If we want to have more wildlife diversity, we need habitat diversity.
In general, things that create changes on the surface of the earth add to diversity. Here is what I have observed on two of the property types with which I’m most familiar.
On our ranch, topography is a natural creator of diversity. The hills create different exposures to sun, wind and rain. A multitude of soils types, modified over time by water runoff and geologic formations and organic mater, create a variety of habitats.
Elevations run from 1,000 to 2,500 feet above sea level. The hills run from gently sloping to very steep. The four main habitats on our ranch are oak grassland, oak woodland, chaparral and riparian.
Because the ranch is remote, has shallow soils and slope that discourages access, the land has remained unchanged over the last 150 years, with a few exceptions. The biggest exception is the introduction of non-native European grasses that make up a large percentage of the flora. Theses annual grasses have choked out many of the native bunch grasses. The resulting changes to the habitat have eliminated or greatly inhibited some native species. One of the most impacted is the kangaroo rat and the local sub-species, the Berkeley kangaroo rat is considered extinct.
The black-tailed deer is an animal that uses all the habitats on our ranch, while other species live primarily in only one or two habitat types. Species that cannot adapt to more than one habitat are more inclined to be threatened. Deer are an ancient species that has survived because of it’s ability to adapt to change.
In an area with multiple habitats, transitions zones may also benefit wildlife.
Duck clubs are generally developed on ground that is nearly level or gently sloping. Seasonal marsh creates diversity as water levels vary. On the other hand, a permanent pond has little change in water level and has minimal diversity.
John Cowen, who managed the Gray Lodge Wildlife Management Area for many years, once told me of his preference for managing ponds. He flooded ponds up during the winter and liked to let the pond slowly dry out in spring. The receding water would create rings of growth around the deepest portion of the pond. The outer ring would be upland habitat that benefited the pheasants ( grasses and broad-leaf plants). The portions to dry out first would grow plants that required less water and cooler temperatures for germination (for example – smart weed). The pond bottoms would dry out last and would grow the seasonal marsh plants that preferred moist soil and hot weather for germination ( examples – swamp timothy and water-grass). Mixed in would be various types of bull-rush, cattail, fat-hen and cocklebur.
The marsh would create a tremendous food source for returning waterfowl in the fall and also resident birds and mammals all year-long. This type of habitat and habitat management is now threatened by many problems. Two problems I see are large scale changes in water availability and mismanagement of land intended to be managed as marsh ( due to either a lack of skill or a lack of will).
Confusion about habitat management and misunderstanding how marsh benefits wildlife is a common problem.
We need more land dedicated to and managed for habitat diversity.