DISCUSSION

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:

1. Watersheds are functioning properly in terms of surface and subsurface supplies and flows, as well as soils and parent materials;
2. Ecological processes are intact and the system is self-sustaining;
3. Water, air, and soil quality comply with or exceed state standards; and
4. Terrestrial, semiaquatic and aquatic habitats of all sensitive species are of sufficient quantity and quality to sustain viable populations.

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.

STANDARD: SOILS

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

• Presence of at least 70% ground cover, such as vegetation or rocks sufficient to protect sites from accelerated erosion.
• Presence of sufficient litter to protect the soil surface.
• Presence of sufficient, vigorous plant species diversity with a variety of root depths throughout the growing season, to stabilize and enrich soils, promote percolation, and provide adequate wildlife forage.
• Absence or minimal evidence of accelerated erosion such as rills, gullies, pedestaling, altered flow patterns, soil crusts/surface sealing, or compaction of subsurface layers.
• Presence of biological soil crusts in sites where ecologically appropriate.

STANDARD: SPECIES

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

• Presence of wildlife habitats, including seral stages, vegetation structure, and patch size sufficient to promote diverse and viable wildlife populations.
• Presence of a variety of perennial plant species age classes sufficient to ensure self-sustaining populations of perennials.
• Adequate plant vigor to ensure reproduction and recruitment of desirable plants when favorable climatic events occur.
• Presence of adequate spatial distribution and cover of plant species and their habitats to allow for reproduction and/or recovery after localized catastrophic events.
• Presence of an adequate diversity of plant species with various phenological stages and rooting depths on sites where ecologically appropriate.
• Absence or sufficiently low levels of non-native plants and animals to ensure that they do not adversely affect native species.  Noxious and invasive species must be contained at acceptable levels.
• Evidence that populations of special status species are healthy to ensure that their populations are stable or increasing in habitat areas sufficiently large and connected to support viable populations.
• Presence of adequate organic matter (litter and standing dead plant material) to protect the site and promote decompositional replenishment of soil nutrients.
• Presence of biological soil crusts that are not excessively fragmented, where ecologically appropriate.

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

• Presence of sufficient plant cover to protect banks and dissipate water flow energy during periods of high runoff.
• Presence of adequate age-classes and community structure of woody riparian plants which are appropriate for the site.
• Presence of sufficient overstory shading of water to provide optimal thermal conditions for fish, amphibians, and other riparian/wetland/water species.
• Presence of adequate inorganic and woody debris where ecologically appropriate to provide ground cover and minimize exposure of soil surfaces.
• Presence of a diversity of plant species with various phenological stages, rooting depths and root masses that are sufficient to stabilize stream banks and shorelines.
• Presence of “indicator” plant species which provide evidence that soil moisture characteristics are being maintained.
• Absence or sufficiently low levels of invader/shallow-rooted plant species, such that they do not adversely affect native, deep-rooted plants.
• Presence of adequate organic matter (litter and standing dead plant material) to protect the site and promote decompositional replenishment of soil nutrients.
• Presence of adequate streambank stability, bank angles, stream width, pool frequency, riffle frequence, bottom sediments, and suspended material, appropriate for the stream type and watershed.

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

• Presence of sufficient plant cover to dissipate water flow energy during periods of high runoff.
• Presence of adequate age-classes and communitiy structure of plants which are appropriate for the site.
• Presence of adequate inorganic and woody debris where ecologically appropriate to provide ground cover and minimize exposure of soil surfaces.
• Presence of a diversity of plant species with various phenological stages, rooting depths and root masses to stabilize banks.
• Absence or sufficiently low levels of invader/shallow-rooted plant species, such that they do not adversely affect native, deep-rooted plants.
• Presence of adequate organic matter (litter and standing dead plant material) to protect the sites and promote decompositional replenishment of soil nutrients.
• Presence of sufficient native vegetation to promote self-sustaining populations of native wildlife species which are appropriate for the site.
• Evidence of reproductive success sufficient to maintain appropriate native wildlife populations.
• Absence or low levels of vegetation and animals detrimental to native wildlife species.
• Presence of herbivores to cause positive impacts on soils.

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

• Presence of sufficient native or beneficial vegetation to promote self-sustaining populations of native wildlife species which are appropriate for the site.
• Absence or low levels of vegetation and animals detrimental to appropriate native wildlife species.
• Evidence of reproductive success sufficient to maintain appropriate native wildlife populations.

GUIDELINES

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

1. Livestock grazing and farming operations will be conducted to maintain and promote adequate vegetative ground cover, including live plant material and litter, both of which support infiltration, permeability, moisture storage and stability of soils, appropriate for the specific ecological habitats within the agricultural management units.  The ground cover should sustain soil microorganisms, plants, and animals which in turn support hydrologic, nutrient, and energy flow processes.
2. Native plant species are recommended for use in all revegetation or plant community enhancement projects when economically viable unless native species are incapable of achieving self-maintaining populations, or do not meet the objectives of educational programs.
3. The development of permanent or ephemeral water sources will likely maintain viable hydrologic and ecologic processes.

Guidelines for Livestock Grazing

4. Implement grazing programs that regulate both the timing and the intensity of grazing.  Uninterrupted, continuous season-long grazing should only be practiced if it produces a healthy, self-sustaining rangeland system.  Grazing plans should specify the season of use based upon appropriate plant phenology and geohydrologic processes.  On annual rangelands, target forage use levels should be defined to ensure that sufficient amounts of residual dry matter or standing plant material is maintained throughout the grazing season.  Exceptions to grazing plans should be made only during the green season when substantial regrowth is expected or if lower residual dry matter levels are needed to meet particular rangeland objectives, such as reducing competition for a desired species.  It should be noted that planning always anticipates replanning.
5. Timing of livestock use of perennial plants should be managed to avoid overgrazing and maintain soil cover.
6. Grazing must allow existing native species to complete that part of their life cycles necessary to sustain the spatial distribution of microsites that will maintain viable populations.
7. Use grazing systems that are compatible with the persistence of desirable species.  Grazing also should leave appropriate levels of plant residue which in turn promotes the persistence of desirable plants and animals.
8. Grazing management practices must promote the reproduction of riparian-wetland species that will in turn enhance energy dissipation, sediment capture, groundwater recharge, streambank stability, as well as hydrologic, nutrient, and energy flow processes.
9. Grazing practices should maintain a minimum vegetative cover on all stream-side, riparian and wetland areas at the end of the growing season to meet the requirements of bank protection, and sediment entrapment as well as promote new plant growth.
10. Water sources, wetlands and riparian areas should be fenced to manage impacts of livestock.
11. Salt blocks and other supplemental feed should be located away from riparian/wetland areas.
12. Livestock handling and management facilities should be located outside of riparian and wetland areas where possible.
13. Grazing plans must incorporate other land uses, such as widlife and recreation, etc.  Diverse uses must be coordinated so that overall use is not detrimental to rangeland health and productivity.

Guidelines for Cropland Farming

14. Farming practices that incorporate best management practices for nitrogen and water use in irrigated agriculture should include:  (a) limiting the application of nitrogen fertilizer to meet optimum crop needs; (b) timing the application of nitrogen fertilizer to coincide as closely as possible with periods of maximum crop plant uptake; (c) placing nitrogen fertilizer at the zone of maximum crop plant uptake; (d) applying only the amount of irrigation water required to meet crop needs to minimize waste of water and nitrogen through leaching; (e) timing the period of irrigation to minimize nitrogen loss by leaching and runoff; (f) using tillage practices that maximize water and nitrogen uptake by crop plants; and (g) using any other methods that minimize nitrogen loss from leaching, runoff, or backflow.
15. Farming practices that meet sustainable and economically viable agriculture criteria should be implemented on all croplands.  These practices may include planting cover crops or green manures, multiple cropping, intercropping, crop rotation, low till or no till where appropriate, contour-strip cropping, subsurface irrigation, drip irrigation, and planting hedgerows, buffer strips or other plants that increase “edge.”
16. Reduced use of pesticides and herbicides should be accompanied by increased use of Integrated Pest Management or other practices that encourage biological control of pests.  Examples of biological control measures include insectary and wildlife hedgerows, tailwater ponds, hill ponds, livestock grazing and animal impact, raptor perches, nest boxes for barn owls, raptors and insect eating birds, and bat houses.

Guidelines for Urbanized Areas

17. Revegetation projects in urbanized areas should use native plants common to the area and provide a diversity of species structure sufficient to encourage native animal species.
18. Non-native or detrimental animal species should be eradicated or minimized.  Feral domestic animals and introduced species, particularly roof rats and European starlings, must be monitored and controlled or removed in order to encourage self-sustaining populations of native animals.

             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):

1. Compatibility with the objectives of the landholder and with the primary use of the land.
2. A resolve by management and staff to succeed, supported by careful planning with realistic goals, costs, and strategies.
3. Cooperation among groups that influence the decision-making: the College of Agriculture departments of Crop Sciences, Animal Sciences and Natural Resources, and the Biological Sciences Department.
4. A program of information and education that includes positive reinforcement of desirable practices for participants, such as increased revenues or funding.
5. A thorough understanding of the ecology and behavioral biology of target wildlife species and the impacts of management programs on plant and animal communities.
6. A habitat development program that has proven successful at a practical level for targeted wildlife species, including the establishment of suitable plant communities and their maintenance over appropriate physiographic regions.  For example, the establisment of a saltbush (Atriplex sp.) hedgerow, a guzzler, and roosting and cover sites (brush piles), is a proven successful method of attracting California quail to a site.
7. Flexibility in time, space and resources to allow for buffering of the changeable physical environment, including weather, chemical and biotic factors, farm policies and programs, and land use practices of the landholders.
8. An ongoing evaluation and refinement process (with adequate financial support) that allows the program to respond to changing circumstances, and sufficient time to measure the degree of success of the program.  It should be noted that “time” refers to the long term success of the natural systems, which can be upwards of 40 years.
9. Stability of land ownership.

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).

Crop Rotation

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

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).

Conservation Tillage

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

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).

Subsurface Irrigation

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.

Hedgerows

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

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).

Hill Ponds

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.

Monitoring Guidelines

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:

• Small mammal surveys should be conducted in late spring to early fall, to account for peak abundances of adults and offspring.
• Reptile and amphibian surveys should be timed as appropriate for targeted species.
• Breeding bird surveys or census for resident breeders should be conducted during spring and early summer.
• Wintering bird surveys should be conducted during winter months, and could be tied into the annual Audubon Winter Bird Count.
• Migrant bird surveys are best conducted during late spring/early summer and again in fall/early winter.
• Nesting bird surveys are desirable for the riparian areas to determine the status and reproductive success of sensitive neo-tropical migrant species.
• Plant communities surveys should be conducted during mid- to late spring to assess productivity status and reproductive success.