Biological characterization of study sites
STANDARD TRAPPING TECHNIQUES USED TO ASSESS
BIO-DIVERSITY IN THE BEACH – DUNE SYSTEM
The following trapping techniques are used and tuned to local needs to assess bio-diversity:
- Tetradirectional pitfall cross traps: These traps consist of 10 cm high strips of fibreglas 2 m long and connected together to form a cross. At the corners of the cross four plastic containers, 10 cm in height, are placed in the sand from the shoreline limits to the back. The trap is oriented in order to capture walking arthropods in the four cardinal directions.
- Intercepting front: A continuous transept from the shoreline limits to the dune is made placing pitfall traps 10-cm in height every 5 m and joining them by 10-cm high strips of fibreglas. This is a very efficient system of traps that can intercept crawling arthropods.
- Mobile cages of unitary units: These traps consist of gaze cubes (1 m3) placed over the vegetation. All forms, flying, crawling and burrowed, are collected with this system.
- Hand Nets: These traps consist of cloth bags connected with a long wooden stick. These are used to collect flying forms associated to the vegetation.
- Sampling square units of sand: These traps consist of squares (0,50 x 0,50) pushed in the sand to a depth of 10 cm. All sand in the square is collected and sieved in a 2 mm mesh sieve. This method permits to sample burrowed species.
- Baited traps: These traps consist of plastic cups pushed in the sand that contain baits (meat, honey and beer, vinegar) and glycol ethylene. These traps are used to attract animals.
Detailed methods used in Tunisia.