Seed production areas (SPAs) can be a useful alternative to seed banking for species with recalcitrant seeds, which cannot be stored long-term under conventional seed bank conditions. For these species, SPAs can become a gene bank of living plants that also produce seeds for restoration.
SPAs can also be used together with seed banking for species that have orthodox seeds but are difficult to collect in the wild. This might be due to biological reasons, such as a species that doesn’t produce seeds every year, or logistical reasons, such as a species that only occurs in areas that are very difficult to access. However, you may be able to collect enough seeds to establish an SPA for such species.
A field genebank (FGB) is a complementary strategy for conserving genetic resources in the form of SPAs. An FGB is an ex situ method that maintains genetic variation away from the place of origin of the species being conserved, and it is especially useful for species with short-lived or recalcitrant seeds. Field-based conservation is not recommended for the long term due to its high maintenance costs and exposure to pests and/or diseases, which sometimes cause the failure of FGBs, as entire collections may be exposed to loss. In vitro culture techniques (growing plants in sterile media inside containers, also called micropropagation or tissue culture) can be used in a complementary way to an FGB, since they allow a more efficient conservation process; however, in vitro conservation does require specialized laboratory techniques and conditions. For threatened species, this type of technique can be convenient and necessary, since it can offer conditions where plants can adaptively evolve over time, as long as it is complemented with in situ techniques (conservation of plants in their natural environment).
In the context of ecological restoration, SPAs are often managed plantings of wild-sourced plants for the specific purpose of increasing the number of seeds available for restoration. They can range from small seed beds managed by one organization to large networks of SPAs under government or commercial management.
Restoration seed reserves (RSRs) are another type of SPA, which can also be an option if your organization is interested in reproducing seeds with improved characteristics. RSRs are modified systems based on seed orchards, which are traditional systems intended for important commercial species to improve their genetics. RSRs aim to improve the adaptation potential of species for restoration and intend to conserve species with reduced or threatened populations. The inclusion of diversity of species is also a key point in order to allow future populations to have the ability to adapt to abrupt changes in their environment and thus avoid the decline or extinction of priority species. RSRs are provisional sources of seeds of unproven genetic superiority, but which have been improved by eliminating unwanted phenotypes (physical forms). RSRs are desirable seed sources where you can easily collect seeds, as individual plants are managed, for example, by spacing, thinning, and pruning. For further details, please see the publication “Restoration seed reserves for assisted gene flow within seed orchards” (Echt & Crane 2017) and the conference paper “Establishing gene conservation banks in Southern Region National Forest seed orchards” (Echt et al. 2011).
SPAs can focus on one species or contain a mixture of species. If you face challenges with seed sourcing or seed banking, establishing an SPA (or connecting to an existing SPA network) might be a useful option. However, it is important to distinguish an SPA for restoration from SPAs for agricultural or other commercial purposes, which may focus on traits such as minimizing dormancy (speeding germination) or synchronizing germination (so that seeds germinate at the same time). While these traits make it easier to grow plants, this eliminates a lot of natural genetic diversity found in wild plants, which ultimately causes the plants to be poorly adapted to natural conditions in restoration sites. In addition, even restoration-focused SPAs face risks to genetic diversity resulting from cultivation, so it is critical to plan and manage SPAs carefully. To learn more, we recommend the articles “Seed production areas for the global restoration challenge” (Nevill et al. 2016), “Seed production areas are crucial to conservation outcomes: benefits and risks of an emerging restoration tool” (Zinnen et al. 2021), the report “Introducing Seed Production Areas: an answer to native seed shortages,” and examples of SPAs in the Brazilian Amazon and Argentina.