the pattern has strengthened over the past 30 million years. Here, we assess how the latitudinal gradients in functional diversity and trait space have evolved relative to climate and humans in North America and Europe.
Do pollen species matter to ecosystem function? A case study from high-elevation Utah
Estimates of plant functional diversity are tightly linked to how resilient ecosystems are to variations in climate and human influences. That is to say, ecosystems housing a wider range of diversity should be more resilient than those ecosystems with less diversity, due to a wider breadth of responses. Inherent to this is the question: Do species matter to ecosystem function and resilience? To test this, time series of functional diversity from a high-elevation site in Utah are compared to pollen richness.
Grants, Scholarships & Fellowships
While attending the University of Utah:
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Donald A. & Susan P. Lewon Graduate Fellowship, University of Utah ($7950)
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U.S. National Committee for Quaternary Research INQUA Congress Fellowship Program ($1990)
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University of Utah Alumni Association, New York Chapter ($6550)
While attending the University of Wyoming:
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Roy J. Shlemon Center for Quaternary Studies, University of Wyoming ($1000)
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Grants-in-aid of Research, University of Wyoming ($1000)
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Roy J. Shlemon Center for Quaternary Studies, University of Wyoming ($1000)