September 23rd, 2019 – Lab 05

This class and lab period (12:45 to 17:00) was used as another field trip to collect samples of M. guttatus and observe them in their habitats. Two areas were visited: the Red Rock Beach Cold Spring and a lower trail path near Muir Woods.

The spring is located near Stinson Beach and potable water from the Mount Tamalpais watershed flows through three pipes located in the area. The constant flow of water means that even though the spring is located in a rather sunny and hot area (especially on the day of the lab where temperatures continued to climb well beyond a normal 70 degrees), M. guttatus is able to flourish there.

M. guttatus’s “landing strip” for bees is also pictured below.

Because it’s pollinated by bees and the area of M. guttatus is limited by its access to water, the populations of M. guttatus in the area are likely inbred due to that limitation.

The second area had much more access to water–even though the water level of the creek is lower due to the fact that we’re just getting into fall and the winter rains haven’t fallen yet, there’s still enough water to support various populations of M. guttatus and facilitating their gene flow through water and pollination.

Some populations were located in areas that could be flooded before they properly disperse their seeds, which introduces questions on effective population size vs. population size and how conservation efforts should approach species in different areas.

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