The New Jersey Pine Barrens are in the most densely populated state in the United States, where water replenishment to the groundwater aquifers are crucial for the water needs of the inhabitants there. Most people in the New Jersey Pine Barrens rely on the Kirkwood-Cohansey (KC)
Results/Conclusions
In this forest, transpiration as measured with the sap flux technique was significantly reduced by 19% in 2007 compared to 2005 but surprisingly similar to 2006, when drought occurred. Prolonged drought has seemingly a stronger effect on the hydraulic balance than reduced foliage or partly seasonal defoliation suggesting compensation through the remaining foliage. Latent heat flux and evapotranspiration measured with the eddy covariance system was also reduced during defoliation (92 mm vs. 193 mm from June 1 to July 15th), and sensitive to drought conditions. On an annual basis, evapotranspiration averaged 646 mm yr-1 in 2005-2006, but only 442 mm yr-1 in 2007.
Differences between sap flux and eddy covariance measurements suggested that different controls over biological and physical factors affected water flux in this stand. Under future climate change, frequency and intensity of precipitation may then have a larger influence on local water balance than disturbance effects in the New Jersey Pine Barrens.
