Post‐fire recovery of revegetated woodland communities in south‐eastern Australia

Abstract

The primary goal of restoration is to create self-sustaining ecological communities that are resilient to periodic disturbance. Currently, little is known about how restored communities respond to disturbance events such as fire and how this response compares to remnant vegetation. Following the 2003 fires in south-eastern Australia we examined the post-fire response of revegetation plantings and compared this to remnant vegetation. Ten burnt and 10 unburnt (control) sites were assessed for each of three types of vegetation (direct seeding revegetation, revegetation using nursery seedlings (tubestock) and remnant woodland). Sixty sampling sites were surveyed 6 months after fire to quantify the initial survival of mid-and overstorey plant species in each type of vegetation. Three and 5 years after fire all sites were resurveyed to assess vegetation structure, species diversity and vigour, as well as indicators of soil function. Overall, revegetation showed high (>60%) post-fire survival, but this varied among species depending on regeneration strategy (obligate seeder or resprouter). The native ground cover, mid-and overstorey in both types of plantings showed rapid recovery of vegetation structure and cover within 3 years of fire.This recovery was similar to the burnt remnant woodlands. Non-native (exotic) ground cover initially increased after fire, but was no different in burnt and unburnt sites 5 years after fire. Fire had no effect on species richness, but burnt direct seeding sites had reduced species diversity (Simpson's Diversity Index) while diversity was higher in burnt remnant woodlands. Indices of soil function in all types of vegetation had recovered to levels found in unburnt sites 5 years after fire. These results indicate that even young revegetation (stands <10 years old) showed substantial recovery from disturbance by fire.This suggests that revegetation can provide an important basis for restoring woodland communities in the fire-prone Australian environment.

Impact of high-severity fire in a Tasmanian dry eucalypt forest

“…Corresponding estimates for fire-induced whole-plant mortality were 44% overall, 25% for eucalypts and 33% for acacias. This value for eucalypts is considerably higher than the 0-5% reported for dry forests in several other studies (Potts 1986;Wardell-Johnson 2000;Croft et al 2007;Pickup et al 2013), and higher than the 15% reported for evergreen eucalypts in a northern Australian savanna as a result of an unusually severe fire (Williams et al 1999). Although fire appeared to have little impact on eucalypt survival at some sites, at two sites, fewer than 10% of eucalypt stems were alive.…”

“…However, surprisingly few studies have quantified the mortality and resprouting responses of trees after fire in these forests (Fairman et al 2015). Survival of eucalypts has been reported as being similar to, or only slightly lower (<5%), in recently burnt than in long-unburnt dry eucalypt forests (Potts 1986;Wardell-Johnson 2000;Croft et al 2007;Pickup et al 2013). Gill (1978) measured the impact of fire on small Eucalyptus dives trees in south-eastern New South Wales; all survived the fire, but lost 30-50% of their initial height.…”

Reforestation with native mixed‐species plantings in a temperate continental climate effectively sequesters and stabilizes carbon within decades

“…Some Acacia species in the plantings (e.g., Acacia dealbata) recruited prolifically from root suckers during a recent extended drought (1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010). Developing (<20 years) native mixed-species plantings in a nearby region showed rapid recovery of structure and cover, with no loss of species, within 5 years of fire (Pickup et al, 2013).…”

Progress with restoration and management of Eastern Suburbs Banksia Scrub on North Head, Sydney

“…Pickup et al . () reported that species richness in a burned vegetation community did not reach that of a nearby unburned community until 2–5 years after fire. Experiments with small fires at the York Rd ESBS community are yet to demonstrate statistically significant increases (Perkins et al .…”

“…Recovery of species diversity and abundance of ESBS areas to a level similar to healthy reference sites is likely to take time, whether after fire, thinning or planting. Pickup et al (2013) reported that species richness in a burned vegetation community did not reach that of a nearby unburned community until 2-5 years after fire. Experiments with small fires at the York Rd ESBS community are yet to demonstrate statistically significant increases (Perkins et al 2012).…”