Palos Verdes Biogeography Projects Summer 2009

One goal of this project is to create a floristic key for the Palos Verdes Peninsula, which does not depend on flowers to make identifications. There are many excellent floral keys around, and Southern California is covered by several. Due to the visual dominance and species uniqueness of floral displays, keys tend to focus on them early on in the "troubleshooting" process. Unfortunately, plants do not obligingly flower all year round, and it can be quite a hardship slogging through several keys and the Munz and Jepson floras to figure out what a plant could be if it isn't that species' blooming season -- and many plants have their own unique season not necessarily shared by their neighbors! This problem can be quite annoying for any teacher planning a field trip focussing on biogeography, ecology, botany, or environmental issues (some of us find that particular species "slip our gears" between field trips!).

Species lists exist for Palos Verdes (Brinkmann-Busi and Lipman et al.). With somewhat over 225 species recorded here, the list may be small enough to create a floristic key for Palos Verdes that does not depend on flowers early in the process of identification. Such a key, if workable, would be of great utility to educators planning field trips, to docents, and to residents and visitors to the Peninsula.

Another goal of this project is to identify "classic" specimens of as many species as possible, with GDEP research interns using GPS to pinpoint their locations and taking 3-5 digital photographs of each individual and its context. This will provide a useful tool for users of the key.

A big theme this summer, as it was last summer, has to do with the prevalence of exotic species on the Peninsula, especially those that strongly displace native species, degrade the habitat for native animal species, and/or alter fire régimes in a way that might further stress native species. Some of the worst offenders will be mapped in the field to assist in managing them.

An interesting question has come out of last year's Palos Verdes biogeography project, led by Dr. Paul Laris, and the thesis research of Geography graduate student, Ms. Kyra Engelberg. Can a native species behave like an invasive species? Ms. Engelberg's work with the Palos Verdes Peninsula Land Conservancy has raised this issue with respect to lemonadeberry, Rhus integrifolia, and GDEP 2009 will collect field data on the sizes and ages of some of the more spectacular clumps and try to pick them out of a series of ærial photographs that Dr. Laris has. We'll try to evaluate several hypotheses to account for R. integrifolia's behavior locally: Might it be the monospecific climax for the area where fires have not recurred? Might it actually not be native to the Peninsula (though it is native to the other coastal mountains of Southern California)?

Dr. Paul Laris' project last summer focussed on identifying parcels in the field, which his examination of air photos and archives indicated had been plowed in the 1920s to the 1950s. These sites "pop" out in terms of the extreme abundance on them of invasive species, notably mustards. We'll be working on this issue, too, establishing the mechanisms by which long-ago mechanical disturbance is still visible in terms of the vegetation mix. Some of the invasives involved noticeably shorten fire recurrence intervals. They are more tolerant of fire disturbance than the Peninsula's coastal sage scrub, so the combination of mechanical disturbance, invasive species, and altered fire régimes might pose a greater danger to CSS and the animals that depend on it than previously realized.

Goals for Summer 2009 include:

• Completion of the key by Dr. Rodrigue during GDEP 2009
• Testing of the key's utility, ease of use, and clarity by GDEP research interns
• Entering the "classic" specimen plants' locations as a layer into the vegetation GIS produced by Dr. Laris' team
• GDEP research interns preparing the photographs to consistent dimensions, file sizes, and resolutions in Photoshop and uploading the optimized images onto a web-based archive
• Construction by Dr. Rodrigue of a web page for the flora of Palos Verdes, featuring an interactive GIS map for accessing information about the plants
• The work done by GDEP research interns in Summer 2009 will be the basis for follow-on work by GEOG 442 students in Fall 2009 and Spring 2010 to acquire photos of the GDEP-located plant specimens at different times during the year to create an archive of their appearances throughout the year
• In Summer 2010, the completed key and its interactive web page will be presented by GDEP to the Palos Verdes Peninsula Land Conservancy and other interested parties
• In May 2010, the 2009 GDEP interns will be asked to present their work to the Southern California Academy of Sciences and/or the California Geographic Society and/or in November 2009 to the Southern California Conference on Undergraduate Education. This dissemination is important to let the educational community know of the new resource for their own field-trip planning activities.