In honor of Michael Hamilton, the Director of BORR, who introduced me to the ecosystem and gave me the opportunity to do research there; to Jeff Wilcox, the Steward of BORR, who introduced me to the Reserve property and regularly transports me and my equipment between the city of Berkeley and BORR. Finally, in honor of my faculty supervisor, Professor Todd Dawson of the University of California, Berkeley, his wife Stephania Mambelli, an

d the members of the Dawson lab, from whom I get support, knowledge, and competence in performing research on stable isotopes from.

    The Blue Oak Ranch Reserve (BORR) habitat consists of Mediterranean, hilly oak savannah: mostly grassland with some shrubs and dispersed oak trees on it. Many oak trees on the BORR property are infested with parasitic mistletoes.

    The Reserve landscape is so hilly that without a 4WD you shouldn’t drive around by car. But if you have the opportunity to visit and drive the roads, it is amazing how much wildlife you might be able to see. Michael and Jeff showed me Blue Oak Ranch Reserve the first time. During my fist loop around the Reserve we saw a coyote (Canis latrans),  which was startled by the truck. We saw some black-tailed mule deer (Odocoileus hemionus columbianus)  grazing at the side and several birds like the red wing black bird (Agelaius phoeniceus) and the western bluebird (Sialia mexicana).

    But one of the most impressive appearances was this:

the artists are acorn woodpeckers (Melanerpes formicivorus).

The bird stores acorns in the trunks of several oak species to make sure that it has acorns available during the whole year and nobody else except itself has access to the stock. Acorns in a trunk - isn’t it interesting? When you look around BORR and have a look to all those dispersed trees in that open savannah grassland it becomes conspicuous to see no juvenile trees anywhere. Why not? Are there to many herbivores like the acorn woodpecker or the black tailed mule deer? Or is that due to its being used as a cattle ranch in the past? Nobody really knows, but it would be important to know in order to protect this habitat as an oak savannah.

    Another funny experience is to encounter the California quail (Callipepla californica). It’s not hard to believe why their nickname is “clown bird” because when you observe them moving with their tiny head plume drooping forward it makes you laugh because it looks funny. And for sure you’ll never meet just one of them; no, there are often whole families running like clowns and taking off afterwards with the sound of a bunch of propellers.

    At the beginning of my BORR time I was so impressed to see wildlife all the time, especially snakes (we have just six snake species in Germany (ring snake (Natrix natrix), smooth snake (Coronella austriaca), dice snake (Natrix tessellata), aesculapian snake (Elaphe longissima), crossed viper (Vipera berus) and aspic viper (Vipera aspis); you have to be very lucky to see just one, and all of them are non-venomous).

    Once, in May, when I was finished with my workday, I decided to take a bike ride and enjoy the sunset. On this ride I saw my first snake just by the wayside. It was a beautiful animal and since that day the biggest snake I’ve ever seen in wilderness. It was a California kingsnake (Lampropeltis getula californiae). Check out this little movie I recorded of that moment:

Afterward, I went to Cabin Pond, which is named for a cabin close by. I dropped the bike and sneaked around the pond so that I could observe garter snakes (Thamnophis couchi atratus) hunting the tadpoles of Pacific chorus frogs (Psuedachris regilla)

    On another day I wanted to leave the office (inside the barn) to use the restroom. When I left the room and stepped into the big hall in front I nearly stumbled across a gopher snake (Pituophis catenifer), which had entered the barn. Jeff released it outside afterwards.

Along with the previously mentioned non-venomous snakes there is one more I have seen. It’s the Western yellow-bellied racer (Coluber constrictor), a little thin snake with grey-green shiny skin. You usually see them warming up along any of several pathways at BORR, or you see them at Barn Pond, which is the closest pond to the barn.

Once, after my predawn measuring, I while hanging my sleeping bag on a clothesline, I heard a strange noise that I had never heard before. It was a noise that curdled my blood, and I was scared for a moment. The origin of the noise was near of my feet. Carefully, but also curious, I looked down at my boots and directly into the eyes of a rattlesnake ready to strike forward. As I looked down, I carefully stepped backwards to get away from a potentially dangerous situation. I told Michael the experience I had and he came to show me how to relocate a rattlesnake a snake forceps. 

As a German, I am not experienced with venomous animals, but I felt the natural respect one should have. If one follows the rules of respect, one will remain on the safe side. I also highly recommend wearing boots at the Blue Oak Ranch Reserve so that you are safely prepared for any situation. Another thing which makes you feel safe knowing that it’s a big effort for the rattle snake to produce the venom they use, and humans are not it’s prey. The snake tries to save the venom for its traditional pray like birds, rodents, or bunnies, for example. So it usually warns you with the noise of it’s rattle, but will only bite you if it fears for its own life. Hence, as long as you avoid provoking the rattlesnake, you are rarely in danger.

Rattlesnake are not the only dangerous animal you might hook up with. Inside the barn there are several black widows in the shadows: (13. Photo: black widow). But there are not only adventures possible with animals. In the kingdom of plants there is one species at BORR you should avoid to touch as much as you can: poison oak (Toxicodendron diversilobum).

    This oak savannah with all its wildlife illustrates a typical landscape of California, and for a typical landscape in California it is typical that it burns sometimes. Because no rain falls for roughly six months the vegetation dries out and becomes very sensitive to fire. Fire can cause a problem for humans and animals, but for the native vegetation it can signify a set-up for habitat, and  for nutrient availability as well.

We already know a lot about fire-adapted vegetation. Native plant species, in particular, seem to be adapted to fire; however some recent invasive species are not. Why are those species invasive then? Which plant species are invasive? How sensitive are they against fire and what role do they play within a burning environment? How big is the impact of fire to the nature and regeneration of a landscape? Which sequence of plant species appears within secondary succession after a burn? 

    It would be important to know about all that to get an idea about how to use fire in the future to protect biodiversity. It might be possible to use fire as a tool to defend native plant species from the invasion of neophytes. 

To answer some of those questions, controlled burns were conducted in the past on BORR. One of those fires was planned for the beginning of July this year and took place while we had the Asctec Falcon 8 available – a flying robot platform developed by the German company “Ascending Technologies,” which was used as a camera platform for taking aerial images. We are using this vehicle for my research to map the vitality of vegetation via aerial near-infrared photography, but because we had it available during the prescribed fire, we could record fantastic moving images from a view directly above the advancing flames of the fire.

    Unique for BORR as a research site is its closeness to San José; the Silicon Valley. All over the world Silicon Valley is well known for its companies of innovative technology like Tesla, for example. Another company, “Crossbow,” develops sensor nodes for measuring ecophysiological data like moisture and temperature from the soil. Recently, Crossbow installed several of these sensors, in a network, on BORR. Researchers can check the data they record easily via the internet. In addition, BORR has a real-time weather station whose data you even can view through the BORR homepage (look for advice for at the welcome page).

    With the support of these developments you can track the climate conditions within the BORR ecosystem and compare them to plant physiological data or behavior and development of animals. All in all it helps you to understand the ecosystem’s circles like they are in reality and not like the usual simulated lab trials. These conditions make BORR very special for of all kinds of ecological, geographical, or biological research.

About the research I do

    Maybe it’s time to introduce myself, now. I am Ute Runkel, from Germany, and I am here at BORR to do plant physiological research for my diploma/master thesis in collaboration with the Dawson Lab at the University of California, Berkeley (http://ib.berkeley.edu/labs/dawson/). I arrived in Berkeley at the beginning of May in 2009 for a six-month visit to collect data for my thesis and experience BORR`s wildlife. I related many of my wildlife encounters above; now, let me briefly explain the research I do.

    My research is directed at understanding the water demand on oak trees in different topographic conditions at two different elevations at BORR. I measure and compare the water potential and stomatal conductance of Californian valley oaks (Quercus lobata) and their hemiparasitic mistletoe (Phoradendron villosum). I perform these measurements with sensitive, specialized instruments in a two-hour diurnal sequence, every second week, at two different elevations. I also record air moisture, air temperature, soil temperature, and soil moisture that I download from Crossbow`s remote sensing and monitoring network (www.xbow.com). Finally, I collect leaf samples for stable isotope analysis of sugars (because of sugars are the product of photosynthesis) which I do afterwards in the Dawson lab back at UC Berkeley. I compare the data I described above with near infrared aerial images taken with a digital camera fixed on the flying robot platform Asctec Falcon 8 from the German company Ascending Technologies GmbH (www.asctec.de).

    Because of different elevations I mentioned at the beginning there are caused different structures at BORR. The lower elevation for example gets the fog from the Californian bay area and the higher level not.

For understanding the impact of fog at the water conditions for a water limited environment like BORR is, for understanding the water stress of plants due to water availability from soil and atmosphere during the day and the vegetation period for understanding the fire sensibility due to dry vegetation for example this kind of research is needed to protect biodiversity in future especially due to climate change and other human impact.

    There are still so many questions left. Questions about the absence of juvenile trees, about fire sensitivity, about interactions between species, about how the environment changes due to climate change, about the impact of invasive species and human treatment to the nature and how to protect biodiversity sustainable and some other questions more you might have an idea about.

Ute Runkel

Graduate Student

Universität Trier, Germany

October 2009