Ecological SystemsMaintaining and Enhancing Natural Features and Minimizing Adverse Impacts of Infrastructure Projects

Course Review

Emily Mitchell Ayers, Ph.D.The Low Impact Development Center, Inc.

emayers@lowimpactdevelopment.org

• Human activities often have adverse environmental impacts

• Learning to design infrastructure systems that successfully integrate with the environment requires an understanding of ecology and a knowledgebase of sustainable design techniques

Key Message

7-3

• To become familiar with the basic principles of ecology

• To learn to anticipate the ecological impacts of infrastructure projects over their entire life cycles from planning to decommissioning

• To learn techniques to prevent, minimize, and mitigate these impacts

• To learn how to design infrastructure systems that contribute to productive, environmentally restorative and socially desirable uses of land and protection of native flora and fauna

Course Objectives

7-4

1. Course Overview: Ecosystem services and the importance of ecologically-sensitive design

2. Introduction to Ecology: Ecological theory

3. Impacts of Infrastructure: What are the major ecological impacts caused by infrastructure, and how do infrastructure projects cause these impacts?

Modules of the Course

7-5

4. Protecting Habitat: Assessing habitat, prioritizing and creating conservation areas

5. Integrating Infrastructure: How to design infrastructure projects that work in harmony with their surroundings

6. Restoring Ecological Function: An overview of the general theory of ecosystem restoration, with examples of restoration in specific contexts

Modules of the Course

7-6

• Ecosystems provide essential services on which humans depend

• Provisioning services

• Regulating services

• Supporting services

• Cultural services

• Disturbance of ecosystems can lead to loss or degradation of ecosystem services

Ecosystem Services

7-7

• What are ecosystems?

• What principles govern ecosystem behavior?

• How do ecosystems respond to change?

Introduction to Ecology

7-8

• Ecosystem: a unit that consists of living and non-living components interacting to form a system

• Ecosystems are made up of populations of species organized into communities interacting with their physical environment

• Ecosystems are almost always open systems with inputs and outputs

What is an Ecosystem?

7-9

• Ecosystems develop complex feedback mechanisms to conserve materials and energy.

• Organisms self-organize into food webs and nutrient cycling pathways.

• Each species inhabits a unique ecological niche, and plays a role in maintaining the system.

• Keystone species play essential roles. Loss can disrupt ecological function.

What Principles Govern Ecosystem Behavior?

7-10

• Ecosystems are always changing, either due to pulsing predator/prey relationships, disturbance, or gradual succession from pioneer to climax systems

• Ecosystem stability is described in terms of resistance to change and resilience

• Stability depends on biodiversity, size, location, and connectivity

How Do Ecosystems Respond to Change?

7-11

• What ecological impacts are associated with infrastructure?

• How do ecosystems become degraded?

• What are the local, national, and global implications?

Impacts of Infrastructure

7-12

• Habitat loss

• Habitat fragmentation

• Pollution

• Altered river and estuary hydrology

• Climate change

• Road kills

What Ecological Impacts Are Associated With Infrastructure?

7-13

• Direct habitat loss

• Habitat fragmentation

• Damage to physical environment

• Chemical toxicity

• Hunting and harvesting

• Introduction of exotic species

How Do Ecosystems Become Degraded?

7-14

• Habitat loss and fragmentation

• Depletion of fresh water resources

• Eutrophication

• Hydromodification

• Air pollution

Impacts in the United States

7-15

• Depletion of fresh water resources

• Climate change

• Excessive nutrient loading

• Loss of biodiversity

• Habitat loss

Global Impacts

7-16

1. Know where you are

2. Avoid sensitive areas

3. Minimize infrastructure impacts

4. Mitigate unavoidable losses

5. Improve ecological function where possible

Ecologically-Sensitive Design Process

7-17

• Site assessment

• Identifying critical resources

• Conservation design techniques

Protecting Habitat

7-18

• Ecologically-sensitive design begins with a thorough site assessment

• Identify important habitat areas

• Understand how site fits into larger regional landscape

Site Assessment

7-19

• Conserve the most important habitat areas

• Viable, intact communities

• Vulnerable, rare, or sensitive communities

• Endemic communities (locally unique)

• Maintain and improve connectivity to promote wildlife movement

Identifying Critical Resources

7-20

• Focus development in areas that are:• Previously disturbed• Fragmented• At the edges rather than the center of intact

communities

• Maintain and improve connectivity to promote wildlife movement

Conservation Design

7-21

Integrating Infrastructure

• The energy signature

• Anticipating infrastructure impacts

• Minimizing infrastructure impacts

7-22

The Energy Signature

• Infrastructure projects interact with the ecosystems in which they are situated

• Minimizing infrastructure impacts requires understanding and protecting the energy signature of the ecosystem

• Energy signature: the set of forcing functions affecting an ecosystem

7-23

Forcing Functions

• Sunlight level

• Temperature

• Precipitation

• Hydrologic regime

• Fire regime

• Inputs• Organic matter• Nitrogen• Phosphorus

7-24

• Maintain pre-development hydrology

• Maintain pre-development nutrient inputs

• Minimize pollution

• Maintain pre-development plant cover

• Avoid introduction of exotic invasive species

Key Considerations for Infrastructure

7-25

• Basic principles of ecological restoration• Focus on function, not appearance

• Rely on self-organization as much as possible

• Examples of restoration techniques• Streams

• Wetlands

• Lakes and Ponds

• Upland ecosystems

Restoring Ecological Function

7-26

• Consult with experts

• Remove barriers to ecological function

• Establish key species to jump-start self-organization

• Provide connectivity to existing habitat

• Be patient!

Basic Principles of Ecological Restoration

7-27

• Multiple choice

• Covers material from each module

• Tests understanding of key concepts

• Application of principles

Examination

7-28