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Tuesday, December 31, 2013

Where to Broadcast our most Precious Prairie Seed?





How do we make the most 
of rare seed?  

How do we decide where and when to plant it?  

Some stewards are getting to be very strategic with their seed.



This patch looks good in summer, but it's begging for spring seed.
Consider three patches, 
near to each other 
in the same preserve.

The first one, 
at right, is dense 
with such 
conservative plants as 
dropseed, lead plant, prairie clover, and more.

But it has no 
bastard toadflax, shooting star, betony and, indeed,
 few other spring 
conservatives.

The spring niches are open, hungrily waiting. 

Fire and competition have eliminated most invasives and temporary "weeds." All we have to do now - to restore most of the missing spring species - is just broadcast their seed in fall or winter. 

We also sometimes broadcast summer-ripening seed as soon as it's ripe, assuming that the species knows how to cope with what it's coped with for eons.  On the other hand, early sowing may be wasteful. Perhaps much of the early-distributed seed gets eaten by various seed eaters.  (We know that some spring species, left to their own, hold their seed until fall. It would be good if someone experimented under natural conditions with various sowing times. The seed of many early-blooming species is so rare (or hard to get) that it would be worth the time to test to see what approach is best.) 

I wouldn't broadcast seed of rare summer or fall flora in this patch, even if the species is still missing. Probably a very small percentage would succeed, as in nature, but what a waste of very rare seed, from a restoration perspective. Instead, if I located seed of a species that would likely add natural diversity here, I'd put it into a nearby less competitive area and let the seed of the many likely recruits there add to the seed rain so that the species could disperse from there naturally over time.

The second patch, below, may not look like much at first, but it is wildly exciting to me for its 
Here fleabane and bare ground are exciting indicators.
potentials. Here's the place to restore summer prairie conservatives. Dropseed, prairie clover, Leiberg's panic grass, prairie gentian, lead plant, and azure and smooth blue aster would quickly thrive in this matrix. The area is begging for all the species that make high prairie quality (but which you rarely see dominant in prairie restorations, in part because they don't compete well against more aggressive plants in plowed or herbicided bare ground).

How do I know that the cream of the crop will do well here? One give-away are the pale pathetic little white flowers. They are fleabane, an annual or biennial. Wherever annuals or biennials are frequent in a relatively stable sod, you know that niches have somehow opened up so that new species have a good chance. In this case, fire and competition have recently eliminated some short-term competitors. As I remember, they included bluegrass, timothy, red clover, and gray dogwood. Other species in the photo that indicate this area is ripe for seed are early goldenrod (top corners) and bergamot. If we don't quickly seed, those two plus rattlesnake master (white spheres) will likely soon become over-abundant. But, if seeded now, scores of conservative species will compete well against what's here. Last fall we did broadcast our "conservative turf" mix here. In a mere five years or so, quality prairie should be evident (even if the plants are still small) in every square foot.

Here's the last patch to consider
in this post.

It's intermediate and needs an intermediate strategy.

Big bluestem, Indiangrass, wild quinine, gayfeather, and other mildly conservative plants are dense. That is not a matrix in which most rare seed will especially thrive.

Many spring species (especially betony) will do well. But summer and fall conservative seed would be better invested where it will thrive more.

On the other hand, it sure would be good to get at least a beachhead of dropseed, prairie clover, and their pals in here. So in a place like this I'll invest a small proportion of the best seed, expecting just a few plants to take here and there - but then to start to disperse their own seed decade after decade and ultimately do fine.

Of course, once the more receptive areas have all been well seeded, it will then soon be possible to harvest much larger volumes of rare seed, and a fine little spot like this could then be bombarded with lots of rare seed as long as needed.

Make sense to you?
Have any comments that might help others learn from your own experiences?
Have any questions?
Feel free to contribute to the discussion.
Thanks.

And in the meantime ...

... below, in case you're interested, are some additional tidbits about the photos:


What kinds of seeds are these? I have to admit that these are spring woodland seeds, rather than prairie seeds, because they're the best photo I could find. Most are various kinds of sedges. The wrinkled ones top left are early meadow rue. The reddish-and-white ones just below them are bellwort. Reddish brown seeds on the right edge are bloodroot. Black ones at bottom right look like wild leek. The ones that look something like apple seeds in the mid-lower left look like baneberry. Aren't they just the richest hoard you could ever imagine!

All the plants in this photo were broadcast by seed into a former pasture that, when we started, was mostly bluegrass, wild carrot, timothy etc. (Well, all but two. Can you guess which two?)

If you don't know these species, or aren't sure, would you like to learn them?
Try making a list, and comparing it with the list below?

Starting with the most obvious: the rose-purple flowers are prairie clover. White balls are rattlesnake master. Big plant with much-divided leaves is compass plant. Gray-green foliage with purple flowers in fingers is leadplant. Big simple leaves with tall naked flowering stalk (top right) is prairie dock. Yellow in the foreground and near the compass plant is early goldenrod. Slender stems in the foreground with many greenish-white buds running up the sides are rough blazing star. Fine grass leaves in clumps are the beloved prairie dropseed. Tall thick grass culms here are big bluestem. The largish leaves in the bottom right are a re-sprouting, burned-off elm tree. Coming out of the elm is one flower of wild bergamot. The fine, tiny leaves just to the left of the bergamot are heath aster, which won't head up to bloom for months. 

The two species that aren't here because of our strategically broadcast seed are early goldenrod (the only survivor from the old pasture) and the elm tree.  

20 comments:

  1. Hi Stephen, I have been contemplating artificially disturbing small patches throughout an established restoration to reduce competition for my most valuable seeds. I was merely going to turn over shovel fulls of soil distributed over an area with heavy competition to give sown seeds a head start. My thought is these species probably could compete if they could only get established. I have also been contemplating trying the same procedure with plugs. I think reducing competition while the plants are getting established would be of great benefit.

    Sincerely,
    James

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    Replies
    1. Sounds worth some experiments, in the right place. We tried something like that on the North Branch long ago with negative results. We found that the turned-over-soil areas became hostile to seedling establishment (perhaps because the very well-established adjacent plants sucked out all the water - and the bare spots baked in the sun?). The surprise to us was that some of the seeds we put there somehow got into the surrounding vegetation, and they did better there.

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    2. This Spring I planted plugs of Upland White Aster (Solidago ptarmicoides) on a south facing slope with thin gravelly soil at Spring Valley Nature Sanctuary. I planted half the plugs only removing enough soil to fit the plug in the ground and cover it slightly. When planting the other half of the plugs I took a full shovel full of soil and crumbled it up around the plugs to make a zone free of root competition with loose soil that could be easily colonized by new roots. I returned this fall to compare the difference. Although all the plugs I marked had survived, the plugs planted into the loosened soil free of root competition where about twice as big.

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    3. Interesting experiment. Thanks, James, for the report. I've also done some similar ones with similar results, although with differences from species to specious and location to location. My experiment with upland white aster was with seed. I scattered it (also on thin gravelly soil) and watched for a few years. Sure enough, many plants have emerged. I like the fact they they established where they found the right conditions, rather than where I put them. But the ones you planted may have a chance to produce seed for a few years, and then the plants will be doing that same experiment themselves. I often find that species do best some place other than the place I choose, and that's all the better. James, let us all know what happens with yours.

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    4. The reason turned-over-soil areas are hostile to seedling establishment is the seedlings are pummeled by the full force of our heavy spring rains. The seeds in the surrounding vegetation were able to establish because the vegetation protected them. I know this now because I have had the plants I am propagating destroyed time and time again by these heavy rains. I now cover seed trays containing seedlings with a shade cloth, card board, or whatever is available before thunderstorms roll through so the seedlings are protected.

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  2. I would like more of an explanation of why particular seeds/plants would do well, or not, in a certain situation. Why would spring seeds do well in the intermediate area, but not summer and fall conservatives? All I ever hear is "this would work" or "this would not work." I have not been able to construct much of a basic understanding. Or are there too many variables?

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    Replies
    1. Thanks for the question. The "intermediate area" already has dense summer and fall prairie species. They're very competitive, and they've used up most resources. So most summer and fall species will find very tight competition there.

      But there are few spring prairie species there (partly because we had so much less hard-to-get spring seed when we broadcast the easier-to-get seed), so there would now be resources and space for competitive prairie spring species. One reason why spring niches have probably opened up in the "intermediate" area is that many of the Eurasian species that were dominant have growing seasons that last well into the summer. They have been knocked back by more-competitive summer prairie species. Many of the spring prairie species (e.g. shooting star and violet wood sorrel) finish up their growing seasons very quickly. So a new spring niche may be left as the warm season prairie species weaken the "invaders" that had been monopolizing spring. Of course this is all speculative. The "truer" answer is experiential. Tom Vanderpoel and I and others have found that the spring prairie species seem to establish readily in any burned grassland that doesn't have them - unless it's dominated by such malignant species as teasel, reed canary, crown vetch, etc.

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  3. With the first and third patches that have high competition of summer and fall conservative species but still missing a few members, it would seem to me that if you are successful establishing wood betony and bastard toadflax in these patches then one could follow up later with adding the missing summer and fall species in the spaces created by wood betony and bastard toadflax (hemiparasites weakening host plants hence creating some open space)? I have been messing around with these hemiparasite species for many years now. Mostly in trying to open up space in dense warm season grass reconstructed prairies. Progress has been very slow and limited by available seed and, of course, specific know how. I think of the limited progress (in terms of increasing species diversity using hemiparasites) I have made over the years as compared to a local remnant that is loaded with hemiparasites and has outstanding species diversity. It makes my lifetime seem like just a “tick” of the millennium clock’s second hand. Anyhow, I do think understanding the competitive relationship of all the prairie’s plant species members is key to being able to increase species diversity. In an attempt to tease out more diversity, I see managers using fire, grazing or selective herbicides, but not many purposefully using plant species against plant species.

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    Replies
    1. David, I agree with your wise comment about wood betony. And, yes, in general, it's probably true in the long term that every conservative species that we manage to add will somehow contribute to new niches that will allow "our ecosystem patients" to recover the richness and resiliency we see in the best remnants.

      On the other hand, most people I know have had poor success trying to restore bastard toadflax, despite its obvious desirability, as you point out. Do you have techniques that have been working for you?

      Thanks also for your compelling language on trying to adjust our thinking to the ecosystem's majestically slow time scale.

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    2. It is too soon to tell on the bastard toadflax. I do not have much of it growing in the degraded remnants on our property. I have only been able to find and collect seed in two of the last nine years. Part of this seed I have sown directly in the planted prairie and part of it was sown in a host plant plug that was later planted. Nothing so far from seed!

      I have tried some very limited transplanting (toadflax with host plant) and have plants that will be entering into their third and fourth growing season this year. The transplanted plants have expanded very little (3 – 8 stems in a group) in size but have moved a foot or two away from the original planting location. All the transplanted plugs are located in very dense warm season grass reconstructed prairie. I should also note that I have had a fair amount of predation on the toadflax. I think it is some insect (cutworm perhaps?) that likes to fell the individual stems like a little lumberjack. Frustrating!

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  4. David, I understand "frustrating." There is nothing more maddening than the seeming inability to (re)establish species that you just know should be on a given site. But restorations seem to move on their own timetables, even on remnant sites. There is so much that we don't know. Much of the timetable seems to revolve around soil conditions, and how quickly (or slowly) they improve with management.

    It easy to focus on the things that should be better - "Why is there so much Indian grass this year? What should we do?" At our site I find it helpful sometimes to think in terms of the change over several years. Yes, we still have a lot of Indian grass. But look at how much the dropseed and Kalm's brome have spread. The Baptisia and Astragalus that never bloomed have now flowered two years in a row, and one of those was a tough weather year. Prairie Indian plantain appeared for the first time this year, and without being seeded. The prairie clover is everywhere. The associates near this monitored species are definitely more conservative than they were a few years ago. The site will let us know when it is ready for toadflax, and in all likelihood have a few pleasant surprises along the way.

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    1. Mark, I found your comments engaging. I've had similar experiences, and I wonder how we could use components of what we're all individually learning in some sort of "crowd sourcing" way that will benefit us all.

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    2. That's a good question, Steve. Your posts are invaluable because they stimulate a lot of thought and discussion, but some face time would be beneficial too. Here's a top-of-the-head thought to start more discussion. How about periodic steward summits, including sessions where people present management problems from their sites for open brainstorming? A short photo presentation or even handouts could be used to kick a session off. Other sessions could feature success stories. I know I would get a lot out of such a gathering, which would much be more focused than, say, the Wild Things conference.

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  5. So far, I have pretty much followed what I have understood to be the North Branch practice of distributing seed mixes in the appropriate places based on shade and moisture, and letting the plants sort themselves out. Going to the next level of selective seeding makes a lot of sense if I can figure it out based on what others have learned. Your initiative is an excellent start. The topic would be a welcome focus for future steward walks.

    One specific item that caught my attention is the role of betony. I have started to introduce it into tall grass monocultures in hopes of increasing diversity, but it never occurred to me to put it into high or even medium quality areas. I have seen a few small areas where it seems to be suppressing all other plants. I would like to learn more about the experiences of others.

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    1. Kent,

      Richard Henderson wrote a very interesting piece for the Proceedings of the 18th North American Prairie Conference about proposed “keystone” species and their role in maintaining diversity in a prairie ecosystem. Wood betony is one of the primary keystone species. Here is a link to it in Google books. http://books.google.com/books?id=kYWo4aHgEh8C&pg=PA63&lpg=PA63&dq=wood+betony+keystone+species+henderson&source=bl&ots=U3PTv3g2xc&sig=PWgZNHg6LJwBC45siGaN5Uf2W0s&hl=en&sa=X&ei=ezfNU

      David

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  6. Thanks for the good discussion and opportunity.

    We have the various stages of restoration development that you describe, which is complicated enough. To be sure, the more I learn, the more confounding it can be. In considering the what, when and where of seeding, though, I have observed something that's rather odd, I think. At least it seemed odd until I thought more, so maybe not.

    Some time ago, I read an article in "Ecological Restoration" that talked about soil not being evenly gradient as it gets deeper, but rather there's a few very important inches at the top, followed by several feet of another composition, followed by a great number of feet of another composition, etc. Layered in uneven chunks, not evenly gradient. Over simply stated, but perhaps you get the gist. What I have observed, though, is that when seeding into eroded areas, the response of the seed is remarkably quick with rapid diversity when compared to areas that we've burned and prepped with invasive control, and appear to now be ready to take in the first stage seed mix.

    We have seeded into a borrow pit which we know was completely barren for over fifty years, not even white sweet clover or teasel found it to its liking. In a matter of about three years, we saw not only little blue and prairie dropseed, but blazing star, pale purple coneflower, short green milkweed and others. It's now been about eight years and this ~1/8 acre section is about half filled in, but no teasel and very minimal white sweet clover. In other sloped, eroded areas, we found a quick response as well, with no invasives, although erosion continues and likely will until these areas fill in.

    It occurs to me that perhaps it is not a matter of having those first few inches of top soil there, which would seemingly be critical, but rather what is not there that allows for this. I wonder if perhaps those first few inches of top soil in other areas we are trying to ready are actually contaminated and retardant by the compost from invasives, left over mulch from large scale clearing and many years of nasty seeds. These areas may appear to be ready for seed with niching, but the composition of the soil may still be wrong which makes it seem like our good seed is taking a slow boat to China.

    The eroded areas don't attract a new crop of invasives, so there's not the competition from them. The invasive seed from years gone by, decades actually, have been washed away. Yes, it takes a while for the natives to fill in to a point that will gain control over the erosion, but, is that a bad thing? Generally speaking, do we not pay enough attention to the quality of those few inches before we start seeding? Would we not benefit from scraping away those inches instead of arguing with them for years?






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    1. Pat, you surely raise some challenging questions. In my experience, like yours, many prairie species are better than weeds at getting established in extremely damaged soil. Prairie species are masters at overcoming hardship. On the other hand, the communities on those poor soils tend to remain limited. In the richer soils, although the competition is greater and the prairie species establish more slowly, within a couple of decades they will likely have much richer plant and animal communities than the degraded soil areas. Fortunately we have both types at Orland. So we can watch and compare.

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  7. Like so many aspects of prairie restoration, including how to target limited seed, "it depends." In Nachusa Grasslands' sandy well drained soils we find that even 10 to 12 years into the life of highly diverse and thriving restorations, there is still plenty of bare soil. When we identify under-represented species we set aside that seed for "stepping in." A finger pinch of 5 to 15 seeds is dropped onto bare soil and "stepped in" with either the twisting foot motion of putting out a cigarette or, for you rock climbers, a foot smear. This extra soil to seed contact yields germination rates that are dramatically higher than seeding without "stepping in." Although we need many more years to prove it, I think you can successfully step in conservative seed into competitive areas if you target bare spots. You might ask "if stepping in works so well, why don't you plant all your seed that way?" It seems unnecessary in many cornfield to prairie plantings where there is limited competition initially, but the real limitation is time and energy.

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  8. Excellent post and comments, really got me thinking about how to be more strategic about seeds, seed placement, and techniques for "stepping in" seeds. And I am going to look at those places with daisy fleabane as exciting opportunities for seeding more conservative species.

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  9. I know this! It's called Reading Pictures!

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