Spatiotemporal Dynamics in Microzooplankton

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Thanks to automated imaging approaches developed by NES LTER researchers, unprecedented insight has been gained into variations in microzooplankton biomass and diversity across a broad range of space and time scales. In addition, studies in Narragansett Bay documented strong microzooplankton grazing pressure on phytoplankton throughout the year, irrespective of season.  

Shifts in Phytoplankton Phenology are Associated With Warming Trends

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Phytoplankton bloom dynamics at Martha’s Vineyard Coastal Observatory (MVCO) are sensitive to temperature variability on both seasonal and decadal scales. Multi-year sampling has shown that the genetic background of phytoplankton is diverse and changes rapidly in coastal shelf waters. Ongoing NES LTER observations emphasize the complementary nature of multiple approaches (sequencing, imaging, and flow cytometry)… Read more »

Conceptual and Empirical Advances in Desert Microbial Ecology

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Credit: Anny ChungResearchers at SEV LTER led efforts to characterize fungi and bacteria in drylands and document their responses to environmental change. SEV LTER pioneered new assays of microbial function, including carbon use efficiency and ecoenzymatic stoichiometry. They quantified how microbes in roots maintain plant species coexistence and temporal stability in plant communities and how… Read more »

Hurricane Frequency Impacts Forest Biodiversity and Ecosystem Function

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The long term Canopy Trimming Experiment revealed many important aspects of hurricane disturbance, particularly that canopy opening caused more change in biota and biogeochemistry than debris deposition. More frequent disturbance led to canopy opening but less debris deposition, and changed forest species composition, which may alter resilience in the face of future disturbances. Frequent hurricane… Read more »

Microbial Dormancy and Diversity

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Credit: Ashley N. Bulseco et alA decade of nutrient enrichment significantly increased rates of oxygen uptake and nitrate reduction in sediment. Surprisingly, the proportion of the dormant microbial population increased (overall composition of the microbial community remained unchanged). This response to a perturbation may reflect the microbial community’s strategy for maintaining diversity in a highly… Read more »

Consumers Respond Unexpectedly to Nutrient Enrichment

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For the first six years of an ongoing 13-year nitrate addition experiment in tidal creeks, benthic algae, invertebrate prey, and a small fish, the mummichog, showed a classic positive bottom-up response to added nutrients. However, after six years, creek banks began to collapse and mummichog abundance in fertilized creeks declined relative to reference sites, likely… Read more »

Non-Equilibrium Dynamics are Nearly Ubiquitous and Spatially Complex

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Credit: Jill HaukosExperiments at KNZ LTER have identified significant time lags between treatment initiation and sustained community effects. At a minimum, these times lags are 3-6 years for water and nutrient manipulations, but can be decades according to fire suppression and woody plant expansion studies. Decreases in plant diversity evident in the first few years… Read more »

Giant Kelp Shapes an Entire Ecosystem

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Credit: Brandon DohenyResults from long term measurements and experiments reveal that climate-driven disturbances that alter giant kelp abundance cascade through the kelp forest community, affecting biodiversity and ecosystem function. These effects are due to kelp’s overwhelming influence on environmental conditions and habitat availability rather than its effects as a food source for fauna.

Severe Fires Drive Shifts from Black Spruce to Broadleaf Dominance

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  Severe late summer fires consume the soil organic layer, allowing deciduous tree species, such as aspen and birch, to establish at high densities. The fast decomposing litter and rapid evapotranspiration of deciduous trees maintain a thinner, drier organic layer that does not sustain spruce forests or insulate permafrost. This ecosystem state change alters an… Read more »

Browsing by Large Herbivores Influenced Ecosystem Function

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Browsing by moose and snowshoe hares affects plant species composition, growth, population dynamics, nutrient cycling, and ecosystem function at both stand and landscape scales, causing effects that can persist for decades. Both species selectively consume willows, leading to the dominance of alder, an important nitrogen-fixing species that is chemically defended against herbivory. Snowshoe hare abundance… Read more »

Started from the Benthos, Now We’re Here—a Holistic Approach to Lake Ecology

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Freshwater fish in a lake

In 2018, M. Jake Vander Zanden and Yvonne Vadeboncoeur were invited to give a plenary lecture at the International Society for Limnology (SIL) meeting in Nanjing, China. They spoke about their efforts to synthesize a more holistic understanding of the role of benthic productivity and food web pathways in lakes.  The two began their journey… Read more »

LTER at Ocean Sciences Meeting 2020

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In 2017, the LTER Network saw the addition of three new marine and coastal sites. The new sites—Northeast U.S. Shelf (NES), Northern Gulf of Alaska (NGA) and Beaufort Lagoon Ecosystems (BLE)—are all well-represented among the 41 talks and posters presented by LTER researchers at the 2020 AGU Ocean Sciences Meeting. Presentations from these and other… Read more »

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