The effects of site preparation equal those of seeding at a dryland restoration site: 6 years of plant community development

Abstract

Dryland ecosystems generally require active restoration to recover from severe land degradation caused by resource and energy extraction operations. While seeding remains one of the most used forms of active restoration, land managers in dryland systems have generally had difficulty re‐establishing desirable plant communities, due in part to alterations in supporting ecosystem processes and the episodic nature of resource availability. In this study, we examined the impacts of site preparation, seeding, and livestock grazing on developing plant communities after the construction of a buried natural gas pipeline corridor in the southwestern United States. We monitored plant species cover and composition beginning with the second season of growth through the sixth. Analysis of each individual year show that conclusions from the initial year of data collection did not well represent the findings in the following years. The site preparation and topsoil treatment had an ongoing positive effect on richness and cover compared to the nearby baseline conditions, while seeding only further increased cover and richness in the first year of monitoring (second season of growth). However, without seeding, the plant communities were driven by ruderal, annual species, whereas the seeded plant communities were driven by desirable seeded perennial grasses and forbs. Grazing and trampling effects were not significant overall, and the effects of livestock may have been confounded with effects of small mammals due to the exclosure configuration. We suggest that the site preparation, topsoil treatment, and configuration linearity of the disturbance corridor allowed for high levels of natural recruitment.

Restoration richness tipping point meta‐analysis: finding the sweet spot

“…A net positive effect of the critical interventions tested demonstrates that restoration in drylands will benefit from these efforts similar to previous syntheses that report successes (Miguel et al 2020; Weidlich et al 2020; Copeland et al 2021; Farrell et al 2021). However, the lands in this synthesis with relatively more species did not necessarily benefit more from the restoration efforts.…”

“…Nonetheless, species richness is not necessarily used as a predictor or an evaluation tool for the ecological trajectory of a system undergoing ecological restoration (Winikoff et al 2020). Managing the richness of invasive species (Weidlich et al 2020) or seeding different native species mixes are frequent restoration interventions (Farrell et al 2021), but we propose that species richness can be much more widely used as a tool to explore the capacity of varied restoration efforts. Admittedly, richness is a simplification of the complexity inherent in all grasslands (Bardgett et al 2021), but identifying the strength of simple and widely accessible conceptual starting points in restoration is needed to support strategy development.…”

Fuel connectivity, burn severity, and seed bank survivorship drive ecosystem transformation in a semiarid shrubland

“…Because the propagules of the original assemblage are no longer present, methods that rely on natural succession may not be sufficient (Suding et al, 2004). One‐off seeding treatments have a low probability of success (Arkle et al, 2022; Pyke et al, 2020), and more labor‐intensive methods involving site preparation (Farrell et al, 2021), seed coating, and priming (Pedrini et al, 2020), as well as planting live plants (Pyke et al, 2020), may improve the probability of success, as will prioritizing efforts in cooler, wetter years (Bradford et al, 2018; Hardegree et al, 2018; Shriver et al, 2018). Estimating burn severity using satellite imagery may be used in conjunction with site suitability and climate forecasts to help land managers identify areas with a greater likelihood of successful seeding.…”

Different ways to success: Plant community trajectories over time and a soil moisture gradient in restored wetlands

“…In addition, alien species were found to be more common in dry grassland, confirming the sensitivity of these habitat to invasion as response to soil and landscape disturbances (Boscutti, Sigura, et al, 2018; Geppert et al, 2021). It is also plausible that the high diversity values found at the early stages of the succession might be sustained also by to the use of native seeds during restoration (Boscutti et al, 2016; Farrell et al, 2021).…”