Urban Greenways – Grazing Cattle
Wilderness conservation movements are going to have to embrace enterprise and public use to garner mainstream and political support. Habitat restoration, species preservation, and environmental remediation can be compatible with agronomy and other enterprises, if proper and proven techniques are followed.
Urban greenways need to pay for their land and maintenance with tangible products and practices. Livestock grazing is often at odds with wildlife conservation. Since the 1970s1 ranchers and environmentalists have battled (sometimes literally) over the use of public lands as pasture. However, in urban greenways, where the habitats are typically not as pristine and the native species more tolerant of disturbance, there is room for compromise.
Urban greenways could only be used for pasture if toxins are low and sources of contamination are not in the proximity. Frequent environmental monitoring will be required. Urban livestock must have a reputation for clean, safe meat if there is to be adequate consumer demand at a fair market value. Individual ranchers and municipalities will have to decide their standards. USDA organic certification may be difficult near urban areas with excessive emissions drift and questionable land use histories. But, conventional standards are easily met with proper remediation and buffer zones.
The greenways must be a mixture of rangeland and woodland. Cattle are grazers and require a diet of grasses with only occasional forbs (herbaceous plants). Forage grasses grow best in open spaces, but cattle also need wooded areas as shelter from storms and excessive heat.
The size of the area will determine the number of cattle allowed to graze. Conservative estimates will be required for adequate forage and minimal ecological damage.
Deferred grazing proved to be compatible with habitat restoration goals in a study at Dixon Springs Agricultural Center in Illinois’ Shawnee National Forest conducted by the University of Illinois.2 Deferred grazing land is in pasture only from mid summer to autumn. (This technique is similar to those used on rangelands to promote forage vegetation recovery.) Many native wildflowers would have time to develop, flower, and seed before the cattle arrived. Deferred grazing can also be used in conjunction with haying or biofuel harvesting. Once the material has been harvested in July, the land can be put to pasture. In this study deferred grazing areas had higher species richness than even ungrazed areas.3 This has led some to consider prescribed grazing as an environmental management tool.
Rotating pasture and fallow area will be common practice in urban greenways.
Winter pastures should not include any areas of conservation or preservation value. In the UI study the winter pasture areas had the highest number of invasive and ruderal species and the lowest number of woodland sensitive species.4 Winter pastures also had a higher incidence of tree injury. Parklands, orchards & nut groves, coppicing thickets, buffer zones, and other areas of low ecological diversity can serve as winter pastures.
Livestock is divided between grazers and browsers. Grazers prefer a diet of grasses. Browsers, on the other hand, favor nutritious forbs, twigs, and saplings. If habitat restoration and species richness are important factors, then grazers (cows, bison, elk…) are preferable to browsers (deer, goats, giraffe…).
Miniature cattle are perhaps the best species for urban greenway grazing. Their smaller stature means they have less impact (footfall, waste) on the environmental than their larger cousins. They require a third of the food of the larger breeds, so they can be grown on smaller lots.6 Plus, they have a docile temperament and tasty, tender meat.
Sheep are also a possibility. They are intermediate feeders but prefer grazing. In areas of high contamination, sheep can be raised for their wool, if not their meat.
Environmental Benefits of Grazing
Prescribed grazing can be a form of environmental land management just like prescribed burns. Grazing, like mowing, keeps grasses vigorous and helps reduce erosion.
As stated earlier, deferred grazing can be a tool to promote understory diversity in restored woodlands.
Many thanks to Ann Dennis for writing “Effects of Livestock Grazing on Forest Habitats” (chapter 14) for Conservation in Highly Fragmented Landscapes edited by Mark W. Schwartz