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1. Overcoming toxicity: How nonantagonistic microbes manage to thrive in boom-and-bust environments

   https://doi.org/10.1073/pnas.2424372122  

   Wang, MingYi; Vladimirsky, Alexander; Giometto, Andrea (June 2025, Proceedings of the National Academy of Sciences)

   Antagonistic interactions are critical determinants of microbial community stability and composition, offering host benefits such as pathogen protection and providing avenues for antimicrobial control. While the ability to eliminate competitors confers an advantage to antagonistic microbes, it often incurs a fitness cost. Consequently, many microbes only produce toxins or engage in antagonistic behavior in response to specific cues like quorum sensing molecules or environmental stress. In laboratory settings, antagonistic microbes typically dominate over sensitive ones, raising the question of why both antagonistic and nonantagonistic microbes are found in natural environments and host microbiomes. Here, using both theoretical models and experiments with killer strains ofSaccharomyces cerevisiae, we show that “boom-and-bust” dynamics—periods of rapid growth punctuated by episodic mortality events—caused by temporal environmental fluctuations can favor nonantagonistic microbes that do not incur the growth rate cost of toxin production. Additionally, using control theory, we derive bounds on the competitive performance and identify optimal regulatory toxin-production strategies in various boom-and-bust environments where population dilutions occur either deterministically or stochastically over time. Our mathematical investigation reveals that optimal toxin regulation is much more beneficial to killers in stochastic, rather than deterministic, boom-and-bust environments. Overall, our findings show how both antagonistic and nonantagonistic microbes can thrive under varying environmental conditions. 

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2. A review of community impacts of boom-bust cycles in unconventional oil and gas development

   Klasic, Meghan; Schomburg, Madeline; Arnold, Gwen; York, Abigail; Baum, Melissa; Cherin, Maia; Cliff, Sydney; Kavousi, Parisa; Tillett Miller, Alexandria Jordan; Shajari, Diana; et al (October 2022, The journal of energy research and social sciences)

   Unconventional oil and gas development (UOGD) has become the most widespread form of energy production in the United States. The booms and busts associated with UOGD are not unique to the industry, but the impacts to local communities are. As the industry continues to dominate the nation's energy landscape, and marginalized communities are disproportionately exposed to the extraction processes, it is important to understand the full scope of the environmental and social impacts experienced by communities during booms and busts. We review the literature on both the ecological and social boom-bust impacts of UOGD, noting the dearth of research on bust-time impacts. We conclude by calling for greater research on the long-term impacts of busts, in particular, and on understudied aspects of social impacts like those to public services, infrastructure, and social capital. 

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3. Niche theory for within‐host parasite dynamics: Analogies to food web modules via feedback loops

   https://doi.org/10.1111/ele.14142  

   Ramesh, Ashwini; Hall, Spencer R. (January 2023, Ecology Letters)

   Abstract Why do parasites exhibit a wide dynamical range within their hosts? For instance, why does infecting dose either lead to infection or immune clearance? Why do some parasites exhibit boom‐bust, oscillatory dynamics? What maintains parasite diversity, that is coinfectionvsingle infection due to exclusion or priority effects? For insights on parasite dose, dynamics and diversity governing within‐host infection, we turn to niche models. An omnivory food web model (IGP) blueprints one parasite competing with immune cells for host energy (PIE). Similarly, a competition model (keystone predation, KP) mirrors a new coinfection model (2PIE). We then drew analogies between models using feedback loops. The following three points arise: first, like in IGP, parasites oscillate when longer loops through parasites, immune cells and resource regulate parasite growth. Shorter, self‐limitation loops (involving resources and enemies) stabilise those oscillations. Second, IGP can produce priority effects that resemble immune clearance. But, despite comparable loop structure, PIE cannot due to constraints imposed by production of immune cells. Third, despite somewhat different loop structure, KP and 2PIE share apparent and resource competition mechanisms that produce coexistence (coinfection) or priority effects of prey or parasites. Together, this mechanistic niche framework for within‐host dynamics offers new perspective to improve individual health. 

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4. Contrasting invasion histories and effects of three non-native fishes observed with long-term monitoring data

   https://doi.org/10.1007/s10530-023-03146-9  

   Pintar, Matthew R.; Dorn, Nathan J.; Kline, Jeffrey L.; Trexler, Joel C. (August 2023, Biological Invasions)

   Boom-bust population dynamics are long-recognized phenomena during species invasions, but few studies documented impacts of these dynamic changes. The Florida Everglades is the largest wetland in the United States, is undergoing a multi-decade hydro-restoration effort, and has been invaded by several tropical freshwater fishes. We used a 26-year dataset of small native marsh fishes and decapods to assess potential effects of African Jewelfish (Hemichromis letourneuxi) invasion and compared their effects to those of a more recently invading species, Asian Swamp Eels (Monopterus albus/javanensis), and a long-established non-native species, Mayan Cichlids (Mayaheros urophthalmus). Unlike boom-bust dynamics of jewelfish, swamp eel abundance increased and stabilized over the course of this study. After accounting for effects of hydrologic variation, the densities of several native species were more reduced by either jewelfish or swamp eels than by native fish predators, while effects of Mayan Cichlids were similar to those of native fish predators. Impacts of the jewelfish boom in Shark River Slough were smaller (density reductions ≤ 50%) and more temporally limited than those of swamp eels, which produced near-complete loss of four species in Taylor Slough. Following the jewelfish bust, the density of affected species approximated pre-invasion predictions based on hydrology, but their recovery is now threatened by the subsequent invasion of swamp eels in Shark River Slough. Long-term monitoring data provide opportunities to probe for population-level effects at field scales, and indicate that impacts of non-native species can be context-dependent and vary across ecosystems and temporal scales. 

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5. Thermal acclimation influences the growth and toxin production of freshwater cyanobacteria

   https://doi.org/10.1002/lol2.10197  

   Layden, Tamara J.; Kremer, Colin T.; Brubaker, Delaney L.; Kolk, Maeve A.; Trout‐Haney, Jessica V.; Vasseur, David A.; Fey, Samuel B. (May 2021, Limnology and Oceanography Letters)

   Abstract Understanding how altered temperature regimes affect harmful cyanobacterial bloom formation is essential for managing aquatic ecosystems amidst ongoing climate warming. This is difficult because algal performance can depend on both current and past environments, as plastic physiological changes (acclimation) may lag behind environmental change. Here, we investigate how temperature variation on sub‐weekly timescales affects population growth and toxin production given acclimation. We studied four ecologically important freshwater cyanobacterial strains under low‐ and high‐nutrient conditions, measuring population growth rate after acclimation and new exposure to a range of temperatures. Cold‐acclimated populations (15.7°C) outperformed fully acclimated populations (held in constant conditions) across 65% of thermal environments, while hot‐acclimated populations (35.7–42.6°C) underperformed across 75% of thermal environments. Over a 5‐day period, cold‐acclimatedMicrocystis aeruginosaproduced ~2.5‐fold more microcystin than hot‐acclimated populations experiencing the same temperature perturbation. Our results suggest that thermal variation and physiology interact in underappreciated ways to influence cyanobacterial growth, toxin production, and likely bloom formation. 

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