Research update: July 2015

July was truly summer time up on the roofs – hot, muggy, sunny, buggy. I have to remind myself that all of these distracting things are the ones I miss during the cold winter months. The fact that the green roofs are pretty darn beautiful makes up for it!

My prairie plants are beautiful when they're blooming up on the green roof!

My prairie plants are beautiful when they’re blooming up on the green roof!

A native bee from the genus "Anthidium" visits my blooming prairie plants on the green roof.

A native bee from the genus “Anthidium” visits my blooming prairie plants on the green roof.

The good news is that most of the plants have enjoyed the rainy July and are still looking quite well. Some species that weren’t looking too good last year at this time now have flowers. This means that they’re reproducing (or trying to anyway) and that there is a good chance that their offspring will be around on the green roofs next year. With my experimental green roof trays, I conducted the water retention and evaporation experiment again that I’ve described in past blog posts. Conditions need to be totally dry to do this experiment and with the extra rain in Chicago this month, it was tough to schedule this in. But, with help, I just barely made measurements before it started to rain again and was able to get the data I need. I think I’ve collected enough data from this experiment this summer to make some interesting conclusions, but I’ll have to see. Maybe I’ll do it again next summer to compare the effect of the plants when they’re a year older? We’ll have to see.

A bumble bee, prairie grass and a green roof ecologist: a pretty picture on the green roof in July

A bumble bee, prairie grass and a green roof ecologist: a pretty picture on the green roof in July

For my other experiment that measures the movement of pollen between green roof populations, I continued to cover flowers in florescent dye and look for movement of the dye by pollinators. Unfortunately, after trying this experiment on 8 different days, I didn’t see any evidence that the pollinators were moving the dye. Does this mean that they’re also not moving pollen between plants on the green roofs and the ground? I’m not sure. I’ll collect seeds from these plants and use DNA-fingerprinting techniques in the lab this fall to find out more information. For now, the plants are finished flowering and have all been moved from their ground-level or roof sites to be watched until their fruits ripen and I can extract their seeds and DNA. Aside from being attacked by a colony of biting ants (over 20 of them that somehow crawled into my shirt – talk about uncomfortable!), things seem to be moving along.

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Research update: June 2015

I was as busy as a bee in June. Just like this carpenter bee I saw on one of my green roofs. It's too big to get in this flower's opening so the bee is actually poking holes in the flower with it's mouth to drink the nectar. So smart!

I was as busy as a bee in June. Just like this carpenter bee I saw on one of my green roofs. It’s too big to get in this flower’s opening so the bee is actually poking holes in the flower with it’s mouth to drink the nectar. So smart!

Summer, summer. The busiest and probably the most fun time of the year in terms of research. There’s lots to do out on the green roofs now that all the plants are growing and the pollinators are flying, but this is what I look forward to all winter long when I’m in the lab or working on my computer.

 

My green roof plots are starting to look like shortgrass prairies! I'll keep measuring them with my big 100-square grid.

My green roof plots are starting to look like shortgrass prairies! I’ll keep measuring them with my big 100-square grid.

 

I was happy to talk about the benefits of green roofs with the many visitors that came to the World Environment Day celebration at the Chicago Botanic Garden

I was happy to talk about the benefits of green roofs with the many visitors that came to the World Environment Day celebration at the Chicago Botanic Garden

This past month, I visited all five of my green roof research sites. I measured all the plants to see which ones had survived the winter and how much taller they were since last year at this time. I’m happy to say that there were a lot of survivors. Many of the plants are starting to bloom and some are bigger than last year. My prairie plots are actually starting to look like short grass prairies! After working on them for years, it’s quite nice to see!

I add the same amount of water to all my green roof trays when I measure their transpiration rate.

I add the same amount of water to all my green roof trays when I measure their transpiration rate.

This month, I also continued to work on some experiments with my green roof trays. I measured the transpiration rate in the experimental trays again – that’s a measurement of how fast water evaporates from the growing media and leaves the plants through their leaves. So far it looks like the prairie mixes in the trays are able to hold on to water in the same way that trays planted with non-native succulent plants can. This is a good sign because it means that native plants would still be useful for green roofs that are designed to hold rainwater.

My summer volunteer, Mike, and I clean the soil from the roots of the weeds we found growing in the green roof trays. It's a good project to do in the lab on a rainy day.

My summer volunteer, Mike, and I clean the soil from the roots of the weeds we found growing in the green roof trays. It’s a good project to do in the lab on a rainy day.

Some people think that using the non-native succulent plants will help prevent unwanted weeds from growing on a green roof, so this summer I’m measuring that too. It’s not too difficult but a little time consuming to measure this. Basically, I just pull out all the weeds, wash the soil from their roots, dry them in an oven and weigh the dried plant tissue. So far it looks like the common idea holds true – the trays that have succulent plants have fewer weeds. I’ll keep measuring this over the summer so I can make sure this trend is supported all year long (or maybe not… we’ll see).

And in June I also added a new experiment to see if pollinators are moving between my plants of interest on the roof and gardens on the ground. To do this, I placed some potted plants called Penstemon hirsutus or “hairy beardtongue” (I know – what a funny name!) on a green roof and at the base of the building on the ground. Then I painted the flowers on these plants with a powdered fluorescent dye. I returned to the plants at the end of the day with a UV light that helps me see even small specks of dye to see if any dye has been moved from the ground to the roof or vice versa. So far, there’s no evidence that this has happened but I’ll keep looking. If I see that the dye has been moved then I’ll know that a pollinator has been to both of my hairy beardtongue populations. I’ve got my fingers crossed!

This little syrphid fly visited this plant right after I finished painting the flower with florescent dye. I didn't find any red dye on the other populations from this little guy but I'll keep looking.

This little syrphid fly visited this plant right after I finished painting the flower with florescent dye. I didn’t find any red dye on the other populations from this little guy but I’ll keep looking.

Research update: May 2015

It’s hard to believe that spring has already come and gone. Yep, May is over and summer is officially here. It’s been a good past month for research with a lot of chances for me to collect more data on the green roofs and spread the word about the importance of native plants in cities.

The experimental green roof trays at Loyola University are looking good!

The experimental green roof trays at Loyola University are looking good!

Early in the month, I wrote a blog post of a different kind for the main blog at the Chicago Botanic Garden, describing different ways in which botanists like me can share their research with a wide variety of people. About a week later I was also able to “walk the walk” as they say, and give a presentation to the Will County Audubon Society about how native pollinators can be supported by using native plants in urban gardens like the green roofs I study. The audience was very attentive and had some great questions – they even built their own “bee condos” which are homes for native mason bees. Later in the month, I was an audience member myself at an event hosted by the West Cook County chapter of WildOnes, an organization that promotes awareness of native plants and animals. At their annual Native Plant Conference, I was able to hear Dr. Doug Tallamy speak – he is a real champion of native plants and both his presentation and his book, Bringing Nature Home, were really inspiring!

 

The temperature probes have all been read and are now buried in the green roof soil again. A little lady bug was also interested in my data!

The temperature probes have all been read and are now buried in the green roof soil again. A little lady bug was also interested in my data!

The native plants on the green roofs are still small but looking pretty good!

The native plants on the green roofs are still small but looking pretty good!

Out on the roofs, my research plants are looking good. For the most part. Of the 5 locations where I planted prairie plants, 4 of them are going strong and the other one… well… about 90% of the plants are dead. It’s a bit disappointing but that’s science for you. Not to worry though, I still have plenty of projects to keep me busy. In May, I finished collecting all of the temperature probes from the green roofs so I now know just how cold it got on all the roofs this past winter (very cold, in case you’re wondering!). I started recording data on all the plants that survived the winter and how much they’re grown since last summer. I’ll continue to gather these data for the rest of the summer, so stay tuned.

 

To record all the temperature data, I bring a computer up to the roofs. And then I cross my fingers that it doesn't rain.

To record all the temperature data, I bring a computer up to the roofs. And then I cross my fingers that it doesn’t rain.

I collected some interesting data about the evaporation rates in the green roof trays.

I collected some interesting data about the evaporation rates in the green roof trays.

This past month, I also started a new experiment, where I’m measuring the rate of water capture and evaporation from my experimental trays. I think that the trays with native prairie plants and the ones with the non-native succulent plants will be able to capture rainwater at the same rate. It is important for all green roofs to keep rainwater on the roof so it doesn’t run into already-stressed stormwater/sewer systems in the city. It’s also important for the green roofs to be able to release this water slowly in warm weather because this evaporation helps keep buildings cool. I measure evaporation rate by weighing wet trays every few hours. This was a great way to collect data but I learned that it’s also very physically demanding! Each time, you bend down to pick up a heavy (about 25-30 pounds) tray,  bend down to put it on the scale, bend down to pick it up, and bend down again to put it back in its place. Multiply that by 40 trays and 6 rounds of measurements in 24 hours… well you do the math on that. Let’s just say that there’s no need to go to the gym on these evaporation measurement days!

I carefully took about 600 tiny seedlings out of their petri dishes and put them into small test tube. I'll extract the seedlings' DNA soon.

I carefully took about 600 tiny seedlings out of their petri dishes and put them into small test tube. I’ll extract the seedlings’ DNA soon.

To get a break from the outdoor work, I also finished the task of germinating the seeds for my paternity experiment. I was hoping that the seedlings would get a bit bigger but they were just growing in this jello-like substance and they didn’t have the nutrients they needed to grow anymore. So I took about 600 of the seedlings, put them in tiny test tubes, and put them in a very cold freezer. I’m hoping that on rainy days this summer I’ll be able to start extracting their DNA and determine if pollen is moving between green roof to produce seedlings with parents from more than one green roof. There will be a lot more work involved with this experiment in the future.

And finally, this month I was officially inducted as a Northwestern University Presidential Fellow! I am honored to be part of an incredibly amazing group of graduate students and am really looking forward to learning from them as well as sharing my research with this talented group of fellows.

Research update: April 2015

Welcome spring – I think it’s finally here to stay!

April was a good month and things are finally starting to look a little more exciting up on the green roofs. For a botanist, “exciting” means that the plants are back!

The experimental seeds in the incubator are getting bigger!

The experimental seeds in the incubator are getting bigger!

My little germinating seeds in the incubator are beginning to grow up a bit. But even more exciting is that after a long winter (well, a typical winter – but in Chicago this always tends to feel a bit long), I am happy to report that many of the prairie plants that I planted on the green roofs last year or the year before are coming back. A lot of the species seemed to have made it through the winter and are starting to pop up through the surface of the rocky green roof soil. Among the dried leaves from last year are little bits of green – exciting to see!

The prairie plants are starting to grow again on the green roofs!

The prairie plants are starting to grow again on the green roofs!

Blades of a grass called "little bluestem" are starting to emerge around last year's dried up leaves.

Blades of a grass called “little bluestem” are starting to emerge around last year’s dried up leaves.

 

The winter data from the temperature probes has been recorded and they're ready to record data all summer long.

The winter data from the temperature probes has been recorded and they’re ready to record data all summer long.

It’s still a bit too early in the year to start taking measurements of the plants (that task will start next month) but I was able to find all the temperature probes that I buried in the fall. I dug them up, downloaded their data onto my computer, and re-buried them so that they keep recording temperature data all year long. It was interesting to see that it got pretty cold up on the roofs over the winter. Sometimes my probes were even encased in blocks of ice and continued to record 0 degrees Celsius (that’s 32 degrees Fahrenheit, or the freezing point of water) for many days and nights in a row. These green roof plants are a lot tougher than I am – no way I would have survived all winter up on the roofs!

 

The honey bees are buzzing on the green roofs again.

The honey bees are buzzing on the green roofs again.

In addition to the plants coming back to the roofs, some of the animals are back too. Although they are not part of my research, it’s still fun for me to see honey bees buzzing around their hives, geese nesting and little killdeer laying eggs on the roofs. Sometimes the green roofs where I work are not accessible to other people and I’m collecting data by myself so it’s nice to know that I’ve got a couple green roof buddies… even if they’re all of the flying variety.

 

 

A killdeer nest on a green roof. I can't wait to see the cute little baby killdeer!

A killdeer nest on a green roof. I can’t wait to see the cute little baby killdeer!

A mother goose keeps her eggs warm on one of the green roofs where I have my experiments.

A mother goose keeps her eggs warm on one of the green roofs where I have my experiments.

Dr. Kevin Rice visits from California and talks about his plant science research.

Dr. Kevin Rice visits from California and talks about his plant science research.

As the outdoor data collection season starts to ramp up, I’ve also been doing some indoor work, especially giving and organizing presentations. I had the privilege of helping to organize a visit from Dr. Kevin Rice, a plant scientist from the University of California in Davis. Along with some smaller meetings and social events, Dr. Rice gave a presentation about his research. It was really interesting to learn from a more experienced scientist, especially hearing about how he and his research team have been saving blue oak trees from severe drought in California.

"Design your own green roof" worksheets from my new activity book, Growing UP in the City, are ready to bring to a group of 5-8 graders.

“Design your own green roof” worksheets from my new activity book, Growing UP in the City, are ready to bring to a group of 5-8 graders.

I also gave four presentations myself this month, three of them in Pittsburgh through the Phipps Conservatory and Botanical Gardens as a current Botany in Action Fellow. During my trip to Pittsburgh, I talked to about 120 students at an all-girls school, a group of interested community members, and various Phipps staff members.

 

 

I bring a variety of resources and some of my research tools to my presentations so people can get a better visual of what I discuss in my presentations.

I bring a variety of resources and some of my research tools to my presentations so people can get a better visual of what I discuss in my presentations.

Back in the Chicago area, I gave a presentation to a local group of beekeepers who were interested in learning more about native pollinators and native plants. It was a pleasure to be able to talk about my research to such a diverse group of people and I look forward to doing a lot more of this type of science communication in the future.

I had a great time talking with a group of 5th-8th graders in Pittsburgh about my life as a botanist.

I had a great time talking with a group of 5th-8th graders in Pittsburgh about my life as a botanist.