Tanner, E. V. J., and P. J. Grubb. 1999. NPP Tropical Forest: John Crow Ridge, Jamaica, 1974-1978. Data set. Available on-line [http://www.daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A.
The John Crow Ridge study area (18.08 N 76.65 W) comprises four sub-sites (one measured at two similar locations), selected on the Grand Ridge of the western Blue Mountains, between Morce's Gap and John Crow Peak. Each sub-site consists of 8 or 10 contiguous permanent plots, each 10 m x 10 m. The forest is of low stature, and appeared to be completely undisturbed at the commencement of the study. The forest floor at one sub-site (Mor Ridge) was overlain by a 30-50 cm layer of mor humus with a high C/N ratio.
Above-ground net primary productivity was estimated to be in the range 654-997 g/m2/year (sum of litterfall and trunk/branch increment), or 854-1057 g/m2/year (including tree mortality). These figures are lower than for lowland tropical forest, with a greater proportion accounted for by leaf turnover; this is reflected by the relatively low stature of the upper montane forest. Long-term climate data is available from Cinchona Botanic Gardens, approximately 3 km south of the John Crow Ridge study area and at similar elevation. Daily precipitation data, December 1973 - March 1983, are also available on request. However, Tanner (pers. comm.) found a poor correlation between bi-weekly precipitation at John Crow Ridge and Cinchona, presumably because of the mountainous terrain.
Tel. +44 (1223) 333912/ 332462
Fax +44 (1223) 333953
E-mail: evt1@cus.cam.ac.uk
Alternative Contact: Dr. Peter J. Grubb
Department of Plant Sciences
University of Cambridge
Downing Street
Cambridge CB2 3EA
U.K.
Tel. +44 (1223) 333911/ 332100
Fax +44 (1223) 333953
E-mail: pjg12@cus.cam.ac.uk
Click on the following linked phrase to view
references and summaries.