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Friday, September 29, 2017

Plant Refugees

Many once-common plant species are today rare, threatened, or endangered. For millennia, they were the basic building blocks of rich ecosystems; now they are hardly remembered. Some are vanishing over huge former ranges. Other species are at least losing most of local ecotypes. Today some of these species hide away in obscure habitats (that may indicate little about their former haunts).

Could they become common once again? Certain good experiments suggest that they could.

Before we get to a slightly longer list, consider two species – as they were described by H.S.Pepoon in 1927.

Lathyrus ochroleucus (wild sweet pea, wood pea, cream vetchling, or pale vetchling) is listed as threatened in Illinois. Pepoon characterized this plant as “Common on hillsides, in open woods.”

How often do we see the wood pea in woods today? Very rarely. There are probably two reasons: 1) the lack of fire has made our woods too dark, and 2) badly overpopulated deer seek out this delicious ‘sweet pea’.
Wood pea once grew commonly under white and bur oaks with rue anemone, fire pink, large false foxglove, shooting star, two-flowered Cynthia, wood betony, Seneca snakeroot, wood rush, wood vetch, and other first-quality species. (Photo from Wikipedia)

Viola conspersa (dog violet) is listed as threatened in Illinois. Pepoon characterized it as “very common.” I have three times seen it emerge when woods were thinned of trees making excessive shade. Mostly, these days, it’s found it wet woods – perhaps because shade from invasives is slowest to increase in very wet (or very dry) habitats. Wilhelm and Rericha list its habitats as “wet to dry-mesic woodlands" and include such associates in drier habitats as Penn sedge and bastard toadflax.
Violets hard to identify? Look at the stem (above). It shows a distinguishing character of dog violet. See how a main stem has many leaves and flowers branching off? In contrast, the common blue violet has no branching stems; the simple stems of every flower and leaf sprout directly from the root. 

As woods are restored, at least in some experimental cases, the full range of species that likely were part of the original community should be established. Some officials are reluctant to permit managers to restore now-rare or threatened species. Why should that be? If a plant was once common, what harm could come from giving it chances to become so again? Would its presence not likely help the whole ecosystem, as we try to provide the opportunity for it to restore itself to full health and diversity?

If authorization is granted, that authorization often limits restoration of the species to “proper” habitats. Why be so concerned about this? Might it not seem a bit arrogant of us to insist that we know the full amplitude of former habitats? All restoration and natural area management initiatives are experiments. These experiments should be carefully documented. And at least on some sites, the experimenters should give free rein to let the plants sort themselves out.

For me at least, I find the need for species restoration increasingly compelling the more I review species on the refuges list. The cases of seven more species are summarized below.

Pale Indian plantain (Cacalia atriplicifolia). Pepoon wrote: “Wooded hillsides. Common.” Today: Very hard to find original populations in woodlands.

Sanicle (Sanicula marylandica). Pepoon wrote: “Woods … common everywhere.” Today: Can be found in some savannas but in our darkening woods it has apparently been almost entirely replaced by clustered black snakeroot.

Smooth tick-trefoil (apparently Desmodium Dillenii and paniculatum in Pepoon). Pepoon wrote: “The common species … In open woodlands.” Now: Uncommon or missing in most woodlands.

Violet bush clover (Lespedeza violacea). Pepoon wrote: “Common on all dry soils.” Today: Rare enough that Swink and Wilhelm do not list it for Lake County, IL. But it showed up spontaneously in at least two Lake County savanna restoration areas, in one case, only after the burns started.

Wide-leaved panic grass (Panicum latifolium). Pepoon wrote:  Woods, common … An abundant, fine grass.” Today: A happy surprise when we occasionally see it.

Wild licorice (Galium circaezans). Pepoon wrote: “Woods common throughout.” Now: occasional or absent.

Wood vetch (Vicia carolina). Pepoon wrote: “Hillsides and dry open woods, frequent.” Today: I haven’t seen one in Cook County for many years.

These and hundreds of other refugee species deserve a natural and sustainable home.
We should not ill-treat these refugees. We have the ability to restore them to ecosystems that are recovering diversity and health.

Legumes (some of which have long-lasting, hard seed coats) may emerge from the seed bank in some cases. I have seen apparently missing legumes (Lathyrus ochroleucus and Lespedeza violacea) emerge from seed banks when restoration started (or possibly from surviving plants that weren’t recorded at first because they consisted only of a few leaves hanging on from year to year thanks to the little sun they did get). But on most sites, the seed bank is more of a myth than a reality. Most species, on most sites, do not spontaneously re-emerge. Restoring them by seed from nearby populations is one good experiment that should be encouraged at some sites.

When volunteers and staff launched the Somme Prairie Grove experiment in savanna and oak woodland restoration, we could find none of the species listed above. Now most of them are common or at least frequent. 
     Exceptions: We have found no nearby seed of Vicia carolina and thus have none at Somme. The recovery of Lathyrus ochroleucus seems only to be just getting started; but the similar Lathyrus venosus (which we started caging years ago) is thriving. Viola conspersa is recovering well in Somme Woods but not in Somme Prairie Grove.  

We should find as diverse populations of these refuges as we can – and restore the seeds (and some soil, if possible) to areas where full ecosystem restoration experiments are under way. Some experts have recommended restoring seeds from only one site for a given restoration. But in some cases, seed sources may consist of only one or just a few plants. Even where there may be many, we may be looking at a clone, or all may have descended from one or two individuals that survived some bottleneck when the farmer let loose his sheep or pigs or whatever. Perhaps most populations have lost some of the “genes” (alleles) that better fitted them for wetter or drier or sunnier or more-browsed-by-deer or whatever conditions. Thus one experiment, as least in some cases, should be to restore species from many nearby small populations, if possible. Perhaps then populations can re-assemble the “natural richness” of their gene pools – and surprise us with their behavior. 


Note on names: Most names above still follow Swink and Wilhelm. When Swink and Wilhelm (Plants of the Chicago Region) refer a Pepoon account to another name, this post uses the S&W common name for that referred species.
The contemporary associates given above are mostly from Swink and Wilhelm (plus, in a few cases, I wrestled with the new Wilhelm and Rericha and added species from that important source).

References.

Pepoon, H.S. Flora of the Chicago Region. 1927.
Keep in mind that when he studied plants (late 1800s and early 1900s), the ecosystem had already been degrading for many decades.
  
Fralish, James S. 2004. The Keystone Role of Oak and Hickory in the Central Hardwood Forest. Gen. Tech. Rep. SRS-73. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. pp. 78-87.
     An important article to read, for context. See abstract, below.
     Abstract—Communities of the central hardwood forest have been dominated primarily by oak and hickory for the past 5000 years. Over this time period, they have become keystone species within the ecosystem and are of major importance in maintaining biodiversity. Not only do the large number of oak and hickory species by themselves contribute to community richness but they are known to provide food and support for a substantial number of wildlife species. Moreover, the structure created by dominance of oak and hickory in the forest community provides an environment for a highly diverse herbaceous understory. Data from oak-hickory stands with a maple-beech understory of saplings and small trees show a 90 percent drop in photosynthetically active radiation (PAR) at ground level accompanied by a 35 percent increase in litter weight compared to stands without an understory. The result is over a 90 percent drop in species richness and cover. This drastic loss of biodiversity, foliage, and fruit has serious implications for insect and bird populations and also suggests a potential for increased soil erosion and loss of nutrients. Extensive research into the loss of biodiversity is advised.


26 comments:

  1. Steve, great post as usual. BTW did you mean Panicum latifolium, broad leaved panic grass (and not implicatum, or old field panic grass)?

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    1. Good point. Thanks for catching that, Pete. I made the change.

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    2. I would like to know when Stephen Packard first started this blog. I would like to read some of his early entries. Thank you.

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    3. Thanks, Contessa~Kamara, for the interest. I have two blogs. The oldest posts are at http://vestalgrove.blogspot.com
      I find posts back to 2012. They may go back to 2011? I believe that Blogger may hide the older ones, and I'm not always able to figure out how to access them. (I'm not that great at computer stuff.)

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  2. Also, several of these are present in Deer Grove, but in diminished numbers. It would be of interest to become better skilled at propagating these rare species to increase their abundance.

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    1. Yes, Deer Grove has small numbers of these and many other formerly common and now uncommon-to-rare plants.
      You may know that, before you were the dedicated steward of Deer Grove, the Forest Preserve staff authorized both Citizens for Conservation and the North Branch Restoration Project to gather seeds there. Many of the plants that are still in small numbers at Deer Grove are thriving by the thousands at CFC and NB sites.
      Part of what that suggests is that it takes only two steps to recover robust populations of these species. The first step is to restore a sufficiently open canopy for them to thrive. The second is to gather the seeds and broadcast them in the right places.
      In some cases, the seeds of the currently thriving populations at CFC and NB came ONLY from Deer Grove. So you could use such seeds to restore Deer Grove if you wanted.
      I know that you, Pete, as steward - along with an ambitious new project funded by Openlands - is opening the Deer Grove canopy in many areas. The potential for recovery is great. Congratulations on this good result of your fine work over the years.

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  3. It seems rather counterintuitive that officials would be reluctant to let people working on restoration establish the species that need it the most. Unfortunately, this line of thinking in conservation is not all that uncommon. Sometimes people think in absolutes. For example, the thought that the activities of people caused a species to become rare therefore anything done by people will harm the species. The best way to refute this type of thinking is to continue to share and celebrate the successes of conservation efforts.

    This type of thinking is not only restricted to rare species. Some people in conservation believe that conservative species should not be used in the restoration of disturbed habitats. This thinking is particularly difficult for those conducting ecological restoration since most of the native species have a high coefficient of conservatism. The coefficient of conservatism was designed to quantify the quality of natural areas so those working on preservation could prioritize land acquisition. When this index is extrapolated for imposing decisions on those working on ecological restoration this index frequently correlates poorly to experimental results. Often species with a high coefficient of conservatism are restricted to undisturbed natural areas because their seed does not disperse far. In contrast, species with a low coefficient of conservatism dominate disturbed habitats because they have become masters of dispersing their seeds. Frequently, what we prize as a rare and conservative species is nothing notable in other states.

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    1. My experience backs up James' comment. When we broadcast conservative species into old field sod and then burn regularly, the conservatives are some of the species that restore themselves the best. Very successful species in this case include dropseed grass, purple prairie clover, Leiberg's panic grass, prairie betony, lead plant, cream false indigo, prairie gentian, and many others.

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    2. Here are some examples to consider.

      Nachusa grasslands turning cornfields into eastern prairie fringed orchid habitat, page four.

      http://www.nachusagrasslands.org/uploads/5/8/4/6/58466593/2014_friends_of_nachusa_grasslands_annual_report.pdf

      Drainage from an old iron mine’s tailings creating habitat for a “staggering” amount of orchids.

      http://news.nationalgeographic.com/2016/05/160512-millions-orchids-blooming-abandoned-mine/

      The eruption of Mount St. Helens. “The biological communities that have developed since 1980 are extremely diverse.” Also, “The naturally recovering communities may play an important role in the regional biodiversity of the Pacific Northwest.”

      https://www.fs.fed.us/pnw/mtsthelens/research/index.shtml

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  4. I have actually heard people with endangered-species-connected jobs say - without apparent embarrassment - that their jobs could suffer if people made rare species common. Fortunately, most people in conservation do believe in the mission.

    Some of the more challenging decisions come in the case of restoring remnants. These areas have the most potential for full recovery - and the most potential for being damaged by mistaken decisions. We need much more robust knowledge to make good decisions - and much more courage to make good decisions despite uncertainties and risks.

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    1. It sounds like the problem is good people are being given bad incentives. If people's pay checks were based on measurable improvement instead of maintaining a status quo then they would behave much differently.

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  5. Some plants mentioned in Pepoon (1910's) that might be considered uncommon today:

    Amelanchiers - some listed as 'common' others as 'frequent'.

    Bellwort - abundant

    Apocynum androsaemifolium (not sibiricum) - common

    turk's cap lilly - very abundant

    Prunus nigra - common

    Hypoxis hirsuta - very abundant

    Aster macrophyllus - common

    Hepaticas - very common

    Maidenhair fern - common, abundant on steep banks, Des Plaines river and Niles.

    sweet grass - Hierocholoe odorata - abundant locally throughout

    Calmagrostic Canadensis - blue joint grass - "one of our most common marsh grasses, everywhere abundant"

    dierrhena diandra - beak grass - wooded banks, common throughout.

    In the Art World there is a fine balance between maintaining originals and at times needing to restore them. Then there was the awesome rebuilding of Michelangelo's Horse. the enabling act of many forest preserves is to hold lands full of plants and animals and scenic beauties for people to visit and enjoy.

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    1. This is another inspiring list. I'd be especially interested in finding beak grass (Diarrhena diandra). Mohlenbrock describes it as "one of the more handsome woodland grasses in Illinois." Swing and Wilhelm list it for Cook, DuPage, and Will Counties. Does anyone know where any is?

      Maidenhair fern? We've found none.

      Hepatica? One patch with a few score plants. Elsewhere in the preserve we find only one other individual plant. Common in the future? We've scattered seed from the original patch in many places. We hope!

      The other species above are mostly already doing well in the recovering Somme preserves. One exception is black plum (Prunus nigra), of which we only recently found just one mostly-shaded-out clone.

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    2. i have seen hepaticas in a preserve.. i don't know if they are wild or planted. my guess is wild. not far from you in northbrook actually. are you saying you would like to know were they are?

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    3. To Anonymous, Oct. 4, 2017. I'm somehow only seeing this now. Yes. Sure. I'd like to know about near-to-Somme conservative plant populations. Hepatica? Yes. Best way to reach me is through there "Info" email at http://www.sommepreserve.org . Thanks.

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  6. i have seen the cacalia atriplicifolia at the buffalo grove prairie. i was not sure if you were aware of that..

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    1. The Cacalia atriplicifolia at Buffalo Grove Prairie may have come from the North Branch seed mix (which all came from that one McHenry County site).

      I helped with the stewardship of that site in the seventies and eighties without seeing it, so it's probably not original there. Also, it seems to be a savanna plant, rather than a prairie plant (except in "restorations" where it's often planted). And Buffalo Grove seems to have originally been prairie.

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  7. Yes! Too many believe it is wrong to establish new populations of now rare plants or that regionally native plants that show up somewhere new don't have value. We treat the fauna differently, and it makes now sense.

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  8. An excellent piece, Stephen. I've seen lots of these changes in the 40 or so years that I've been interested in our local natural history, but at least we now have a lot of great folks working hard to save what we have left.

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  9. Cacalia atriplicifolia is interesting. At Dennis Dreher's Boloria Meadows site in McHenry County it was introduced and has acted like a sunflower or tall goldenrod, and Dennis has had to remove some of it given its extreme aggressiveness. This is in open wet to mesic prairie. Perhaps in more wooded situations it would "behave" better...While I'm on Cacalia, how about C. plantaginea as a candidate for increasing, given Pepoon's description of how abundant it once was in wet prairie habitat?

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    1. I have seen rare and isolated populations of refugee cacalia plantaginea expand and thrive quite spectacularly with a faithful fire regime, clearing and hydrological re-wetting. In several places they went from "don't put the brush pile there or you will wipe them all out". To swathing the landscape. Love the Swiss cheese bug that lives with them and toys with their leaves.

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  10. stephen.. would you be interested in saving some antennaria.. respond and i will get in touch with you

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    1. If it's an original population within 25 miles of Northbrook, yes, I'm interested in some seed. Keep in mind, we accept seed from protected areas only with the approval of the manager. Thanks for asking.

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    2. its in des plaines and not in a protected area.. more a median grassy strip.. its strange to me that it is there since i dont think of it as a plant that moves around. i cant tell you if it is a original population. i think they are going to fix the road soon and it may be lost.

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    3. Thanks. One way to try to determine whether a population is original is by its associates? Are there other prairie species nearby? Especially those that aren't normally in "prairie restoration" mixes? Antennaria isn't often planted, I don't believe. Which Antenaria is it? We have quite a bit at Somme, but it would probably be good to add more local diversity. If you had time to collect some seed next year.

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  11. Steve, I have some specific questions about a prairie overseeding project in Ohio, and would really appreciate your thoughts. My email is dave.nolin@gmail.com.

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