The Subterranean Biodiversity of the Arab World: A Forgotten Realm
Importance of Subterranean Fauna and Need for its Protection.

Mohammed Messouli & Asma El Alami El Filali
UCAM- FS Semlalia, Département de Biologie, LHEA, BP 2390 Marrakech, Morocco
e-mail: messouli@ucam.ac.ma

Abstract

The Ramsar definition of wetlands includes one that is not often used or well known; that is ”subterranean hydrological systems." However, the subterranean realm is the world's largest terrestrial biome, occurring at all altitudes and in all climatic zones. In spite of efforts during the two last decades, few underground systems have been thoroughly investigated in the Arab World (AW). Sparse information is available for many hupogean habitats, but significant amounts of data, are available only from Morocco. As a result, of all the natural habitats of the AW, underground habitats are undoubtedly the least well known and probably the worst treated. And yet the underground environment harbors an important endemic fauna of troglobites and stygobites. In spite of being limited in terms of repartition and species richness, subterranean biodiversity in the Arab Region has exceptional value as regards the biogeography of the faunas and their potential in the study of landscape change. Indeed, levels of regional stenoendemism are notably high, some of which are of Pangean origin. However, AW as a hole is one of the poorest of information on subterranean fauna. As well as this, the impacts of drivers and associated pressures on these ecosystems are rarely if ever considered.

Subterranean biodiversity in the AW has never been considered before. In this paper we first discuss the origin of the hypogean fauna and then identify patterns and hot-spots of endemism over the area of concern using biogeographical techniques and GIS for mapping biodiversity. Distribution ranges have been mapped for the majority of species so providing an important tool for application to the conservation and development planning process. An updated data base on distribution patterns of subterranean biodiversity in the AW will be used for and amended by future research projects. Special attention is allowed to some surface organisms that seem to be undergoing the process of colonization even now. The full dataset is to be made freely available through the internet. The underground environment is largely ignored in planning the conservation estate, and the fauna is largely ignored in groundwater quality assessment and monitoring.

Major threats are identified as loss and degradation of habitat, in particular from sedimentation due to deforestation, and climatic change. From evolutionary and hydrological considerations, it is likely that the areas occupied by these relict faunas are small and isolated. In these conditions, the threat of unwittingly harming these ancient relictual communities is ever present, and most of the “red lists” are in urgent need. It is to be hoped that harm can be avoided or at least minimized by an active program of discovery and description of these newly discovered unique faunas followed by sound management of the resource. The AW hypogean fauna is in danger, and probably many species have already been extinct without discovering them.