Dominance Value And Community Production Of Desert Arthropoda In Qatar

Abstract

Diurnal sampling of epigeal Arthropoda from different desert habitats in Qatar was carried out at the end of the summer season (October) and in spring (April) of 1995, 1996 and 1997. Dominance values of the species collected and community production at various trophic levels have been determined. Judging by the 0-300% scale of dominance value, all arthropod species collected lie between 0-100% which indicates their small numbers and rarity. The tenebrionid beetle Adesmia cancellata L. and the thysanuran Thermobia sp. scored the highest domincance value. A week positive correlation between plant biomass and arthropod density was shown. No correlation was found to exist between plant biomass and arthropod diversity or biomass. Detnvores are dominant in both density and diversity but come second to herbivores in biomass. Carnivores exhibit a low but a stable level. The ratio of arthropod biomass to plant biomass, demonstrates that herbivores make use of 0.45% of the available primary production. Carnivores make up the equivalent of 20.5% of herbivore biomass. Detrivore biomass represents as much as 44% of the total of herbivore and carnivore biomass but the equivalent of only 0.24% of plant biomass.