CHAPTER 3 BLM 3.3.6 HANDOUT Thought Lab 3.3: Super Competitor: Knapweed
Purpose: Assessing the biotic and abiotic factors of an introduced species in established ecosystems.
Procedure Investigate the biology of spotted knapweed. Specifically, find out how it reproduces, what animals eat it, how it was introduced into North America, and how it is spread.
Analysis 1. Study the graph shown.
Copyright © 2007, McGraw-Hill Ryerson Limited, a Subsidiary of the McGraw-Hill Companies. All rights reserved. This page may be reproduced for classroom use by the purchaser of this book without the written permission of the publisher. CHAPTER 3 BLM 3.3.6 HANDOUT Thought Lab 3.3: Super Competitor: Knapweed (cont’d)
a) Describe what has happened to the population of spotted knapweed since its arrival in British Columbia.
b) Predict the number of hectares that will be covered by spotted knapweed in 2020. Explain your prediction.
2. Explain why some introduced species can become so invasive and damaging to native species and ecosystems.
Copyright © 2007, McGraw-Hill Ryerson Limited, a Subsidiary of the McGraw-Hill Companies. All rights reserved. This page may be reproduced for classroom use by the purchaser of this book without the written permission of the publisher. CHAPTER 3 BLM 3.3.6 HANDOUT Thought Lab 3.3: Super Competitor: Knapweed (cont’d)
3. Why is spotted knapweed not a pest in its native habitat in Europe?
4. a) Populations of spotted knapweed are present in Alberta. How could spotted knapweed be spread throughout the province?
b) Predict how this might affect: i) farming and ranching ii) native ecosystems
5. Each of the statements below involves a situation that will affect the growth of a population. Classify each of the statements as abioitc or biotic. a. Rainbow smelt and yellow perch attempt to occupy the same area. The more aggressive smelt survive; the perch do not. b. A severe flood brings a lot of sediment and silt into Lake Winnipeg. The turbidity of the lake increases greatly. c. A drought decreases the water level in Lake Winnipeg. The ability of the lake to support organisms decreases.
Copyright © 2007, McGraw-Hill Ryerson Limited, a Subsidiary of the McGraw-Hill Companies. All rights reserved. This page may be reproduced for classroom use by the purchaser of this book without the written permission of the publisher. CHAPTER 3 BLM 3.3.6 HANDOUT Thought Lab 3.3: Super Competitor: Knapweed (cont’d)
d. Due to the introduction of rainbow smelt, Lake Winnipeg becomes crowded and some fish species do not survive. e. Since northern pike prey on yellow perch, an increase in the perch population causes an increase in the pike population. f. Many fish die due to an increase in water temperature. g. Due to over-fishing, the number of walleye in Lake Winnipeg decreases. h. A population is growing quickly when parasites cause disease to spread quickly. i. Since lake sturgeon migrate long distances to spawn, many do not survive the trip.
Copyright © 2007, McGraw-Hill Ryerson Limited, a Subsidiary of the McGraw-Hill Companies. All rights reserved. This page may be reproduced for classroom use by the purchaser of this book without the written permission of the publisher.