Floodplain_Vegetation_Monitoring_by_Okavango_Research_Institute_2017_onward

Study Extent

The monitoring site consists of at least 15 permanent plots measuring 5m by 5m. It is located along the distal south eastern part of the Chiefs Island in the Okavango Delta, along the Boro Channel. All the monitoring plots are situated in the adjacent seasonal flood plain lying between the eastern part of the Boro Channel before and the woodlands further to the north. These plots are sampled on a quarterly basis before, during and after the flood regime.

Sampling

Since the purpose of the monitoring exercise is to examine the impact of the flood regime on floodplain vegetation, water level is measured in each. In addition, all the species in the plot are identified in the field, followed by the estimation of percentage cover using the Braun-Blanquette protocol. The physiological status of the vegetation is also determined. All the unidentified specimen are packed in a plant press and transported to ORI herbarium for further confirmation and verification by herbarium personnel

Quality Control

A handheld GPS is used give the general location of each plot at the monitoring site. Metal rods have been used to permanently mark the four corners of each of the monitoring plots. Before conducting any survey, a metal detector is used to locate the metal rods in order to verify the true position of the plot. Then a measuring tape is used to establish the plot boundaries and it true measurement before vegetation survey is carried out. Vegetation identification is conducted by experienced Herbarium and Field personnel using field guide books, such as : 1).Field Guide for the Plants of Northern Botswana, Heath 2009. 2).Grasses of Southern Africa, Van Wyk 1992. 3).“Wild Flowers, water Plants and Grasses of the Okavango Delta and Kalahari. Roodt 2011 4)“Wild Flowers of Southeast Botswana, Kirby 2013.

Method steps

1. Identification of all species within the 5m by 5m plot is performed by 2-3 people and noted on a data sheet. Then the cover for each species is estimated following the Braun-Blanquette approach. If the plot is inundated, the water level will also be determined using a ruler or tape measure. This measurement is taken at the centre of the plot. Datasheets are later transcribed to digital format for archiving and publishing online.

herbaceous identified to species level

1. Imperata cylindrica
   common name: flame grass rank: species
2. Oryza longistaminata
   common name: wild rice rank: species

The study site is located at the distal part of the Chiefs Island in the Okavango Delta along the Boro Channel