Seed enhancement: getting seeds restoration-ready

Authors: PEDRINI, SIMONE - Curtin University; BALESTRAZZI, ALMA - University Of Pavia; MADSEN, MATTHEW - Brigham Young University; BHALSING, KHIRAJ - Curtin University; Hardegree, Stuart; KILDISHEVA, OLGA - University Of Western Australia

Submitted to: Restoration Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/16/2020
Publication Date: 4/23/2020
Citation: Pedrini, S., Balestrazzi, A., Madsen, M., Bhalsing, K., Hardegree, S.P., Kildisheva, O. 2020. Seed enhancement: getting seeds restoration-ready. Restoration Ecology. 28(S3):S266-S275. https://doi.org/10.1111/rec.13184.
DOI: https://doi.org/10.1111/rec.13184

Interpretive Summary: Approximately 40% of the land on earth is composed of desert, semi-desert, grassland and rangeland. These arid and semi-arid lands are increasingly disturbed by fire, invasive weeds and improper management, and large areas of these lands are in need of restoration. Restoring desirable plant cover in these areas, however, is extremely difficult due to high variability in water availability, pests and pathogens, soil crusting, and competition from non-native weedy species. New technologies are needed to improve the success rate of seedling establishment in these relatively harsh and unpredictable environments. In this paper we reviewed current technology and potential uses of two seed treatments that could be used to improve seedling establishment success in variable and harsh arid and semi-arid systems: seed priming and seed coating. These procedures can be used alone and in concert to speed up or slow down seed-germination response rate in order to take advantage of specific ecological conditions at a site, to mitigate or negate chemical and biological hazards to seed germination, or to diversify seed germination response as a bet hedging strategy to ensure successful germination in a variable and uncertain environment. Novel and innovative techniques for enhancing germination response can contribute significantly to a broader restoration strategy to address multiple issues related to site condition, species availability and species performance on our extensive arid and semi-arid lands.

Technical Abstract: Seed enhancement technologies such as seed priming and seed coating, developed by the agricultural seed industry, have been in use for decades with standard procedures for the majority of crop and horticultural seeds. However, such technologies are only just being evaluated for native seed despite the potential benefits of such treatments for improving restoration effectiveness. Key approaches include: seed priming where seed are hydrated under controlled conditions to pre-germinate seed; seed coating encompasses a diversity of treatments where external materials and compounds are applied onto the seed. These technologies are commonly employed to accelerate and synchronize germination, improve seed vigor, seed delivery to site (size uniformity of dispersal units), seedling emergence, plant establishment and yield. In recent years, seed enhancement technologies have been tested on native seeds to overcome logistical and ecological barriers in restoration. However, further research is needed to extend the application of seed enhancements to a broader array of species/ecosystems/regions and to evaluate new and innovative approaches (such as the incorporation of microorganisms in the coatings). As techniques in native seed enhancement develop, these approaches need to be capable of being scaled-up to provide the tonnages required for global restoration.