Abstract
Resource pulses in the world's hot deserts are driven largely by rainfall and are highly variable in both time and space. However, run-on areas and drainage lines in arid regions receive more water more often than adjacent habitats, and frequently sustain relatively high levels of primary productivity. These landscape features therefore may support higher biotic diversity than other habitats, and potentially act as refuges for desert vertebrates and other biota during droughts. We used the ephemeral Field River in the Simpson Desert, central Australia, as a case study to quantify how resources and habitat characteristics vary spatially and temporally along the riparian corridor. Levels of moisture and nutrients were greater in the clay-dominated soils of the riverine corridor than in the surrounding sand dunes, as were cover values of trees, annual grasses, other annual plants and litter; these resources and habitat features were also greater near the main catchment area than in the distal reaches where the river channel runs out into extensive dune fields. These observations confirm that the riverine corridor is more productive than the surrounding desert, and support the idea that it may act as a refuge or as a channel for the ingress of peri-desert species. However, the work also demonstrates that species diversity of invertebrates and plants is not higher within the river corridor; rather, it is driven by rainfall and the accompanying increase in annual plants following a rain event. Further research is required to identify the biota that depend upon these resource pulses.
Highlights
Most hot deserts are characterized by low and uncertain rainfall, very low levels of soil nutrients and generally short and unreliable pulses of primary and secondary production [1], [2], [3]. Many of these deserts are punctuated by drainage lines, rivers and floodplains that are thought to be more consistently productive and which receive more water than the surrounding desert areas [4]
While much research has focused on aquatic organisms in desert rivers
In their review of the ecology of arid Australian environments, Stafford Smith and Morton [4] suggested that the resources, habitat structure and characteristics of desert rivers differ in several important ways from those of other desert landscapes
Summary
Most hot deserts are characterized by low and uncertain rainfall, very low levels of soil nutrients and generally short and unreliable pulses of primary and secondary production [1], [2], [3] Many of these deserts are punctuated by drainage lines, rivers and floodplains that are thought to be more consistently productive and which receive more water than the surrounding desert areas [4]. In their review of the ecology of arid Australian environments, Stafford Smith and Morton [4] suggested that the resources, habitat structure and characteristics of desert rivers differ in several important ways from those of other desert landscapes. Abundances and diversity of leaf-eating insects (Orthoptera, larval Lepidoptera and Hemiptera) should be greatest along river channels due to the presence of trees and shrubs; and
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.