Lone Star Habitat

2016-12-28_tx-heard-nature-sanctuary-pan-1acsI’ve been thinking a lot about the word “habitat.” My friends and I throw the term around a lot. We talk about pristine or disturbed habitat; interesting, unusual or downright odd habitat; preserving habitat and restoring habitat.

What the heck are we talking about?

The Heard Natural Science Museum and Wildlife Sanctuary in McKinney, Texas showcases a variety of habitats, from wetlands and forest to prairie. On a recent visit, I took a walk that wound through several different habitats, three of which were unlike anything I see back East. Along the way, I started to muse about the meaning of habitat.

HABITAT (noun): the natural environment of an organism; place that is natural for the life and growth of an organism. (Dictionary.com)

It’s the place an animal or plant lives. It’s comprised of everything an organism, or a population of organisms, needs to survive, from soil, moisture and light to food and shelter. Habitats range from a large area like a forest to a small site, such as the inside of a rotten log.

My friends and I use the term in a wider, more colloquial way to refer to a geographical area of varying size, where the soil, geology and plant communities are fairly uniform. Technically, that’s a “biotope”, but the terms are so similar that we say “habitat.”

161228_tx-heard-nature-sanctuary_7643aDallas lies in the Texas Blackland prairie region. Before much of the land was converted to agriculture and residential use, grassland, oakland and savanna habitats once covered the area.

At the Heard Sanctuary, the trail wound through remnants of Blackland prairie. A type of grassland, prairies typically have deep fertile soil, on which grasses and wildflowers grow. Trees and shrubs may be present, but cover no more than 10% of the area. For centuries, animals such as bison, pronghorn and deer, as well as wildfires, kept woody plants and trees at bay and preserved the land as prairie.

161228_tx-heard-nature-sanctuary_8179aGrasses found in the prairie include big and little bluestem and Indian grass. In winter, golden browns, russets and tans adorn the land. In the growing months, these hillsides are ablaze in wildflowers.

161228_tx-heard-nature-sanctuary_7931acsAt the Heard Sanctuary, I encountered a swamp for the first time. They call it a wetland, but it’s a swamp. “Wetland” is a term that encompasses any land area saturated with water at some time of the year. Bogs, marshes and swamps are all wetlands, but a bog is not a marsh and a marsh is not a swamp. Marshes, like those at John Heinz NWR near home, are dominated by soft-stemmed herbaceous plants and grasses.

161228_tx-heard-nature-sanctuary_7926acsSwamps like this are dominated by woody plants, aka trees.

The swamp here is ephemeral, meaning it is not flooded the whole year. In the summer, it dries up. During the dry period, annual plants sprout.

161228_tx-heard-nature-sanctuary_7956acsThen the autumn rains come, and the plants die. Their seeds and leaves become an important source of food for the wetland visitors and inhabitants. The swamp is again a watery wonderland.

161228_tx-heard-nature-sanctuary_8015acsFurther along the trail was another interesting habitat, the Cedar Brake. I wondered what a “brake” was. From what I’ve been able to find, it’s a tangle of dense brush and briars. So the cedar brake was a thick cedar grove with a thick brushy understory?

161228_tx-heard-nature-sanctuary_8022aLife is not so simple. As you can see, there was almost no understory to this cedar brake. Lots of trees, yes, but no brush. Deep in the woods, the trees were bare of foliage for most of their length.

161228_tx-heard-nature-sanctuary_8111acsOnly when I looked to the sky did I see the greenery.

161228_tx-heard-nature-sanctuary_8083acsAbout those trees… They may be called “cedars”, but they are not true cedars. Instead, they are junipers in the Cypress family.

Junipers are evergreen trees or shrubs with small scale-like leaves and cones surrounded by a fleshy covering that looks like a berry.

Junipers often occur in oak-juniper woodlands in Texas, but here it was a monoculture of cedar trees.

161228_tx-heard-nature-sanctuary_8060acsExactly which juniper tree remains a mystery, to me at least. Identifying junipers is very difficult, even for experts.


Possibly Eastern redcedar, Juniperus virginia, which usually has a single trunk.

Ashe juniper, Juniperus ashei, known as post cedar or Texas cedar, is common in Texas, but usually has multiple stems and is shorter.

Both have blue seed cones, and the two species hybridize.

161228_tx-heard-nature-sanctuary_7537aEvery region has its own types of habitat, and exploring different regions of the country is a great way to get to experience distinctive environments. When I am in Texas, I always seek out natural places that have something new to show me. With a wonderful variety of habitats, the Heard Sanctuary did not let me down!