Current rates of habitat loss, alterations in land use, and species extinction led conservationists to devise methods and tools for species protection and preservation such as the integration of germplasm banks (Hamilton 1994). Plant reintroduction into natural or semi-natural habitats is a strategy that is aided by preserved genetic material through seed banking (Maunder 1992). Plant reintroduction is a deliberate establishment of plant species previously expunged in areas or habitats due to introduced invasive species, human activities and climate change (Maunder 1992). The goals of reintroduction is to increase plant population to create a viable self-sustaining habitat (Maunder 1992).
When species becomes extinct in wild habitats, one of the few sources of material for reintroduction will be ex situ storage in seed banks. Seed banking is used as an ex situ conservation method that aims to maintain seed viability and genetic variability of a wide range of species for an indefinite periods of time (Hong and Ellis 1995). Banked seeds are stored in environment conditions that minimizes seed deterioration to maximize seed quality for future use (Cochrane et al, 2007). Furthermore, seed banking provides a long-term protection from species extinction or genotype loss until threats are removed from the habitat (Cochrane et al., 2007).
Habitat restoration through seed banks comes with limitations. The interactions between the environment and plant development pose potential concerns for ex situ reintroduction of plant species from seed banks (Hamilton 1994). According to a study, the restorability of habitat depends on a variety of factors such as land type, duration of disturbance on habitat and longevity of the seeds stored (Wang et al, 2015). It was found that restoration of wetland through seed banks declined in success over the years of continuous disturbances (Figure 1).
Germination of seeds retrieved from seed banks are also dependent on its seed longevity (Probert et al., 2009). A study executed on different plant species showed that variability in germination is related to the seed structure, the local climate of the area where the species originated as well as the gene-bank condition under which seeds were stored (Probert et al., 2009). Viability of seeds stored in seed banks decrease with the increase of storage period (Figure 2).
Although York University does not have its own seed bank program, there are numerous Canadian seed bank agencies and institutions. The U.N.’s Convention on Biological Diversity had initiated the development of the Canadian Biodiversity Strategy that puts botanical gardens in the forefront of the national ex-situ conservation program on native Canadian rare and endangered plants. In addition, the Canadian Botanical Conservation Network (CBCN), a project of Royal Botanical Gardens, aims to maintain and encourage national contribution to the conservation of biological diversity through botanic gardens, arboreta, governmental agencies and other partners all over the country.
Employment of seed banks to the restoration of the banks at Glendon Campus would be advantageous as it offers a wide range of plant species information on evolution, adaptation, and ancestry that can guide conservationists to the best route of action for the execution of habitat recovery and restoration projects (Maunder 1992). Seed banks provide an effective safeguard for threatened species in habitats invaded by introduced species, human activity or climate change. For example, the restoration of the habitat at Glendon Campus from the invasion of Japanese Knotweed is possible if reintroduction of native plant species via seed banks is utilized as means of recovery from the ecosystem damage. Success of the habitat restoration and recovery of the river banks at Glendon Campus depends on the consideration of limitations in using seed banks. To conclude, restoration initiatives through the employment of seed banks can be an efficient and effective method for restoration and recovery if dynamic factors that challenge success are considered.
Cochrane, J. A., Crawford, A. D., & Monks, L. T. (2007). The significance of ex situ seed conservation to reintroduction of threatened plants. Australian Journal of Botany. 55(3), 356-361.
Hamilton, M B. 1994. Ex Situ Conservation of Wild Plant Species: Time to Reassess the Genetic Assumptions and Implications of Seed Banks.Conservation Biology 8(1): 39–49.
Hong, T. D., and R. H. Ellis. 1995. A Protocol to Determine Seed Storage Behaviour. IPGRI Technical Bulletin.
Maunder, M. 1992. Plant Reintroduction: An Overview. Biodiversity and Conservation 1(1): 51–61.
Probert, R.J., Daws, M., and Hay, F.R. 2009. Ecological Correlates of Ex Situ Seed Longevity: A Comparative Study on 195 Species. Annals of Botany 104(1): 57–69.
Wang, GD., Wang, M., Lu, XG., and Jiang, M. 2015. Effects of farming on the soil seed banks and wetland restoration potential in Sanjiang Plain, Northeastern China. Ecological Engineering. 77: 265-274
For more information about Japanese Knotweed, check out my previous post: