Union of Concerned Scientists

The Big Thicket area of East Texas has been nicknamed the "Biological Crossroads of North America" and the "American Ark" because of the exceptional diversity of plant and animal species that reside there. Several of the major forest types of the eastern United States can be found in this relatively small geographical area. Upland areas of the Big Thicket, which were once dominated by longleaf pine, are now mostly loblolly and slash pine plantation forests.

Wetter parts of the Big Thicket are home to loblolly-shortleaf pine forests. The most rapidly expanding type of forest is oak-hickory-pine forest. Bottomland hardwood forests, which are forested wetlands found in the low-lying river flood plains, harbor a wide array of tree species such as sweetgum and water oak.

The forested areas of the Big Thicket also support a high diversity of vertebrate animals. These forests are the primary habitat for the endangered red-cockaded woodpecker. Several other endangered bird species make their homes in the Big Thicket's coastal prairies. The Big Thicket is also a popular area for people to enjoy fishing, hunting, birding, hiking, camping, and canoeing.

Climate change could affect the diverse plant communities of the Big Thicket in several ways, including:

• altering how fast plant species grow
  
• changing the intensity and frequency of disturbance; and
  
• promoting invasion by exotic plant species

In the past, fire has played a critical role in determining the dominant vegetation of the Big Thicket. Since fire prevents hardwood saplings from taking root in pine forests, it allows for successful recruitment of young pines. Fires are likely to become more frequent if climate change leads to drier conditions in the area. With greater demand for water from the Neches River in the future and less moisture in the soil, invasion by Chinese tallow trees is likely to intensify.

Climate change will also influence the spread of pests, especially the southern pine beetle, in an area where losses to the forest industry from beetle damage are already running at around $236 million per year. Moreover, any barriers to the large-scale movement of plants and animals would lessen their ability to respond to changes in climate.