Plant selection for pollinator restoration in seminatural ecosystems

Abstract

Individual plant species play valuable roles in meeting restoration goals for pollinators. However, the selection of plant species for pollinator restoration is rarely informed using empirical evidence and is usually developed in agroecosystems, which experience frequent human interventions to ensure plant success as compared to seminatural ecosystems. We highlight concepts and future research needs to design planting mixes that fulfill the ecological requirements of pollinators in seminatural ecosystems. Native plants that are attractive to pollinators, increase the stability of pollination services, and provide consistent floral resources across the landscape and growing season should be prioritized in pollinator restoration projects in seminatural ecosystems. Furthermore, condensing criteria of desirable plant traits into a composite score can aid managers in selecting plant species that meet restoration goals. Developing restoration strategies for pollinators on seminatural lands is important for preserving organisms essential for biodiversity maintenance and ecosystem function.

Existing flower preference metrics disagree on best plants for pollinators: which metric to choose?

“…We make this assumption for three reasons: first, that it would be impractical to try and determine the floral preferences of each species in a community and therefore it is efficient to operate at the community level rather than that of the species or individual; second, that it has been shown to work (Maia et al, 2019); and third, because it would be useful. For example, incorporating a metric into a restoration framework, such as the one provided by Glenny et al (2023), will help practitioners to decide how to spend limited resources to maximise insect conservation efforts. Furthermore, preference metrics can be calculated for a single species or groups of species, which can be useful when determining the flower preferences of species of conservation concern (Glenny et al, 2023) or when targeting pollinators of a particular crop (Robson, 2014).…”

“…For example, incorporating a metric into a restoration framework, such as the one provided by Glenny et al (2023), will help practitioners to decide how to spend limited resources to maximise insect conservation efforts. Furthermore, preference metrics can be calculated for a single species or groups of species, which can be useful when determining the flower preferences of species of conservation concern (Glenny et al, 2023) or when targeting pollinators of a particular crop (Robson, 2014).…”

“…We found that the PI metric is the best to use of the five examined in this study because it behaves how we would expect a preference metric to, it is insensitive to undersampling, it is relatively easy to use and it is flexible such that it can calculate the preferences of an entire community to the preferences of a single species. The inclusion of this metric in a larger decision‐making framework (Glenny et al, 2023; Robson, 2014) or the modification of this metric to address other community‐shaping factors should be explored in future research.…”

“…Furthermore, establishing vegetation for pollinators, such as wildflower strips and gardens, is expensive and time‐consuming (Campbell et al, 2017), especially when using locally adapted seeds (Isaacs et al, 2009). Given the difficulty and expense, practitioners need a floral selection method that maximises possible benefits for the pollinator community (Glenny et al, 2023; Scheper et al, 2021).…”

Native Bee Habitat Restoration- Key Ecological Considerations from Recent Literature

“…In some circumstances, non-native plants can support bees. Although incorporating native pollinator-friendly plants in urban and semi-urban habitats can increase pollinator abundance (Berthon et al, 2021;Rahimi et al, 2022;Glenny et al, 2023), non-native plants can also provide valuable floral resources for bees in urban areas. Non-natives are often tolerant of urban conditions, attract a wide variety of pollinators, and flower throughout the year (Frankie et al, 2019).…”