HOME > Projects > Summer ’05 Research Projects

Bernard Field Station Use Summer 2005

Research Projects

Request No.: 05C0C2AEC6
Submitted on: 6/2/05 at 5:30 PM
User: Hannah Alberts, Undergraduate student, Scripps
E-mail: halberts@scrippscollege.edu
College phone: 210-391-5713
Instructor/Advisor: Scot Gould, 73197, gould@jsd.claremont.edu

Number in research group: 1
Dates: 06/02/2005 to 08/01/2005
Frequency: Other - two or three times throughout the summer
Time of day: Morning, Afternoon
Areas to be used: oak forest, corner, infirmary, north field
Facilities or equipment needed: None
Will any plant or animal species be studied? yes - black widow spiders (Latrodectus hesperus)
Will plants or animals be collected? yes
Will vertebrate animals be collected or manipulated? no
Will markings or flags be used? no

Description of research project: I will be collecting 8 to 10 black widow spiders for use in my summer research project. My intent is to analyze a sample of each spider's silk with an atomic force microscope to better understand both silk and web structure.

Request No.: 05BA785B39
Submitted on: 5/23/05 at 1:13 PM
User: Stephen C. Adolph, Faculty member, HMC
E-mail: adolph@hmc.edu
College phone: 607-1872

Number in research group: 6
Dates: 05/25/2005 to 08/31/2005
Frequency: Several-days/week
Time of day: Morning, Afternoon, Evening
Areas to be used: oak forest, infirmary
Facilities or equipment needed: We may sometimes need electrical power via an extension cord (we'll let you know).
Will any plant or animal species be studied? yes - Sceloporus ocidentalis
Will plants or animals be collected? no
Will vertebrate animals be collected or manipulated? no
Will markings or flags be used? yes - We may use small flags to indicate the locations of each of our sensors.

Description of research project: Project title: LizardNet

PI's: Steve Adolph (Biology, HMC) and Mike Erlinger (Computer Science, HMC)

Funding: Howard Hughes Medical Institute Grant to Harvey Mudd College (David Asai, PI; internal grant to M. Erlinger and S. Adolph); Harvey Mudd College Center for Environmental Studies, internal grant to M. Erlinger and S. Adolph.

This project involves developing a wireless computer network that will perform environmental sensing. The sensors will measure temperature microclimates that western fence lizards would experience in their natural perch positions, such as on tree trunks. Most of the network development will take place at HMC. We will then install a small number (4-6) of "motes" at BFS to measure environmental temperatures and transmit the data back to Harvey Mudd. Motes are devices comprising a microcontroller (CPU and radio transmitter/receiver), sensors (in this case, thermocouples), and a power supply (AA batteries). Each mote is about the size of 2 decks of cards. The motes will be located in inconspicuous places, probably on tree trunks. Initially, we plan to have them in place for much of the summer. If our project is successful, we would like to have the motes in place permanently.

In conjunction with getting environmental temperature data, the LizardNet team members will spend a few hours observing western fence lizards at BFS, mainly so that we can choose sensible locations for the temperature sensors. We may also collect lizard activity data to compare with microclimate data obtained via the network.

The goal of this summer's pilot project is to develop a working network that transmits and stores real-time microclimate temperature data. Ideally, our "proof-of-concept" project will lead to further projects involving environmental monitoring at BFS.

Request No.: 05B826C0CB
Submitted on: 5/19/05 at 7:10 PM
User: Daniel Martinez, Faculty member, Pomona
E-mail: dmartinez@pomona.edu
College phone: 9096077926

Number in research group: 4
Dates: 05/01/2005 to 12/31/2009
Frequency: Other - Sporadically
Time of day: Dawn, Morning, Afternoon
Areas to be used: pHake Lake
Facilities or equipment needed: None
Will any plant or animal species be studied? yes - Hydra spp.
Will plants or animals be collected? yes
Will vertebrate animals be collected or manipulated? no
Will markings or flags be used? no

Description of research project: Two hydra species inhabit pHake lake: the brown hydra Hydra oligactis and the green hydra Hydra viridissima. Both species have been included in a molecular phylogeny currently being built in the Martinez Lab at Pomona College. Hydra from pHake lake are collected sporadially for training purposes.

Request No.: 05B77902E6
Submitted on: 5/18/05 at 4:49 PM
User: Joan M. Leong, Faculty member, Cal Poly Pomona University
E-mail: jomleong@csupomona.edu
College phone: 909-869-4050

Number in research group: 4
Dates: 05/25/2005 to 08/31/2005
Frequency: Several-days/week
Time of day: Morning, Afternoon, Evening
Areas to be used: eastern CSS, north field, south field
Facilities or equipment needed: Outdoor classroom,
Will any plant or animal species be studied? yes - Centaurea melitensis; Tocalote
Will plants or animals be collected? yes
Will vertebrate animals be collected or manipulated? no
Will markings or flags be used? yes - Flags will be placed in areas marked above to locate experimental plants

Description of research project: The agricultural weed Centaurea melitensis, commonly known as tocalote or Maltese starthistle, has a mixed breeding system, unlike its notorious relative yellow starthistle (Centaurea solstitialis). Tocalote is considered to be of lesser invasiveness (List B of the California Invasive Plant Council), but could be a more serious invader than is currently recognized (California Invasive Plant Council 2005). Centaurea melitensis is distributed over much of the western U.S., and in California occurs in at least 44 counties (CalFlora 2005) throughout the California Floristic Province and in some desert areas. The largest populations in California occur predominantly in central-western and southwestern areas of the state (Gerlach and DiTomaso 2000).

The mixed breeding system of Centaurea melitensis consists of cleistogamous capitula or flower heads that are self-pollinating (by autogamy) and chasmogamous capitula that have the potential to be cross-pollinating, but are also capable of selfing (Poras and Alvarez 1999, 2000b; Gerlach and Rice 2003). The relative amount of selfing versus outcrossing that occurs in chasmogamous heads of C. melitensis is not well characterized, and current studies yield conflicting results. Poras and Alvarez (1999, 2000b) note morphological adaptations of the florets of chasmogamous heads to insect pollination, as well as pollen/ovule ratios consistent with an outcrossing breeding system. They observed insects from four orders visiting C. melitensis heads; the most commonly observed floral visitors were bees. However, they also found a high selfing rate among chasmogamous florets. Thorp et al. (2000) also recorded the presence of bee visitors to C. melitensis heads on Santa Cruz Island. Pollinator exclusion experiments and seed set comparisons reported by Barthell et al. (in press) also suggest low outcrossing rates for chasmogamous C. melitensis capitula on Santa Cruz Island. In contrast, chasmogamous heads of C. melitensis in a Northern California population were shown to be pollen-limited (Gerlach and Rice 2003). In particular, their experiments indicate that a type of selfing (geitonogamy), which requires pollen transfer between neighboring florets of the same individual, significantly increased seed production in chasmogamous heads. The need for geitonogamous or "neighbor" self-pollen is also consistent with the fact that individual florets of chasmogamous heads are protandrous, so release of mature pollen precedes stigma exertion and maturation. Therefore, limited opportunities may exist for a floret's pollen to contact it's own receptive stigma lobes.

The previous studies suggest two ways in which insect pollinators could contribute to C. melitensis chasmogamous seed production: through cross-pollination of florets or through "neighbor" selfing of florets, geitonogamy. The latter mode of pollination, geitonogamy, is often overlooked as an insect-mediated pollination process, as the progeny produced through geitonogamy are genetically indistinguishable from those produced through autogamy, which does not require insect mediation. The goal of this project is to better understand and quantify the role of insect pollinators in chasmogamous seed production of Southern California populations of Centaurea melitensis. I will focus on three primary research objectives: (1) What fraction of the total seed production is produced by cross-pollination? (2) What fraction of the total seed production is produced by geitonogamous pollination? (3) What kinds of insect pollinators are likely to contribute to C. melitensis seed production? Information gained from this study will provide basic knowledge on the reproductive biology of a common invasive weed, which in turn, can be applied to inform biological control measures that seek to reduce seed reproduction in this weedy species.

Methodology

Research Objective 1: What fraction of the total C. melitensis seed production per capitulum is produced by cross-pollination?

In one or two field populations of C. melitensis I will set up a pollinator exclusion experiment to determine what proportion of seeds produced/capitulum is due to outcrossing. Twenty randomly selected plants per population will receive three treatments each. (1) Just prior to flowering, a randomly selected chasmogamous flower head will be bagged or caged with 1 mm mesh netting to prevent visitation by insect pollinators (as in Barthell et al. 2001). After all florets have finished flowering the netting will be removed. (2) On the same plant, a second randomly selected head of roughly the same developmental stage will be assigned as the control or open treatment. This capitulum will be open to insect pollination. (3) A third randomly selected head on the same plant will be assigned to an outcross hand-pollination treatment. This flower head will also be open to insect pollination and will receive supplemental outcross pollen by hand pollinations over a period of four days as described in Gerlach and Rice (2003). A couple of weeks later, seed heads will be harvested and the numbers of seeds and ovules will be counted in the lab. Previous studies using similar bagging treatments have not found evidence for a bagging effect on either C. melitensis or C. solstitialis (Barthell et al. 2000, 2001, in press).

Comparison of the seed production of open versus bagged heads will yield an estimate of the amount of seed set produced by cross-pollination. Comparison of the seed production of open versus open and outcross hand-pollination capitula will indicate whether C. melitensis seed production is outcross-pollen limited. Additionally, weights of entire seed heads (receptacle, all seeds and residual floral components) may be measured, as Barthell et al. (in press) have demonstrated a significant relationship between numbers of viable seed per head and seed head weight.

Research Objective 2: What fraction of the total C. melitensis seed production per capitulum is produced by geitonogamous pollination?

To accomplish this objective I will add another treatment to the experiment outlined above. In addition to the three treatments already discussed, I will add a bagged and self hand-pollination treatment to a fourth capitulum. On the same plant, a fourth randomly selected head of roughly the same developmental stage will be bagged with netting just prior to flowering. When floret stigmas are receptive, they will receive supplemental self pollen by hand pollinations over a period of four days as described in Gerlach and Rice (2003). Self pollen will be added by transferring pollen from other flowering capitula on the same plant to the stigma lobes of the selected head. The mesh bagging will be removed during hand-pollinations and immediately replaced afterwards. After all florets have finished flowering the netting will be removed. Comparison of the seed production of bagged versus bagged and self hand-pollination capitula will estimate the proportion of seed production that is possible through geitonogamous pollination.

Research Objective 3: What kinds of insect pollinators are likely to contribute to C. melitensis seed production?

Insect visits to C. melitensis flower heads will be observed within marked 2-m x 4-m quadrats located randomly within flowering populations or patches. Each quadrat will be observed for 15-20 minutes and the number of visits made by each kind of insect pollinator will be recorded. Two or more observers will record observations at different quadrats. At one or two sites, 6-8 quadrats will be monitored for visitation between 0900-1700 h. Because insect visitation activity varies with time of day, observations will be blocked into four time periods to control for temporal variation: early 0900-1100, middle 1100-1300, afternoon 1300-1500 and late 1500-1700. Each quadrat will be observed once per time period. The sequence of quadrat observations will be randomized for each time period and day of observation. Visitation observations will be made every 10-14 days during the flowering season of C. melitensis. Weather data such as wind speed, relative humidity, and temperature will be recorded during each observation period

Field identification of many native insect visitors is not possible at the species level due to their small size and similar coloration patterns. Therefore, during observation periods, native pollinators visiting flowers may be categorized according to taxonomic order, family, genus, or other visually distinctive features. Voucher specimens of insect visitors to C. melitensis flower heads will be collected by net and pinned for subsequent identification and examination of pollen loads. Where appropriate, insect specimens will be sent to taxonomic specialists for confirmation of genus and species level identifications.

Request No.: 05B6313A04
Submitted on: 5/16/05 at 3:05 PM
User: Hal Van Ryswyk, Faculty member, HMC
E-mail: hal_vanryswyk@hmc.edu
College phone: x73908

Number in research group: 2
Dates: 05/23/2005 to 07/29/2005
Frequency: Several-days/week
Time of day: Morning, Afternoon
Areas to be used: central CSS, eastern CSS, south field
Facilities or equipment needed: None
Will any plant or animal species be studied? no
Will plants or animals be collected? no
Will vertebrate animals be collected or manipulated? no
Will markings or flags be used? yes - We will continue to use the flags marking the Foothill transcept in area 2, plus establish a Mills transcept in area 10.

Description of research project: We are measuring lead in soil from vehicle emissions. We are establishing baseline values in the undisturbed chaparal adjacent to US 66 and Mills Ave.

Request No.: 05AF0DD08D
Submitted on: 5/5/05 at 1:52 AM
User: Mikel Grenzner, Undergraduate student, HMC
E-mail: mgrenzner@hmc.edu
College phone: x70550, Other phone: 425-422-0011
Instructor/Advisor: S. Adolph, (909) 607-1872, adolph@hmc.edu

Number in research group: 2
Dates: 05/16/2005 to 07/22/2005
Frequency: Daily
Time of day: Dawn, Morning, Afternoon, Evening
Areas to be used: north field, south field
Facilities or equipment needed: We just need the field area to place our pots. We hope we can use the area close to the hose, to make watering easy. More information can be found with the attachment sent to the webmaster.
Will any plant or animal species be studied? yes - The pairs of species we intend to use are English ivy (Hedera helix) and Prairie sagewort (Aralia californica), Pennyroyal (Mentha pulegium) and Yerba Buena (Satureja douglasii), Fountain grass (Pennisetum setaceum) and California Meadow Barley (Hordeum branchyantherum), Pampasgrass (Cortaderia selloana) and Pacific hairgrass (Deschampsia holciformis), Turnip weed (Rapistrum rugosum) and San Diego wild cabbage (Caulanthus heterophyllus). If seasonal variability prevents us from obtaining any of the above, we have a long list of alternative species to draw from.
Will plants or animals be collected? yes
Will vertebrate animals be collected or manipulated? no
Will markings or flags be used? yes - We just need to mark off the area in which our pots will be sitting.

Description of research project: The main goal of our research is to examine the effects of common sources of pollution on the establishment of native and exotic species. This research will be done in two parts. The first part deals with the establishment of native and exotic species in polluted environments while the second part directly observes the establishment of invasive species in the BFS, in relation to distance from sources of run off pollution.

In the first half of this project, we will prepare soil with differing types and amounts of pollution. Our choices in pollution come from an EPA guide to non-source point pollution (http://www.epa.gov/owow/nps/). We plan on using two sources of pollution found predominantly in urban and suburban areas. The first source will consist of a combination fertilizer and pesticide, while the second source will consist of motor oil, gasoline and antifreeze. We chose to use combinations together to both simulate real world conditions and to cast a wide net looking for plant-pollutant interactions. We will utilize three concentrations of each pollutant group. For the fertilizer/pesticide combo, one will consist of half application strength, one consisting of application strength, and one consisting double application strength. For the hydrocarbons group, a similar process will be used, with a local measurement used as a standard. A control group consisting of no added pollution will also be used.

As far as the soil itself is concerned, we will be using an even mix of potting soil, and soil from the Field Station. The soil will then be sterilized with an autoclave. The pots themselves will hold one species, to eliminate the issue of plant competition. We plan on using a total of ten species, halt native and half exotic. They will consist of fast growing annuals, from herbs to grasses. Half of these will be native species to the region of southern California while the others will be exotics. Native and exotic plants will be paired by functional traits, so grasses with grasses and so on.

The pairs of species we intend on using are English ivy (Hedera helix) and Prairie sagewort (Aralia californica), Pennyroyal (Mentha pulegium) and Yerba Buena (Satureja douglasii), Fountain grass (Pennisetum setaceum) and California Meadow Barley (Hordeum branchyantherum), Pampasgrass (Cortaderia selloana) and Pacific hairgrass (Deschampsia holciformis), Turnip weed (Rapistrum rugosum) and San Diego wild cabbage (Caulanthus heterophyllus). If seasonal variability prevents us from obtaining any of the above, we have a long list of alternative species to draw from.

Given two sources of pollution, three concentrations, ten species, controls and replicates, we will be planting 480 pots. This includes 6 replicates per species/pollutant combination. These will lie in the open, in a clear area of the Bernard Field Station, arranged in a manner reducing systematic error. We feel that the outdoor conditions, when combined with the polluted soil will best simulate the conditions exotic and native species would face in a non-laboratory conditions. To protect the soil of BFS from harm, we will use plastic sheeting to prevent pollutants from leaching into the soil.

Plants will be watered on a regular basis, and will be protected by a mesh screen to prevent animals from consuming or damaging the experiment. At the end of each week we will record the height of each plant. Once the plants have been growing for around seven to eight weeks, we will bring them back into the lab at HMC. This will occur before the seeds are ready, to prevent any contamination at BFS. The above ground biomass will be harvested, and dried in an oven to constant mass. When compared to the controls, we will then be able to gauge the effects of the different pollution sources, and see who fared better over all between the natives and the exotics.

The second half of the study will consist of a series of observations on invasive plants to be taken while our other plants are growing. Once our plants have been placed in the field, we will be examining the established invasive species at BFS. We will be primarily concerned with the identification of invasive species, and their proximity to the perimeter of BFS. Additionally, we will be looking for areas of plant biodiversity and plant monoculture. We feel that this data can help us draw conclusions from the first half of our experiment, and provide useful data to plant ecology in the future.

Request No.: 0594E8D5AC
Submitted on: 2/1/05 at 9:39 AM
User: Marius van der Merwe, Faculty member, JSD
E-mail: mvandermerwe@jsd.claremont.edu
College phone: 909 621 8758

Number in research group: 1
Dates: 02/20/2005 to 06/01/2005
Frequency: Several-days/week
Time of day: Dawn, Evening
Areas to be used: eastern CSS, oak forest
Facilities or equipment needed: Floor space for storage of large container with sand.
Will any plant or animal species be studied? yes - California ground squirrel (Spermophilus beechyi)
Will plants or animals be collected? no
Will vertebrate animals be collected or manipulated? no
Will markings or flags be used? yes - I will use feeding stations (consisting of artificial food patches) at different points in the habitat. A food patch will simply be a plastic container filled with sand, into which food is mixed.

Description of research project: Predatory threats often vary with features of the environment, some areas favoring predators and some favoring prey. Dangerous areas may be under-utilized whereas safe areas may be over-utilized, resulting in patterns of habitat use shaped by risk or fear. Areas that differ in predation risk can be visualized as a landscape of fear, with valleys representing areas of relative safety, and peaks areas of relative danger. The foraging cost of predation can be measured at specific locations in the environment using the giving-up-density of food of a foraging animal in artificial food patches. The aim is to extrapolate from such measurements to spatial 3-D maps representing landscapes of predation cost or fear, and specifically, to gain insights into factors affecting predation risk, and therefore habitat use, of California ground squirrels (Spermophilus beechyi).