The effect of a single burn event on the aquatic invertebrates in artesian springs

Abstract

Fire can often occur in aquatic ecosystems, which may affect aquatic invertebrates. Despite the importance of aquatic invertebrates to ecosystem function, the effect of fire on these environments has been little studied.We studied the effects of fire on aquatic invertebrates in artesian springs in the arid zone of South Australia. Artesian springs are a unique and threatened ecosystem, containing several rare and endemic species. Evidence suggests these wetlands were routinely burnt by indigenous Aboriginal people before European settlement over 100 years ago. Recently, burning has been suggested as a reinstated management tool to control the dominant reed Phragmites australis. A reduction in the cover of the reed may benefit the threatened flora and fauna through enhancement of water flow. Three artesian springs were burnt and aquatic invertebrates sampled from the burnt and three unburnt springs. A single fire in late winter completely burnt the dominant vegetation, followed by recovery of Phragmites over the following 2 years. A single fire event did not deplete populations of endemic aquatic invertebrates in artesian springs, but probably did not substantially benefit these populations either. Isopods, amphipods, ostracods and three species of hydrobiid snail survived the fire event, and most had increased in number 1 month post fire but then returned to pre-burnt numbers by 1 year post fire. Morphospecies richness of all identified invertebrates increased over time in all springs, but did not differ appreciably between burnt and unburnt springs. If burning artesian springs is to be adopted as a management tool to suppress the growth of Phragmites australis, we conclude that the endemic aquatic invertebrates will survive a single burn event, without negative effect to their populations.

Direct and indirect impacts of wildfire on faunal communities of Mediterranean temporary ponds

“…These habitat alterations and trophic changes concur with most studies dealing with wildfires and aquatic systems (Lewis et al, 2014;Minshall et al, 2001). This fast increase in shredder abundance has also been observed in other lentic habitats (Lewis et al, 2014;Munro, Kovac, Niejalke, & Cunningham, 2009;Scrimgeour et al, 2001). However, these changes did not affect colonisation by active dispersers and instead seemed mainly to alter the available resources.…”

“…However, we found that as the hydroperiod commenced, within the first 2-4 months after fire in burned ponds, shredders had higher abundances. This fast increase in shredder abundance has also been observed in other lentic habitats (Lewis et al, 2014;Munro, Kovac, Niejalke, & Cunningham, 2009;Scrimgeour et al, 2001). This rapid rise and subsequent decrease F I G U R E 6 Changes in abundance of piercers (a), scrapers (b), and shredders (c) along the hydroperiod for the high-intensity ponds (black circles with solid line), low-intensity ponds (grey triangles with dashed line) and unburned ponds (white squares with dotted line).…”

Limited understanding of bushfire impacts on Australian invertebrates

“…Post‐fire recovery of invertebrate communities can occur via multiple mechanisms including survival in situ , recolonisation by dispersal or reproduction from egg banks (e.g. Munro et al ., 2009; Robson et al ., 2018). However, without a better understanding of the fundamental ecology of invertebrate taxa and how these mechanisms of resilience support post‐fire recovery over extended spatial scales, our ability to predict and manage for recovery is limited.…”

The ecology of narrow-range endemic macro-invertebrates of Great Artesian Basin springs

“…In GAB springs, the majority of endemic species are invertebrates with highly restricted ranges, specific habitat requirements (Ponder et al 1989;Rossini et al, 2017), and exposure to the same threats as better-protected species like the fishes (e.g. predation by invasive species (Clifford et al, 2013), habitat degradation associated with disturbance (Kovac & Mackay, 2009;Munro et al, 2009). If we are to maintain biodiversity in this system, more attention needs to be afforded to endemic invertebrates and their conservation.…”

“…Efforts to collect data have generally been idiosyncratic; published research has employed different methods with effort focussed on particular regions and taxa (Table 3-1). Targeted studies of diversity or abundance are rare, meaning rapid methods with no implicit spatial component within the spring are the norm (Munro et al, 2009) (Table 3-1). Relatively few studies use 'coring' (Table 3-1), although this method is common in other submersed vegetated environments (e.g.…”