Overlooked and undervalued: the neglected role of fauna and a global bias in ecological restoration assessments

Abstract

Globally increasing rates of mine site discontinuations are resulting in the need for immediate implementation of effective conservation and management strategies. Surveying vegetation structure is a common method of assessing restoration success; however, responses of fauna to mine site restoration remain largely overlooked and understudied despite their importance within ecosystems as ecological engineers, pollinators, and restoration facilitators. Here we review the current state of the use of fauna in assessments of mine site restoration success globally, and address biases or shortcomings that indicate the assessment approach may undershoot closure and restoration success. We identified just 101 peer-reviewed publications or book chapters over a 49-year period that assess responses of fauna to mine site restoration globally. Most studies originate in Australia, with an emphasis on just one company. Assessments favour general species diversity and richness, with a particular focus on invertebrate responses to mine site restoration. Noteworthy issues included biases towards origin of study, study type, and target taxa. Further searches of the grey literature relating to fauna monitoring in mine site restoration, which was far more difficult to access, yielded six monitoring/guidance documents, three conference proceedings, two book chapters without empirical data, and a bulletin. As with peer-reviewed publications, grey literature focussed on invertebrate responses to restoration, or mentioned fauna only at the most basic level. We emphasise the need for global re-evaluation of regulatory standards to address these major limitations in assessing the capacity of the mining industry to comprehensively and representatively restore faunal communities after mining.

Methodological Ambiguity and Inconsistency Constrain Unmanned Aerial Vehicles as A Silver Bullet for Monitoring Ecological Restoration

“…We found few examples of fauna monitoring using UAVs in a restoration context, potentially reflecting the global paucity of literature relating to fauna recovery following disturbance [55]. However, RGB-equipped UAVs have been employed to assess distribution and density in fauna species that are challenging to survey on foot, such as orangutan (Pongo abelii) [56] and seabird colonies [57,58].…”

Using monitors to monitor ecological restoration: Presence may not indicate persistence

“…Historically, there has been an emphasis placed upon assessing vegetation structure and community dynamics in post-restoration monitoring (Ruiz-Jaen & Mitchell Aide 2005;Koch et al 2010). Consequently, animal taxa are often overlooked in assessments of restoration success (Lindell 2008;Cross et al 2019;2020a) despite their role in providing critical ecological services, such as soil decomposition (Jouquet et al 2006;Lavelle et al 2006), pollination (Phillips et al 2010;Menz et al 2011;Frick et al 2014) and regulation of predator-prey dynamics (Mace et al 2012).…”

Restoration goals: Why are fauna still overlooked in the process of recovering functioning ecosystems and what can be done about it?

“…There have been numerous calls for fauna to receive greater consideration in restoration projects (Majer ; Lindell ; Majer ; Cross et al ). While some studies report on the responses of fauna to landscape revegetation, for example in agricultural areas of Australia (Munro et al ), the poor representation of fauna in studies of ecosystem recovery continues to be reported across numerous landscape degradation processes, including broadacre agriculture (McAlpine et al ; Catterall ), forestry (Jansen ; Rodrigues et al ), mining (Cross et al ) and the creation of novel ecosystems, for example through climate change (Kennedy et al, ).…”

“…Summarised as the Field of Dreams Hypothesis, or ‘build it and they will come’ (Palmer et al ; Cristescu et al ), this assumption is appealing in theory and seems to be entrenched in the attitudes of practitioners to ecosystem recovery. However, this theory fails to recognise critical plant–animal interactions that are integral to ecosystem function (Tomlinson et al, ), and few studies have rigorously tested whether fauna from different functional groups do return to restored ecosystems (Hale et al ; Cross et al ). While some studies assess faunal responses to variation in habitat conditions (e.g.…”

“…While it is possible that the Field of Dreams Hypothesis holds true for some faunal assemblages and ecosystems, recovering diverse animal communities to pre‐disturbance biodiversity and abundances can be exceptionally difficult (Cristescu et al ; Perring et al ; Cross et al ). For example, presence/absence studies are useful tools in monitoring populations and identifying critical habitats and resources for population support (Mackenzie ) but provide little evidence of the ability of communities to reproduce at self‐sustaining rates (Aldridge & Boyce ; Lindell ).…”