Collection and production of native seeds for ecological restoration

Abstract

The global push to achieve ecosystem restoration targets has resulted in an increased demand for native seeds that current production systems are not able to fulfill. In many countries, seeds used in ecological restoration are often sourced from natural populations. Though providing seed that is reflective of the genetic diversity of a species, wild harvesting often cannot meet the demands for large‐scale restoration and may also result in depletion of native seed resources through over harvesting. To improve seed production and decrease seed costs, seed production systems have been established in several countries to generate native seeds based on agricultural or horticultural production methods or by managing natural populations. However, there is a need to expand these production systems which have a primary focus on herbaceous species to also include slower maturing shrub and tree seed. Here we propose that to reduce the threat of overharvest on the viability of natural populations, seed collection from natural populations should be replaced or supplemented by seed production systems. This overview of seed production systems demonstrates how to maximize production and minimize unintended selection bias so that native seed batches maintain genetic diversity and adaptability to underpin the success of ecological restoration programs.

Seed storage: maintaining seed viability and vigor for restoration use

“…For example, the Blue Drum Kits projects provide low-tech drying equipment for seed collection, processing, and storage (Martens 2018). will be undeveloped and will lose viability when dried, or even fail to germinate altogether, whereas seeds collected too late may have reduced viability (see Pedrini et al 2020).…”

“…As a general rule, maximizing viability and, therefore, optimal potential longevity, is achieved by collecting seeds at or close to the timing of natural seed dispersal (Hay & Smith 2003). For more information and guidance on native seed collection, see Pedrini et al (2020).…”

Seed use in the field: delivering seeds for restoration success

“…Transfer of seed‐rich hay (Fig. 5) provides a means of capturing multiple species of local ecotypes to restore depleted native or near native grasslands and highly disturbed areas (Kiehl et al 2010; Kirmer et al 2012; Pedrini et al 2020b). Green hay is harvested from appropriate donor sites (Fig.…”

Ensuring seed quality in ecological restoration: native seed cleaning and testing

“…Following collection or harvest (Pedrini et al 2020a), seeds and associated materials are typically dried, processed or cleaned, and packaged for immediate use, short‐term storage, or long‐term conservation banking. Seed handling and storage practices used immediately after harvest and during cleaning can impact seed viability, longevity, and dormancy status (Hay & Probert 2013).…”