Conserving Refugia: What Are We Protecting and Why?

Abstract

Refugia play an important role in contributing to the conservation of species and communities by buffering environmental conditions over time. As large natural landscapes worldwide are declining and are increasingly threatened by extreme events, critical decision-making in biological conservation depends on improved understanding of what is being protected by refugia and why. We provide three novel definitions for refugia (i.e., persistent, future, and temporary) that incorporate ecological and evolutionary dynamics into a land management decision framework and are applicable across changing temporal and spatial settings. Definitions are supported by identification, core value, and management strategy criteria to assist short- and long-term decision-making. We illustrate these concepts using the World Heritage Gondwana Rainforests (WHGR) of eastern Australia, briefly exploring the spatial and temporal factors that can inform the development of conservation management strategies following the extreme fire events of 2019–2020. For the WHGR, available knowledge can be used to protect critical assets by recognizing and implementing buffer zones and corridor connections, and by undertaking emergency translocations of target species into safe areas that will act as future refugia. More broadly, we suggest that the identification and protection of ecological and evolutionary processes across varying temporal and spatial scales is central to securing improved biodiversity conservation outcomes.

Tracking habitat or testing its suitability? Similar distributional patterns can hide very different histories of persistence versus nonequilibrium dynamics

“…Within this broader context, we test the following hypotheses: (1) that distribution‐wide and fine‐scale genetic structure should be higher in a biogeographically persistent species (here, D. sassafras ) than in a recent invader (here, T. ciliata ); (2) that the distribution of diversity is more structured and localised with limited gene flow present between highly differentiated sites in a persistent species, and generally low levels of diversity as detected in some populations outside of Australia (Liu et al. 2008, 2009) and gradual loss of diversity toward the expansion limits in a recent invader; (3) that modeled temporal changes in habitat availability corroborate the landscape genetic patterns observed by identifying climatically stable refugial areas supporting the persistence of populations (Rossetto and Kooyman 2021) and consequently maintaining higher levels of genetic diversity than less stable, recolonized areas.…”

“…Consequently, the presence or absence of a species from an area does not necessarily imply that local conditions are optimal or inadequate for that species. While suitable habitat that remains stable for a long time (persistent refugia, Rossetto & Kooyman 2021) enables endemic species to persist locally, extreme circumstances can create disturbances that admit invaders and facilitate changes in community composition. Correspondingly, less stable habitat (temporary refugia, Rossetto & Kooyman 2021) can still play an important role in the evolutionary potential of species by allowing the expansion and admixture of otherwise differentiated populations.…”

What type of rainforest burnt in the South East Queensland's 2019/20 bushfires and how might this impact biodiversity

“…Juaŕez‐Orozco et al (2017), however, found few studies identified the rainforest fire intensity and or severity, yet they identified this would determine fire impact. While rainforest fires are often attributable to changed land use and agricultural practices there has been increasing documentation of rainforest fires associated with drier conditions following El Nino years (Juaŕez‐Orozco et al, 2017; Rossetto & Kooyman, 2021). Extreme drought conditions have been responsible for tropical forest fires due to the lack of moisture (Cochrane, 2003; Swaine, 1992).…”

“…Due to urbanization and agriculture developments, less than 10% of remnant vegetation remains in southeast Queensland (SEQ: Accad et al, 2019; Shapcott et al, 2015). This, further fragments the rainforests of SEQ, increasing their vulnerability to the impacts of climate change and potentially fires (Pressey et al, 2007; Shapcott et al, 2017; Lindenmayer et al, 2020; Rossetto & Kooyman, 2021). While moist closed‐canopy evergreen forests are remarkably resistant to fire in Australia, rainforest edges are likely to burn due to adjacent flammable sclerophyllous vegetation (Bowman, 2000b; Leonard et al, 2014; Zimmer et al, 2015).…”

Gondwanan survivor lineages and the high‐risk biogeography of Anthropocene Southeast Asia

“…Recent studies have variously quantified the evolutionary histories, sources, distributions, and concentrations of paleo‐lineages in relation to key abiotic gradients at ecosystem scales, and they have provided significant insights into bio‐regional vegetation history and contemporary conservation in both the Old World tropics (Manchester et al, 2009; Kooyman et al, 2019) and the Neotropics (Jaramillo et al, 2010; Carvalho et al, 2021). Many fossil lineages occur today in refugial areas characterized by high biodiversity and endemism (Rossetto & Kooyman, 2021). Predicting the likelihood of survival of known fossil lineages in contemporary environmental conditions and their future distributions in relation to climate change remains a formidable challenge (Ivory et al, 2019; Tagliari et al, 2021).…”