Here is the second part of my digressions on seed gathering. The first, “Getting Serious About Seed Gathering” was published a couple weeks ago.

There are several undercurrents of ideas regarding the use of “locally adapted” seed, and the strategy of gathering that seed from existing native vegetation to accomplish this. The ideas center around the concept of genotypes, sub-populations of species that share combinations of genes (and thus traits). In effect, a genotype is a derivative of the idea of the species, dividing species into smaller and smaller increments. The core concept of the species is a group of organisms which can breed and have viable and fertile progeny. That definition is much more difficult and messy than it sounds, but even without introducing the myriad exceptions to the rule (and absolutely needing to ignore micro-organisms) there is the stumbling block that, while populations of plants and animals may breed true, that doesn’t mean that they are interchangeable. Many of the species that I find in my prairies have ranges that encompass much of the continent, and occasionally are even found in Eurasia. Genetic differences develop in different geographies. A personal example which brought this fact home occurred when I seeded the original restoration in 2018. The blanketflower seed that I purchased turned out to be grown in Colorado, and looks very different from the blanketflower that is found in my relict prairies. It is not as winterhardy as the plants native to my prairies, and starts blooming earlier than my native plants. While some are still alive, their eventual demise seems certain. Clearly there are genetic differences which make it less suited to a long, productive life on my restoration; thus, even without any deeper knowledge of its genome, I feel safe in calling it a different genotype. This was clearly not locally adapted seed.

It is fair to ask, then, what implications this has for the stability and longevity of my restorations. One of my stated and explicit goals for the restorations is enhanced populations and spread of the prairie plants that have been able to survive on these gravelly, godforsaken hills my grandfather purchased well over a hundred years ago, my local genotypes. Have I already shot myself in the foot, or whatever old metaphor you like for describing ineptitude? Well, I admit that I would really like to have known everything that I know now when I began this process, and had not purchased blanketflower which originated in Colorado. Why didn’t I just use seed from my relict prairies?

First, as I wrote about in the last post, it is very difficult to gather enough seed for a complete restoration. Relict prairies with sufficient seed to gather are not a dime a dozen. I have gathered as much of my blanketflower as I have been able and has seemed prudent, but it has only made a small contribution to the restoration. That is one reason that I want so badly to expand the reach of my genetics. Second, adding new homes for my local species is only one of the purposes of the restorations. There is a whole panoply of ecosystem services that I hope my farm can deliver, and I need more seed than I can gather to accomplish the other goals of carbon sequestration, food for pollinators, wildlife habitat, water quality enhancement, etc. Thus, the question isn’t really whether I will add more seed than I can gather; rather it is how to get the most out of the seed that I do gather, and how to purchase seed that can further all my goals. Before I return to the idea of the value of my gathered seed, I will delve into its limitations and potential weaknesses

First, imagine what the prairies looked like 175 years ago, before the plow found the prairies. There was an expanse of grassland that extended over 1000 miles from north to south, and perhaps 400-600 miles from east to west. Individual prairie species rarely inhabited this entire geography, but many covered hundreds of thousands of square miles. If a species inhabited even 100,000 square miles and occurred an average of only 1 plant per acre, that would still give a population of 64,000,000 plants of that species. Many species likely had populations in the billions. On a local level, if an event occurred that extirpated that species in an area, there was an almost limitless ability of the surrounding landscape to resupply seed to recolonize. If an ice age began or ended, there was a path for each species to follow the climate north or south, east or west, to find its niche; to literally put down roots. Because of the number of plants of each species that were reproducing in an area there was also almost unlimited opportunity for each species to accumulate genetic mutations, weed out deleterious changes and, in effect, create a storehouse of possibilities in the genomic bank that was available for future use. In evolutionary terms they were increasing their “fitness”, the ability of their descendants to thrive and reproduce. Unfortunately, times have changed.

Now, on my land, I have a substantial amount of the diversity of species one would hope for in this area, but the number of plants available to provide that depth of genetic possibility is greatly diminished. The conversion of prairies to cropped acres, overgrazing and herbicide use on remaining native pastures and the insidious spread of smooth brome have all impoverished the genetic storehouse. Not only are there far fewer plants of each species creating new genetic possibilities with mutations and crossbreeding, but even the bank of genes that remains diminishes as the plants come and go. Mutations regularly occur that have no immediate positive nor negative effect and thus can quietly creep into the metagenome of a species. However if there is no positive selection pressure which insures that plants with those mutations survive, and there are only a few plants of that species in a geographic area, pure chance will mean those mutations, those traits and potential traits, will often disappear. In a large, robust population pure chance will more often leave some individuals with that mutation reproducing. Later, when that gene becomes important because of a change in conditions, it is available to allow that species to thrive even while challenged by a new disease, insect, or a change in climate. To fully explain the process, called genetic drift, would take examples and perhaps graphics, but in short, more is better, and a lot more is a lot better. A larger population will provide more genetic possibilities to respond to the inevitable challenges to survival.

Here’s an example I have been thinking about lately. There are perhaps 30 plants of standing milkvetch (Astragalus adsurgens) on my prairies, and I don’t know how far one would have to go to find the next example, perhaps several miles. It will only take a very small bit of bad luck to lose the entire population, and genetic drift is likely diminishing the variability of the groups’ collective genome, leading to inbreeding. If I want to save my local population steps will have to be taken. Without help this local population is likely to eventually perish. What is my response to this?

A good starting point is trying to gather the seed from my prairies and other nearby prairies, giving me the confidence that the seed that I plant is adapted to the climate and soils of the adjacent restoration, and to use that seed to establish a lot more plants. However, as discussed earlier, the amount that I can gather is insufficient and perhaps impoverished genetically to respond to challenges going forward. Simply increasing the number of reproducing plants, providing a larger number to create new mutations, new genes, is a big deal. Turning 30 standing milkvetch plants into 300 is a big deal. That’s still not many plants, however, and again, it’s derived from a very narrow genetic base, likely with low diversity of genetic possibilities. Thus, while increasing the number of plants with obviously adapted genetics is great, I feel that I need to do more. I feel a need exists to import some new genetics to add to my burgeoning population.

The question now becomes: From where? How do I best accomplish this genetic enrichment? For some species I have the obvious choice of gathering seed from the prairies owned by friends. Most notably, we have several native pastures in my wife’s grazing unit, Whetstone Grazing, 30 miles east of the restoration. This is a more mesic site than my restoration, and at 800’ lower in elevation it will provide genetics adapted to a little warmer and wetter climate, just what we are likely to get over the next hundred years. Near the Whetstone Grazing pastures is a small prairie owned by my best friend, on a dry mesic site, and he has kindly allowed me to gather seed there the past several years. There are a couple other corners that I get to gather on, and these have been my main sources along with the relict prairies adjacent to the restoration. They have been a good source of 40-50 species, but that leaves 40-50 species for which I would like to find additional genetics, including the standing milkvetch.

Which brings me back to purchasing seed. Many of those 40-50 species are sold by native seed vendors, and now that I am a more informed shopper, I can try to buy more seed that I have the ability to gain some knowledge about, to ascertain the source. I am doing that with Milborn Seeds in Brookings, my main supplier, and will begin communicating with Prairie Moon Seeds in southeast Minnesota, my secondary source. I have come late to this knowledge, as I am almost past adding seed to my first 100 acres of restoration, but am trying to do a better job on the last couple patches, the last 40 acres., and on any future restorations that I contribute to.

And now to circle back, going back to the title of the piece, the great worth of the gathered seed is that it has a base of adapted genetics which might not be available in the marketplace. I know for certain that the seed from my relict prairies is going to have the ability to grow in my soils and the present climate of my site. In that sense it is almost priceless and irreplaceable, and all my hours of wandering and gathering is priceless as well. I might only gather $50-100 worth of seed in a session, if measured as retail price of that species from a seed vendor, but I feel it could be worth many times that to me as the beating heart of the restoration. That is not to denigrate the purchased seed, for even poorly adapted purchased seed, such as my stupid Colorado blanketflower, may have genes that are valuable and can enter the gene pool through cross pollination. There is a concern I have read that poorly adapted genetics will weaken the population of the local plants, but I doubt that is likely. Deleterious crosses will lose out, and will be destroyed in the meat grinder of evolutionary pressure. Good riddance to bad garbage. Traits and crosses that add to evolutionary fitness will thrive and increase, sending their progeny down the generations to the future. I know that sounds like a hopelessly optimistic view of the brutally efficient process of evolution, but the logic is really pretty direct. Occam’s razor says the simple, direct explanation is most likely to be the correct explanation, and I think this is it: Evolutionary processes, survival of the fittest, will sort out the genetics that can survive and reproduce at my site, and that genotype with maximum fitness may change as time goes on. Efficient working of that process will depend upon the base of the adapted genetics from gathered seed, a large population that allows a multitude of mutations and crosses to occur, and additions of new genetics, outbreeding if you will, to provide a deep bench of traits which will provide resilience down the years.

And it depends upon time, a lot of time. I have stated in several posts that I am playing the long game here, and I am presently waiting for an offer from the US Fish and Wildlife Service for a perpetual easement on about 200 acres of restoration and pasture which will guarantee the time for this to become a real prairie. It is often said that once prairie is plowed up it will not return, and even the best restoration is but a pale imitation of the glory of the real thing. Baloney! People who believe that are correct if their time scale is ten or twenty years. Twelve thousand years ago the glaciers were melting away and we didn’t even have a prairie until perhaps 8000-9000 years ago. Somewhere in that span of time a dynamic prairie developed, and changed with time and the management of the indigenous people who lived there. Patience is required. If my descendants care to look at and walk in the restoration in three or four hundred years my bet is that they will find a functioning ecosystem. I can’t say what that will look like, and I certainly can’t say what the climate will be. However, I expect that the restorations will be whatever native prairie has become in South Dakota in the 23rd century. And with that I humbly bow, and submit to the unknowns of the future with a smile and a wave.

Postscript: I recently received an offer from the US Fish and Wildlife service to accept a permanent easement on 140 acres of the restorations and I immediately accepted the offer. The restorations will have their time to develop. Maybe my descendants really will get to see what happens.