Ancient Blue Oak Project

Year 1 Briefing

Mature blue oak trees dominate this grassy knoll at the Wright Mountain site in the southern Diablo Range near New Idria, .

R.D. Griffin, D.W. Stahle, J.R. Edmondson, D.J. Pollan, L.R. Gibson, M.K. Cleaveland, and M.D. Therrell

University of Arkansas Tree-Ring Laboratory December 2, 2004

Figure 1. This map illustrates the current status of the blue oak tree-ring collections. The northern study area will be sampled in year two (2005), and gaps in the network of sites will be filled in year three (2006).

Table 1. Blue oak (Quercus douglasii) tree-ring chronologies under development for California. Each blue oak collection is listed with the three letter code, county, lat.-long. coordinates and elevation. We also list the mean inter- series correlation and mean sensitivity for the fully replicated chronologies at each site. The number of dated/measured radii and the inner and outermost dates are also listed for the randomly sampled and fully replicated chronologies.

Random Full Site Name & Code County Latitude Longitude Sample Sample Elev.(m) Series Intercorr. Mean Sensitivity Random Radii Full Radii

Coast Ranges

Eel River (EEL) Mendocino 39.82140 123.07726 610 0.638 0.233 42 *1535-1996

Clear Lake (CLR) Lake 39.01132 122.81276 427 0.693 0.255 71 *1642-1996

Mount Diablo (DIA) Contra Costa 37.87920 121.96580 182 0.774 0.449 56 *1645-1997

Mary’s Ranch (B24) Santa Clara 37.39546 121.77755 475 0.648 0.320 37 42 1823-2003 1697-2003

Pacheco Pass (PP2) Merced 37.03683 121.20917 434 0.792 0.478 34 140 1763-2003 1510-2003

Rock Springs Ranch (B27) San Benito 36.48966 120.87765 1067 1379-2003

Pinnacles (PN2) San Benito 36.47948 121.17927 487 0.815 0.467 70 *1578-1996

Hastings Reserve (HAS) Monterey 36.39475 121.54715 755

Wright Mountain (B32) Fresno 36.33613 120.51533 1219 0.814 0.494 25 61 1625-2003 1409-2003

Indians (IND) Monterey 36.11681 121.46189 646

American Canyon (AC2) San Luis Obispo 35.27694 120.26893 561 0.800 0.458 71 *1577-1996

Figueroa Mountain (FIG) Santa Barbara 34.73524 119.99709 1036

Sierra Nevada

Finley Lake (FIN) Tehama 40.26828 121.86393 853 0.543 0.218 93 *1515-1996

Feather River (FEA) Butte 39.52391 121.44773 305 0.588 0.254 70 *1637-1996

American River (AR2) El Dorado 38.75652 121.11288 167 0.666 0.311 40 128 1778-2003 1603-2003

Don Pedro (DPR) Tuolumne 37.70640 120.43320 274 0.639 0.312 28 *1669-1992

Millerton Lake (JOA) Madera 37.02984 119.67536 137 0.811 0.438 28 *1710-1996

Dennision Peak (DEN) Tulare 36.28572 118.77582 1132 0.644 0.290 38 84 1650-2003 1596-2003

Dead Mule Saddle (DMS) Tulare 35.90800 118.66680 1237 0.714 0.318 39 91 1669-2003 1448-2003

Kern River (KR2) Kern 35.53226 118.62754 715 0.841 0.501 38 86 1783-2003 1585-2003

* to be updated and expanded

Figure 2. This flowchart documents the steps performed in a Geographic Information System to arrive at the Ancient Blue Oak Predictive Model. Two primary source digital map datasets were utilized in this model development. The alphanumeric code in the bottom right corner of each box represents the file name prefix assigned to each of the datasets generated during this process.

Figure 3. (A) The blue oak woodlands greater than 40 acres in size from the 40-100% canopy closure classes from the PMR classification were clipped to the extents of the Pillsbury blue oak distribution map. This map represents the dataset ‘D3’. (B) The ancient blue oak woodland predictive model consists of areas mapped in ‘D3’ greater than 640 acres in size. 196 discrete polygons are mapped, totaling 1,038 square miles (dataset ‘D3a’). (C) The 640 acre blue oak predictive model is being assessed at 30 randomly selected sample points. (D) Roughly 15% (156 square miles) of the blue oak woodlands mapped in the 640 acre predictive model lie on public conservation lands in California.

Figure 4. Six new blue oak tree-ring chronologies from central and southern California.

Figure 5. Winter season Salinas River streamflow at Paso Robles, California from 1940 – 2003 (mean = 1059 ft3/second). This timeseries correlates with nearby blue oak chronologies between 0.64 to 0.77.

Figure 6. Old-growth blue oak savanna at Pacheco State Park in the Diablo Mountains of the central Coast Ranges.

Figure 7. Ancient wind sculpted blue oak trees near the pass at Pacheco State Park.

Figure 8. A colossal blue oak on Red Hill at the University of California Hastings Natural History Reserve in Monterey County, California.

Figure 9. A stately blue oak tree at Rock Springs Ranch in the Central Diablo Range, San Benito County, California

Figure 10. David Stahle extracts a cross section sample from a standing dead blue oak tree at Rock Springs Ranch. Dead wood was used to extend the Rock Springs Ranch chronology (still in progress) 300 years back in time (1378-2003).

Figure 11. A blue oak savanna at Figueroa Mountain in the Los Padres National Forest in Santa Barbara County, California.

Figure 12. An overage blue oak tree graces the landscape at Figueroa Mountain.

Figure 13. Blue oaks at Folsom Lake State Recreation Area () in the foothills of the north-central , El Dorado County, California.

Figure 14. Undergraduate research assistants Jesse Edmondson and Justin Pollan sample randomly selected blue oak trees at Dennison Peak in Sequoia National Forest, Tulare County, California.

Figure 15. A savanna opening in the blue oak woodlands below Dennison Peak in the Sequoia National Forest.