MSHweek 1activity final 1 PDF

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from professor dolan. assignment for biology 1108...

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BIOL 1108 Dolan Spring 2021

UGAID (e.g., eldolan):

Mt. St. Helens Ecosystem: Pre and Post Eruption Analysis Adapted from Drs. Carrie Pucko and Jessica Barb

To be completed during class Week 1. Please upload an electronic copy (photo, PDF, or doc) of your completed assignment on eLC by 11:59 pm Monday January 25. You are welcome to work with classmates but you must submit your own work in your own words. Worth 10 pts. 1. The single greatest surprise to scientists entering the blast zone after the eruption was the realization that many organisms survived the eruption. Brainstorming with classmates or working on your own, hypothesize 3 types/examples of organisms that survived the blast and, in one-sentence each, explain your reasoning about why they could have survived.

In order to think about how ecosystems become established/re-established and change over time, you will examine data from a series of experiments conducted by the USDA Forest Service: Mount St. Helens Ash and Mud: chemical properties of ash from MSH and their effects on the establishment of trees and plants (1981). The paper is posted on eLC if you are interested in reading the details. USDA scientists collected samples of ash from the 1980 volcanic eruption of Mount St. Helens in western Washington soon after the May 18th eruption. They studied the chemical properties of these ash samples and their effects on seed germination and seedling establishment for five tree species as well as four species of browse plants (i.e., plants important for herbivory by animals). For comparison, they also collected a soil sample from the Toutle River, which is located 32 km west of the volcano outside of the eruption impact zone. The purposes of this study were to:  

describe how the eruption affected the chemistry of the soil around MSH, and determine how these changes may affect the growth and establishment of plants that try to recolonize the area.

2. Examine the data in Table 1 and fill in the right-hand column, indicating how the chemistry of the ash samples from MSH compares to the soil sample from the Toutle River. Table 1. Chemical properties of ash and soil samples from Mount St. Helens Nutrient

Units

Ash sample 1

Ash sample 2

Ash sample 3

Soil (control)

Mg K Ca Fe Mn Zn Cu S Total N Ammonium N Nitrate N P pH

ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm ppm

78 260 1130 33 4 2 6 630 137 7 1 198 6.8

40 150 910 28 5 1 5 380 143 1 2 186 7

76 340 1270 25 3 3 3 770 155 1 1 246 6.7

112 140 1100 66 4 2 3 340 182 80 20 149 5

How does the ash sample compare to the soil sample (same, lower, or higher?)

3. Primary nutrients are elements that organisms need in large amounts because they are required to make macromolecules. Secondary nutrients are needed in more modest amounts. Highlight or circle which nutrients in Table 1 are considered primary nutrients.

4. Which primary nutrients are LOWER in the ash samples than the soil sample? Which secondary nutrients are LOWER in the ash samples than the soil sample?

5. The scientists measured three different forms of nitrogen (N) in this experiment. Why do you think they did this? Why does the form of N matter?

6. Table 2 shows results of two replicates of an experiment in which 100 seeds were sown on an ash sample vs. the control soil sample, and the percent of seedlings that became established was determined. Fill in the right-hand column the table, indicating whether the seedlings were more, less, or equally likely to become established in the ash relative to the soil sample. Table 2. Percent establishment of seedlings sown on different media (ash vs. soil) Plant species

Ash

Soil

Douglas fir sample 1 Douglas fir sample 2 Western hemlock Western red cedar Lodgepole pine Lupines Dwarf English trefoil Catsear Orchard grass

13% 26% 14% 19% 54% 18% 48% 92% 88%

39% 79% 51% 56% 89% 20% 46% 88% 92%

How does likelihood of establishment in the ash sample to compare to the soil sample (more, less, or similar?)

7. Which species had a similar likelihood of growth in the ash and soil samples?

8. Which species were less likely to grow in the ash sample than in the soil sample?

9. Working on your own or with classmates, google the species in Table 2 to learn about each of them. Identify and list at least two (2) characteristics that the each group of plants have in common. A. Common characteristics of plants that had a similar likelihood of growing:

B. Common characteristics of plants that were less likely to grow in ash:

As you learn about each species, think about how the differences among them might or might not affect their growth in the ash sample. Keep the results from Table 1 in mind....