A review of the challenges and opportunities for restoring animal-mediated pollination of native plants

Abstract

Ecological restoration is increasingly implemented to reverse habitat loss and concomitant declines in biological diversity. Typically, restoration success is evaluated by measuring the abundance and/or diversity of a single taxon. However, for a restoration to be successful and persistent, critical ecosystem functions such as animal-mediated pollination must be maintained. In this review, we focus on three aspects of pollination within ecological restorations. First, we address the need to measure pollination directly in restored habitats. Proxies such as pollinator abundance and richness do not always accurately assess pollination function. Pollen supplementation experiments, pollen deposition studies, and pollen transport networks are more robust methods for assessing pollination function within restorations. Second, we highlight how local-scale management and landscape-level factors may influence pollination within restorations. Local-scale management actions such as prescribed fire and removal of non-native species can have large impacts on pollinator communities and ultimately on pollination services. In addition, landscape context including proximity and connectivity to natural habitats may be an important factor for land managers and conservation practitioners to consider to maximize restoration success. Third, as climate change is predicted to be a primary driver of future loss in biodiversity, we discuss the potential effects climate change may have on animal-mediated pollination within restorations. An increased mechanistic understanding of how climate change affects pollination and incorporation of climate change predictions will help practitioners design stable, functioning restorations into the future.

The role of functional diversity and facilitation in small‐scale pollinator habitat

“…2011, Cariveau et al. 2020). Although biodiversity is associated with ecosystem services and productivity (Cardinale et al.…”

“…Enhancing habitat for pollinators, which could help support habitat connectivity through stepping stones (small patches of pollinator habitat) or corridors and buffers (along agricultural field sides, riparian areas, or road verges), could mitigate some of the decline caused by fragmentation and habitat loss (Menz et al 2011, Wintle et al 2019). More theoretical and empirical research is needed to adequately inform the design of measures intended to improve habitat quality so it can support pollinators and their connectivity across the landscape (Tuell et al 2008, Burgess 2013, M'Gonigle et al 2017, Cariveau et al 2020.…”

Restored and remnant Banksia woodlands elicit different foraging behavior in avian pollinators

“…Despite this critical role, plant–pollinator relationships are rarely considered in ecosystem restoration (Cariveau et al., 2020 ; Forup et al., 2008 ; Frick et al., 2014 ; Menz et al., 2011 ; Munro et al., 2011 ; Williams, 2011 ). Instead, ecological restoration has largely focused on plant species richness and habitat structure and, consequently, restoration success has been typically measured against the achievements of these structural properties (Ruiz‐Jaén et al., 2005 ).…”

“…Many “non‐target” animal species, such as pollinators, are assumed to passively colonize restored areas (Catterall, 2018 ; Williams, 2011 ). However, attributes of restored ecosystems, such as vegetation structure, plant species composition, density of reproductive plants, and degree of geographic isolation, can influence pollinator abundance, diversity, and behavior, ultimately affecting plant fitness (Cariveau et al., 2020 ). Therefore, there is a need to measure, manage, and promote ecosystem functionality in restored sites, by extending the emphasis from plant establishment to self‐sustaining populations, where pollinator community interactions are also assessed (Cariveau et al., 2020 ).…”

“…However, attributes of restored ecosystems, such as vegetation structure, plant species composition, density of reproductive plants, and degree of geographic isolation, can influence pollinator abundance, diversity, and behavior, ultimately affecting plant fitness (Cariveau et al., 2020 ). Therefore, there is a need to measure, manage, and promote ecosystem functionality in restored sites, by extending the emphasis from plant establishment to self‐sustaining populations, where pollinator community interactions are also assessed (Cariveau et al., 2020 ). However, a major challenge in determining the restoration of plant–pollinator interactions is the requirement to benchmark measures against natural systems, which are inherently complex and variable (Moreno‐Mateos et al., 2020 ).…”