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Final Report, September 1998

Vegetative Cover Monitoring, Public Perception Survey, and Public Outreach Programs for
Chino Winds Demonstration Project

(Phases I and II):
Use of BMPs on Arizona Rangelands to Minimize NPS Discharges from Grazing Activities


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A Coordinated Resource Management Plan was implemented on the Yavapai Ranch that commits the Ranch, the U.S. Forest Service and cooperating organizations to work together the manage the entire area of the ranch as a whole, including both private and public lands, for common goals.

Structural improvements completed during the Demonstration Project provide the water and fencing needed to control when and length of time that livestock graze specific areas of the Ranch. New improvements include 54 miles of fence, 30 miles of pipelines, 21 storage tanks, 33 drinkers, and one well.

The number of livestock on the ranch, and when and for how long they graze each pasture is planned each spring and fall based on forage availability and resource objectives. Records of livestock use in each pasture are maintained.

A major reduction of approximately 50% of the total livestock on the ranch was made in the fall of 1996, due to extremely low rainfall and lack of forage growth in the fall, winter, and summer of 1995-96.

Vegetation canopy cover (> 1 cm height) measured in the spring of each year on all three key areas varied annually in response to seasonal precipitation and season and intensity of livestock utilization. As is to be expected, the canopy cover generally was lower for the grazed plots than for the ungrazed plots, especially on the loamy bottomland site in the spring of 1996 where the canopy is primarily annual weeds that were trampled by livestock grazing the area in the fall of 1995 and very little regrowth due to the dry winter and spring of 1995-96.

Green vegetation and litter cover at the soil surface for grazed and not grazed plots on the limy and loamy upland sites in 1998 were similar to the 1992 baseline data and were relatively stable over years.

A large increase in litter on the soil surface was an immediate response in 1993 to both the time controlled grazing and no grazing on the bottomland site. The cover on the soil surface of this site for both the grazed and not grazed plots was near 90% in 1998 compared to about 20% in 1992.

An increase in canopy cover on the ungrazed plot on the loamy upland plot from 45% in 1992 to 81% in 1998 was dramatic in visual appearance, but the increase in cover at the soil surface from 1992 to 1998 was little different than for the grazed and high animal impact plots.

The 1995-96 drought was the dominant influence on the vegetation for the monitoring period, 1992-1998. A major death loss of plants on both grazed and ungrazed plots on the limy upland site occurred in 1996 in response to the 1995-96 drought. Locoweed, snakeweed, and pingue, all considered cool season growth plants and plant not normally grazed by livestock, suffered severe death loss. Some sideoats grama plants also died on this site at this time. A population of sand dropseed plants that was becoming established on both the grazed and ungrazed plots of the loamy bottomland site from 1994 to 1996 did not survive to the fall of 1997. Key areas established in Deep Well and Powerline Pastures on October 11, 1995 provided baseline data prior to the extremely low rainfall year (1995-96). As was the case for the locations on the Demonstration Cell, cover on the soil surface remained near 60 to 70% total cover from 1995 through 1997. Plant species that grow in the cool season were greatly depleted in 1996 compared to 1995. The species are: squirreltail, western wheatgrass, rabbit brush, snakeweed, globe mallow.

Simulated runoff volume from all the grazed and ungrazed plots on the limy upland and the grazed, animal impact and ungrazed plots of the loamy upland were similar at about 36% of the simulated rainfall amount of 33 mm over 30 minutes for both the 1992 and 1998 cover data. Soil surface cover was similar, averaging near 60%, among these plots in 1992 and 1998.

The amount of canopy cover provides the perception of how well the soil is protected from erosion, but the amount of canopy cover on the plots, at least for the two years for which WEPP simulations were run, was not correlated to either water runoff or sediment yield.

Simulated runoff for both the grazed and ungrazed plots on the loamy bottomland were similar, averaging about 27% of the simulated rainfall amount. Runoff was predicted as slightly less in 1998 than in 1992 and appeared to be explained by the higher litter on the plot surface in 1998 than in 1992.

Simulated sediment yield from the plots was variable among plots and 1992 and 1998 data. The soil surface random roughness indices appeared to be the input data that best explains the difference among treatment plots.

Further research is needed to determine if the sensitivity of the WEPP model to the random indices is a realistic representation of the real world. Further research also is needed to refine calculations of site specific soil parameters used within the model along with surface cover to calculate runoff and sediment yield.

Baseline cover data were collected September 23, 1996 at the site of a proposed commercial fuelwood sale and an adjacent area not to be cut as a key area monitoring sites within the Cienega Demonstration Cell. The area that was proposed to be cut had not been cut by April 28, 1998.

An historical exclosure is present within the Demonstration Cell, and observations inside and outside of the exclosure are key areas for monitoring vegetation change. The exclosure was constructed in 1939 and cattle have been excluded from the area within the exclosure since construction. Data in 1940 and 1953 show that the vegetation within the exclosure and outside were both dominated by blue grama. In 1994 blue grama dominated outside the exclosure and squirreltail was the dominant species within the exclosure. Much of squirreltail inside the exclosure did not survive the 1995-96 drought. Further data collection on soil characteristics and soil surface cover are warranted at these key areas to determine long term livestock exclusion on potential for sediment yield from a site.

A sample of 286 individuals in Yavapai county were interviewed in the baseline survey of public perceptions and opinions regarding topics related to the Cino Winds Demonstration Project on the Yavapai Ranch. Approximately 90 percent of the sampled individual perceived the rangelands in Yavapai county as both interesting and appealing. The most frequently expressed negative perception of rangelands was that they were eroded (42 percent). Only 35 percent saw a specific connection between erosion and water quality in local streams.

Public participation in vegetation monitoring and Yavapai County Extension office workshops and field trips have provided public outreach for the Demonstration Project.

Fall and spring monitoring of vegetation and soil surface cover documented some annual changes due to season precipitation and livestock use, but soil surface cover, except for the loamy bottomland site, was similar in 1998 to what it was in 1992 for both ungrazed and time control grazed plots. Vegetation in the historical exclosure was similar in 1953 to what it was in 1940. In 1994 the vegetative communities were different inside and outside the exclosure. Documenting change associated with precipitation and management is expected to be a long term effort for the Yavapai Ranch environment.

The Yavapai Ranch Coordinated Resource Management Plan and the Demonstration Project structural improvements are in place. The Ranch and many of the Coordinated Resource Management Team are committed to continue the management and monitoring that has been started with the Demonstration Project.

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