Reading the Land

It was one of those beautiful autumn days as I walked through a patch of western Missouri timber. Skies were a brilliant blue and a gentle breeze caused the treetops to sway rhythmically as I took in my surroundings. The stand of timber consisted mostly of young post oaks interspersed with hickories and a few red oaks. Growing conditions had caused most of these trees to grow tall and straight, with few lateral branches, as each stretched skyward in a race to capture the most sunlight. Dry leaves crunched underfoot, but now and then, in patches where the litter was sparse, native legumes such as desmodium and hog peanut grew in abundance. Up ahead, I noticed a different shape in the canopy. As I drew closer, I could see it was a tree quite unlike most of the others in the woods. The trunk diameter was much larger than the other trees I had been seeing, but also notable was the protrusion of numerous, wide-spreading side limbs that gave the crown a domed appearance unlike that of most of its younger neighbors.

Based on the information in the preceding description, can you deduce anything about the history of this land? For those with a trained eye, modern clues can tell us a lot about the history of the land in terms of the natural communities that once thrived there, but perhaps no longer do.

Plants, Soils, and Site

Whether your interests lie in the aesthetics and satisfaction of a restored native community, enhancing habitat to improve hunting on your farm, or someplace in between, it’s important to understand the factors that affect plant community dynamics. Failure to consider these factors can result in wasted time and effort in instances where the land’s capability doesn’t match the desired management result. In short, it’s always much easier to work with nature than against it, and an ability to read the land will facilitate a more efficient use of resources and likely, a more satisfactory outcome.

In much of Missouri, the vegetative communities we see today are considerably different than those enjoyed by the Osage and other native peoples prior to European contact. As our state and nation expanded, immigrants from across the Atlantic introduced agrarian and engineering practices that fundamentally changed the forces that had shaped Missouri’s natural communities for millennia. Fire suppression, land clearing, fencing, and market hunting greatly affected terrestrial communities, while these same factors plus channelization and impoundment of rivers altered our state’s wetlands. But nature is a resilient and tenacious force. And while many ecosystems are no longer fully functional in their original state, remnants of their past frequently exist in sufficient numbers that if we look with an ecological eye, we can discern what it was in the past, and quite likely, what it still wants to be.

Several factors determine the dominant plant communities that occupy a given area at any given time. Chief among these factors are soils and site. Missouri’s soils vary widely in their texture and origins, and subsequently in their fertility and capacity to hold water. Sandy and rocky soils tend to drain quickly, while heavy river bottom clays, with their extremely fine particles, may hold water for weeks or months following a rain. As a result of their propensity to hold or pass water, these diverse soil types host a wide range of plant species and communities in Missouri, ranging from very dry sites with prickly pear cactus to permanent swamps growing bald cypress.

Likewise, site characteristics can also affect the plants found. Ridgetops, side slopes, and valley bottoms may be within just a few hundred yards of one another, but the plants found on those different slope positions can vary considerably. Another feature with a profound impact on moisture retention and soil heating is aspect. Aspect is the direction a slope faces. While at first this may seem unimportant, it can be a critical driver of plant communities, based on their tolerance of drought and fire. Savvy forest managers know that east and north aspects are cooler and wetter, and usually grow higher quality timber, while the trees on the drier slopes facing south and west tend to be more fire scarred, scattered, and shorter, and often are even different species.

Where to Look for Clues to the Land’s Past

We’ve established that we’ll be more effective and efficient at managing the land towards what it wants to be, which in most cases is what it used to be. But how do we do this? Where do we find clues as to the land’s past? The following are several likely places that we can look to the land for evidence of its past.

Roadsides and Utility Easements

Southern Missouri’s Ozarks are certainly a national treasure and it’s no secret that they represent the greatest volume of timber in the state. But what many folks don’t realize is that the forests we see today are, in most cases, not what those same landscapes looked like 200 years ago. Plenty of historical accounts suggest that at the time of European settlement, this region was not densely wooded with a thick carpet of fallen leaves and no understory, but rather often consisted of more widely spaced trees with an herbaceous understory. In fact, these landscapes were often open enough to drive a team and wagon for many miles, a feat that would be mostly impossible today.

On your next walk or drive through the Ozarks, look carefully at the vegetation growing along the edges of the road or in other areas where the trees are kept at bay. What you’ll regularly see is that in these areas that receive more sunlight, native grasses such as big and little bluestem often thrive, along with forbs such as coneflowers, prairie dock, milkweed, asters, and blazing stars. That these plants grow in such places is no accident, rather, they represent what was once a vast woodland community characterized by an herbaceous understory stretching out beneath a canopy of fire tolerant trees such as post oak and shortleaf pine.

Additional clues to a wooded area’s past can be found by closely studying the plants that occur in the understory. Native legumes tend not only to tolerate fire but thrive with it. If you’re finding plants such as goat’s rue, wild peas, leadplant, hog peanut, native lespedezas, and desmodium, then you’ve found what biologists and foresters call indicator plants. These floras are sure indicators of a past that included fire and most likely grazing, and a forest structure that was likely different from what we see today.

But if your botanical skills are lacking, don’t fret. Simply pay attention to the time of year that most of the herbaceous plants bloom. In a true forest ecotype, most herbaceous understory plants bloom in the early spring, prior to leaf emergence on the trees. These spring ephemerals have adapted over time to reproduce early, while they can capture sunlight, because by late spring there is too much shade to afford good growing conditions. Conversely, woodlands have a more open canopy that allows more sunlight to reach the ground. As a result, the suite of herbaceous plants has a much longer growing season, and will bloom throughout the late spring, summer, and fall.

Low Spots and Wet Areas

Whether it’s a perpetually wet spot in a field that makes it difficult to grow crops, or that patch of willows or prairie cordgrass growing in the pasture, when we know what to look for, we can often find clues to what will grow best. The presence of wet-tolerant plants such as smartweed, spikerush, arrowhead, bulrushes, willows, silver maple, green ash, and buttonbush strongly suggests that an area is best suited for wetland plants. Often, satellite imagery such as Google Earth can be used to identify the locations of wet areas. Dark spots in a springtime crop field, or green areas in an otherwise dry summertime pasture suggest the presence of excess moisture. In many cases, these areas have very tight clay soils that don’t permit much water percolation. Planting these areas with species adapted to dry or mesic conditions is likely to fail, as those species are unlikely to tolerate the wetness. Instead, identify these areas, verify that they are excessively wet, and then use plants that are adapted to handle those conditions.

Railroad Rights of Way

Many railroad beds in Missouri are well over 100 years old. In most cases, these rights of way were built through plant communities that still represented the same ones that existed at the time of European settlement. Because the right of way was often protected from excessive grazing or plowing, in many cases these areas today represent the plant communities that existed in the past. As an example, many rights of way contain prairie remnants. These plants offer insight into what used to grow there, and the types of plants that soils in that area can support.

Tree Stumps

The cross sections of tree stumps can also offer insights into an area’s past fire history. Specifically, we need to look at the stumps of large diameter trees, as these were old enough to have had an extensive fire history. Fires often scar a tree when the heat kills a portion of the trunk as the flames move past. By learning to identify fire scars, habitat managers can make educated guesses as to the fire history of a site and the natural communities that may have historically occurred on their land.

Woodlands and Savannas

While forests and prairies are easy to conjure up in your mind, for many people a mental picture of a woodland or savanna may be considerably more elusive. These communities consist of both trees and herbaceous plants and were historically maintained by fire and grazing. In these communities, the trees are usually fire tolerant oaks, while the understory consists of many species of native grasses, forbs, and legumes. Because the trees are more widely spaced, they typically will develop a wider crown. Historically, a great deal of the southern Missouri Ozarks consisted of much more open woodland landscapes than we find today. Historic accounts often describe woods open enough to drive a team and wagon for many miles. Species typical of woodlands and savannas include post oak, bur oak, blackjack oak, shortleaf pine, big bluestem, purple coneflower, goat’s rue, desmodium, native lespedezas, and little bluestem.

• Typical tree species: post oak, bur oak, blackjack oak
• Scattered shade/sun
• Understory: summer and fall flowers, native legumes
• Frequent fires
• Tree growth: shorter, wide crowned trees; many lateral limbs
• Covered much of the Ozarks historically

Forests

• Typical species: red oak, white oak
• Deep shade
• Understory: spring ephemerals
• Less frequent fires
• Tree growth: tall, straight boles, few lateral limbs

Prairies

• Typical species: big bluestem, little bluestem, Indian grass, native sunflowers, blazing star
• Full sun
• Warm season grasses and forbs
• Frequent fires
• Few trees
• Mostly converted to crops & pasture

Glades

• Typical species: little bluestem, prickly pear, yellow coneflower, evening primrose
• South/west aspects
• Shallow soils
• Stunted trees, if any
• Native grasses and forbs