HARVESTER TERMITES AND ORGANIC MATTER FLOW IN A SEMI-ARID
WATERSHED: IMPLICATIONS FOR ECOSYSTEM MANAGEMENT
Andrew Wilby, Moshe Shachak and Helga Dixon
Ben Gurion University of the Negev, Mitrani Department for Desert Ecology,
The J. Blaustein Institute for Desert Research, Sede Boqer Campus 84990, Israel.
Shachak@bgumail.bgu.ac.il
This study aimed to elucidate how the harvester termite, Anacanthotermes ubachi , controls organic matter flow in a shrubland of the Negev Desert, Israel. Experimental and observational studies were employed to investigate how this ecosystem role is affected by natural and human-modified patchiness in the landscape.
Preliminary calculations suggest that A. ubachi translocates 68% of the litter deposited by ephemeral plants from above to below ground, thus preventing leakage and redistribution of organic matter by wind and runoff water.
Two aspects of termite activity were studied; site selection by swarming alates and foraging by established colonies. After swarming, alates were shown to select, preferentially, nest sites close to shrubs or to sites which were artificially enriched with ephemeral-plant litter. Subsequent foraging activity was also associated with shrub patches, but not with the enriched patches.
Termite response to human-modified patchiness was marked suggesting that management techniques designed to alter water flows in the landscape also influence organic matter flow via their influence of termite activity.
The extent of termite activity suggests that termites are important controllers of organic matter flow in this ecosystem. The sensitivity of termite activity to landscape management suggests that certain management practices may drastically alter organic matter flow in this ecosystem. Persistence of termites in severely degraded patches indicates that they may play a role in restoration of desertified areas.