The Vernal Desert

In Texas the beloved and common indicator of springtime’s arrival is the Bluebonnet.  The wildflower is also the hallmark of spring road trips in the state.

There are six species of these members of the genus Lupine in the state and all are considered to be the state flower (state law also grants that any new species discovered will be recognized as an official state flower), thus Texas has the distinction of actually having six state flowers.

Of those six, there are two endemic species: Sandyland Bluebonnet (L. subcarnosus) and Texas Bluebonnet (L. texensis).  The latter is the most widely known.  L. texensis is also the most widely cultivated in the state due to the fact that it tolerates a broad range of soil types.  L. subcarnosus is intolerant of non-sandy soils, develops chlorosis on limestone sites, and thus is edaphically restricted (Nixon 1964).  These limitations prohibit seed increase work of L. subcarnosus at the commercial scale, though a seed dealer in North Texas does offer the species for sale.

Even then, L. texensis will remain the preferred Lupine species in the commercial seed market.  It is tried and true, well known, easily obtained, less expensive than L. subcarnosus, and is grown at commercial-scale quantities by many seed farms.

Four of the six species of Lupine are termed “winter annuals” – they germinate in the fall and overwinter as a rosette, then flower the following spring and into early summer before setting seed and dying. Two species, Perennial Lupine (L. perennis) – found only in Hardin and Jefferson Counties and last collected there by botanists in 1978 (Flora of TX), and Nebraska Lupine (L. plattensis), found in Hartley County in the Panhandle, are perennial.

Lupinus havardii in a roadside habitat, where it is more commonly seen today.

In the rugged Big Bend region of Far West Texas exists the largest and most robust Lupine species in the state. Big Bend Bluebonnet (L. havardii) flowers from January to June and can grow to heights of 4’ on good sites. This species was first collected in 1881 in the vicinity of present day Presidio.  Based on my travels, it appears the species is limited to habitats within 20-30 miles of the Rio Grande.

Thelypodium texanum in a badland clay ecological site. A wild mustard.  Bentonite mining destroys this plant’s habitat.

Other associated wildflowers that can be seen in flower at this time are Texas Thelypody (Thelypodium texanum), an annual of bentonite clay soils, Bladderpods (Lesquerella spp.),  and Desert Marigold (Baileya multiradiata).

A profusion of Baileya multiradiata occupying an expansive open site devoid of graminoid competition. This forb can flower nearly year round in the warmer regions of its habitats.

Forb and grass species that grow and flower within the same period and, when viewed together in photos, can tell the viewer the season of year without he/she ever having to step out of doors.  This is referred to as aspect dominance, or the “adjustment of species to seasonal changes” (Weaver and Clements 1938).  There are four types of aspect dominance: “prevernal (early spring), vernal (spring) , aestival (summer), and autumnal (Weaver and Clements 1938).

References

Nixon, E.S. 1964. Edaphic Responses of Lupinus texensis and Lupinus subcarnosus. Ecology 45:459–469.

Flora of Texas Database. [Internet].  Accessed 2/19/2015. http://orchid.biosci.utexas.edu/Texas_list.html

Weaver, John E., and F.E. Clements. 1938. Plant Ecology. New York City, NY, USA: McGraw Hill Book Co. 601p.

 

 

The Old Stuff

In the days of the old prairie, its members reveled in dormancy and cast their seeds with a starry eye and a mind full of hope toward the next vernal season.  Returning each growing season only from seed, those with a monocarpic life cycle, such as the obligate annuals, have no rooted memory of their hard work; only genetic memory contained in the germ left behind.  The perennials however, are deeply rooted with a semi-permanence of interred vegetative memory and are much longer lived; some individual clonal species may be several decades or even centuries old.  Some perennials may flower many times and produce an abundance of seed throughout their life.  Others may flower and set seed just once, even after living for many decades.  These polycarpic plants are the most experienced at building soil organic matter and carbon stores with their complex root systems, forming the wonderful prairie sod that once bound to the earth the land of the Great Plains.  The old perennials rejoice in being renewed by fire, the ancient and highly experienced steward of all landscapes.  Some years, the perennials appear harshly set back by inevitable periods of drought, and then replenished during the wetter times, resulting in showy, floral expressions that are never quite captured with any sense of justice by paint or by lens.

Now though, the old prairie has been around long enough to know that its future is questionable, and in many places imminently ill-starred.  Even then, the prairie does not sugarcoat its complex truths or imminent dooms, even as it becomes rapidly lost in the Anthropocene.  Many of the prairie’s vital fires are put out with a fearful vengeance by man, and the once abundant precipitation is now mired – increasingly so along an east to west gradient – in swiftly changing climatic patterns that are absent of any historical precedence.  However, the prairie has the good fortune, with its knowledge measured in aeons, of having witnessed the rise and fall of many kingdoms of man and beast.  It knows man replaces nearly all of the old and complex things with his simple, self-proclaimed artifacts of progress.  How progressive those artifacts are remains harshly debatable along the sharply contrasted rural-urban divide, yet highly doubtful are their long-term virtues if one pays attention to the plethora of landscape dysfunction indicators.  Such signs are prevalent within and between every plant community worldwide (especially the much abused grasslands) and no excuse can attempt to cover the denial that any terrestrial impairment does not exist.

The old prairie’s members have been shunned by common garden plant elitists in favor of high-maintenance plants with no North American evolutionary identity.  Vast herbaceous communities that once ebbed and flowed a great grassland symphony in concert with the ever-present and unbroken winds are now oppressed by developers of all labels, rendering communication to other disjunct, fragmented and broken associations intermittent, faltering, and incomplete at best.  A prairie is destroyed initially by fragmentation, then slowly but surely by the invasion of exotics brought in by the construction of roads and their definite edge created by their use and maintenance.  Man’s equipment and clothing and automobiles bring forth propagules, many of exotic origin and noxious propensity, acting as a silent yet common seed dispersal vector.  A great many biological invasions begin with the cutting of earth to make a new road, and any prairie, man-made or remnant, is generally the first to receive the negative news.

But even against the rushing onslaught of the modern world’s challenges, launched through its myopic lenses and hollow political glad-handing, the prairie flies the flags of its true self right to the end, never deviating from a millennium-old fortitude of character and charm, nor departing from the beauty that still remains unmatched anywhere else on the globe.  Such pulchritude at a vast landscape scale is unfathomable to us and therein lies the major draw to this herbaceous landscape community. And to those who have paid attention, the resulting loss of terrestrial greatness sensed upon fully realizing what once was is no longer with us, is akin to a fist in the gut.  Even deeper is the loss, and unknowingly so, by those who give not the slightest care to the removal of the old and replacement with artificial; words and photographs seem not to move them away from their seemingly willful state of apathy.  For a person to not know a prairie, especially one born and raised in a prairie state, is to disown the very reason why modern man is here at all: without the soils that the prairies built, there would be no breadbasket to feed us. And despite all our modern ingenuity, soil is the one thing we humans cannot manufacture.

After all, the old prairie was once a part of the greatest and largest contiguous grassland biome the planet had ever seen. Never again will man, beast, or climate see the prairie’s expansive assiduous empire where the sky began, or even its most recognizable and characteristic flora and fauna, many of which are at the precipice of becoming gone with the winds.  Such an instance is exemplified by the severe decline and dramatic loss of Little Bluestem in every aspect of its range and habitats across the tall and mixed grass prairies throughout the Southern Great Plains.  Centuries ago, Little Bluestem dominated much of the area, especially within the Lone Star State’s dynamic landscape, and sadly, that no longer holds true.  What once was once near-solid stands of steely blue in summer’s early fields, and a rusty red empire swaying to and fro in every blustery autumn, is now a broken and squared off landscape.  The old prairie is replaced with a stiff and lifeless fabric; a land of tawny, tame, blandly homogenous, and solely anthropocentric visuals.  A land now of little function and service to wildlife and absent of any native aesthetics.

Perhaps in hindsight, but largely without such realization by those of the 62nd legislature, this is why Sideoats Grama was ordained as the state grass of Texas: as Little Bluestem declines in prosperity and abundance from the long-practiced and damaging deed of overgrazing — a cultural practice of increasing regularity since the southern bluestem range was first overstocked in the late 1780s — Sideoats Grama naturally becomes its successional replacement on a majority of sites.  But even today Sideoats Grama is slipping away, exiting stage left and heading to the far horizon of never-again, joining Texas Cupgrass and Texas Bluegrass, among untold others, in the land before time.  Practically all of the old prairie’s diverse floral homeland has been lost to the plow, disrupted and overtaken by exotics, religiously overgrazed, occupied by modern infrastructure, or converted to so-called “improved” grasses.  The remnants of the old original are far, far better and always will be.

And for some prairie players, only their stories remain in obscure biological references under a coat of shelf-dust, and in the memories of the swift and sweeping prairie winds; those whispered stories carried by clouds that only the jet stream and the eagles know.

“The Great Plains have been plowed, irrigated, overgrazed, planted with trees, depopulated of native wildlife, and built upon with cities and sprawling development. Though native plants survive in places, no natural prairie, functioning as it evolved to function, still exists.” – Mary Taylor Young

Though their days are surely numbered, there are some fine bluestem ranges remaining in Texas. This one is passed and ignored by thousands daily, the majority of them oblivious to such obvious beauty as they race down the highway. But just off the highway, one can travel along this old gravel road and marvel at the sights of Big and Little Bluestem, Switchgrass, Indiangrass, and ancient Post Oaks. Along the margins of the road at various intervals, King Ranch (KR) Bluestem (a native of Eurasia and of poor range value) is attempting to invade the prairie. At this site, KR is simply a roadside weed and is unable to penetrate the dense, true sod formed by the big veteran grasses. Here, and scattered widely among other places, the old prairie’s tall, waving graminoids make their last stand as a part of the old stuff.

The Discovery of Spotted Knapweed in Texas: Why Seed Origin Matters

In the summer of this year, Spotted Knapweed (Centaurea stoebe), for the first time ever, has become the latest exotic member of the flora of Texas.  Its seeds arrived as a contaminant of a wild harvest originating in the Central or Northern Great Plains, which was purchased by a Texas-based seed dealer. This introduction has many negative ecological implications for the state as a whole, and highlights the many risks and flaws that are inherent and eternal to the wild harvest model (WHM).  The initial discovery was made at the Balcones Canyonlands National Wildlife Refuge in Travis County.

Because almost all of the native prairies in Texas have been plowed up and converted to “improved” pastures full of exotic species (species that are noxious weeds, regardless of legal listings), and all remnant (unplowed) prairies have been invaded by exotic plant species, some seed dealers elect to supplement their seed stocks by purchasing bulk “wild harvests” from northern seed growers. This is done in addition to harvesting their own locally grown seed stocks. However, those wild harvests are within the distribution ranges of many northern exotic species like Spotted Knapweed (C. stoebe), Dame’s Rocket (Hesperis matronalis), and Smooth Brome (Bromus inermis), and once exotic seed is in the harvest mix there is no getting it all out. A handful of exotic seed is all it takes to start an invasion.  This is but one example of many why the WHM has no future in TexasThat model carries too much ecological risk, namely in facilitating exotic plant invasions via non-certified seed.  Unfortunately, there are companies who do wild harvests in Texas and sell that seed, which carries equal risk of noxious weed seed contamination, especially the exotic grasses KR Bluestem, Johnsongrass, and Buffelgrass.

Grassland restoration in Texas is largely implemented using the select native germplasm model (SNG), first used by the Soil Conservation Service in 1935, now the NRCS Plant Materials Program. The SNG model is being further developed and used with great success by South Texas Natives and Texas Native Seeds (Central and West Texas), modeled after the highly successful Iowa Ecotype Project (now the Natural Selections Program) at the Tallgrass Prairie Center of the University of Northern Iowa. South Texas Natives (STN), a part of Texas Native Seeds (TNS), is a partnership led by the Caesar Kleberg Wildlife Research Institute (CKWRI) of Texas A&M-Kingsville, working on developing certified ecotypic native seed sources, and advancing restoration research and implementation. Texas Native Seeds operates their research and development in South, West, and Central Texas at this time. Certified native seed is the fundamental aspect of their initiative and model.

With their model, STN has ensured seed for restoration through 25 ecotypically-appropriate plant releases. Presently, certified seed to re-seed about 30,000 acres annually is available to restoration consumers through cooperating commercial seed companies. Aside from the fact that such seeds are a far better choice simply because of certification standards and a very high quality of cleanliness and germination, the wild harvest model will never match that capacity year in and year out. Nature and land fragmentation work against the WHM — drought and lack of quality harvest sites being the major limiting factors — forcing WHM companies to supplement seed stocks with commercial varieties of native seed.

A major economical positive of the SNG model is the lower price point for consumers and a higher profit margin for the producers.  More seed per species per acre can be grown using selected germplasms than can be harvested using the WHM.  Non-selected germplasms (considered maladapted ecotypes until proven otherwise) generally have a much lower germination rate than selected germplasms, which have consistently higher germination rates and higher genetic purity — which can be readily maintained for best ecotypic use — than the wild harvested seeds, whose genetic purity cannot be maintained (or even known), simply as a fundamental flaw of the WHM. Often, wild harvested seeds are of lower genetic diversity than SNG seeds because most wild harvests in Texas come from a few small, locally isolated stands. By contrast, most SNG seeds are comprised of multiple populations (multiple genetics), with the hope of making the seed products adaptable across a larger region and across multiple soil types.

On the issues of the inherent and eternal flaws of the WHM, some might ask, “Why care about which model contains the most or least flaws? What does it matter?” It matters because we have Spotted Knapweed in Texas. Spotted Knapweed has never been in the state before and now it is because of the high risk of seed contamination associated with the WHM. The list below highlights many of the major faults inherent and eternal to the WHM.

The Inherent Faults and Eternal Flaws of the Wild Harvest Model

  • Seed production is highly variable. Some years the production and quality are the mother-lode; other years it’s a bust. Such inconsistent seed production and quality makes wild harvests unpredictable and costly, leading many wild harvest-based companies to supplement their seed stocks with commercial germplasms during years of lean seed production in “wild” stands. Consequently then, lack of supply also leads to use of exotic grasses in mandated seedings.
  • Origin(s) of WHM seeds are often unstated. While some companies may tell you the origins of the harvest or the seed lots, many will not. Beware of those who refuse to give out that critical information. You, as a consumer, have a right to know where the seed originated from!
  • Wild harvested seed is often 2-3 times more expensive than select native germplasm seed. As a straight comparison, based upon pure live seed (which is unstated for wild harvested seed), certified SNG seeds may cost as little as 1/10th the price of wild harvested seed. Your dollar goes further and covers more acreage using the SNG model.
  • Because the wild harvest model is limited to sites that are large enough to make it cost effective for the use of combines and labor, so too are the genetics within each site limited.
  • The issue of exotic species contamination is huge with the wild harvest model. The Spotted Knapweed fiasco illustrates this very clearly: because of the many inherent holes in the WHM, we have Spotted Knapweed in Texas today!
  • The vigor of plants in the populations from which the seeds are harvested is unknown. Plant vigor and performance is critical to restoration success and competitive ability amongst the many exotic species in the state.
  • Areas of adaptation of wild harvested seed is not known. They are untested and unproven in many areas. Local-only purists are often against evaluation of plant adaptations and performances because they believe that scientific aspect somehow doesn’t fit in with their narrowly-focused narrative of “true” prairie restoration.  Evaluations prove potential restoration success on a species by species basis, and certification proves origin. In most SNG seed sources, great care is taken to not alter the original genetic makeup of wild populations.

Following the last point, many of the criticisms placed upon the SNG model by the local-only crowd (inappropriate genetics, potential for genetic swamping, creates larger seeds, current prairie genetics cannot be improved upon, etc.) ignore the fact that severely degraded sites require much more intervention in order to implement the restoration of the plant community that existed prior to the degradation. Simply harvesting seeds with a combine in a “wild” prairie and then scattering them on hyper-degraded sites sets up ecological bankruptcy, wasting time, money, and hard effort.  Restoration today is not as simple as broadcasting unproven seed onto the ground; it requires dedicated research of extensive available literature, replicated evaluations at multiple sites, and further testing in demonstration plantings.  Jones (2013a) expounds upon this when he writes, “While these arguments [that local is best] have considerable merit, they may be less applicable for seriously degraded lands. The best management practices for sustaining mostly pristine lands may differ from those for restoring novel ecosystems. This is particularly noteworthy because such ecosystems are expanding at the expense of pristine landscapes worldwide.”

When it comes to persistence amongst exotic species, SNG seeds have the upper hand in germination-competitive abilities over the unknown track record of wild harvested seed.  As stated by Jones (2013b), “a failure to recognize the importance of augmented genetic variation in restoration plant materials demonstrates a lack of confidence in the reality and utility of natural selection”.  Furthermore, Jones (2013b) states, “one cannot continue to rely solely on local genotypes [simply] because they are local and theoretically best adapted if experience demonstrates otherwise.”

High quality, clean seed is the key to restoration.  No matter how carefully the seedbed preparation and planting is done, using wild, maladapted seed sources will usually lead to planting failure.  Often, those who experience failure when using questionable seed sources do not try again with native species but instead use exotic species, which further perpetuates many of the problems grassland ecologists are dealing with.  Certified native seed of selected native germplasms is the only way to go in helping to maintain native plant communities against exotic species increases and implement successful restoration plantings.

In summary, if the seed you are looking to purchase isn’t certified native seed as regimented under a state agricultural program, if no origin information is given or the seed grower won’t or “can’t” tell you the origin (listing county of origin does not in any way give up a collection source), if it’s not sold on a Pure Live Seed (PLS) basis and only on a bulk pound basis with no germination rate(s) given, then it’s a crapshoot and is anyone’s guess as to what really germinates in a planting.

And thanks to the many holes within the wild harvest model, we now have Spotted Knapweed in Texas. The use of certified seed could have prevented this!

If you have purchased non-certified native seed from a Texas-based seed dealer at any time in the last two years, you are at risk for having Spotted Knapweed in your planting(s).  Many ecologists expect Spotted Knapweed to show up outside of Travis County, especially along roadsides and in private plantings where its population increases are expected to be highest, simply because private landowners are less strict in their monitoring.

References:

Jones, T.A. 2013a. When local isn’t best. Evolutionary Applications. 6:1109-1118.

Jones, T.A. 2013b. Ecologically Appropriate Plant Materials for Restoration Applications. BioScience. 63(3):211-219.

From left to right, top to bottom: Plant view of Spotted Knapweed; flower; flower bud; midstem leaf; and basal leaves.  Photos courtesy of USFWS Balcones Canyonlands.
From left to right, top to bottom: Plant view of Spotted Knapweed; flower; flower bud; midstem leaf; and basal leaves. Photos courtesy of USFWS Balcones Canyonlands.  Do not confuse Spotted Knapweed with the native forb American Basketflower (Plectocephalus americanus [new name] Centaurea americana [old name]).

2014 TX/SW SER Conference: Presentations and Thoughts

The Texas Chapter of the Society for Ecological Restoration has made available the presentations from the 2014 joint conference (TXSER and SW Chapter).  They can be found here.  Be aware that some of these PDF files are large and may take awhile to load.  There are also many photos from the conference on the TXSER Facebook page.  The conference was a great success, with 105+ people forming new professional relationships, strengthening the old ones, and demonstrating through presentations, field trips, and talks that the work restorationists do does matter. Continue reading