Tree Migration Part 3 – Assisted Migration Program
We have done a great deal of research to try and get the principles of assisted migration correct. Luckily, we were able to contact some of the authors of the research papers we used. Generally, they all agreed we had the right data. Some were glad to see their research being implemented and some were much more cautious.
We wanted input from the MNRF about our program. In a nut shell, the MNRF is focusing on updating the seed zones and in the future they may be able to deal more directly with assisted migration.
For us, Phase 1, has been to get articles and information available and getting a conversation going. We need to have all industry and government talking. And we need to keep talking. This is not an easily resolved issue nor is it a static program. As climate changes we must reevaluate our targets and watch how our transplanted forests respond.
We will be starting Phase II, this spring, where we will vastly expand our seed collection sites. We need to start growing more southerly originated stock in order to start blending provenances.
We have also created genetic maps for our clients to keep track of seed sources used. In every planting we want to create the broadest genetic base possible. Irregardless of assisted migration, the key to any resilient forest or small planting is genetic diversity.
We will gladly dialogue with all interested parties and government and update our program accordingly.
This is just the beginning…we are going to have so much fun!
The Working Principles of our Assisted Migration Program
We are basing our decisions, at the nursery, on current scientific data that predicts climate change is causing climatic envelopes of tree species to move beyond the ability of trees to naturally migrate. In order for species to migrate with their climatic envelopes, they will have to be human assisted. Humans will intentionally move southern species northward. We will relocate species and populations. The negative affects of climate change are occurring faster than most species’ evolutionary responses.
The Nuts and Bolts for the Program
1) No static seed provenances. Convert to composite provenancing. The most important factor for trans location success is composite provenancing. This means seed selection must occur from a large number of mother trees at various distances from the out planting site. This is so crucial ; selecting seeds from a large variety of parent plants is necessary for ensuring genotypic diversity of the trans located population. Resiliency of a forest is based on genotypic variances.
Another target in composite provenancing is to ensure 10% – 30 % of seeds should be taken from parent plants greater than or equal to 60 kilometers from the out planting site. This technique has significantly increased genotypic diversity within a trans located species.
The biggest change, we foresee, is identifying seed source by a geographical map point vs a huge seed zone. By using map points we will have superior composite provenancing.
2) Assist southern species northward. Trans location of species to their northern core limit projected by the 2040 climate model using Natural Resources Canada plant hardiness predictions. It is estimated that trees must migrate 150 – 200 kilometers within the next 100 years to ensure continuation of tree species within favorable climatic conditions. The distances seem huge but scientific data estimates that 70% of tree seeds planted would germinate and become productive at 130 kilometers.
3) Assisted range expansion – Usually assisted range expansion is used in conjunction with assisted migration. This is human assisted movement of species to an area neighboring its current habitat range.
4) Adopt the diversity principle. Mix local seed sources with composite provenancing. Mix it up. This will increase adaptation of trans located species to local conditions as natural selection occurs.
5) Match trans located sites to needed growth conditions of tree species. Actually, this is nothing new. Though climate is changing, basic requirements such as soil, drainage, water availability, pH are still consistent needs for each tree species. Trans location sites should match tree requirements.