Biology 370 – Environmental Science

Name: .

Environmental Science Lab #2

“A Field Study of Ecosystems”

(20 points)

INTRODUCTION

In 1935, Sir Arthur Tansley coined the word “ecosystem” from the two words “ecological” and “system”. By combining these two words he acknowledged for the first time the interconnected nature of the surrounding ecological world. In today’s lab you will learn about an ecosystem by interacting with it and understanding its unique tapestry. Today’s lab objectives are:

  1. Understand and be able to identify in the field the two (2) broad components of an ecosystem.
  1. Understand how components interact via the “lines of dependency”, that makes up ecosystem “structure” and “function”.
  1. Understand and explain how humans exist and affect ecosystem structure and function.

ECOSYSTEM BACKGROUND

In today’s lab, we will visit the MacDonald-DunnExperimentalForest located near Corvallis, Oregon. Adjacent to the forest is OSU’s Peavy Arboretum. We will access the forest through the arboretum and drive through a gate to an area near CronemillerLake. Once at the lake, your task is to work in groups of two or three students to hike and observe the lake trail and answer a series of 10 questions regarding the surrounding ecosystem. The questions are designed to help you understand how ecosystems are structured (i.e. the strands of the tapestry) and how they function (the picture of the tapestry once the strands are woven together). I will be hiking with you and will help you with clues to the answers. Please don’t hesitate to ask and work together. As we progress through the term we will investigate several themes in the labs:

A.How are ecosystems structured?

B.How do ecosystems function?

C.What are ecosystem “services”?

D.What role(s) do plants and animals play in the structure and function of an ecosystem?

E.How do humans affect the structure and function of ecosystems as they derive ecosystem “services”?

The Mac-DunnForest is an Ecosystem (definition):

Simply stated, ecosystems are the sum of all living and non-living organisms in an area that, as structured, function as a whole unit. In the picture below, locate the biome (ecosystem) that Mac-DunnForest fits in terms of precipitation and temperature.

Questions

  1. What are the two primary components of an ecosystem? In which biome does the Mac-DunnForest fit?
  1. Locate the water source for CronemillerLake (if you can)?
  1. As you hike around the Lake, be observant and note the types and amount of vegetation. How many species of plants do you suppose are found in the immediate vicinity of the lake? How many species are found in the lake?
  1. Note the number and types of animals around the lake. How many did you see? Remember, the time of the year – the number of species found here increases during late spring and summer. Speculate why such a difference between the seasons?
  1. How does water move through this system? In other words, trace the path of water from the lake to plants and animals. How does water leave plants and animals? Where does it travel next?
  1. Besides water, what other types of substances are important for plants and animals in this system? How do they (plants and animals) derive those substances?
  1. Explain in some ways how animals (land and water) interact with each other in this system.
  1. Explain in some ways how plants (land and water) interact with each other in this system.
  1. Finally, explain how plants and animals interact with each other in this system.
  1. How would/could you define the boundary of this ecosystem?

When you have finished your hike, return to the van, so that we can compare answers and discuss them.