Ecological succession and the competition-colonization trade-off in microbial communities.

Background: During range expansion in spatially distributed habitats, organisms differ from one another in terms of their patterns of localization versus propagation. To exploit locations or explore the landscape? This is the competition-colonization trade-off, a dichotomy at the core of ecological succession. In bacterial communities, this trade-off is a fundamental mechanism towards understanding spatio-temporal fluxes in microbiome composition.

Variance in Landscape Connectivity Shifts Microbial Population Scaling.

Understanding mechanisms shaping distributions and interactions of soil microbes is essential for determining their impact on large scale ecosystem services, such as carbon sequestration, climate regulation, waste decomposition, and nutrient cycling. As the functional unit of soil ecosystems, we focus our attention on the spatial structure of soil macroaggregates. Emulating this complex physico-chemical environment as a patchy habitat landscape we investigate the effect of changing the connectivity features of this landscape as forms a metapopulation.

Emergence of Resistant Mutants in Microfluidic Antibiotic Gradients.

Spatiotemporal structures and heterogeneities are common in natural habitats, yet their role in the evolution of antibiotic resistance is still to be uncovered. We applied a microfluidic gradient generator device to study the emergence of resistant bacteria in spatial ciprofloxacin gradients. We observed biofilm formation in regions with sub-inhibitory concentrations of antibiotics, which quickly expanded into the high antibiotic regions.

Expansion, Exploitation and Extinction: Niche Construction in Ephemeral Landscapes.

We aim to understand general consequences of niche construction on metapopulation dynamics in ephemeral landscapes. To this effect, a contact process-like stochastic spatial model is introduced where local populations colonize and go extinct on a dynamic landscape of habitable and destroyed patches. In contrast to previous models, where the extinction threshold is a consequence of available niche rendered by global rates of patch destruction/renewal, here we investigate how the metapopulation persists when they are the sole generators of their own niche.

Climate variation alters the synchrony of host-parasitoid interactions.

Observed changes in mean temperature and increased frequency of extreme climate events have already impacted the distributions and phenologies of various organisms, including insects. Although some research has examined how parasitoids will respond to colder temperatures or experimental warming, we know relatively little about how increased variation in temperature and humidity could affect interactions between parasitoids and their hosts. Using a study system consisting of emerald ash borer (EAB), , and its egg parasitoid , we conducted environmentally controlled laboratory experiments to investigate how increased seasonal climate variation affected the synchrony of host-parasitoid interactions.

What Does Not Kill You Makes You Stronger.

Colicin production is an extreme form of labor division; cells lyse after making the toxin! Stochastic phenotype switching allows producers to outcompete sensitive strains since colicin release frees up vacancy. If patch dynamics does not kill you, it stimulates adaptation to a dynamic habitat landscape which selects for rapid dispersal.