In search of a lost natural community: the Ozark savanna edition

Calvin Maginel is the Ecological Resource Scientist at Shaw Nature Reserve in Gray Summit, Missouri.

Anyone hoping to join the articulate stream of Missouri articles about natural communities ought to lovingly reference Paul Nelson’s “The Terrestrial Natural Communities of Missouri” (2010). In that vein, we will start our journey with page 233, the Savanna.

Paul differentiates savannas largely by overstory, topography, and light level characteristics. Primarily, savannas are grasslands that happen to hold little pockets, family clusters, of trees, that mosey through the swaying grass like the slowest of turtles. The natural history of these clusters is as such: a mature parent hosts numerous offspring around her perimeter that shelter her from the repeated onslaughts of prairie fires, while she in turn nurtures offspring on the lee side which will eventually replace her. They are separate from woodlands in that savannas exhibit a tree canopy of less than 30%, while woodlands can range from 30% to 90% canopy. Paul further describes the ground flora layer of savannas as being highly indicative of a prairie, holding the majority of a site’s diversity, and being strongly adapted to frequent fire.

Of the six savanna communities Paul describes, as nostalgia blurs the typeset, two are considered S1 (critically imperiled) and four are SH, or state historic. A glass of cold water to the face: no known examples remain when something is classified as state historic. To put numbers on this, an estimated 6.5 million acres of savanna in Missouri are now represented by <1,000 recognized acres. Robin Wall Kimmerer aptly wrote: “If grief can be a doorway to love, then let us all weep for the world we are breaking apart so we can love it back to wholeness again.”

Stylized drawings of the prairie-forest continuum, borrowed from The Tallgrass Restoration Handbook by Packard and Mutel.

Recognizing a savanna

As nice as it is to reminisce about and romanticize processes long devastated by European colonizers, if there are (nearly) no savannas left, then why does it matter? Well, there still is hope! While Missouri has a fair percentage of public land (11.2%), most of which has received extensive visits by ecologists throughout the years, the other 88.8% of private lands in Missouri often harbor as-yet-undescribed natural communities that may classify as savanna. In an effort to heighten awareness of these potential gems in the fire-starved hills, I offer a photo tour of a private site in southwest Washington County, near the town of Courtois, that could be described as a savanna. A few points about this site: it is currently being managed for its ground flora character, with repeated fire and herbicide, specifically to the detriment of encroaching cedars and woody re-sprouts. For 25 years prior to the current ownership, it received two fires and periodic mowing to maintain its relatively shrub-free character. Prior to that, it is assumed that this was a hay meadow, cut annually for livestock that were grazed in the valley nearby but not itself grazed. There is a rusty but strong sickle-bar mower still parked in the grass that is set up for a mule to pull, with patent dates from the 1920s.

Since Paul begins with the overstory, so too will this tour. Anecdotal descriptions of certain areas in the Ozarks by foresters refer to “wolf trees”, trees with spreading branches that were removed from the woodlot since those individuals were considered to be exhausting resources around themselves, much as wolves were believed to be harmful predators that exhausted prey species. An example of this can be found in Photo 1, where a large white oak shows the breadth of branches characteristic of an “undesirable” wolf tree. As mentioned in the caption, the health of the lowest branches can tell something about a site’s history. Overgrazing by cattle or other domestic animals often defoliates these branches until the tree sheds them entirely, so an observation of a tree similar to this one might mean that this site was hayed but not grazed intensively.

Now that photos have been mentioned, we’ll begin the photo tour in earnest. All photos are from August 22nd, 2021, unless otherwise stated. To the right side of Photos 1, 2, and 3, you will notice a young shortleaf pine (Pinus echinata) with a wolfish future, and in Photos 2 and 3, there is a distinctive Eastern Red Cedar (Juniperus virginiana) that seems to have lost half its top. All other photos will contain at least a blurry version of those two distinctive trees, in an effort to maintain scale. Speaking of scale, the distance between the white oak wolf tree and the red cedar is a little over 250 feet (76 meters). Photos 2 and 3, of almost the same area at different phenologies, hold the first real hope of a savanna classification. The structure is distinctively grass- and forb-dominated. While clearly the floral display is greater during June, this is not unexpected in an intact prairie system where suitable micro-habitats are dominated by the best-adapted competitors for those micro-habitats. For example, the glade coneflower in Photo 3 is distributed between the foreground of the photo and the base of the pine tree, but seems to decrease in abundance towards the red cedar in the upper left of the photo. Presumably, soil or other characteristics make the former area highly suitable for glade coneflower, despite the fact that no bedrock or other glade indicators occur in those areas. That said, it stands to reason that glade coneflower, currently relatively restricted to glade communities, must have had a mechanism to lay claim to those communities. Possibly this species was historically as ubiquitous in Ozark savannas and prairies as it currently is in glades.

Photo 1. Forgive the valiantly bolting hickory grubs and mowed path, but this white oak (Quercus alba) exemplifies the spreading nature of a relatively open-grown specimen. Note how the lower branches actually touch the warm season grasses: despite 5 recent years of annual dormant season fire, they are not set back. In fact, one telltale of current or historical colonizer-style grazing is that these perpetually-stretching side limbs are defoliated until they succumb and die. Trees with this character can tell a lot about a site’s history.
Photo 2. With the same white oak as in Photo 1 to the left of the frame, this photo shows the vegetative structure of the site. You will notice a handful of woody re-sprout clumps, but this area is largely dominated by warm season grasses and prairie forbs.
Photo 3. June 14, 2016 is the date on this photo. Note the profusion of wild quinine (Parthenium integrifolium) and glade coneflower (Echinacea simulata), the latter of which is commonly identified by its yellow pollen. The more westerly species with white pollen, E. pallida, does not occur on this site.

In addition to the striking summer floral display in Photo 3, there are distinct waves of blooms throughout the season. Each species, present in profusion in its preferred micro-habitat and scattered elsewhere, blooms en masse and then fades into the background, letting another take the stage like a carefully-choreographed dance.

At this point, you may be noticing that the common names for many of the plants listed in the photo captions refer to a habitat (eg “glade” coneflower, “upland” white goldenrod, “prairie” coreopsis). This name-relation to a community can serve to help with identifying that community, but the overall assemblage of species tells a stronger story. When you consistently encounter species that occur within multiple habitats (Ozark woodlands, glades, and/or prairies), which is true for most of the species shown in these photos, it may be a telltale sign of the missing connection between all of those communities. Similar to the previously mentioned glade coneflower, both downy gentian and the upland white goldenrod are commonly found in glades and open woodlands. They tend to fall out in areas with >60% shade. Almost all of these species are considered highly conservative; species that we expect to maintain high fidelity to intact ecosystems. Missouri is one of the states that maintains a coefficient of conservatism list, with values ranging from 0 to 10, where 9-10s are virtually only found in the highest quality habitats. For example, the downy gentian, white upland goldenrod, savanna blazing star, and southern prairie aster are all c=9 species. Most of the grasses are 4 or 5, as well as the prairie dock, prairie blazing star, and Canada lousewort. When visiting a natural community, generally the more intact, remnant sites boast a bell curve of c-values, with the peak being a good diversity of c = 4-6 species. The distinctive composition at this site, with conservative prairie and glade species present (yet located deep in the Ozarks in an area not considered historic prairie), triggers the savanna vibe.

Photo 4. Savanna blazing star (Liatris scariosa var. nieuwlandii), wild quinine, big bluestem, and ashy sunflower. Savanna blazing star is currently listed as a species of conservation concern in Missouri.
Photo 5. Southern prairie aster (Eurybia hemispherica, old name Aster paludosus), forms a colony with leaves reminiscent of a graminoid until it blooms with striking purple discs.

An additional, striking character of this site is the height of the vegetation (Photos 6 and 7). In particular, Photo 6 includes a species called ashy sunflower (Helianthus mollis). Various botanists and restorationists have used disparaging terms for this species, even the socially problematic term “thuggish,” since this species tends to form thick 2-4 foot tall monocultures to the detriment of other species. Surprisingly, the ashy sunflower at this site is a whopping 0.5 – 1 foot high and comfortably interwoven with other species. The matrix grasses, consisting of mostly of big bluestem (Andropogon gerardii), little bluestem (Schizachyrium scoparium), prairie dropseed (Sporobolus heterolepis), and Indian grass (Sorghastrum nutans) are consistently knee-high or shorter, barring their flowering stems of around 5 feet. In many prairie reconstructions, the big bluestem and Indian grass commonly attain heights of more than 9 feet and encountering each clump of bunchgrass is like climbing up a small mima mound. Here, the grass ramets have presumably reached old age and no longer exhibit the mounding character. Many ecologists attribute the presence of hemi-parasitic species like Canada lousewort (Pedicularis canadensis), scarlet paintbrush (Castilleja coccinea), or blue hearts (c=10!, Buchnera americana) to decreased robustness of warm season grasses. All three of these hemiparasitic species are present at this site, yet the truth is that the science of ecology is still learning about what actually makes remnant sites look consistently different than reconstructed sites. Is it nutrient limitation, due to all niches being occupied in remnants? Maybe it’s mycorrhizal associations determining community composition and structure, since Arbuscular Mycorrhizal Fungi have been shown to strongly affect plant communities. What about beneficial or pathogenic bacteria, or soil structure, maybe parent material, or surely it’s the site’s aspect and moisture profiles? The obvious answer is that it’s a combination, and that we have much to learn about our natural communities. The quote by J. K. Rowling, “Understanding is the first step to acceptance, and only with acceptance can there be recovery,” might as easily have been about natural communities as it was directed at Harry Potter’s life.

Photo 6. Upland white goldenrod/prairie goldenrod (Oligoneuron album) blooms amongst two Silphium species, prairie coreopsis (Coreopsis palmata), and well-mannered ashy sunflower (Helianthus mollis) stems. Rarely is the term well-mannered used in conjunction with ashy sunflower.
Photo 7. Downy gentian (Gentiana puberulenta) looking disheveled prior to its glorious frost-triggered blooms, amidst prairie dock, prairie blazing star, and a grass/sedge matrix. A dominant sedge species here is few-flowered nut rush (Scleria pauciflora).

The last point regarding vegetative species groups are those considered woodland species. Just like in prairies and glades, there are a handful of woodland indicator species that assist with identification of the natural community we call a woodland in Missouri. As a reminder, woodlands have a canopy cover of >30%, all the way up to 90% cover, yet have an open mid-story maintained most commonly with frequent fire. Some characteristic species present at this site that are considered common woodland indicators include deerberry (Vaccinium stamineum), Samson’s snakeroot (Orbexilum pedunculatum), and stiff aster (Ionactis lineariifolia). The last species is especially striking, as botanists and plant geeks commonly observe it in acidic, poor-nutrient woodlands or power line rights-of-way. Yet keep in mind that glade coneflower, a known calciphile, is hanging out with the stiff aster. Whatever processes are allowing this site to host such a mish-mash of Ozark woodland, glade, and prairie flora, it seems to support the understudied idea that there really was a thriving prairie-forest ecotone amongst these aged hills.

Photo 8. Prairie willow in the foreground left (Salix humilis), vying for growing space with prairie dock (Silphium terebinthinaceum), tall tickseed (Coreopsis tripteris), little-leaf tick trefoil (Desmodium ciliare), and others.

Wrapping Up

As outlined above, there are few to no known savannas left in Missouri. While many agencies are trying valiantly to re-create open or closed woodlands, the sawdust of Missouri’s logging culture weighs heavily on our boots and generally there are fewer restoration practitioners aiming for savannas and their lack of timber products. The Nature Conservancy comes to mind, but the majority of their sites classify as true prairie, except maybe Bennett Spring Savanna. That site, like Ha Ha Tonka State Park, tends to maintain characteristics more similar to open woodland, but has lovely intact ground flora with a solid assemblage of prairie species. The critical missing piece is that for most natural community restorations, we have a goal in mind, dictated and informed by multiple examples of that community. With savannas and the lack of high-quality examples, we are left with a great deal more speculation. The hope mentioned in the beginning comes into play with each of you. There is a plethora of private lands that are largely inaccessible to state and federal biologists. If you get a chance to visit a friend’s farm, do so with a thought to some of the characteristics described above. Citizen science really does work, and maybe the next branch of citizen science is natural community identification! As Rachel Carson said, “The more clearly we can focus our attention on the wonders and realities of the universe about us, the less taste we shall have for destruction.”

A ten-year woodland restoration trajectory

Leighton Reid describes a long-term ecological research project at Shaw Nature Reserve (Franklin County, Missouri, USA). To learn more, read the new research paper (email the author for a pdf copy – jlreid@vt.edu) or tune in for a webinar from the Natural Areas Association on April 21 (register here).

In 2000, the Dana Brown Woods were dark and dense. Brown oak leaves and juniper needles covered the sparsely vegetated ground, and invasive honeysuckle was creeping in around the edges. Biologically, the woodland was getting dormant.

In contrast, the woods today are lit by sunlight everywhere except the lowest-lying streambanks, and the ground is hardly visible beneath a green layer of diverse, ground-level foliage. These changes were most likely caused by two actions: burning the woods, and cutting out invasive trees and shrubs.

Many practitioners have seen woodlands recover to some extent when they are burned, but few have documented the recovery as thoroughly and over so long a period of time as Nels Holmberg and James Trager.

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Nels Holmberg (left) discussing the finer points of Rubus identification with Quinn Long in the Dana Brown Woods.

Nels is an ecologist and sheep farmer in Washington, Missouri. He has inventoried the plants at several state parks and natural areas. In 2000, Nels teamed up with Shaw Nature Reserve’s resident natural historian, James Trager, and together they designed a study to describe how ecological restoration was changing the woodland flora at the reserve. They picked the Dana Brown Woods as their study area.

In a nutshell, Nels and James chose 30 random points on a map. They divided the points evenly across three ecological communities. They placed 10 points in mesic woodlands – the gently sloping parts of the property where white oak and shagbark hickory were most prevalent. Ten points were in areas dominated by eastern red cedar – mostly thin-soiled ridgetops that faced the south, and ten points were in forest – the lower, thicker-soiled toe slopes where northern red oak and Shumard oak were dominant in the canopy with paw paws and spicebush down below.

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Three ecological communities in the Dana Brown Woods: (A) red cedar dominated areas which, after removing red cedar, looked more like dolomite glades in some parts; (B) mesic woodlands with lots of oak and hickory in the canopy; and (C) forest – which had a much darker understory.

At each point, Nels hammered in a t-post, then walked 50 m in the steepest direction and hammered in another t-post. This was his transect. Every year for more than a decade (2000-2012), Nels walked the transects and recorded every stem of every species that was inside of 10 0.5-m2 study plots. Actually, he did this twice per year – once in the spring to capture the ephemeral plants, and once in early summer. Over the course of the study he spent more than 200 days in the field.

Canopy Cover

Dana Brown Woods before (left) and after (right) red cedar removal, with Nels’s 30 transects. The horizontal axis of the image is about 0.9 km. Imagery is from Google Earth.

During this time the stewards at Shaw Nature Reserve were busy restoring the woods. From 2001-2012, they burned the woods five times. This amounted to about one fire every three years. In 2005-2006, they brought in a logging crew to remove all of the eastern red cedars.

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James Trager lights a fire in a woodland at Shaw Nature Reserve.

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One of several thousand red cedar stumps from trees that were harvested from the Dana Brown Woods in 2005-2006.

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One of Nels’s sampling quadrats in the Dana Brown Woods. Photo: Nels Holmberg.

I met Nels and James in 2014. I had just joined Missouri Botanical Garden’s Center for Conservation and Sustainable Development as a postdoc, and I was looking for a local research project. I heard that Nels Holmberg had a giant dataset about woodland restoration, so I called him and asked if I could look at it. Nels said “Sure!”. I imagined he would send me an Excel file. Instead he brought in a giant cardboard box full of yellow legal pads where he had recorded his data.

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One of hundreds of datasheets where Nels recorded his detailed observations.

It took a long time to digitize all of the data. There were more than 50,000 data points. But once we had it all together, this is what we learned:

After eleven years of restoration, the number of native plant species in Dana Brown Woods increased by 35%, from 155 species in 2001 to 210 species in 2012. This increase was linear. That is, the number of native species was still increasing at the end of the study. If we repeated the study today, we expect the number of native species would be even greater than in 2012.

The number of native species increased at different speeds and to different degrees in different ecological communities. In the lower and wetter forest areas, the numbers didn’t really shift very much. They jumped around but not in one direction. In the woodland areas, the number of native species increased by about 23% in the first three years and then leveled out. But in the higher and drier areas where red cedars had been dominant, the number of plants increased linearly by 36%.

Native Species Richness

Changes in the number of native plant species recorded over time in the Dana Brown Woods. On the left are overall changes for the whole management unit. On the right are changes for different ecological communities within the management unit. The management interventions are shown in gray.

The plant species that benefited from the restoration were mostly forbs and grasses. A couple of the biggest “winners” were black snakeroot (Sanicula odorata) and nodding fescue (Festuca subverticillata). There were also some “losers”: Virginia creeper (Parthenocissus quenquefolia) and spring beauty (Claytonia virginica) both declined over time. Relatively few of the species that became more common were “conservative” – i.e., dependent on intact habitat. Mostly they were more widespread and tolerant species.

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Co-author Olivia Hajek demonstrates a hog peanut (Amphicarpaea bracteata) – a good representative of the type of species that benefited most from the restoration. Hog peanut is an herbaceous legume that is common in many woodlands, including disturbed ones.

Our study did not include a control treatment, but counterfactuals exist at Shaw Nature Reserve (although they are becoming fewer and fewer with the excellent stewardship of Mike Saxton and many others). There are still thick patches of eastern red cedar covering remnant glades on parts of the property. Woodlands that have not been regularly burned are now filled with bush honeysuckle (Lonicera maackii), wintercreeper (Euonymus fortunei), and other invaders. And low-lying forest that has not been restored is very dark with fire-intolerant sugar maple (Acer saccharum) casting much of the shade. If we had included a control treatment in our experiment, these are probably the trends we would have found – definitely not a spontaneous resurgence of diverse native plants.

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Fragrant sumac (Rhus aromatica) was present at the outset of restoration and remained relatively stable.

Why does this work matter? The biggest value of this study is that it shows a relatively long-term restoration trajectory, and it does so in fine botanical detail. Many managers and scientists already have data to show that fire and tree thinning increase woodland plant diversity. This study adds another dimension. It shows how quickly plant diversity recovered. It also shows how the speed and shape of the recovery varied across the landscape. We hope that other scientists and practitioners will compare the recovery trajectories in the Dana Brown Woods to their own natural areas. To facilitate that, we have made all of the underlying data freely available online.

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Buffalo clover (Trifolium reflexum) is a conservative species that is present in Dana Brown Woods but was not detected in any of the survey plots.

One of the next steps for this research is to figure out how and when to re-introduce some more conservative plants. Although the Dana Brown Woods became much more diverse as it was being restored, most of the plants were early successional or generalist species. We found very few habitat specialists that cannot tolerate disturbance, which suggested to us that some of these species may have been lost from the site at some time in the past. To learn how conservative plants might be re-introduced, we have started a new experiment testing the effects of soil microbes, competition, and time since the start of restoration on the success of introduced seedlings from seven conservative plant species. In the next year or two, we hope to have new information and recommendations for restorationists looking to add more specialized biodiversity to their woodlands.

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Freemont’s leather flower (Clematis fremontii) is a restricted species occurring on dolomite glades in southeastern Missouri. Although it is present at Shaw Nature Reserve less than one kilometer from Dana Brown Woods, it has not colonized the restored glade habitats there. This photo is from Valley View Glade near Hillsboro, Missouri.

To learn more about this research, you can read the original research paper in Natural Areas Journal. Email me for a pdf copy (jlreid@vt.edu). You can also tune in on April 21 for a webinar on this work. Register here.

How does fire affect ant-mediated seed dispersal?

Eva Colberg describes her ongoing research at Shaw Nature Reserve. She is a Ph.D. student in the Biology Department at the University of Missouri St. Louis.

In the late 1940s, Ohio-born entomologist Mary Talbot spent her days crouched in the woods of St. Charles, MO, tracking ant activity in painstaking detail through the seasons. Similarly, last summer I tried my hand at watching ants in the woodlands of Shaw Nature Reserve, with the addition of crumbled pecan shortbread cookies and the help of my field assistant, Dayane Reis. Foraging ants flocked to the buttery feast, the contrast of the crumbs’ sandy color against dark soil and leaf litter allowing us to easily follow the cookie thieves back to their nests.

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A plot of flagged ant nests (found by following cookie-bearing ants) in the Dana Brown Woods, one of the management units at Shaw Nature Reserve.

We watched at least seven different species of ants run off with the cookie crumbs, but I was most interested in the winnow ant (Aphaenogaster rudis). Reddish-brown, long-legged, and narrow-waisted due to a double-segmented petiole (the connection between the abdomen and thorax), the winnow ant worker is an elegant lady. She is also remarkably swift-footed and strong, adept at carrying chunks of pecan cookie or naturally occurring analogs.

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A winnow ant (Aphaenogaster rudis) worker, with the petiole and post-petiole that give the species its svelte waist. From her head to the end of her abdomen, this ant is about 4.5 mm long.

To an ant, a cookie more or less resembles an insect carcass, a staple of many ant diets. Chemically and nutritionally, the seeds of many of Missouri’s spring-flowering herbs also resemble a delicious dead insect (or cookie). From an ant’s point of view, this means food for larvae. From a seed’s point of view, this means dispersal. Hitchhiking to an ant’s nest gives the seed a new location to germinate and grow away from the parent plant, and potentially a multitude of other benefits such as escape from predation or better soil conditions. In any case, this is ant-mediated seed dispersal, or myrmecochory.

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A field ant (Formica subsericea) grabs a bloodroot (Sanguinaria canadensis) seed by its elaiosome, the oily, nutritious appendage that most resembles a dead insect and attracts ants.

In other parts of the world, benefits of myrmecochory include enhanced survival and germination after fire. In arid, fire-prone areas of both Australia and South Africa, ants bury seeds deep enough to buffer the intense heat of fire, but shallow enough that the heat weakens the seed coat and increases the odds of germination. Thus, the ants protect the seed from the flames while still providing exposure to a Goldilocks level of heat.

Just as in Australia and South Africa, fire is (or was, and with the help of land managers is once again becoming) also a frequent occurrence in Missouri. At Shaw Nature Reserve, managers use prescribed burns to restore an open structure to the reserve’s oak-hickory woodlands. But, is ant-mediated seed dispersal interacting with fire the same way here as in those other fire-adapted ecosystems?

This is a key question of my dissertation research at University of Missouri St. Louis. Using cookies to find winnow ant nests last summer helped me test methods and plan out my experiments for this coming year. Specifically, I will be tracking where the ants take their seeds, whether ants disperse seeds more or less in the year after a fire, and whether the presence and timing of surface fire affects the germination of the seeds after dispersal. Stay tuned!

You can keep up with Eva Colberg on Twitter (@ColbergEva) or by checking out her science communication initiative Science Distilled STL.

Tale of two Highlands Part I: Horton Plains, Sri Lanka

This post is contributed by Dr. James Aronson, a restoration ecologist at MBG’s Center for Conservation and Sustainable Development, and his son Thibaud Aronson. James is also a researcher with the CNRS (National Center for Scientific Research) in Montpellier, France.

In Sinhalese Sri Lanka means “Resplendent Isle”, a fine name indeed for this tear-shaped island off the coast of southeastern India, just north of the equator. Last month I travelled with my son on a self-guided Natural History + Ecological Restoration visit, we are finding and photographing cloud forests and birds galore, like the endangered endemic Sri Lanka whistling thrush, Myophonus blighi, and the Kashmir flycatcher, Ficedula subrubra, which over-winters exclusively in the Sri Lanka highlands, from its very restricted breeding grounds in Kashmir, northern India.

We were also looking at the mosaic of grasslands, cloud forests, and lowland forests we find here from a restoration ecology perspective.  That means we’re trying to “read” the landscapes we see in terms of known transformations carried out during the British colonial era (1815 and 1948, when Sri Lanka was known as Ceylon), and since independence. The remarkable Horton Plains National Park is a mosaic of montane grassland (ca. 35%) and cloud forest (ca. 65%), encompassing the headwaters of three major rivers. It was declared a sanctuary in 1969 and elevated to national park status in 1988; it became part of a large UNESCO World Heritage site in 2010. In the central highlands of Madagascar, grasslands appear to occupy about 99% and most people assume they are anthropogenic…. This month, I’m travelling with Leighton Reid in the Central Highlands of Madagascar, and we will be blogging about this soon.

But, the history of preservation in the highlands here goes back a lot further, to the days when the Isle was part of the British empire, along with all of India. According to information we gathered at the extraordinary, and poorly known Hakgala Botanic Gardens, the great English botanist and explorer Joseph Dalton Hooker had advised the British government to leave all montane forests above 5000 ft. (ca. 1300 m) above sea level “undisturbed” and after 1873 the administration prohibited clearing and felling of forests throughout the central highlands. What a great idea that was! It is too bad there were not enlightened laws on hunting of wild animals as well. One Scottish officer in colonial service in Sri Lanka bragged he had shot and killed over 1400 elephants in Horton Plains and nearby. Today, there are none left there and, so far as we could determine, no plans to reintroduce them from the other remarkable parks, including Yalla and Uda Walawe….

So, what is the significance of the absence of elephants in this park? And, what else can we learn from past regimes and historic periods in Sri Lanka? For starters, we discover that conservation, and respect for other organisms goes back much further than the 19th century. Consider the sign at the entrance to Udawattakele Forest Reserve, near Kandy, one of the historic capitals from the long period of successive kingdoms the island had known prior to the European colonial chapter in Sri Lanka’s history:

O Great King, the birds of the air and the beasts have an equal right to live and move about in any part of this land as thou. The land belongs to the peoples and the other beings and thou are only the guardian of it.”

-Arahath Mahinda (a son of the emperor Asoka the Great, who brought Buddhism to Sri Lanka)

How would it be if we could revive that approach to the Web of Life in our own day and age?

So, what has Horton Plains National Park, with its grassland-forest mosaic, its tourists, and its absent elephants got to do with the Central highlands of Madagascar? For one thing, we can see that fire is a big ecological driver in both areas. The abundant arborescent Rhododendrons in Horton Plains tell a vivid tale in this regard.

Rhododendron arboreum subsp. zeylanicum at Horton Plains National Park. It appears to be fire-resistant and is the only tree species present in large areas of grasslands subject to fire.

Rhododendron arboreum subsp. zeylanicum at Horton Plains National Park. It appears to be fire-resistant and is the only tree species present in large areas of grasslands subject to fire.

On the grand scale of things, Sri Lanka’s Central highlands also resemble those of Madagascar’s since both are the crowns of a poor, emerging tropical island with small and very similar human population size (21 million vs. 24 million), despite being much nearly ten times smaller, and with over 30,000 years of human history, as compared to merely two millennia for Madagascar.

Horton Plains also has remarkable conservation value both for its biodiversity and the ecosystem services it provides to people. Also, as I said, it’s a mosaic of grasslands and cloud forest, that in the past was certainly much affected by both elephants and fire.

Finally, both Sri Lanka (along with the Western Ghats of southern India) and Madagascar count among the world’s biodiversity hotspots, easily visible in their fauna and flora, which is one of the main reasons why MBG researchers, and many others travel and work in Madagascar.

Now, let’s turn back to fires. A big fire hit Horton Plains in 1998, and there are serious invasions of two noxious, cosmopolitan weeds, namely Gorse and Bracken fern. Some control work is underway on the Gorse, but the Bracken fern is apparently not seen as being a problem. Rainbow trout were introduced in the 19th c. and apparently have displaced all native fish, and are taking a toll on native shrimp and no doubt other fauna.