Response to ‘Fire practices only ‘best’ if they promote a large seed buildup: comment on the conservation needs of a fire-killed grevillea’ (Lamont 2022)

Keywords: Aboriginal rangers, cross-cultural knowledge and practice, cultural fire, fire ecology, Indigenous knowledge, population dynamics, prescribed fire management, southeast Australia, threatened species, wildfire recovery.

Lamont (2022) re-assessed our data (McKemey et al. 2021b) related to the population dynamics of Grevillea scortechinii subsp. sarmentosa, in response to different types of fire. The original data were collected through our ongoing cross-cultural research and presented in our paper, ‘Indigenous cultural burning had less impact than wildfire on the threatened Backwater grevillea (Grevillea scortechinii subsp. sarmentosa) while effectively decreasing fuel loads’ (McKemey et al. 2021b). We thank Professor Lamont for increasing our understanding of the population dynamics of this rare plant, which will inform the Banbai Rangers’ custodianship of the Backwater grevillea and our long-term monitoring program. In response to Lamont’s comments on our paper, we wish to make three important points around Lamont’s analysis and the lack of acknowledgement of the benefits of cultural burning and cross-cultural research.

Firstly, our paper concluded that cultural burning resulted in a multi-age population. The mature shrubs that survived the cultural burns continued to contribute to the seed bank, and the seedlings that recruited as a result of the cultural burns provided the next generation of grevilleas. In contrast, the wildfire resulted in mortality of almost all (99.6%) of the aboveground grevillea population. In the culturally burnt plots, the mature shrubs were observed to produce large quantities of seeds and were, we would suggest, in the ‘prime’ of their seed production capacity or demographic rate (Harper and White 1974; Enright et al. 2015). Therefore, protecting these shrubs from destruction by wildfire was considered to be a priority conservation action. We question whether Lamont’s reassessment of population size considered the variation in seed production capacity of young versus older adult plants. The recovery process for the grevillea following the cultural burn was enhanced by having the seed bank continually replenished by the remaining mature plants, whereas after the wildfire there was a lag time in which initially there were no adult plants, and following this, young adult plants with a comparatively low seed production capacity. Our ongoing research at this site aims to continue collecting data, with the aim of quantifying seed production of plants in relation to time since fire (i.e. the age of the different cohorts). In line with Lamont’s comments, we are also investigating time to maturation and other aspects of the fire response of the Backwater grevillea. Our paper acknowledged that, like all scientific pursuits, we cannot measure every parameter possible, and like Lamont, we recommended that future work should measure more variables, including the seed bank.

Secondly, Lamont overlooked some of the benefits of using cross-cultural science in monitoring the grevillea. The Backwater grevillea is on the traditional lands of the Banbai people, who regained legal custodial responsibility for managing this site in 1996. The Banbai have observed and monitored changes in the grevillea during this time with great interest. They have applied fine-scale nuanced burning practices and observed the grevillea’s response. The deep cultural and custodial responsibility of the Banbai for this species, and all others at the site, results in observation and experimentation that may not be acknowledged by Western scientific principles; however, is integral to ongoing adaptive management of the site. These Indigenous observations take the place of deeper Western scientific analysis in the original paper, and follow the direction of many national and international conservation organisations and policies that assert the need to respectfully include Indigenous People and their knowledge in contemporary conservation and research pursuits (Ens et al. 2016). In response to Lamont’s paper, Banbai Elder and Ranger Lesley Patterson (Fig. 1) commented:

We do mosaic burning and we look at the Country and see if it needs it – if it doesn’t need it, we don’t burn. You can do it yearly, but you don’t do the same spot. You come back every year or two to check after the fire… With our cultural burning, we weren’t just burning the grevillea, we wanted to do a mosaic on the rest of the property, not just burn the grevillea all the time… Always look at your land; if it’s sick, you burn. You always treat fire with respect because it’ll bite you and do some damage… We should not be burning too frequently. If you are going to burn every year, you do it in a mosaic pattern and by the time you get back to the place where you first burnt, it should be healthy. That’s the whole idea of cultural burning in Australia, you keep the country healthy. You got healthy land, you got healthy people.

Fig. 1.  Banbai Elder and Ranger Lesley Patterson examines the Backwater grevillea (photographer: Michelle McKemey).

Finally, the shock of the catastrophic ‘Black Summer’ fires changed expectations related to fire management and reset ecosystems. Where a cultural burning plan might have previously focused on small, low-severity mosaic fires applied judiciously over time across the long-unburnt landscape of Wattleridge Indigenous Protected Area, that landscape has now been completely impacted by severe wildfire. Lamont recommends fire intervals for the Backwater grevillea in the order of multiple decades, but in an era of climate change, encroaching peri-urban development and more demanding hazard reduction requirements, what is the likelihood that the ecosystems encompassing the grevillea’s restricted range will escape the impact of fire over such a long interval? And although cultural burning was unable to stop extreme wildfire, it was able to slow down less severe wildfires and reduce their impact. The results of our ongoing cross-cultural monitoring will assist the Banbai rangers and their neighbours to manage the Backwater grevillea into the future, armed with key knowledge such as fire response, time to maturity and the location of the few precious remaining mature shrubs (McKemey et al. 2021a). With the health of Country as the paramount consideration, the cultural fire management of the Banbai Rangers, supported by science, provides the most adaptive and nurturing approach to support the complex recovery of the rare Backwater grevillea.

The authors declare that they have no conflicts of interest.