Within the same forest, photosynthesis can vary greatly among species and within an individual tree. Quantifying the magnitude of variation in leaf-level photosynthesis in a forest canopy will improve our… More
Continuous measurements of whole canopy isoprene emissions over an entire growing season are reported from Harvard Forest (42°32′N, 72°11′W). Emissions were calculated from the ratio of observed CO2 flux and… More
An analysis of boundary layer cumulus clouds and their impact on land surface–atmosphere exchange is presented. Seasonal trends indicate that in response to increasing insolation and sensible heat flux, both… More
We report concentrations of atmospheric NOx, nitric acid (HNO3), peroxyacetyl nitrate (PAN), and NOy; eddy covariance fluxes of NOx and NOy; inferred fluxes of HNO3 at the mixed deciduous Harvard… More
The turbulent exchanges of CO2 and water vapour between an aggrading deciduous forest in the north-eastern United States (Harvard Forest) and the atmosphere were measured from 1990 to 1994 using… More
Soil respiration is an important component of the annual carbon balance of forests, but few studies have addressed interannual variation in soil respiration. The objectives of this study were to… More
Temperate deciduous forests exhibit dramatic seasonal changes in surface exchange properties following on the seasonal changes in leaf area index. Nearly continuous measurements of turbulent and radiative fluxes above and… More
Soil carbon dioxide efflux (soil respiration, SR) was measured with eight autochambers at two locations along a wetland to upland slope at Harvard Forest over a 4 year period, 2003–2007…. More
Terrestrial ecosystems currently offset one-quarter of anthropogenic carbon dioxide (CO2) emissions because of a slight imbalance between global terrestrial photosynthesis and respiration. Understanding what controls these two biological fluxes is… More