| VOLUME 3 ISSUE 2 SUMMER 1993
BIO-DIVERSITY, DYNAMIC SYSTEMS AND NATIVE GRASSES
Bio-diversity has been the buzz word in the resource community for the last couple of years, bio-diversity from a local, site specific level up to a landscape level. Bio-diversity is a simple concept but seems to be too complicated for some to comprehend or at least implement. It is very simply t
he maintenance of a diversity of plants within a community and a diversity of communities within a landscape unit. (With the habitat diversity there will then be animal diversity.) I believe this is a healthy approach to land management and stewardship as long as it is related to the historical bio-diversity of the area. I do not support bio-diversity to the extent of introducing trees where they were never meant to be nor grasslands to woodlots where they were never meant to be. It is certainly not feasible to construct a wetland in an upland or vice versa.
One concept which also tends to be all too often overlooked is that nature and the environment are dynamic. There is a lot of misdirected management that deals with nature and the environment as a static system. That type of management over the long run is expensive and when it fails we tend blame the system rather than the management we apply. It makes much more sense to adapt a management scheme which works within the system and deals with it as a dynamic force of nature rather than the static system that so many perceive it to be. It is really quite simple to understand. Think of a photograph versus a movie. If you were to act upon what you saw in a photograph, devise a solution to the problem, the solution would be finite. Now, think if that photograph were only a one-frame clip from the end of a 60 minute movie. Obviously, when looking at the photograph you weren't able to see any of the events leading up to that picture. By not seeing what lead up to that point you would not be able to predict what might happen afterward and your solution would only, at best, be temporary. However, if you were able to see the whole movie, chances are, your solution would be long lasting or better yet one which would change as the system changed.
It was a long way to go but this finally leads me up to what I wanted to say about native grasses. A mixed planting of native grasses and forbs can provide both bio-diversity and work within a dynamic, ever-changing system. The bulk of this discussion relates to quail but can apply to a host of other grassland species.
A vast majority of the literature you read about plants and their usefulness to wildlife states: Used for nesting; or Extensively used as food and cover; or Provides excellent winter cover, or other similar accolades. Typically the uses are for only one or two requirements. We tend to then compartmentalize our plantings to provide food here, nesting there, brood rearing next door and winter cover nearby. We are providing all of the requirements and they are in close proximity, but this is not the best it could be. Predators easily identify these edges between changes in habitat types. It is then arguable whether we are hurting more than we are helping. The beauty of a mixed planting of native grasses and forbs is that we can provide all of the requirements within a single planting, creating a soft edge or nearly no edge, eliminating the types of edges predators key upon.
The advantages of native grasses and forbs to wildlife are best quantified as the structure and growth chronology. Not only does the structure of native grasses change to provide the changing habitat needs of quail but the growth chronology conveniently coincides with quail's changing habitat requirements. Native grasses and forbs change in structure as they mature offering different advantages to wildlife as their requirements change. As the habitat requirements for quail change through the year so does the type of habitat native grasses and forbs provide.
The five major warm season grasses; big bluestem, little bluestem, indiangrass, sideoats grama and switchgrass, all initiate growth at different times during the spring and grow at different rates during the summer.
Traditional quail biology has always talked in terms of a peak nesting season. As more and more research is being done, it has become apparent that quail are nesting throughout the spring/summer; differing nest initiations dates, double and triple nesting, gypsy hens, males incubating and brooding, etc. (Quail biologists have long known that nesting was taking place throughout the summer, only recently have they come to understand that those nests were more than just re-nest attempts.) No matter when they are nesting, quail select the same physical characteristics for nesting, brood rearing, roosting and loafing in May as in August. That is where the significance of a mixed planting becomes evident.
Of the five major native warm season grasses, switchgrass is the earliest to initiate growth in the spring and grows the most aggressively through the spring. It is not uncommon for switchgrass to grow as much as 4 inches a day during May, reaching a height of 2 to 3 feet by early June. (Obviously it doesn't grow 4 inches a day every day, if that were true the grass would be 10 feet tall by the end of the month of May.) Big bluestem, indiangrass, little bluestem and sideoats grama all begin growth about the same time but each grows at a different rate. Big blue will grow to 18 inches through mid-June, up to 2 feet by July. After the first of July big bluestem grows very rapidly, reaching a total height of 6 to 10 feet. Sideoats grama grows and produces seed by mid-July, with a total height of 1.5 to 2 feet. Indiangrass grows relatively slowly through the end of June, sometimes only reaching 12 inches by the first of July. However, indiangrass puts on over 70% of its growth after the first of July, finally reaching 5 to 7 feet. Little bluestem grows to 12 inches by the first of July reaching its total height of 2 to 3 feet by the first of August.
As you can see by these descriptions, at least one species of native warm season grasses can provide any of the habitat requirements at any time during the nesting/brooding season and switchgrass, big bluestem and indiangrass can provide roosting and winter loafing cover. To this point I have left forbs out of the discussion, but it is important that they be included in plantings. Though the native grasses provide all of the cover requirements and some food value, forbs add additional value. The forbs serve to attract more insects to a native grass planting, providing better brood habitat. In addition the structural diversity makes the plantings more attractive as roosting cover and their seeds often have more energy value than the grass seeds. A mixed planting provides bio-diversity in a dynamic system.
Native grasses and quail - what a coincidence that their requirements and characteristics so conveniently coincide with each other, or is it a coincidence?
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