General Site Information
Site ID:US-Ha2
Site Name:Harvard Forest Hemlock Site
Tower Team: PI: William Munger <> - Harvard University
DataManager: Liza Nicoll <> - Harvard University
Technician: Mark VanScoy <> - Harvard University
Elevation (m):360
IGBP:ENF (Evergreen Needleleaf Forests)
Climate Koeppen:Dfb (Warm Summer Continental: significant precipitation in all seasons )
Mean Annual Temperature (degrees C):6.56
Mean Annual Precipitation (mm):1071
Data Products: AmeriFlux BASE Dataset
FLUXNET LaThuile Dataset
Data Availability: AmeriFlux BASE:   10 years (Duration: 2004 - 2013)
FLUXNET LaThuile:   1 years (Duration: 2004 - 2004)
Data Downloads to Date: AmeriFlux BASE:   274 unique downloads
FLUXNET LaThuile:   72 unique downloads
Data DOIs: AmeriFlux BASE DOI: 10.17190/AMF/1246060
Description:The forest surrounding the Hemlock site has remained pristine with two exceptions. In the early to mid-1700s, European settlers cleared the majority of the forest for agricultural purposes. Selective harvesting of hemlock and chestnut trees occurred up until the early 1900s, when the chestnut blight killed all of the chestnut trees. In the current forest, about 83% of the total basal area of trees is hemlock. The remainder is equally divided between eastern white pine (Pinus strobus L.) and deciduous species, including red maple (Acer rubrum), red oak (Quercus rubra) and black birch (Betula lenta). A very thick organic layer (10-20 cm or more) covers the soil surface, and highly decayed coarse woody debris is abundant.
Site image(s):
For additional AmeriFlux site images, see the Web site gallery

Publications relevant to understanding the site
A. H. Magill; J. D. Aber; W. S. Currie; K. J. Nadelhoffer; M. E. Martin; W. H. McDowell; J. M. Melillo; P. Steudler. 2004. Ecosystem response to 15 years of chronic nitrogen additions at the Harvard Forest LTER, Massachusetts, USAForest Ecology and Management. 196:1, 7-28. Reference
B. Bond-Lamberty; C. K. Wang; S. T. Gower. 2004. A global relationship between the heterotrophic and autotrophic components of soil respiration?Global Change Biology. 10:10, 1756-1766. Reference
C. V. Horii; J. W. Munger; S. C. Wofsy; M. Zahniser; D. Nelson; J. B. McManus. 2006. Atmospheric reactive nitrogen concentration and flux budgets at a Northeastern U. S. forest siteAgricultural and Forest Meteorology. 136:3-4, 159-174. Reference
C. Yi; R. Li; P. S. Bakwin; A. Desai; D. M. Ricciuto; S.P. Burns; A. A. Turnipseed; S. C. Wofsy; J. W. Munger; K. Wilson; R. K. Monson. 2004. A nonparametric method for separating photosynthesis and respiration components in CO2 flux measurementsGeophysical Research Letters. 31:17, L17107. Reference
Compton and Boone, Ecology 81:234-2330, 2000. Reference
D. P. Turner; S. Urbanski; D. Bremer; S. C. Wofsy; T. Meyers; S. T. Gower; M. Gregory. 2003. A cross-biome comparison of daily light use efficiency for gross primary productionGlobal Change Biology. 9:3, 383-395. Reference
Hadley and Schedlbauer, Tree Physiology 22:1079-1092, 2002; Foster and Zebryk, Ecology 74:982-998, 1993. Reference
J. L. Hadley. 2000. Effect of daily minimum temperature on photosynthesis in eastern hemlock (Tsuga canadensis L.) in autumn and winterArctic Antarctic and Alpine Research. 32:4, 368-374. Reference
J. L. Hadley; J. L. Schedlbauer. 2002. Carbon exchange of an old-growth eastern hemlock (Tsuga canadensis) forest in central New EnglandTree Physiology. 22:15-16, 1079-1092. Reference
P. S. Bakwin; K. J. Davis; C. Yi; S. C. Wofsy; J. W. Munger; L. Haszpra; Z. Barcza. 2004. Regional carbon dioxide fluxes from mixing ratio dataTellus Series B-Chemical and Physical Meteorology. 56B:4, 301-311. Reference

These pages show the current information available at about this tower.
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