For our first day we did direct observations with the goal of practicing your observational skills along with plant ID for our four plant groups of focus: C3 grasses, C4 grasses, legumes, and forbs. The group I was placed in looked at sites ALF East and ALF West.
ALF West was our first stop. This site featured a fence line and natural hills that has been cut through by a gravel road. The site consisted mainly of C3 grasses. In the ditch and closer to the road we were able to see a handful of different legume and forb species, but the site lacked diversity in general. Due to this lack of diversity and over taking of C3 grasses the site appears to have not had a prescribed fire for a few years. Fortunately, we were able to see some emerging coneflower which is always exciting!
ALF East was very different in diversity in comparison to ALF West. Based on visual observations diversity was a lot higher and most of the plant species found belonged in the legume and forb plant groups. With diversity being so much higher, and the plot featuring several plants that have appeared to have been scorched by fire it was our assumption that ALF West had experienced prescribed fire in recent years. The landscape of ALF West not too visually different other than it featuring a corn field behind the prairie area unlike on ALF East.
My name is Liam Poitra and I am excited to be joing team echinacea for a second consecutive year. This summer I am hoping to deepen my knowledge further about the plant and animal interactions that make our prairies such dynamic ecosystems. For the first day with the whole team back, we spent the morning touring sites with Stuart and learning about common plants on the prairie. In the afternoon we worked as small groups setting out to remnants to familiarize ourselves the outcomes of burning on the prairie. Brittany, Ning, and I set out to observe 2 prairies 1 burned (yohw) and 1 unburned (loefflers corner). Yohw burned this spring was very short still all the plants were ankle height or lower and the soil was completely exposed without a thatch layer to cover it. However several plants showed great growth such as the heart shaped Alexander which seems to have already put out many leaves and was by far the plant to return the most vigorously at the site. Loefflers corner on the other hand showed plenty of brome and a thick thatch between plants. Both places seemed to have similar species however the forbs were easier to pick out at yohw
Today we explored two prairie sites, one which had been burned recently and one which had not. It was startling to see the dramatic difference in the plants inhabiting each site, and the mosaicism that shows in the landscape of the burned site.
ALF West, the site that hadn’t been burned, was overwhelmingly dominated by non-native brome grass, while at the site that had burned, ALF East, we observed more diversity in grass species, as well as a very noticeable absence of the brome grass where it looked like the site had burned. We also noticed the impact of the fire on shrubs and trees in ALF East, and compared that to the new saplings coming up in ALF West. There were two Echinacea angustifolia plants that we observed in ALF West, growing in the gravel on the side of the road.
The shiny heads of the brome grass in the ditch bordering the road, with the burned area behind it
After reviewing the LCW site, I noticed lots of brome near the road, but not necessarily in the site. There were clustered lead plants and low grasses in the middle of the site. There were a few trees scattered throughout the site. I spotted 2 echinacea plants. The LCW site is on lower ground near a ditch and on the left side, there was a large hill. I could also see dry plants covering the soil. My group came to a conclusion that this site was not burned in the spring.
At the YOHW site, I noticed there was less plant diversity than at the LCW site. At this site, there were no tall grasses at all. The grasses and plants were very short. I saw one echinacea tag. There were medium sized shrubs that looked burnt or dried out. There was also no dry plants on the soil, which leads me to believe that this was burnt in the spring. On one bush, I could see the part near the stem was burnt or dried out, but the part near the leaves had growth. Also, at the YOHW site, I could see the soil more clearly becuase the grasses were more spread apart.
The YOHW site has much shorter grasses and plants than the LCW site. At the YOHW site, I could see the soil much clearer than at the LCW site. I suspect this difference is due to the fact that the YOHW site was burned this spring.
The Alf west site had multiple echinacea angustifolia plants and a lot of tall cool season grasses. There was a natural hill, fencing, power lines, and a road by the area.
ALF East
The Alf east site had no echinacea angustifolia plants that I could see, but I saw a lot of diffrent forbs and legumes. There were also many cool season grasses which where more tall and dense near the road. There was a natural hill and trees in the area. I also saw signs of burning, for exsample there were left over burnt shrub branches and the plant life was more diverse.
Conclusions
The two sites differed. The west site which had echinacea angustifolia was less diverse compared to the amount of diffrent plants seen in the East site. The ALF East site was clearly the site that was burned. The leftover burnt branches and the great amount of plant diversity compared to the West site shows this.
In the lab today we were talking about Fibonacci numbers. Somehow these numbers (1, 1, 2, 3, 5, 8, 13, 21, 34, …) relate to Echinacea flowerheads. The number of ray florets (aka “petals”) on ab Echinacea head are often Finbonacci numbers, like 13 & 21, but they are often not those numbers. This Wikipedia page describes the relationship between Fibonacci series and florets on flowerheads.
Here are some images of Echinacea heads from the summer (top views). Do you see any interesting patterns?
Top view of head of Echinacea angustifolia. How may ray florets? Click image to enlarge to see pattern of disk florets.Head of Echinacea angustifolia with two beesTwo heads of Echinacea pallida. This species is not native to Minnesota, but it was planted by accident in a prairie restoration in our study areabeetle on head of Echinacea angustifolia
I am an aspiring botanist. I am specifically interested in ethnobotany/economic botany.
Statement
I am from Newton Grove, NC. In my spare time I like to read, listen to sad music, cook, and try/make new hot sauces
Projects
During my Fall ’23 externship, I processed wmSP and wmS0 heads to be used for Wyatt Mosiman‘s thesis. I used the resulting reproductive data from said heads with the corresponding plant measure data to assess the relationship between cumulative vegetative effort over 5 years (2018-2022) and reproductive effort and success in 2023. The path to my materials is: ~/Dropbox/ccExterns2023/ioHarris
I want to study biology and learn more about plant science.
Statement
I am from Houston, Texas.
In my spare time I like to play the trumpet and play games.
Echinacea Research Project
Introduction
The goal of my externship was a research project about Echinacea where I asked two questions and then conducted a study. The first question is does having taller head height increase pollination rates by insects in Echinacea. My second question is does having more heads increase or decrease pollination by insects in Echinacea.
Background
Echinacea is insect-pollinated mainly by bees and other studies I found have shown that in plants like C. behrii and V. thapsus taller heads are more likely to be pollinated because they are more visible to pollinators. Since we don’t know if head height plays a similar role in Echinacea I am conducting this study to see if there is any correlation between head height and pollination rates in Echinacea.
Another study I found saw more heads leading to greater pollination rates. However, Echinacea is self-incompatible, meaning it can not pollinate itself, unlike the plants in that study so its possible that if an insect stays at a single Echinacea plant with more heads instead of moving on to other plants it could actually hurt its pollination rate. This led me to my second research question to determine if there is a correlation between number of heads and pollination rates in echinacea.
Methods
I used data from a sample of about 229 heads that were put through a data collection process aimed at separated and analyzing the achenes in Echinacea heads. Achenes are the fruit that contain seeds in Echinacea heads so by analyzing if they contain seeds or not we can gather pollination data for this experiment. In the first step of the process we cleaned the heads for achenes. Then we rechecked our first count for accuracy and scanned the achenes into the computer for counting. Lastly, we randomized our achenes, separated them to be x-rayed, and classified them to see which achenes contained seeds giving us our pollination rates.
Question 1
After the data collection process the data was compiled into spreadsheets that were uploaded into R. I put the data on a scatterplot with head height vs pollination rate to create a regression line that had a positive correlation but was also very scattered. To see if that correlation was significant I conducted a linear regression analysis and found that it was significant so taller head height does seem to be related to higher pollination rates.
Question 2
I used boxplots to visualize this data with number of heads for an individual Echinacea plant vs average pollination rate and the pollination rate seems to go up as number of heads increase, the opposite of what I was expecting with self-incompatibility. I then conducted an ANOVA test and found that the difference in average pollination rate by number of heads was not significant so number of heads does not seem to have an effect on pollination rates.
Conclusion
My results gave a positive correlation between head height and pollination rate and no correlation between number of heads and average pollination rate. However, a big limitation to my study was the sample size, especially for question two. Only having one data point for the 5 and 7 heads categories could have a large effect on the data. Lastly, since this was an observational study we can only infer correlation not causation so someone conducting an actual experiment would be a good direction to go in the future.
Acknowledgements and Bibliography
Bibliography-
Dickson, C.R., Petit, S. Effect of individual height and labellum colour on the pollination of Caladenia (syn. Arachnorchis) behrii (Orchidaceae) in the northern Adelaide region, South Australia. Plant Syst. Evol. 262, 65–74 (2006). https://doi.org/10.1007/s00606-006-0472-3
LORTIE, Christopher J., and Lonnie W. AARSSEN. “The Advantage of Being Tall: Higher Flowers Receive More Pollen in Verbascum Thapsus L. (Scrophulariaceae).” Écoscience 6, no. 1 (1999): 68–71. http://www.jstor.org/stable/42901102.
Ohashi K, Yahara T. Effects of variation in flower number on pollinator visits in Cirsium purpuratum (Asteraceae). Am J Bot. 1998 Feb;85(2):219. PMID: 21684905.
Wagenius S, Lyon SP. Reproduction of Echinacea angustjfolia in fragmented prairie is pollen-limited but not pollinator-limited. Ecology. 2010 Mar;91(3):733-42. doi: 10.1890/08-1375.1. PMID: 20426332.
Thanks to Wyatt and Abby for helping me with data collection, Stuart for helping me develop ABTs and to the National Science Foundation for providing funding.
Materials that were used for my project can be found in the filepath: ~/Dropbox/ccExterns2023/conlanRamirez
