Many ecophysiological and biogeochemical processes respond rapidly to changes in biotic and abiotic conditions, while ecosystem-level responses develop much more slowly (e.g., over months, seasons, years, or decades). To better understand the role of the slow responses in regulating interannual variability in NEE, we partitioned NEE into two major ecological terms—gross primary productivity (GPP) and… More

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Century-old forests in the US upper Midwest and Northeast power much of North America’s terrestrial carbon (C) sink, but these forests’ production and C sequestration capacity are expected to soon decline as fast-growing early successional species die and are replaced by slower-growing late successional species. But will this really happen? Here we marshal empirical data… More

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Forested landscapes are shaped by disturbances varying in severity and source. Moderate disturbance from weather, pathogens, insects, and age-related senescence that kills only a subset of canopy trees may increase standing woody debris and alter the contribution of coarse woody debris (CWD) to total ecosystem respiration (RE). However, woody debris carbon (C) dynamics are rarely… More

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Natural and anthropogenic disturbances influence ecological succession and impact the carbon cycle. Understanding disturbance effects and ecosystem recovery is essential to carbon modeling. We hypothesized that (1) species-specific disturbances impact the carbon cycle differently from nonspecific disturbances. In particular, disturbances that target early-successional species will lead to higher carbon uptake by the post-recovery, middle- and… More

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Carbonyl sulfide (OCS), the most abundant sulfur gas in the atmosphere, has a summer minimum associated with uptake by vegetation and soils, closely correlated with CO 2 . We report the first direct measurements to our knowledge of the ecosystem flux of OCS throughout an annual cycle, at a mixed temperate forest. The forest took… More

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Although it may be difficult for us to observe in our short lifetimes, the composition of trees in a forest can be a very variable thing. When a forest is clear-cut or thinned by fire, the first trees to rebound are often the fastest growing—those that can sprout quicker than their competitors. However, over time,… More

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Significant climate risks are associated with a positive carbon–temperature feedback in northern latitude carbon-rich ecosystems, making an accurate analysis of human impacts on the net greenhouse gas balance of wetlands a priority. Here, we provide a coherent assessment of the climate footprint of a network of wetland sites based on simultaneous and quasi-continuous ecosystem observations… More

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Given that forests represent the primary terrestrial sink for atmospheric CO2, projections of future carbon (C) storage hinge on forest responses to climate variation. Models of gross primary production (GPP) responses to water stress are commonly based on remotely sensed changes in canopy ‘greenness’ (e.g., normalized difference vegetation index; NDVI). However, many forests have low… More

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