Effects of management outweigh effects of plant diversity on restored animal communities in tallgrass prairies

Abstract

A primary goal of ecological restoration is to increase biodiversity in degraded ecosystems. However, the success of restoration ecology is often assessed by measuring the response of a single functional group or trophic level to restoration, without considering how restoration affects multitrophic interactions that shape biodiversity. An ecosystem-wide approach to restoration is therefore necessary to understand whether animal responses to restoration, such as changes in biodiversity, are facilitated by changes in plant communities (plant-driven effects) or disturbance and succession resulting from restoration activities (management-driven effects). Furthermore, most restoration ecology studies focus on how restoration alters taxonomic diversity, while less attention is paid to the response of functional and phylogenetic diversity in restored ecosystems. Here, we compared the strength of plant-driven and management-driven effects of restoration on four animal communities (ground beetles, dung beetles, snakes, and small mammals) in a chronosequence of restored tallgrass prairie, where sites varied in management history (prescribed fire and bison reintroduction). Our analyses indicate that management-driven effects on animal communities were six-times stronger than effects mediated through changes in plant biodiversity. Additionally, we demonstrate that restoration can simultaneously have positive and negative effects on biodiversity through different pathways, which may help reconcile variation in restoration outcomes. Furthermore, animal taxonomic and phylogenetic diversity responded differently to restoration, suggesting that restoration plans might benefit from considering multiple dimensions of animal biodiversity. We conclude that metrics of plant diversity alone may not be adequate to assess the success of restoration in reassembling functional ecosystems.

From the ground up: prioritizing soil at the forefront of ecological restoration

“…pH and water availability are also principal factors affecting microorganism abundance and the ecological relationships between them (Gałązka et al 2020). Despite the importance of soil health, ecosystem recovery is most often measured by assessing plant diversity (Ruiz‐Jaen & Aide 2005; Guiden et al 2021). Fungi, bacteria, and invertebrate communities in soil are less frequently assessed due to a bias toward vegetation surveys and the greater difficulty of monitoring these organisms (Fernandes et al 2018).…”

Future restoration should enhance ecological complexity and emergent properties at multiple scales

“…A complexity approach could involve applying a range of methods over a landscape, selecting functional groups that enhance species interactions at the site level (Fry et al 2018) and avoiding more difficult approaches if the aim is no longer to establish a reference system.4) Management throughout a restoration programme can range from the more ‘hands‐off' approach of rewilding to highly interventionist (du Toit and Pettorelli 2019). It is clear that management is a key factor driving the development of restored systems (Guiden et al 2021). Depending on the system, management can involve cutting herbaceous vegetation, thinning woodlands, introducing deadwood, introduction or exclusion of grazers, dredging of river channels, fire management, etc.…”

An objective-based prioritization approach to improve trophic complexity through ecological restoration

“…increase plant cover, prevent erosion). These species mixes have a major impact on restoration success and have an impact on the multitaxa functionality of the restored ecosystems (Guiden et al, 2021). How species mixes can be optimized to maximise restoration goals efficiently within project constraints remains an open question and an urgent task for implementing the United Nations Decade on Ecosystem Restoration.…”

“…However, the restoration of ecosystem services, functions, and animal communities is challenging due to complex processes, life cycles, and dependence on plants as well as other trophic levels Guiden et al, 2021). Plant-animal interaction networks, both mutualistic (pollination and frugivory) and antagonistic (herbivory) are highly nonrandom Lewinsohn et al, 2006;Rezende et al, 2007), and a disruption in these interactions can lead to trophic cascades across and within systems (Knight et al, 2005;Valiente-Banuet et al, 2015).…”