Ecology Lecture 7

Study Tips for the Exam

• Review Lecture Notes: Go over your notes to recall important concepts.

• Read the Textbook: Consult the chapters related to your trouble areas for deeper understanding.

• Practice Questions: Attempt practice questions to reinforce material.

• Re-study Difficult Sections: Focus again on areas where you felt uncertain.

Importance of Knowing Material

• Understanding the Material:

  • Being able to clearly explain concepts to a peer.

  • Successfully solving related problems or analyzing graphs.

  • Drawing connections between lectures and real-world examples.

  • Applying knowledge to new scenarios effectively.

Calculator Clarification

• No Electronics in BIOL 1011:

  • Calculators are not required; questions are designed to need only basic arithmetic.

Conservation Biology Overview

• Definition:

  • Conservation biology applies ecological theory to protect biodiversity.

• Approach:

  • Establishes a scientific basis for conservation decisions.

• Goals:

  • Aims to slow, halt, or reverse biodiversity loss.

Global Conservation: IUCN Red List

• International Union for the Conservation of Nature (IUCN):

  • Maintains a Red List categorizing species at risk of extinction.

IUCN Categories:

• EX: Extinct

• EW: Extinct in the Wild

• CE: Critically Endangered

• EN: Endangered

• VU: Vulnerable

• LC: Least Concern

• DD: Data Deficient

• NE: Not Evaluated

Species Status Overview:

• Approximately 166,000 species assessed

• Around 1.2 million species have been described scientifically

• Rough estimate: about 8.7 million species total.

Case Studies on Endangered Species

• Shortfin Mako Shark:

  • Status: Endangered.

  • Population Size: Unknown.

  • Threats: Overfishing (both targeted and bycatch).

• Sumatran Rhinoceros:

  • Status: Critically Endangered.

  • Population Remaining: About 30 mature individuals.

  • Threats: Human disturbances and poaching.

• Sea Otter:

  • Status: Endangered.

  • Population Trend: Decreasing.

  • Threats: Oil spills, disease, climate change.

Conservation in Canada: COSEWIC

• Committee on the Status of Endangered Wildlife in Canada (COSEWIC):

  • Identifies and assesses at-risk species based on:

  • Population size

  • Recent decline

  • Threats to populations/habitats.

COSEWIC Categories:

• Extinct: Completely gone (e.g., Great Auk).

• Extirpated: Gone within Canada but found elsewhere (e.g., Eastern Tiger Salamander).

• Endangered: Could soon be extirpated (e.g., Loggerhead Sea Turtle).

• Threatened: Potentially at risk of becoming endangered (e.g., Rufa Red Knot).

Biodiversity Conservation Strategies

• Species Level: Protect species at risk through IUCN, COSEWIC, and SARA.

• Genetic Level: Maintain genetic diversity to increase adaptability.

  • Examples include preserving genetically distinct populations (e.g., brook trout).

Ecosystems and Biodiversity Benefits

• Provisioning Services:

  • Goods supplied by ecosystems (food, water, timber).

• Regulating Services:

  • Benefits from ecosystem regulation (climate, disease spread).

• Cultural Services:

  • Non-material benefits (recreation, mental health).

• Supporting Services:

  • Underlying growth processes (nutrient cycling, primary productivity).

Threats to Biodiversity

• Key Threats:

  • Habitat loss

  • Overharvesting

  • Introduced species

  • Pollution

  • Climate change

  • Overpopulation

Impacts of Threats

• Population Dynamics: Lower carrying capacity (K) and negative per capita growth rate (r) lead to extinction risks in small populations.

Understanding Minimum Viable Population (MVP)

• Definition: Smallest population size likely to persist over time (e.g., 100 years, 95% probability).

Effective Population Size (Ne)

• Important for Genetic Diversity: Not everyone mates (sex ratio, mating systems) leads to a decline in effective breeding population size.

• For Grizzly Bears:

  • Total individuals: 1000

  • Effective population size: 400 – 500.

Conservation Biology Objectives

• Prevent species extinction (e.g., Passenger Pigeon, Caribbean Monk Seal).

Ecosystem Connections

• Interconnectedness of life: Trophic cascades, human impacts, niches, food webs, and keystone species are critical for understanding ecosystems.

The Importance of Ecology

• Recognize the implications of climate change, mass extinction, and biodiversity loss for the planet and humanity.

David Tilman Quote:

• "The most striking feature of earth is the existence of life, and the most striking feature of life is its diversity."