Urbanization affects all elements of the pre-urban environment, including soils, hydrology, vegetation, and microclimate. Recently, Saudi Arabia has experienced rapid urbanization and growth. Thus, the country’s biodiversity has been threatened. In the Riyadh region, beetle assemblages were assessed along a rural-suburban-urban gradient. A total of 2791 individuals from 94 species belonging to seven families were collected at 15 sites along three different gradients of urbanization in Wadi Hanifa, which runs for a length of 120 km from northwest to southeast. Tenebrionidae dominated abundance (60.1%) and richness (38%). Beetle abundance, evenness, and diversity were not different among habitats; however, species richness was higher in rural habitats. Detrended correspondence “DCA” and canonical correspondence “CCA” analyses showed distinct differences among sites along gradients. Urbanization intensity, soil variables, and land cover were significantly correlated with CCA axis 1, while elevation and flora were significantly correlated with CCA axis 2. The most critical operating environmental variables in Wadi Hanifa were buildings, elevation, soil organic carbon, litter cover, and litter depth, as well as plant species such as Launaea capitata, Lycium shawii, Alhagi graecorum, and Heliotropium currasavicum. Ten species in our study were associated with urban habitats, six with suburban habitats, and seven with rural habitats. Consequently, expanding urban areas may negatively affect the richness and composition of beetles and may result in the loss of some native species.

A recent plan to extend a highway in south-west Western Australia has been abandoned, but not before a 10–200 m wide strip of vegetation along the alignment had been cleared. Attempts are now being made to rehabilitate the cleared area. The aim of this paper is 2-fold. First, it documents the changes in invertebrate abundance, richness and evenness in this abandoned landmark development. Second, it explores the changes in invertebrate species composition, concentrating on ants, in terms of known trends in biodiversity, with particular emphasis on biotic homogenisation. We report on the immediate changes in invertebrate assemblages from a spatial continuum of sites passing through six discrete woodland communities. A total of 69 species of ants were sampled by pitfall traps from the sites, with 50 being sampled in the 7 reference sites and 46 in the 13 cleared sites. As far as most of these simple indices are concerned, the previously cleared areas generally exhibited values that are not appreciably different from those of the reference sites, except that species richness was marginally higher in the reference sites and ant abundance was higher in the cleared area sites. There was considerable variation in numbers of ant species within Ant Niche Template categories in both the reference and cleared area sites. However, numbers of nest specialists and trophic specialists were significantly lower in cleared area sites; opportunistic species and one generalist were more abundant in cleared areas. The two-dimensional solution of the multi-dimensional scaling ordination grouped all cleared sites close together, with the reference sites and modified native vegetation site being widely scattered across the graph. The tight bunching of the cleared sites suggests that clearing for the proposed highway has resulted in homogenising the ant fauna, creating a characteristic assemblage that differed from all of the original reference sites. When considered at the ordinal level, significantly less Clitellata (worms), Malacostraca (slaters), Araneae (spiders), Blattodea (cockroaches), Dermaptera (earwigs) and Coleoptera (beetles) were sampled from the cleared sites, but significantly more Collembola (springtails), Homoptera and Heteroptera (both types of sucking bugs) were sampled in these sites. Collembola may be responding to the abundance of exotic grasses whereas the sucking bugs may have benefitted from the lush herb and shrub layer associated with the regrowth and rehabilitation efforts.

– Barrow Island is Western Australia’s second largest offshore island and its flora and fauna have been able to evolve without major human disturbances. Chevron Australia Pty Ltd and its Joint Venture Participants made an application to construct a plant to liquefy natural gas on the island in 2001.