ECOLOGY AND THE LAND STEWARD - Texas Wildlife · ECOLOGY AND THE LAND STEWARD Even though both species are viewed negatively, they both play positive and beneficial ecological roles.

T E X A S W I L D L I F E FEBRUARY 20178

E C O L O G Y A N D T H E L A N D S T E W A R D

A good understanding of ecology helps landowners be better land stewards.

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ECOLOGY AND THE LAND STEWARD

All landowners are practicing ecologists, whether they realize it or not. Ecology is not about

hugging trees, environmental activism or even the love of nature. Ecology is the study of the interrelationships between and among all parts of the environment. These parts include the soil, water, plants, animals and atmosphere in all of their diverse forms. Ecology is a science—not an emotional endeavor.

And of course, we know that ecology includes human beings. People have great influence over these interrelationships. We practice good ecology when management operates in sync with the nature’s inner workings. We practice bad ecology when management chronically upsets or interrupts the natural processes. Ecology at the farm and ranch level involves the understanding and application of ecological principles, ecological processes and ecological practices.

ECOLOGICAL PRINCIPLESThere are certain general principles that

govern how nature works. These principles apply to most situations including the management of farms, ranches, forests, watersheds and wildlife habitat. These principles can be thought of as rules of thumb for understanding ecology.

Everything is ConnectedAlthough the various parts of nature

Article and Photos by STEVE NELLE

can each be studied separately, they only function when they are connected to everything else. For example, soil can be studied to determine particle size, aggregation, porosity, density, structure, mineral composition, fertility, water holding capacity and many other attributes, but soil can only be understood when it is studied in context with the microorganisms that live in the soil, the plants that grow in the soil and the animals that feed on the plants. Studying one part when disconnected from the others results in an incomplete understanding.

Side EffectsEverything that is done on a piece of

land produces side effects. Some of the side effects are predictable and well understood, while others are still poorly understood. Every land management practice should be evaluated on the anticipated benefits and the unintended consequences they may produce. Herbicide use, mechanical brush control, prescribed burning, high fencing, introducing exotics, supplemental feeding and grazing practices—these are a few of the practices that produce side effects. The challenging thing about side effects is that they may behave differently on different ranches and in different years. Understanding and evaluating the side effects before the practice is applied is ecologically wise.



Diversity Provides StabilityNatural diversity is not only a sign of healthy ecological

condition, but it also promotes improved stability. In general, the more native plant and animal species, the more stable an ecosystem will be. As natural diversity declines, instability increases.

No Simple Solutions There are numerous ecological problems facing Texas

landowners. The proliferation of exotic grasses and exotic ungulates; over-population of white-tailed deer; subdividing of large tracts into many smaller tracts; over-pumping of alluvial water tables causing the drying of creeks and rivers; and overgrazing of ranges resulting in soil erosion and loss of native plant diversity. Ecological problems are often complex, multifaceted and difficult to fix. The solution to a brush problem is rarely as simple as brush control. The solution to poor soil is not as simple as applying fertilizer. The solution to under-developed antlers is not as simple as killing spikes or introducing supplemental feeding. Simple solutions seldom work for complex problems.

Resiliency The wonderful thing about nature is that it is normally very

resilient. There is a lot of elasticity among the parts and processes that tend to bring things back toward a balance following a disturbance. This is why vegetation rebounds following a wildfire, drought, hurricane, flooding or other natural disasters. If an ecosystem is healthy and functioning, it tends to bounce back better after disturbances. If an ecosystem is weak and wobbly, the resilience and elasticity is greatly reduced; it may not bounce back very well.

Ecological Paradox Nature sometimes plays tricks on people; what seems bad from

one perspective can actually turn out to be good from another viewpoint. Take mesquite for example. Mesquite is a native plant that belongs in Texas and has naturally occurred in varying amounts for millennia. Due to mismanagement over the past 150 years, mesquite has become a severe brush problem across millions of acres, reducing forage production and making it difficult to manage livestock.

Many landowners still believe that the only good mesquite is a dead mesquite. But we now know that mesquite, a legume, enriches the soil beneath it, adding nitrogen, improving soil structure, infiltration and organic matter content. A similar thing happens under dense mature cedar. Although not a legume, cedar rebuilds topsoil on severely eroded and degraded areas.

One of the strengths of TWA is the active program of education, teaching people about the ecological basis of land management which sustains the natural resources of Texas.

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Even though both species are viewed negatively, they both play positive and beneficial ecological roles. Seeking to understand brush and weed ecology should precede our attempts to control them.

ECOLOGICAL PROCESSESAlthough it is an oversimplification, there are four main

processes that govern the health of the land. Landowners have a high degree of influence over these processes. We can cooperate with them or we can hinder them. Although these four processes can be described individually, they are all connected to each other and do not function independently.

Energy FlowEnergy flow is perhaps the most fundamental process of ecosystems. We know that the sun is the basic source of energy, and plants are the means of converting sunlight energy into other forms. In order for this flow of energy to function efficiently on a piece of land, sunlight energy should be intercepted by green leaves on as many square feet and as many days of the year as possible.

Having only warm season plants that go dormant for five months of the year is not an efficient use of sunlight. Maintaining a diversity of cool season and warm season plants, including grasses, forbs and woody plants efficiently converts sunlight into plant energy.

Scientists have discovered that soil microbes depend on actively photosynthesizing green plants. Soil microbes need a constant supply of energy transported to the root system every day. Having the greatest variety of plants including many deep rooted species and cool season plants is the best way to feed the microbes, which in turn keeps the soil healthy.

Water CycleThe water cycle is another important ecological process. The basic premise behind creating a healthy water cycle is keeping the land covered by vegetation and plant litter, which increases the rate of infiltration and retards runoff. Healthy soil, with high porosity, high organic matter and good structure will absorb rainfall faster and store more water than poor degraded soil.

With a good cover and healthy soil, rainfall is naturally processed by the land. Some of the water is evaporated back into the atmosphere, some is used by plants, some seeps downward into aquifers, some comes out as springs and seeps, and some becomes runoff to help sustain creeks, rivers and estuaries.

A good hydrologic cover on the land can include taller grasses mixed with forbs, shrubs, brush and trees and usually a mix of these. Contrary to traditional belief, we now know that cedar, mesquite and other brush species are not necessarily detrimental to a good functioning water cycle. Landowners can rest assured that they can still be good watershed stewards when they choose to retain significant areas of moderate to thick brush.

Mineral CycleThe mineral cycle involves the timely decomposition of dead

plant and animal material, returning essential elements back into

the soil where they can be continuously recycled. Such breakdown of plant material happens best when the dead plant tissue is in close contact with the soil and its microbes.

Grasses that are ungrazed for long periods sometimes accumulate several years of standing dead leaves and stems. If these do not decompose, they tie up important nutrients and inhibit sunlight from reaching the green leaves. Animal impact through planned grazing is one good way to help accelerate decomposition and nutrient cycling.

Healthy land is resilient. This well-managed ranch has responded well following the drought and wildfires of 2011.

Understanding basic ecological processes helps landowners carry out management that keep the land healthy and productive.


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Plant SuccessionPlant succession is the fourth basic ecological process that

landowners influence by their management. Plant succession refers to the somewhat predictable order of replacement of one group of plants by another.

For example, when palatable tall grasses are subjected to long-term overgrazing, these grasses decline and are replaced by less preferred grasses. If overgrazing continues, these secondary grasses also decline and will be replaced by even less desirable, less productive grasses. If the process continues, you end up with bare ground, weeds and unpalatable grasses. This form of downward succession is called retrogression and represents a worsening ecological condition and compromised productivity.

With good grazing management and rotational grazing, this process can be reversed. The vegetation will go through stages of improvement from short, unproductive grasses, to mid grasses, and with enough time and skillful management, the range can often be restored back to a predominance of desirable taller grasses and forbs.

Succession and retrogression also happens with woody plants in relation to browsing animals. Plant succession works differently in each region of Texas, with different plants, soils and rainfall.

ECOLOGICAL PRACTICESAlthough ecology is a complex science, the basic practices that

support stable, healthy lands are straightforward and are being carried out by many Texas landowners.

1. Keep the ground covered. This includes grasses, shrubs, trees, broadleaf forbs and a layer of plant litter and decaying plant mulch. This is the cardinal rule of land management. Nature hates nakedness.

2. Promote plant diversity. The first step is to learn the plants on your land so that you will recognize diversity when you see it. Rotational grazing at conservative, flexible stocking rates and keeping deer and exotic numbers in balance will promote plant diversity.

3. Moderation. Try new ideas first on a small scale; observe and evaluate the results to see if they provide the expected benefits.

4. Do no harm. Nature will restore healthy ecological condition better and faster if we don’t do anything that hinders the natural processes. Continuous grazing, high deer numbers, indiscriminate large-scale brush control or herbicide use, and burning under extreme conditions are examples of management that will hinder natural recovery.

Modern ranching and wildlife management increasingly works to cooperate with nature rather than conquer it or change it. Aldo Leopold described the landowner as a botanical and zoological engineer, who “lubricates the engine we call ‘Nature.’”

This is a good way to think about conservation—understanding of ecological principles and appropriately lubricating ecological processes with our day-to-day practices. Land stewardship provides the inspiration, motivation and conviction to do these things wisely.

Cattle grazing can be a good tool to promote the mineral cycle and energy cycle by reducing the undesirable excess buildup of old dry grass.

One of the cardinal ecological principles is that everything is interconnected.

When management is based on ecological principles and guided by stewardship ethics, wildlife populations will be diverse, healthy and abundant.

ECOLOGY AND THE LAND STEWARD - Texas Wildlife · ECOLOGY AND THE LAND STEWARD Even though both species are viewed negatively, they both play positive and beneficial ecological roles.

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