I have accepted a faculty position in the Odum School at the University of Georgia and will no longer be maintaining this page. Please visit my new website:
https://strausslab.ecology.uga.edu
https://strausslab.ecology.uga.edu
Research Philosophy
I am a quantitative disease ecologist. I study the intersections of disease ecology with community, behavioral, evolutionary, and ecosystem ecology, especially in the context of global change. My research combines three complementary approaches: observations from nature inspire relevant questions, experiments test specific predictions, and mathematical models generalize theory. My empirical work focuses on one aquatic study system (fungal pathogens that infect zooplankton) and more recently, one terrestrial study system (fungal pathogens and aphid-vectored viruses that infect grasses). Together, these systems allow me to ask a variety of conceptually-motivated questions. |
1) Disease x Community Ecology
Does loss of biodiversity increase disease? ‘Dilution effects’ – patterns between diversity loss and elevated disease risk – suggests tantalizing win-wins for conservation of biodiversity and management of disease. Yet dilution effects are controversial and often unpredictable. I aim to strengthen theoretical foundations for disease dilution by focusing on the trait-dependent, mechanistic species interactions - like competition and predation - that can drive this pattern. Check out this blog post to learn more about my perspectives on dilution effect research. Relevant publications: Strauss et al. 2015 Ecology Letters; Strauss et al. 2016 Ecological Monographs; Strauss et al. 2017 Proc. B.; Strauss et al. 2018 Functional Ecology What maintains the diversity of pathogens WITHIN hosts? Coinfections are ubiquitous in nature, but pathogens frequently compete and inhibit one another's growth in coinfected hosts. I am developing and testing models that explain how pathogen diversity is shaped by a balance of processes that operate among hosts - like transmission - and processes that operate within hosts - like competition for shared resources and interactions with the host immune system. Relevant publications: Strauss et al. 2019 Ecology |
Key species from the lakes: focal host Daphnia dentifera (right), competitor & diluter Ceriodaphnia (bottom left), and predator Chaoborus (top). Photo credit: Meg Duffy
|
2) Disease x Behavioral Ecology
When does vector behavior alter disease dynamics? Epidemiological models often assume that vector transmission is proportional to the frequency of infections in the host population. Yet new insights arise from models that treat vectors as foraging animals, which can vary in demographic rates, dispersal behaviors, or feeding preferences. Aphids that vector viruses (barley/ cereal yellow dwarf viruses: B/CYDVs) among grass hosts offer an ideal study system for developing and testing these ideas. For example, aphids that carry the virus show altered feeding behaviors and movement patterns. Rearing conditions can also influence aphids host choices later in life. Relevant publications: Shoemaker et al. 2019 Ecology Letters; Strauss et al. in review |
left: Aphids (R. padi; the black dots) transmitting barley yellow dwarf virus RMV between grasses (oats; Avena sativa) in an 'aphid arena' experiment.
bottom: Narmada Venkateswaran sets up an aphid preference experiment. In each dish, aphids choose among tissues from four different types of hosts. |
3) Disease x Evolutionary Ecology
How do hosts evolve in an ecological context? In theory, hosts should evolve traits that mitigate costs of disease. In reality, hosts often evolve surprising traits during epidemics, in part because rapid trait evolution can also modulate interactions with competitors and elicit ecological costs. The zooplankton study system (host: Daphnia dentifera; parasite: Metschnikowia bicuspidata) is ideally suited to grapple with such eco-evolutionary puzzles. These hosts can rapidly evolve traits such as competitive ability, disease resistance, and parasite avoidance behavior. In turn, rapid evolution of these traits can dramatically transform interactions among hosts, resources, and competitors. Relevant publications: Strauss et al. 2017 Proc. B; Strauss et al. 2019 Proc. B |
|
4) Disease x Ecosystem Ecology
When do parasites catalyze invasions? Invasive species and emerging infectious diseases both pose significant threats to ecosystem function. Disease-mediated invasions arise when these threats combine: Non-native species can displace native hosts by transmitting shared parasites or pathogens. Relevant publications: Strauss et al. 2012 Functional Ecology Do diseases mediate ecosystem processes? Ecosystem models describe fluxes and pools of elements, while epidemiological models track susceptible and infected hosts. Because of these different currencies, ecosystem ecologists rarely ask how infections alters ecosystem processes (e.g., via altered rates of photosynthesis), and disease ecologists rarely ask how elemental ratios shape disease dynamics. I am trying to bridge this gap between disease and ecosystem ecology with theory and experiments. |
|