NPP Tropical Forest: Chamela, Mexico, 1982-1995


[PHOTOGRAPH]
Photograph: Litter trap and throughfall collector in the Chamela forest
(click on the photo to view a series of images from this site)

Data Citation

Cite this data set as follows:

Maass, M., and A. Martinez-Yrizar. 2001. NPP Tropical Forest: Chamela, Mexico, 1982-1995. 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.

Description

Net primary productivity (NPP) of a tropical dry deciduous forest was estimated, based on the integration of ecosystem data obtained in various years between 1982 and 1995, at the Chamela Biological Station of the National Autonomous University of Mexico (UNAM).

The Biosphere Reserve Chamela-Cuixmala, Jalisco, is situated near the Pacific coast of Mexico (19.50 N 105.02 W), 2 km inland and about 40 km south of the town of Tomatlan. This area is characterized by annual rainfall of around 780 mm, distributed mainly from June to October, and a mean temperature of about 25 C, with less than a 5 C difference between the warmest and coolest months. The vegetation is highly diverse, including about 700 plant species (of which over 180 are trees), and there is a well-developed understory of shrubs. One of the most remarkable features is the seasonality of leaf fall, with most species remaining leafless for several months during the dry season. Tropical deciduous forest is widespread in Mexico, covering large tracts along the Pacific slopes from the state of Sonora in the north to Chiapas in the south; it is also found in the northern part of the Yucatan peninsula. The Chamela station covers 3300 hectares and is thought to have been undisturbed for several hundred years -- there are no records or evidence of either natural or anthrogenic fire.

Structural and functional parameters of the forest have been measured on five contiguous watersheds (Ws-I to Ws-V), each 12-28 hectares in size. Most of the measurements of NPP were carried out on three sub-sites of Ws-I along an elevational gradient, termed lower (a permanent plot of 2400 m2 at the bottom of the 15.9-hectare watershed); middle (located in the mid-portion of the watershed); and upper (a permanent plot located in its upper portion).

Detailed data are available for different components of NPP, biomass and nutrient inputs/outputs (P, K, Ca, Mg). Estimated above-ground NPP ranged from 611 to 808 g/m2/year between the three sub-sites (average 682 g/m2/year), and total NPP ranged from 1119 to 1353 g/m2/year (average 1206 g/m2/year). These estimates are thought to represent the lower bounds of NPP because root and stem herbivory have not been taken into account, although leaf herbivory is included.

Contact Information

Contact: Dr. Manuel Maass
Instituto de Ecologia
Universidad Nacional Autonoma de Mexico
Campus Morelia
A.P. 27-3 Morelia
Michoacan 58089
MEXICO

Tel. +52 (4) 320-0516, 320-0561
Fax: +52 (4) 320-0830
E-mail: maass@oikos.unam.mx

Alternative Contact: Dra. Angelina Martinez-Yrizar
Instituto de Ecologia (Sonora)
Universidad Nacional Autonoma de Mexico
Aptdo. Postal 1354
Hermosillo
Sonora 83000
MEXICO

Tel./Fax: +52 (62) 139303, +52 (5) 622-6151
E-mail: angelina@servidor.unam.mx

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