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HomeMy WebLinkAbout2000-01-18 City CouncilCity of Palo Alto ................................ M, agey, s Report TO:HONORABLE CITY COUNCIL FROMi:~CITY, MANAGER DEPARTMENT:~ COMMUNITY SERVICES DATE:JANUARY 18, 2000 CMR: 100:00 SUBJECT:ARASTRADERO PRESERVE RESTORATION ACCOMPLISHMENTS This is an informational report and no Council action is required. BACKGROUND On March I 1, 1996, i~fter numerous unsuccessful attempts to lease the house and barn structures on the Arastradero,Op.en Spac.~e Preserve for various purposes, the Council adopted a five-point plan for the disposition of the structures on the Preserve, and gave direction to staff to explore opportunities for leveraging City resources to ensure future maintenance and oversight of the Preserve. This direction included: 2. 3. 4. 5. Exploration of the possibility of a public/private stewardship; The removal of all building structures; Restoration of habitat in the areas where the structures were located; Exploring the potential for a new modest facility as a gateway to the Preserve; and Creating a mechanism to allow funding for some or all elements of the Preserve Management Plan. On May 13, 1996, Council adopted a work plan to implement the five-point program. This report provides an update on all five elements of the Council approved work plan. DISCUSSION Public-Private Partnership and Removal of Structures On April 28, 1997, Council approved a five-year contract with Bay Area Action to act as the steward of the Preserve and to implement action steps of the Arastradero Management Plan. Using the donated labor of 350 volunteers, Bay Area Action coordinated the demolition of the house, barn and other structures on the Preserve during July and August 1997. The materials from those structures were salvaged for reuse on other buildings, including the Preserve gateway facility. CMR: 100:00 Page 1 of 3 Habitat Restoration After building structures were removed from the former house site on the Preserve in 1997, Bay Area Action immediately set about restoring the site to native oak grassland habitat. In order to reduce the spread of non-native omamental trees and shrubs, plants including pyracantha, cotoneaster, shiny privet and olives were removed. Incidental stands of invasive weeds, such as yellow star thistle, purple star thistle, Italian thistle, bristly ox-tongue, teasel, broom, Harding grass and fennel were also removed by hand. (See Attachment A.). Soil under the buildings was extensively conditioned with mulch and natural nutrients. Volunteers spread and worked into the soil more that 1,400 cubic yards of mulch. In the fall of 1997, over 1,000 valley oak and coast live oak acorns, which had been collected from trees on the Preserve, were sowed around the five-acre house and barn site. Although many of the acorns were eaten by wildlife, by March 1999 hundreds of oak seedlings sprouted and were protected with wire cages or tree tubes. Since the site restoration project began’, student volunteers from Gunn and Palo Alto High Schools, coordinated by Bay Area Action, have donated more than 1,000 hours of labor in collecting and sowing native grass seeds. This directed study program has given students the opportunity to learn about wildlife habitat, preserving local biodiversity, and methods for propagating native grasses and oaks. Bay Area Action has also contracted with botanist and native grass specialist Tamara Kan to map both native California grasses and invasive weeds throughout the 609-acre Preserve. Restoration efforts have been so successful at the former house site and in other areas of the Preserve that the Peninsula Conservation Center Foundation awarded Bay Area Action a Business Environmental Award at the Foundation’s annual ceremony on November 12, 1999. Noting that volunteers have contributed a total of 3,500 hours planting over 3,400 native grass plugs and installing exclusion cages over oak seedlings, the Foundation lauded Bay Area Action for public involvement in its restoration projects. Bay Area Action, together with park rangers, continue to investigate effective methods of eradication and control of vast stands of invasive weeds in meadow areas of the Preserve. The effects of different methods of goat grazing, systematic mowing and black-tarp solar soil sterilizing continue to be monitored for long-term control of non-native, invasive plants. Gateway Facility Staff, together with architects Dav.id Arkin and Annie Tilt, have worked witha community task force to develop conceptual plans for a modest gateway facility, adjacent to the existing Preserve parking lot. Over the course of two years, various building configurations and site alternatives have been considered and evaluated. A design for a 1,150 square foot building, which would include restrooms, storage closets, a small meeting room and a small work space for the park rangers and stewards, was presented to the Architectural Review Board (ARB) in August 1999. A Site and Design application, together with a request for variance CMR: 100:00 Page 2 of 3 from the standard 200-foot setback, is awaiting Planning Commission review. Atter the plans have been reviewed by the Commission on January 12, 2000, ~e project will go to the ARB for design approval in February, then to Council for final project approval in March or April. Fu~aing Strategy When the conceptual plans for a. gateway facility are presented to Council in the next few months, staff will also present strategies for funding the construction of the building. In April 1996, $350,000 was contributed by Preserve neighbors and friends for the implementation of elements of the Preserve management plan related to restoration of the house site to open space and for the construction and maintenance of’a modest gateway facility. A portion of the Arastra Fund, which is managed by the Peninsula Community Foundation, has been used to finance the present stewardship agreement with Bay Area Action. Other than the initial endowment, the fund has not received any additional contributions. RESOURCE IMPACT Funds for the five-year Stewardship agreement with Bay Area Action, in~cluding restoration activities, is funded by the Arastra Fund of the Peninsula Community Foundation. ATTACHMENTS A - Vegetation Status at Three Former Structure Sites PREPARED BY: Greg Betts, Superintendent, Open Space & Science DEPARTMENT HEAD REVIEW~ PAUL THILTGEN Director, Community Services CITY MANAGER APPROVAL: Assistant City Manager CMR: 100:00 Page 3 of 3 Attachment A Vegetation Status at Three Former Structure Sites at Arastradero Preserve Karen Sue Cotter May 31, 1999 Overview: When the Arastraderoproperty was acquired by the City of Palo Alto there were three structures on site, a house, barn and caretaker’s cottage. Bay Area Action removed these structures during the summer of 1997 as part of its stewardship agreement with the City of Palo Alto. In the fall of 1997, all sites were cleared of debris and mulch was laid down to condition the soil, slow the movement of weeds into the site, and reduce the possibility of erosion. Community volunteers began to plant oaks in the Fall of 1997 and grasses were added the next year. The following report outlines the status of planted native vegetation, existing native vegetation, and non-native vegetation at the three former structure sites. 1. Former House Site Oak Plantings: In the fall of 1997, three hundred and ninety coast live oak and one hundred and thirty valley oak acorns were directly seeded into the soil. The survival rate was low; 45% for the coast live oaks and 2% for the valley oaks. There are several factors which may have contributed to the low survival rate. The mulch had only been in place for about two months so that it did not have time to condition the soil and the soil was still solidly packed. As explained in the Oak Propagation and Maintenance report, acorns that are gathered directly off the tree and then tested for viability have a higher survival rate than acorns gathered from the ground. During the planting here and at the barn site in 1997, these procedures were not yet in place, and acorns were gathered offthe ground and planted without checking for viability or adding gopher protection. These three things may have lowered the survival rate. In addition, high numbers were planted in the expectation that we would not be able to water this site and there would be a high die- off Ten of the sprouted acorns were placed in tree tubes, two are in cages and the remainder are exposed. Those acorns that sprouted in tree tubes were three to ten inches in height while those not in tree tubes were less than two inches in height after the first year. In addition to these acorn plantings, two 25 gallon valley oak trees were donated to the Preserve as memorial trees. Bay Area Action volunteers planted these trees and both are doing well. No oaks were planted in 1998 at this site. Existing Oak~: Numerous coast live oaks surround the former house site. They are of medium height and may have been planted for privacy at the same time as the house was built. The house site sites at the edge of an oak woodland. This oak woodland is one of the few locations on the Preserve containing black oak trees. The black oaks are large and in healthy condition. Coast live oak and valley oaks can be found here as well. Again, as in other woodland areas around the Preserve, there are lots of mature oaks and,lots of seedlingS, but not many trees in the mid age classes. Ornamental Trees: Four large eucalyptus with many, many small eucalyptus trees and sprouts (--60) were removed from the house site. This has opened up a vista on the west side. Privet, oleander, cotoneaster, and several other small ornamental trees have been cut and their stumps painted with herbicide. All trees are being monitored for re- sprouts. ,-~ Fruit Trees: Several fruit trees still exist in the former garden area and olive trees are found around the house. These trees will remain as they do not tend to spread easily and contribute to the historical aspect of the park. Coyotebrush: Coyotebrush are found on the north and west sides of the house. There are plenty of coyotebrush. Coyotebrush are sometimes considered an invasive plant in grassland-savannas by closing out the grassland. Others consider the spread of ’ coyotebrush a successional event as they protect young seedlings from predation; ¯ :~eventuallynumerous trees fill in the grassland and convert it to a forest. ~ ¯ Native Grasses: Approximately 1700 plugs ofElymus glaucus were planted in the old garden site of the house. Weeds were removed before planting but still returned, in particular Italian thistle and European grasses. The open, mulched area was deemed not ready for planting but may be seeded in the winter of 2000. Some native grasses are naturally occurring at the house site including Naseila lepida, Elymus glaucus, and Bromus carinatus. Muhlenbergia rigens, deergrass, is also present but it is possible that this was planted as an ornamental. 2. Former Barn Site Oak Plantings: Three hundred coast live oaks and one hundred valley oaks were planted at the former barn site. Only coast live oaks survived, of these, 135 survived. Six were placed in tree tubes and six are in deer exclusion cages. Fruit Trees: Seven olive trees line one side of the former barn site. Four fruit trees are across the road. Sprouts at the base of the olive trees are clipped when needed. Last fall the fruit trees (two apricot, green plum, and an unknown) were pruned to maintain health. Monterey Pine: Three Monterey pines trees appear to be infected with the Pine Canker that is hitting Monterey Pine through the San Francisco Bay and Monterey Bay areas. Since these trees are not native to this site, we are not intervening. Former Caretaker’s Cottage Site Native Grasses: The students from Palo Alto High School have been planting .native grasses at the cottage site in the winter of 97-98 and again in 98-99. They have planted Elymus glaucus, Nassella pulchra, and Nassella lepida. The Nasella pulchra planted as plugs, not directly seeded, are doing very well; the survival rate appears to be over 80%. Fruit Trees: Several fruit trees surround the site including one pear that was ~~ pruned in the fall of 1998. Eucalyptus: One large eucalyptus tree stands near the site. This tree is not putting out sprouts and is really too large for volunteers to remove. We will not be removing this particular eucalyptus. FN: Vegetation Status of Three Former S~ructure Sites Tabl~ 1:1997 and 1998 Acorn Location ~Spe~cies Barn site Coast live oak Barn site Valley oak House site ~ Coast live oak~ House site Valley oak Meadowlark Coast live Trail oak Meadowlark Valley oak Trail Meadowlark Blue oak Trail ~nd Seedling Plantings Year Number Method % Survival Planted Planted Fall 1997 300 Direct Acorn Fall 1997 Fall 1997 Fall 1997 Fall 1999 Fall 1999 Fall 1999 100 390 130 8 14 9 Direct Acorn Direct Acorn Direct Acorn Seedling planted, chicken wire at root and caged Seedling planted, chicken wire at root and caged Seedling planted, chieken wire at root and caged 12 caged/robe + 123 un protected = 45% 0% 9 caged/tubed + 59 unprotected = 17% 3 caged/tube = 2% 88% 89°,6 Table 2:1998 Oak Seedling Ca~ Upper Acorn Coast live Trail oak Upper Acorn Valley oak Trail Cone Madera Coast live Trail (before oak lake) Cone Madera Trail (before lake) East and West side of Caretaker’s Cottage Valley oak Valley oak ~ng and Monitoring Fall 1998 25 Fall 1998 Summer 1998 Fall 1998 Fall 1999 40 36 7 3O Existing seedling caged seedling caged Not protected, young trees coded and tagged Existing seedling caged Existing seedling caged 96% 98% Three trees found chewed near stem - gophers? 100% 96% References Koenig, W.D. and J. Knops. 1995. Why do oaks produce boom and bust seed crops? California Agriculture 49:7 - 12. ’ McCreary, D.D. How to grow California oaks, UC Cooperative Extension, Integrated Hardwood Range Management Program. UC Cooperative Extension at Berkeley, Natural Resources Program. Living.among the oaks: a management guide for landowners. Ordering Information Driwater, Inc. Phone 707-528-9283 Costs: Tube plus insert is $2.40 per quart. Insert refills are $1.40 per quart; shipping not included and can be substantial. Product Description: Dfiwater is a jelled form of water, that will remainin its jell’ed form until it comes into contact with the enzyme cellulaSe. Bacteria that produce the enzyme cellulase are present in most soils where there is moisture. Shelf life is 9 months. Tree Essentials Phone: 800-248-8239 Costs: Tubex Treeshelters are $2.33 / tube for a 3 ft. tube. Wooden support stakes are $1.31 / 35 inch stake. However to reduce shipping costs, wooden stakes can be bought at Orchard Supply for about the same price. Product Description: A tree shelter composed of plastic with perforations so shelter will burst as the tree stem widens. Shelter surround seedlings and protected them from deer, rabbit, and rodents. The shelter creates a green house environment that encourages seedling growth.