Fire resilience of a rare, freshwater crustacean in a fire‐prone ecosystem and the implications for fire management

Abstract

Understanding species’ responses to fire regimes, particularly rare or threatened species, is important for land managers tasked with managing for biodiversity. Hickman's Allanaspides (Allanaspides hickmani, Anaspidesidae) is a rare, primitive, shrimp‐like crustacean, with high conservation value. It is restricted to a single catchment in the island state of Tasmania, Australia, where it occurs within moorland pools typically containing crayfish (Ombrastacoides spp.) burrows. Although its moorland habitat has a long history of firing, adverse fire regimes are a potential threat to the species. A large part of its range is subject to planned burning to help manage the detrimental effects of high‐intensity wildfires. The resilience of A. hickmani to low–moderate‐intensity fires was investigated over 13 years using a replicated before‐after‐control‐impact design. The fires resulted in an initial reduction in vegetation cover and surface water and an increase in water temperature. There was no effect of fire on A. hickmani captures 4 months after small‐scale, low‐intensity autumn burns. However, 5 months later, following an unintended larger‐scale, medium‐intensity spring burn, there was an 80–90% reduction in A. hickmani captures and their numbers did not recover until 6–9 years post‐fire. It is not known whether the reduced catch was due to a reduction in the number of A. hickmani or their movement from pools into crayfish burrows. These findings together with evidence of a varied fire history, including high‐intensity wildfires, within their range suggests that A. hickmani and its habitat are resilient to a range of fire frequencies and intensities provided that the fire regime does not degrade or lead to a complete loss of peat. Climate change predictions for warmer and drier summers in western Tasmania will increase the risk of peat loss. Planned burning is likely to be important for the protection of A. hickmani habitat from predicted adverse fire regimes.

Impacts of the 2019–2020 bushfires on New South Wales biodiversity: a rapid assessment of distribution data for selected invertebrate taxa

“…Even if temporary elevation of water temperatures can be avoided by retreat into deep burrows, subsequent exposure to toxins released by burning, eutrophication and anoxia caused by excessive organic deposition and runoff can nevertheless be detrimental (New, 2014;Emelko et al, 2016;Harper et al, 2019). Although some aquatic crustaceans have demonstrated resilience to habitat burning (Driessen, 2019), little is known about fire resilience of crayfishes, such as Euastacus, which typically favour cool, well-oxygenated, oligotrophic waters. In addition, species of Euastacus regularly leave the stream to forage.…”

Fire and rain: A systematic review of the impacts of wildfire and associated runoff on aquatic fauna

“…Ectothermic species tolerate thermal increases up to an upper limit, defined as the critical thermal maximum, after which further increases in temperature are lethal (Pörtner & Peck, 2010). Although the localized mortality of aquatic organisms is often reported following major wildfire events (Burton, 2005;Driessen, 2019;Johnston et al, 2014;Silva et al, 2020), this review found no evidence of direct mortality of aquatic fauna attributable to extreme water temperatures caused by wildfires. However, periods of warming during and after a fire could result in local extirpation of species if species-specific thermal limits are surpassed.…”

Resistance and Resilience of Desert Riparian Communities to Extreme Droughts

“…The overall status of the plant community reflects the ecological background of a country, and is an important basis for ecological restoration, ecological construction, and the formulation of land use policy. Plant communities (i.e., the collection of plants living in a specific area) possess differences in ecological resistance and resilience to droughts [10,11], other types of short-term climatic anomalies [12][13][14], as well as local disturbances, including a lack of resources [15,16], species invasions [15], or fire [17]. Different plant communities have different species compositions and community structures.…”