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1. Disturbance ecology in a pelagic upwelling biome: Lagrangian frameworks for studying succession

   Stukel, Michael R; Allen, Andrew E; Barbeau, Katherine A; Chabert, Pierre; Dovel, Shonna; Gangrade, Shailja; Kranz, Sven A (September 2025, BioScience)

   Disturbance ecology is underdeveloped in marine pelagic ecosystems relative to terrestrial and aquatic benthic habitats, in part because, when measured relative to a fixed location, postdisturbance recovery involves the advection of entire communities in addition to biotic interactions. A Lagrangian frame-of-reference perspective alleviates this issue. Using results from the California Current Ecosystem, we highlight three approaches: in situ Lagrangian, synthetic Lagrangian, and simulated Lagrangian studies. Within a Lagrangian context, extratropical marine heatwaves and El Niños represent press disturbances or alterations to the disturbance regime. Individual upwelling events are more appropriately viewed as pulse disturbances. Upwelling disturbances stimulate rapid growth of pioneer species (diatoms), with herbivores (copepods) lagging these blooms by approximately 3 weeks. The climax community is an assemblage of small low-nutrient specialists with high Shannon diversity. We suggest that pelagic ecosystems can be ideal systems for investigating disturbance recovery because of the rapid response times of marine primary producers and herbivores. 

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2. Variance reflects resilience to disturbance along a stress gradient: Experimental evidence from coastal marshes

   https://doi.org/10.1002/ecy.4241  

   Wang, Yinhua; Guo, Hongyu; Alber, Merryl; Pennings, Steven C (March 2024, Ecology)

   Abstract Quantifying ecosystem resilience to disturbance is important for understanding the effects of disturbances on ecosystems, especially in an era of rapid global change. However, there are few studies that have used standardized experimental disturbances to compare resilience patterns across abiotic gradients in real‐world ecosystems. Theoretical studies have suggested that increased return times are associated with increasing variance during recovery from disturbance. However, this notion has rarely been explicitly tested in field, in part due to the challenges involved in obtaining long‐term experimental data. In this study, we examined resilience to disturbance of 12 coastal marsh sites (five low‐salinity and seven polyhaline [=salt] marshes) along a salinity gradient in Georgia, USA. We found that recovery times after experimental disturbance ranged from 7 to >127 months, and differed among response variables (vegetation height, cover and composition). Recovery rates decreased along the stress gradient of increasing salinity, presumably due to stress reducing plant vigor, but only when low‐salinity and polyhaline sites were analyzed separately, indicating a strong role for traits of dominant plant species. The coefficient of variation of vegetation cover and height in control plots did not vary with salinity. In disturbed plots, however, the coefficient of variation (CV) was consistently elevated during the recovery period and increased with salinity. Moreover, higher CV values during recovery were correlated with slower recovery rates. Our results deepen our understanding of resilience to disturbance in natural ecosystems, and point to novel ways that variance can be used either to infer recent disturbance, or, if measured in areas with a known disturbance history, to predict recovery patterns. 

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3. Understanding the effects of climate change via disturbance on pristine arctic lakes—multitrophic level response and recovery to a 12‐yr, low‐level fertilization experiment

   https://doi.org/10.1002/lno.11893  

   Budy, Phaedra; Pennock, Casey A.; Giblin, Anne E.; Luecke, Chris; White, Daniel L.; Kling, George W. (January 2021, Limnology and Oceanography)

   Effects of climate change-driven disturbance on lake ecosystems can be subtle; indirect effects include increased nutrient loading that could impact ecosystem function. We designed a low-level fertilization experiment to mimic persistent, climate change-driven disturbances (deeper thaw, greater weathering, or thermokarst failure) delivering nutrients to arctic lakes. We measured responses of pelagic trophic levels over 12 yr in a fertilized deep lake with fish and a shallow fishless lake, compared to paired reference lakes, and monitored recovery for 6 yr. Relative to prefertilization in the deep lake, we observed a maximum pelagic response in chl a (+201%), dissolved oxygen (DO, _43%), and zooplankton biomass (+88%) during the fertilization period (2001–2012). Other responses to fertilization, such as water transparency and fish relative abundance, were delayed, but both ultimately declined. Phyto- and zooplankton biomass and community composition shifted with fertilization. The effects of fertilization were less pronounced in the paired shallow lakes, because of a natural thermokarst failure likely impacting the reference lake. In the deep lake there was (a) moderate resistance to change in ecosystem functions at all trophic levels, (b) eventual responses were often nonlinear, and (c) postfertilization recovery (return) times were most rapid at the base of the food web (2–4 yr) while higher trophic levels failed to recover after 6 yr. The timing and magnitude of responses to fertilization in these arctic lakes were similar to responses in other lakes, suggesting indirect effects of climate change that modify nutrient inputs may affect many lakes in the future. 

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4. Deciphering spatial scales of connectivity in a subsidy-dependent coastal ecosystem

   https://doi.org/10.1038/s42003-025-08354-8  

   Emery, Kyle A; Dugan, Jenifer E; Miller, Robert J; Hubbard, David M; Madden, Jessica R; Cavanaugh, Kyle C (August 2025, Communications Biology)

   Abstract Cross-ecosystem subsidies influence the structure and dynamics of recipient ecosystems and can be sensitive to disturbance. Primary production exported from marine to shoreline ecosystems is among the largest known cross-ecosystem subsidies. However, the spatial scales at which this important connection is manifested are largely unquantified. We used local and regional observations of nearshore kelp canopy biomass and beach kelp wrack inputs to evaluate the scales at which connectivity between kelp forests and beaches is maximized. Regardless of the spatial and temporal scales considered, connectivity was highly local (<10 km) and strongest in winter. Kelp canopy biomass was the primary driver of wrack subsidies, but recipient ecosystem attributes, particularly beach width and orientation, were also important. These drivers of connectivity highlight that disturbance to either ecosystem will have large implications for beach ecosystem productivity. Spatial connectivity can regulate recovery from disturbances such that ecosystem connections must be considered in conservation efforts. 

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5. Bacterial community response to novel and repeated disturbances

   https://doi.org/10.1111/1758-2229.70022  

   Halbrook, Susannah; Wilber, William; Barrow, Mary Elizabeth; Farrer, Emily C (October 2024, Environmental Microbiology Reports)

   Abstract Disturbance response and recovery are increasingly important in microbial ecology, as microbes may recover from disturbances differently than macro communities. Past disturbances can alter microbial community structure and their response to subsequent disturbance events, but it remains unclear if the same recovery patterns persist after long‐term exposure to stress. Here, we compare bacterial community composition in a community that experienced 2 years of monthly salinity addition disturbances with a community that has not experienced salinity additions. We then track the response and recovery to an additional salinity addition based on past disturbance exposure. We tested the following hypotheses: first, communities with a repeated disturbance history will have a different community composition than communities without a disturbance history; second, communities exposed to repeated disturbances will undergo a different recovery trajectory than communities experiencing a novel disturbance. We find that repeated disturbances alter community composition and affect community response and recovery to a subsequent disturbance after 2 years, primarily through increased resistance. This work enhances our understanding of microbial temporal dynamics and suggests that novel disturbances may pose a threat to microbial community structure and function. 

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