The word “forest” conjures up the idea in everyone’s mind of a habitat dominated by trees. This is true at the Houston Arboretum & Nature Center even though trees are not the most numerous species. Their large size not only dominates our view but significantly influences the character and species composition of their environment. The tall spreading canopy produces shade, reducing the light available to other, lower growing species. Their large size demands a great deal of the available water and soil nutrients. They also take up a lot of space both above and below ground. The forest at the Houston Arboretum & Nature Center consists of pines and hardwoods such as oaks and hickories.
A forest has several layers, each of which has its own set of dominant plant and animal species. Four of the most readily identifiable layers are the canopy, the understory, the shrub layer, and the herb layer. One important part of the forest which many people forget about is the soil. Most forest plants have their roots in the soil. Trees often establish symbiotic relationships with fungi. The fungi live in the soil and become attached to the roots of the trees, helping the trees to absorb water and soil nutrients more easily.
A pond is defined as a quiet, shallow body of water with little wave action and a mud-covered bottom. Plants typically grow along the shore. In a pond, temperatures are fairly uniform from top to bottom and tend to change with the air temperature. Within a pond ecosystem there are habitat zones where distinct groups of plants and animals are found.
Some ponds at the Houston Arboretum & Nature Center were left from the activities of Camp Logan, an army training camp that closed in 1919. Other shallow ponds were created artificially in existing low-lying areas in order to attract wildlife and harbor mosquito predators. There are no naturally occurring ponds in this area. Ponds are relatively short-lived ecosystems. They gradually fill with organic debris and vegetation. At the Houston Arboretum & Nature Center we slow this process by periodically digging out certain ponds or removing accumulated organic debris.
A meadow is an area dominated by non-woody (herbaceous) plants such as grasses, sedges, and wildflowers. The presence of a meadow, or grassland ecosystem, is determined primarily by soil types and climate. Grasslands found in the Great Plains region of the United States usually have too little rainfall to support trees. The presence of meadows and prairies in our area (the Gulf Coast) is determined more by soils, fires, and large grazers than a lack of moisture.
The meadow at the Houston Arboretum & Nature Center is a demonstration grassland habitat, although results of soil surveys show that there was once a natural Gulf Coast Prairie in this area. Since that time, pine trees had moved in. These pines were killed by bark beetles and were removed to create this meadow. The presence of pine-specific soil fungi and the absence of large grazers such as deer and buffalo make it necessary to maintain the meadow by occasional mowing. Among the plants which we are encouraging are sunflowers, liatris, bluestem grasses, asters, coreopsis, gaillardia, and basketflowers.