Lab 3_Species Interactions Andrew Carlock

WFA 3133 – Applied Ecology Spring 2023 Lab 3: Species Introductions and Interactions (30 points) Lab 3 is due Friday, March 10 th by 11:59pm. Please submit this document (as a PDF) in Canvas. https://www.youtube.com/watch?v=ytHcPVWJ6vY&list=PLd_93a1Y62rB_5lL4tdaFW002GK8-rAWL&index=10&t=249s ECOLOGICAL BACKGROUND Species interactions describe the relationships among different species living in the same location. As we discussed in lecture, species can have many types of interactions, ranging from mutualisms and commensalism to competition and parasitism. Interactions can occur between species that are native to an area, as well as between native species and species that are introduced into an area. The relocation of these “introduced” organisms across geographical boundaries mostly occurs directly or indirectly by humans, and has been increasing over time as human forms of transportation have improved. In some cases, humans have intentionally dispersed species, such as some reptiles and arthropods that were imported through the pet trade or plants that were transported from Europe to North America for agricultural and ornamental purposes. Other species are transported accidentally by planes, trains, and automobiles, as well as cargo and cargo ships, horticultural and ornamental plants, and wood products. Many of these introduced species are not able to survive in the new ecosystem. Others may find their new environment optimal for establishing, growing, reproducing, adapting, and dispersing to create new populations. Some of these species that adapt well increase their populations rapidly, and potentially have negative impacts on native species, disturbance and ecosystem cycles (e.g., nitrogen or carbon cycle), or the economy. These so- called “i nvasive species ” can alter the ecology and evolution of native species, ecology of ecosystems, and can be important drivers of species extinction. In this lab, you will examine data and relationships among organisms to assess species interactions and the ecological consequences of introduced species. Specifically, you will engage in hypothesis testing and data analysis, and research an introduced species on your own to increase your understanding of the complexities surrounding species introductions and interactions. PART 1: Impacts of Invasive Species on Native/Endangered Species Table 1. Types of interactions between species. Figure 1. Examples of impacts of introduced, invasive species on the aboveground and belowground environment. Figure from Wardle and Peltzer (2017); https://doi.org/10.1007/s10530-017-1372-x .

WFA 3133 – Applied Ecology Spring 2023 Global change causes community composition to change considerably through time, with new combinations of interacting species. To study the consequences of newly established species interactions between range expanding or introduced species and native species, one available source of data could be observational surveys from biodiversity monitoring. This section uses data from a Swiss amphibian monitoring program to assess the impacts of expanding water frog populations (includes phenotypically similar Pelophylax ridibundus , P. lessonae , and P. esculentus ) on population sizes of native natterjack toads ( Epidalea calamita ), common midwife toads ( Alytes obstetricans ), and yellow-bellied toads ( Bombina variegata ), which are endangered in peripheral parts of their range like northern Switzerland. Studies on population impacts of dominant species on population sizes of endangered species using data from biodiversity monitoring programs can help inform conservation policy and to decide whether competing species should be subject to population management. Use the accompanying dataset to answer the following questions and assess the impacts of the water frogs on the native toad population. References Roth, T., Bühler, C., Amhein, V. 2015. Data from: Estimating effects of species interactions on populations of endangered species, Dryad, Dataset, https://doi.org/10.5061/dryad.7gt4m Roth, T., Bühler, C., and Amrhein, V. 2016. Estimating effects of species interactions on populations of endangered species. The American Naturalist, 187(4), pp.457-467. https://doi.org/10.1086/685095 Schmidt, B.R. 2005. Monitoring the distribution of pond-breeding amphibians, when species are detected imperfectly. Aquatic Conservation: Marine and Freshwater Ecosystems 15:681-692. Tanadini, L.G. and Schmidt, B.R. 2011. Population size influences amphibian detection probability: implications for biodiversity monitoring programs. PLOS ONE 6:e28244. Figure 3. Images of the (A) water frog, Pelophylax ridibundus, image by Omid Mozaffari, (B) natterjack toad, Epidalea calamita , image by Alexander Haas, (C) common midwife toad, Alytes obstetricans , image by Iñigo Martínez-Solano, and (D) yellow-bellied toad, Bombina variegata, image by Dr. Joachim Nerz.

WFA 3133 – Applied Ecology Spring 2023 Q2) Did you find any variation in the range of elevations for the species? Yellow Belly Toads seem to be at a decline at the higher elevation pf sea level, where the other ones increase. Q3) Think about your results from Q1 and Q2. Review the accompanying dataset, including the “Metadata” and “Lab 3 Data” tabs, and write three hypotheses detailing how you think the water frogs might be affecting 1) natterjack toads, 2) common midwife toads, and 3) yellow-bellied toads. Natterjack toads: Because of the increase in the water frog population, there is a decrease in the Natterjack toads population. Common midwife toads: Because water frogs populate a lower elevated area, Common midwife toads have to move to higher elevations for less competition. Yellow-bellied toads: y = 0.0539x - 8.124 R² = 0.0496 0 20 40 60 80 100 120 250 350 450 550 650 750 Natterjack Toad Count Elevation (meters above sea level) NJT Count by Elevation y = 0.06x + 12.335 R² = 0.0026 0 100 200 300 400 500 600 700 800 900 250 350 450 550 650 750 Water Frog Count Elevation (meters above sea level) WF Count by Elevation

WFA 3133 – Applied Ecology Spring 2023 Yellow-bellied toads seem to populate at a lower elevation, along with water frogs. This means they compete for resources. Q4) There are a couple different ways to analyze the data in the accompanying dataset. For example, we can use the water frog count data as is or transform it to a presence/absence variable where 0 = no water frogs and 1 = presence of water frogs and then look at the mean (average) number of toads when there are no frogs versus when there are frogs. Let’s use this second option to develop a figure and test your hypothesis. Be sure to calculate and include standard error bars on your figure (see “Metadata” t ab for standard error calculation). Include your figure below. Q5) For your figure and analysis from Question 4, what are your independent and dependent variables? Are they numerical or categorical? If numerical, are they discrete or continuous? If categorical, are they ordinal, nominal, or binary? This is a numerical variable by counting the number of frogs there are in their populations. It is also discrete by having a clear separation between the values of each animal. Q6) What are the effects of the water frog populations on the native toad community? How did the toad counts vary based on frog presence and absence? Were your hypotheses supported or not supported by your data analysis? Note: this is a very simplified analysis as there are a lot of other factors that we would ordinarily include to model the effects of water frogs on native toad communities, but that is for a more advanced class… With the presence of water frogs, the toad population of each different species is significantly lower. This does support my hypothesis that the water frogs are decreasing the number of toads and their populations. 0 2 4 6 8 10 12 Yellow-Bellied Toad Common Midwife Toad NatterJack Toad Mean Toad Count (± SE) Water Frogs? Absent Present

WFA 3133 – Applied Ecology Spring 2023 Q7) Has there been any effort made to control this species? If so, how? A mustard-based solution helps irritate the worms and bring them up to the surface to be picked and disposed of. Q8) What resource(s) did you use to find this information? Farmer, S. (2022, April 22). Invasive jumping worms can change their world . US Forest Service. Retrieved March 10, 2023, from https://www.fs.usda.gov/features/invasive-jumping-worms-can- change-their-world Holsopple, K. (2022, August 2). How to prevent invasive jumping worms from ruining your garden . The Allegheny Front. Retrieved March 10, 2023, from https://www.alleghenyfront.org/how-to- prevent-invasive-asian-jumping-worms-from-ruining-your- garden/#:~:text=To%20kill%20adult%20jumping%20worms,to%20the%20surface%20for%20pi cking. University of Georgia. (n.d.). Jumping worm, amynthas spp.. Haplotaxida: Megascolecidae - EDDMapS . EDDMapS.org. Retrieved March 10, 2023, from https://www.eddmaps.org/species/subject.cfm?sub=58695 USDA Forest Service. (n.d.). Asian jumping worm . Asian Jumping Worm | National Invasive Species Information Center. Retrieved March 10, 2023, from https://www.invasivespeciesinfo.gov/terrestrial/invertebrates/asian-jumping-worm