Living in Ireland since the beginning of June has made me extremely aware of the lack of trees specifically in this country, but also worldwide. Even small pieces of forest are very rare in Ireland, a country which used to be covered in trees. Instead there are wide open grasslands and worse: turf lands made of black soil on which almost nothing grows. In many places the ground is cracked and reveals large pieces of pure quartz underneath. One can only speculate what happened here in the past…
At the same time I am finding wonderful initiatives worldwide for saving seeds, freeing the seeds and creating seed sovereignty. However most of these initiatives are focused on food, esp. horticulture & heritage crops. I am realising that we may miss the opportunity to collect and save the seeds of esp. rarer tree species which are often particularly found around temples, castles, tombs in botanical gardens, on graveyards where pieces of native forest have survived.
Among the very few examples of existing tree seedbanks we are aware of are:

The seedbank of the New Zealand Plant Conservation Network which is now also featured on the Nature page of this website:

Akira Miyawaki’s work who has created a collection of > 10 million identified seeds of wild plants, particularly trees in Asia esp. Japan.

Millennium Seed Bank in Wakehurst, UK, the world’s largest seedbank of 2.4 billion seeds of > 39,000 plant species which includes trees. This is an underground seed bank, with all seeds stored in one place and hence obviously easy to destroy.
I feel that we need more local, decentralised seed collections particularly for trees. These seeds need to be collected & stored properly depending on the requirements for local species. If collected too early in the year, the seeds may not be fully developed which negatively affects germinate rates. When collected at the right time, and dried & stored properly the seeds can be kept for decades without damage. It seems to me that this need can be turned into fun local community initiatives, perhaps involving youth and school projects.
Look for a local seed collection & propagation guide, or eco-sourcing guide, often offered by conservation departments or plant conservation networks. Just in case you may wonder, eco-sourcing refers to the seed collection from local, native plants and their re-planting within the same geographic area – using local seeds for reforestation and rewilding which are adapted to local environmental conditions.
We would love to hear from you if you are aware of projects for collecting tree seeds and creating seed banks. If enough material comes together we will create a later more comprehensive post about this important topic.
If you are looking for food seedbanks, here are some examples from the global scale to the local community level:
Global networks
National networks
Community networks