NPP Grassland: Olokemeji, Nigeria, 1956-1964


[PHOTOGRAPH]
Photograph: Olokemeji site after burning, mid-dry season (click on the photo to view a series of images from this site).

Data Citation

Cite this data set as follows:

Hopkins, B. 1997. NPP Grassland: Olokemeji, Nigeria, 1956-1964. 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

The ecology and productivity of a humid derived savanna were studied between 1956 and 1968 at the Olokemeji study site which operated in collaboration between the University of Ibadan, the Federal Department of Forest Research, Ibadan, and the Western Region Forestry Department, Ibadan, Nigeria.

Monthly dynamics of above-ground plant matter (total live biomass plus dead matter) were monitored from 1956 to 1958. Further single measurements were made of peak leaf area index (LAI) in 1963-64, and biomass for nearby areas in 1960 and 1964. Annual above-ground net primary production of the herbaceous layer was estimated at around 680 g m-2, on the basis of peak total clipped matter.

The 50 m x 50 m savanna (i.e., wooded grassland) study site was situated within the 7,100-hectare Olokemeji Forest Reserve (7.42 N 3.55 E), about 40 km west of Ibadan - at the boundary between the derived savanna and forest zones, 110 km north of the coast of south-western Nigeria. The savanna part of the Olokemeji Reserve is characterised by annual burning during the dry season (November - February). Prior to 1900, the area was subject to bush fallow cultivation of cassava, yams and maize, with "many villages...and a great proportion of open grassland". After reservation in 1899, agricultural activity within the reserve declined except near Olokemeji village and as a part of forest-planting operations; none took place near the study site after 1940.

In addition to data on above-ground production, information is available on burning temperatures (above 540 C at ground level, estimated with heat-sensitive paints) and amount of matter consumed by fire (mean = 84% of herb layer). Data from nearby areas are labelled as treatment "burned2" in the NPP data file.

In the absence of a long-term climate data set for this site, an additional alternative climate data set is provided for Lagos, Nigeria (6.58 N 3.33 E).

All data have been personally checked by the original principal investigator.

Contact Information

Contact: Dr. Brian Hopkins
7 Highland Road
Chichester
West Sussex PO19 4QX
U.K.

Telephone: +44 (1243) 536858
E-mail: NOT AVAILABLE

Click on the following linked phrase to view references and summaries for the Olokemeji site.