Santa Cruz Island Reserve

04 Aug, 04 AM - 09 Aug, 08 AM

Not studied since the early 1930s, plant macrofossils on Santa Cruz Island in the Channel Islands, CA have the potential to show the change in vegetation communities in response to climatic change at the Pleistocene-Holocene boundary (~11,500 years ago). On the western side of the island in Cañada de los Sauces (Willow Canyon) are preserved log and fossil remains deposited in sedimentary layers that were probably part of alluvium deposited by an ancient stream in the canyon (Figure 1). The most abundant species of plant remains in the alluvium are those of conifers and dictyledons, as documented in a preliminary list published by Chaney and Mason (1934). Analyzing and identifying these plant macrofossils will open a window to the past, documenting to show what vegetation communities existed on the Channel Islands during the Pleistocene at the time of the last glacial maximum. Studying these macrofossils also has implications for understanding the rainfall, temperature, and soil type on the islands at this time period. Chaney and Mason found samples of Bishop pine (Pinus muricata), Douglas-fir (Pseudotsuga menziesii), and Gowen cypress (Cupressus goveniana) on Santa Cruz Island. These species, aside from Bishop pine, no longer grow on the island. The closest Douglas-fir stand is found 100 km to the northwest in Santa Barbara County. Most of these closed-cone species are now found in northern California and Baja California. Evidence suggests that as climate changed into the Holocene, vegetation changed on the island to what is now coastal shrublands and grasslands (Anderson et al., 2008). Better understanding the vegetation that grew during the Pleistocene, locating a preserved transition between the Pleistocene and Holocene, and comparing this to the vegetation seen on the island today will help to clarify the impact current climate change may have on present day ecosystems. It also will assist in clarifying aspects of the current controversy surrounding the potential changes associated with a hypothesized asteroid impact at the transition (Israde-Alcántara et al., 2012; Pigati et al., 2012; Pinter et al., 2011). To accomplish this research, I plan on detailing the complete stratigraphy of a number of sites in Cañada de los Sauces. In addition, I will also complete a survey in the canyon to provide the accurate elevations and locations of the macrofossils with their respect to distances into the canyon and the height above present sea level. Samples collected will consist primarily of sediments from levels that contain abundant plant remains, but I will also collect wood fragments from the section, also to be identified. All of samples and equipment will have to be carried into and out of the canyon each day. In order to make any sample collections, I will have to apply for a collecting permit of the site from the Santa Cruz Island Reserve (http://nrs.ucop.edu/reserves/santac_cruz_island/santa_cruz_island.htm). Most specimens will be identified in reference to the NAU Herbarium and Dr. Andersons plant collection, but wood specimens will be identified at the Forest Products Laboratory in Madison, WI. Samples will then be radiocarbon dated to determine their age through Direct AMS at Accium Biosciences. References: Anderson, R.L., Byrne, R., and Dawson, T. 2008. Stable isotope evidence for a foggy climate on Santa-Cruz, California at ~16,660 cal. Yr. B.P. Palaeogeography, Palaeoclimatology, Palaeoecology, 262: 176-181. Chaney, R.W., Mason, H.L., 1934. Studies of the Pleistocene Palaeobotany of California. Carnegie Institute of Washington Publications, 415: 1-24. Israde-Alcaintara, I., Bischoff, J.L., Vazquez, G.D., Li, H.C., DeCarli, P.S., Bunch, T.E., Wittke, J.H., Weaver, J.C., Firestone, R.B., West, A., Kennett, J.P., Mercer, C., Xie, S., Richman, E.K., Kinzie, C.R., Wolbach, W.S. 2012. Evidence from central Mexico supporting the Younger Dryas extraterrestrial impact hypothesis. PNAS Early Edition, 1-5. Pigati, J.S., Latorre, C., Rech, J.A., Betancourt, J.L., Martinez, K.E., and Budahn, J.R. 2012. Accumulation of impact markers in desert wetlands and implications for the Younger Dryas impact hypothesis. PNAS- Early Edition, 1-5. Pinter, N., Scott, A.C., Daulton, T. L., Podoll, A., Koeberl, C. Anderson, S.R., and Ishman, S.E. 2011. The Younger Dryas impact hypothesis: A requiem. Earth- Science Reviews: 106, 247-264.

Visit #35018 @Santa Cruz Island Reserve

Approved

Under Project # 28724 | Research

DIsappearance of Coastal California Forests on Santa Cruz Island at the Pleistocene-Holocene Boundary

graduate_student - Northern Arizona University

Reservation Members(s)

R Scott Anderson Aug 4 - 7, 2014 (4 days)
Ken Scientist Aug 4 - 7, 2014 (4 days)
Scott Anderson Aug 4 - 9, 2014 (6 days)
Monique Belanger Aug 4 - 9, 2014 (6 days)

Reserve Resources(s) | Create Invoice

Vehicle Use - By Day 1 Aug 4 - 9, 2014
Vehicle Mileage 72 Aug 4 - 9, 2014
Christy Ranch Facilities Use 2 Aug 4 - 9, 2014
Christy Ranch Set-Up (subsequent visits) 1 Aug 4 - 9, 2014
Christy Ranch Facilities Use 2 Aug 4 - 7, 2014