Sea-level Rise and Storms are Altering Salt Marshes

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Credit: Sergio FagherazziFor marshes where rates of sea level rise exceed about 3 mm/year, external sediment supply is critical to marsh survival. Although riverine sediment inputs to the Great Marsh are low, PIE LTER research has shown that marsh edge erosion during moderate intensity storms currently supplies enough sediment to maintain the marsh platform. However,… Read more »

A Landscape that Requires Disturbance

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Credit: Jill HaukosKonza Prairie Biological Station features a replicated watershed-scale experiment with contrasting fire frequency and grazing treatments. Fire frequency affects plant composition and ecosystem state (i.e. whether an ecosystem is grassland, shrubland, or woodland). Fire also affects nutritional quality and quantity of vegetation, which influences foraging decisions by large herbivores at multiple scales. Herbivore… Read more »

Variable Resistance, High Resilience of Tallgrass Prairie to Climate Change

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Credit: Barb Van SlykeClimate change forecasts for mesic grasslands include increased climate variability and extremes. Experimental climate manipulations at Konza Prairie reveal a spectrum of responses to climate change, ranging from a lack of resistance to extreme drought, to great resilience to increased precipitation and heat wave variability. Although community composition changes with climate extremes,… 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 »

Fires Mobilize Nutrients to the Ocean

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Credit: SBC LTER/Dan ReedFire and land use affect the amount and timing of nutrient organic matter and sediment delivery from watersheds to the ocean. Drought and fire followed by rain causes large fluxes of terrestrial nutrients to the coastal ocean. During storms, runoff plumes containing high concentrations of nutrients remain close to the coast, but… Read more »

Kelp Forests are Surprisingly Resilient to Unprecedented Warming

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Credit: Sarah SampsonA marine heat wave of extreme magnitude and duration in 2014-15 allowed SBC LTER researchers to test predictions about the effects of climate change on kelp forests. Although kelp was diminished by the prolonged high temperature and low nitrate conditions, it rebounded quickly, and most other flora and fauna were not greatly affected…. Read more »

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 »

Thawing Permafrost and Increasing Wildfires Will Likely Amplify Climate Warming

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Measurements across latitudinal gradients, field experiments, and laboratory incubations all point to significant releases of CO2 and CH4 from soils that have been frozen or waterlogged since the last ice age. Over decadal time scales, this carbon release could overwhelm increased plant carbon uptake. In a warmer world, the boreal forest could be transformed into… 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 »

Small Water Bodies with Big CO2 Effects

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water-pocked landscape of coastal tundra

Credit: Via @ArcticLagoons on Twitter Arctic coastal watershed systems are some of the most threatened regions on Earth and have undergone substantial climatic, physical, and biological change with the warming of our Earth. Now, researchers at the Beaufort Lagoon Ecosystems LTER site have discovered that small coastal water bodies, especially ponds, are releasing carbon to… Read more »

Sea level rise impacting nitrogen cycle in tidal freshwater marshes

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GCE LTER researchers simulated the effects of long term (press) and short term (pulse) salt water intrusions in tidal freshwater marshes. Press conditions were more disastrous for the ecosystem, altering the N cycle, while the landscape was able to recover from pulse conditions.

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