What the Heck is “Early Successional Habitat”?
early successional habitat (ur.lee suk.sesh.un.al hab.uh.tat) : n. Weed patches.
Readers who follow habitat management literature have probably run across the term “early successional management.” This is one of those terms that biologists and land managers use often. But because it’s not used much by anyone else, it may leave many scratching their heads about what it means. In short, it means weed patches. For a more in-depth discussion, read on.
The key concept to understand here is that of plant succession. This is the change in plant communities as a result of some kind of disturbance. In ecology, we study two different types of succession: primary and secondary. Primary succession is the initial colonization by plants of bare rock, cooled lava beds, or other areas that have never been occupied by plants. Secondary succession (which is the type of succession we deal with when managing quail and other wildlife) is the change in plant community types that occurs over time.
Everyone has witnessed secondary succession, and it goes on (or tries to) around us all the time. Visualize a mature forest, which is a very advanced form of plant succession (climax community). Then cut down all the trees. When the trees are removed, succession is reset. And if no one or nothing else disturbs the area, succession will progress through a fairly predictable set of stages. During year one, mostly annual “weeds” and some annual grasses appear. In years two and three, some annuals will still show, but by this time, many perennial grasses and broadleaf plants will become established. By year 10, many shrubs and sapling trees will appear, and annual plants (which depend on bare ground to seed and spread) will begin to decline. Left unchecked, by year 100, succession likely will have proceeded to mature forest again. Advanced succession isn’t always forest. In hot, dry climates it may be grassland or shrubland.
So what makes early succession so important for quail and hundreds of other wildlife species (such as grouse, deer, turkeys, pheasants and rabbits) that benefit from early successional habitats? First is structure. Early successional habitats often have an open understory with scattered plants that create an umbrella-like canopy. The widely spaced stems allow easy mobility, while the tops of the plants interlace to provide shade and overhead concealment. This structure facilitates easy movement and insect foraging for quail chicks because there is no heavy accumulation of thatch to inhibit travel or hide food.
The second characteristic that makes early successional habitats conducive to quail is seed production. Most of the plants that emerge following a heavy disturbance are annuals. Annual plants, because they live only one growing season, must produce lots of seeds in order to perpetuate their kind. They only have one shot, so it has to count. Typical early successional plants in Missouri include common ragweed, croton, pigweed, foxtail, giant ragweed and partridge pea. If you just said to yourself, “Those are all important quail foods!”, then give yourself a gold star. Heavy seed production is another benefit of early successional plant communities.
The final big benefit of early successional communities is that they are very diverse. To be an effective quail manager, you don’t have to be a botanist, but you do need to be observant enough to recognize whether you have 30 common plant species or three. Habitats with 30 species will always be better for quail than habitats with three species. This is why fescue and Bermuda grass pastures and even idled native grass fields are poor quail habitat. Succession has advanced to the point that only a few species completely dominate the field, choking out everything else. Management practices such as burning, disking, grazing or herbicide application can set succession back to an earlier, more beneficial state.
With few exceptions, the most limiting habitat factor facing quail across Missouri (and most of their North American range) is adequate brood habitat. Chicks fare better in early successional vegetation, where they can move about easily and find plenty of bugs and seeds. Quail will begin hatching next month. Do you have enough weed patches to ensure chick survival?