Photos

Field and greenhouse experiments

Open top chambers are an inexpensive and effective way to increase temperatures in the field. Miguel and Vince are testing how warm the insides feel relative to ambient temperatures.

Liam is trying his best to instal temperature loggers in the open top chambers.

Liam is making sure that our plants stay hydrated! He thinks that all we do at work is 'spray the plants'. The light here looks purple because we use special fixtures that emit the wavelengths of light that plants like best (blue and red, which makes purple).

Are those ghosts? Nope, they're whole-plant pollinator exclusion bags! Chamaecrista fasciculata has indeterminate growth and produces flowers along all of its branches, so covering the entire plant was the only option for excluding pollinators. I purchased all of the bridal tulle and hula hoops I could find within 20 miles to construct these.

Excluding pollinators from plants to allowed me examine flowering schedules in the absence of reproductive resource investment.

I simulated future thermal regimes in the field using the Experimental climate warming arrays at the Koffler Scientific Reserve at Jokers Hill. The blue netting keeps the birds from eating the Chamaecrista fruit!

To see if rainfall drives pulse flowering in Chamaecrista fasciculata, I manipulated precipitation regimes using rain-out shelters.

To examine the impact of climate change on natural plant populations, we are simulating climate change with early snow-removal treatments.

Early-snow removal treatments reduce snowpack, advance snowmelt, limit soil moisture availability, and expose plants to frost events.

To keep track of individual seeds in the field, we carefully plant them in to these grids. Each cell has a unique coordinate and each grid is assigned a unique identifier.

Is seed dormancy affected by climate change? I'm exploring that question now by excavating seeds buried in a snow-manipulation experiment. To differentiate between a dormant and non-viable seed that didn't germinate, I dissect them and submerge them in a stain that will turn respiring tissue pink. This is what dormant embryos look like after they have been stained!

This is (part of) the Rocky Mountain Biological Laboratory, or RMBL. The work that we do on Boechera stricta is based out of this field station.

The Rocky Mountain Biological Laboratory is nestled at the foot of Gothic Mountain in western Colorado.

Study species

Chamaecrista fasciculata flowers are unique and interesting - they are enantiostylous, the large petal acts as a landing pad for bumble bees, and the curved petal is rigid and ensures that bees access the flower from the side where the style is located.

Chamaecrista fasciculata is touch sensitive; its leaves will close in a few seconds after you touch or water it.

Chamaecrista fasciculata disperses seeds through explosive pod dehiscence! If you're not careful, you can bump in to your plant and feel and hear yourself losing data...

Individuals of Chamaecrista fasciculata from populations across two latitudinal gradients. From left (north) to right (south): Minnesota, Pennsylvania, Illinois, Virginia, Missouri, North Carolina (2 plants). This photo makes the cline in branchiness and plant height very apparent.

A Bochera stricta seedling planted in a grid in the field. For reference, the white square around it is 1 cm x 1 cm!

We plant Boechera stricta in to the field as both juvenile rosettes and seedlings.