Standards And Guidelines For Enhanced Ecosystem Diversity
Management of wildlife on farmlands and rangelands is a critical need in today’s society. Many wildlife species have declined in agricultural lands as a result of expansion and intensification of agriculture land use. The opportunity exists now to promote agricultural practices that are both beneficial to wildlife and compatible with agricultural goals. This requires that sound wildlife management programs be integrated with other resource-conserving programs in such a way that neither biodiversity nor agriculture are compromised or diminished. Successful agricultural/wildlife habitat management programs are often dependent upon how well managers integrate the ecological, political, economic and social “mileau” into an habitat initiative (McConnell 1981).
The future agriculturalists and biologists are in our classrooms today. The Cal Poly campus and nearby ranches can be made field laboratories where these students will have the opportunity to learn and practice modern principles which will allow them to become the best graduates in their fields while protecting and enhancing the environment they live in. Cal Poly can be at the cutting edge of unifying field biology and agriculture by addressing together those issues which are of concern to both specialties and by formulating a program that is compatible with both of their needs.
Any management plan for the wildlife on Cal Poly properties should contain a set of standards and guidelines that will both maintain and enhance the existing native biological diversity and encourage the reestablishment of those wildlife species with records of presence prior to development of the University, while supporting the educational activities of the University. This plan can easily become a model for all campuses within the California State University system and should be incorporated into Cal Poly’s Master Plan as an integral part of its Environmental Review.
Knowing that wildlife diversity and abundance will be as rich as the quantity and quality of habitat available to them, the first requirement of any management plan is to define and describe what constitutes a healthy landscape in terms of both agriculture and wildlife. The key characteristics are as follows:
For purposes of this management plan, standards are defined as expressions of physical and biological conditions or degree of function required for healthy, self-sustainable lands. A standard serves as the criterion to determine whether or not a management action is resulting in the maintenance or attainment of healthy lands as described by the four fundamental characteristics listed above.
A guideline serves as the vehicle to implement a management action related to wildlife or agricultural conditions which, when accomplished, will result in a healthy land standard. Guidelines indicate the types of wildlife management, grazing, farming, and other land uses, methods and practices that are determined to be necessary, sufficient, and appropriate to ensure that standards can be met. For any standard and guideline to work, it must be achievable, based on sound science and common sense, and it must be measurable, understandable and economically feasible.
Soils must exhibit functional biological and physical characteristics appropriate to the soil type, climate, and land form such that precipitation is able to penetrate through the soil surface at appropriate rates. Soils must be adequately managed to prevent erosion and fertility must be maintained at appropriate levels.
Natural Conditions that Maintain Healthy Soils
Viable, productive, self-sustaining and diverse populations of native and desirable species must be maintained or enhanced. Their success must be measured by their reproductive success, and they must adequately support the hydrologic, nutrient, and energy flow processes both spatially and temporally.
Natural Conditions that Maintain Healthy Species
STANDARD: RIPARIAN AND WETLAND
Riparian and wetland vegetation structure and diversity, as well as water, stream channels and floodplains must be self-sustaining and sufficiently stabilized to meet regional and local water, wetland, and riparian quantity and quality objectives. The vegetation and soils interact to (a) capture and transfer nutrients and sediment; (b) sustain infiltration and percolation which maintains the groundwater table; (c) stabilize the channel shorelines and banks; (d) sustain high water quality; and (e) promote biodiversity appropriate to the soils, climate, and landform of the area.
Natural Conditions that Maintain Healthy Riparian, Wetland and Open Water Systems
STANDARD: GRASSLAND, OAK WOODLAND AND BRUSHLAND
Vegetation structure and diversity must be self-sustaining and sufficiently stabilized to (a) capture and transfer nutrients, and sustain infiltration and percolation which maintains the groundwater table and promotes biodiversity appropriate to the soils, climate, and landform of the area; and (b) maintain or enhance viable, healthy, productive, self-sustaining and diverse populations of native and desirable wildlife species.
Natural Conditions that Maintain Healthy Grassland, Oak Woodland and Brushland
STANDARD: URBANIZED AREAS
Urbanized areas must incorporate native vegetation that both minimizes irrigation needs and encourages the establishment of native wildlife populations. In as much as urbanized areas also are used for recreation and leisure purposes, measures must be in place that (a) minimize attracting wildlife that may pose a risk to students, faculty, staff and the public; and (b) prevent dispersal of native wildlife species, especially sensitive species.
“Natural” Conditions that Maintain “Healthy” Urban Sites
Guidelines are presented by type of enterprise. Because these enterprises may occur over a variety of habitats, such as grassland, chaparral, riparian, etc., guidelines for specific habitats are considered covered by those for the various enterprises.
Guidelines for Livestock Grazing and Cropland Farming
Guidelines for Livestock Grazing
Guidelines for Cropland Farming
Guidelines for Urbanized Areas
Feral cats roaming the Campus Core are a special threat because of their proven detrimental effect on native birds (American Bird Conservancy 1997, Coleman and Temple 1993, 1995, Coleman et al. 1997, Davis 1995, Dunn and Tessaglia 1994, Fitzgerald 1988, Jurek 1994, Mitchell and Beck 1992, Roberto 1995). The termination of the existing “Cat Program” at Cal Poly, which supports the 200 feral cat colony on the Campus Core, is recommended.
RECOMMENDED AGRICULTURAL PRACTICES
Successful wildlife and wildlife habitat programs in agricultural environments are a “people process” that facilitates achieving a consensus. These programs should include the following elements (Warner and Brady 1994):
The following list is not all inclusive but attempts to provide an indication of the types of practices that Cal Poly land managers and staff should strive to implement.
Livestock Grazing Rotations and Time Management
Livestock grazing practices such as those suggested by the Center for Holistic Management and Allan Savory (Savory 1988) provide the basis for attaining and maintaining a healthy and diverse ecosystem. Management of time as livestock move through various paddocks should increase positive impacts on the lands and the plant communities.
This type of grazing management is not new to Cal Poly; Professor Robert Rutherford, Animal Sciences Department, makes use of holistic management on sheep grazing which has resulted in increased plant mass during the dry season, and improved water, nutrient, and energy flow processes, as measured by methods recommended by the Center for Holistic Management (Bingham and Savory 1990).
Sustainable agricultural practices conserve natural resources. Properly planned and managed crop rotations can provide a means of increasing crop productivity while enhancing the mineral cycle, water cycle and energy flow (Pierce and Rice 1988).
Green Manure and Cover Crops
Green manure crops are crops grown to improve soils and increase the yield of subsequent crops. Green manure crops also increase the organic matter in the soil, prevent leaching of nutrients from the soil during non-planting periods, mobilize the minerals in the soil and, if the crop is a legume, can increase the supply of nitrogen. Cover crops protect the soil surface while standing, and can be used as green manure crops. (Martin and Leonard 1967).
Multiple cropping, the practice of growing more than one crop in the same field during one year, represents intensified cropping which reduces soil erosion by providing soil cover for a longer period of time. Multiple cropping also enhances the soluble soil nutrient retention by providing root systems throughout the year and it increases the efficiency of water and nitrogen cycles. Various methods of multiple cropping can be implemented, depending on the needs of the land and the managers, such as intercropping, sequential multiple cropping, ratoon cropping, alley cropping. (Phillips 1999).
Soil losses due to erosion in US farmlands in 1982 were at a high of 3.4 billion tons of top soil per year. With the implementation of conservation tillage, this figure was reduced to 1.95 billion tons of soil per year by 1997. Practices such as ridge-till or no till reduce the amount of erosion and enhance nutrients in the soils. (Phillips 1999).
Contour-strip cropping is used primarily to control erosion by interspersing contour strips about 90-120 feet wide of close-grown crops between strips of row crops. This practice frequently results in an interspersion of cover types providing habitat for wildlife while maintaining the primary land use (Warner and Brady 1994).
Permanent bed buried drip irrigation provides control over water, fertilization and pests. This practice aids in minimizing the excessive use of water, minimizes runoff and prevents leaching of valuable nutrients from the soil.
Field borders, fence rows, and other noncrop farm areas can be planted with hedgerows of compatible native plants creating wildlife habitat areas that attract beneficial insects and provide competition against invasive weeds. With appropriate establishment and management techniques, hedgerows can provide a useful and attractive alternative to areas that would otherwise become sources of weed seeds (Robins 1998).
Tailwater ponds provide multi-purpose benefits. Without intervention, irrigation water turns into unrestricted runoff which removes topsoil from farmland and deposits it downstream, at unwanted places throughout the watershed and beyond. The construction of small double-pond systems that catch and store at least part of the runoff water provide a cost-effective solution to this widespread problem in farmlands. While the small pond works as a sediment trap, the second larger pond provides water storage, ground water recharge, water return systems, and plant and wildlife habitat (Robins 1998).
Ponds constructed in low hills collect and store storm runoff from small watersheds and provide watering sites for domestic livestock and wildlife. They can provide wintering or courtship habitat for waterfowl, and if properly vegetated, nesting sites as well. (Robins 1998)
Livestock and Wildlife Watering Points
Livestock water troughs on rangelands can be modified to provide watering points for wildlife by placing them at ground level or providing mechanical access. This practice does not deter the livestock from utilizing the watering site and provides much needed water to wildlife during the dry summer months. Guzzlers, a combination underground storage site for precipitation and watering hole for animals, can also be designed and constructed to provide water for both livestock and wildlife.
Attracting Beneficial Wildlife
Some wildlife species are beneficial to agricultural settings. For example, the Barn owl (Tyto alba) is often called the most beneficial bird in the world because of its hearty appetite for gophers, voles, mice and rats. Recent studies have confirmed their preference for gophers (van Vuren et al 1998), a well known agricultural pest.
American kestrels (Falco sparverius) and other raptors eat rodents, crop pest birds, insects and other crop pests, ranging in size from small field mice to large ground squirrels and rabbits. Birds of prey also scare away birds considered to be potential pests in orchards and vineyards. Installation of raptor perches provide raptors with sites to roost and search for potential prey, scaring away avian pests at the same time. Placement of appropriate nest boxes for Barn owls and American kestrels throughout farmlands should provide a steady supply of these birds throughout the year.
Insectivorous passerine birds also are beneficial to farmlands by preying upon insect pests. Placement of nest boxes for cavity nesting passerines causes no harm to the crops and should result in reduced populations of insect pests.
Bats are the most important predator of night-flying insects; for example, a single little brown bat (Myotis sp.) can consume up to 600 mosquitoes in an hour, and a typical colony of 150 big brown bats eats 38,000 cucumber beetles, 16,000 June bugs, 19,000 stink bugs and 50,000 leafhoppers as well as thousands of moths in a season. The twenty million Mexican free-tail bats from Bracken Cave, Texas, eat 25 tons of insects nightly (Robins 1998). Bat houses attract bats which benefit both the agricultural fields and the bats, which have declined dramatically in numbers in recent years due to habitat loss and human disturbance of roosts.
A fundamental element of successful management is planning. Successful planning requires monitoring, controlling and replanning. The presence/absence surveys performed by Cal Poly students provide a baseline for the wildlife status of these lands. On subsequent years, more quantitive surveys must be performed in order to assess the success or failure of new practices and methods.
Several types of annual monitoring surveys should be conducted throughout the properties to identify shortcomings in the recommendations and readjust future plans. The surveys can all be performed by Cal Poly students, providing them with ownership in the Plan and including them in the stewardship of the lands.
BIOLOGICAL MONITORING OF RANGELANDS
Good monitoring depends on a broad awareness of the state of the land. The status of community dynamics or succession, the water cycle, the mineral cycle, and energy flow within a given piece of land, will provide the information needed to evaluate the success or failure of livestock management practices. Monitoring methods such as those described by Bingham and Savory in Holistic Resource Management Workbook (1990) are recommended and are already being used by Cal Poly Professor Robert Rutherford, to assess the success of his sheep grazing methods.
WILDLIFE MONITORING OF THE PROPERTIES
Surveys should be conducted on a yearly basis to provide a continuous database of wildlife status on Cal Poly properties. The following are recommended survey protocols for various wildlife species and plants: