Departmental Papers (EES)

Document Type

Journal Article

Date of this Version

March 2000


Stream water chemistry responds substantially to watershed disturbances, but hurricane effects have not been extensively investigated in tropical regions. This study presents a long-term (2.5-11 y) weekly record of stream water chemistry on eight forested watersheds (catchment basins) in the Luquillo Mountains of Puerto Rico. This includes a period before and at least 2 y after the disturbance caused by the 1989 Hurricane Hugo. Nitrate, potassium and ammonium concentrations increased after the hurricane and remained elevated for up to 2 y. Sulphate, chloride, sodium, magnesium and calcium showed smaller relative significant changes. Average stream water exports of potassium, nitrate and ammonium increased by 13.1, 3.6 and 0.54 kg ha -1 y -1 in the first post-hurricane year across all watersheds. These represent increases of 119, 182 and 102 of record. The increased stream outputs of potassium and nitrogen in the first 2 y post-hurricane are equivalent to 3of the hurricane-derived plant litter. Effects of hurricanes on tropical stream water potassium and nitrogen can be greater than those caused by canopy gaps or limited forest cutting, but less than those following large-scale deforestation or fire.


Copyright Cambridge University Press. Reprinted from Journal of Tropical Ecology, Volume 16, Number 2, March 2000, pages 189-207.

NOTE: At the time of publication, author Fred Scatena was affiliated with the USDA Forest Service. Currently (June 2006), he is a faculty member in the Department of Earth and Environmental Science at the University of Pennsylvania.



Date Posted: 23 June 2006

This document has been peer reviewed.