Ecosystem structure, function, and services - UGA … · Ecosystem structure, function, and...

Ecosystem structure,

function, and services

Kyle McKay

601-415-7160

[email protected]

Ecological Modeling Workshop

New England District

September 2015

mailto:[email protected]

Innovative solutions for a safer, better world BUILDING STRONG®

Lecture Overview

Framing restoration in ecology

Measuring ecological outcomes

Defining “success” in restoration


Ecosystem Restoration in the Corps

Purpose: “…to restore significant structure,

function and dynamic processes that have

been degraded.” (ER 1165-2-501)

Intent: “…to partially or fully reestablish the

attributes of a naturalistic, functioning, and self-

regulating system.” (EP 1165-2-502)

Scope: “Nationally and regionally significant

wetlands, riparian and other floodplain and

aquatic systems” (ER 1105-2-100)


Understanding an ecological

template


Ecological

Hierarchies

Ecology is literally the

“study of the household”

Levels of organization ► Corresponding sub-disciplines

► These are NOT spatially defined

Incre

asin

g u

nce

rta

inty

an

d c

om

ple

xity


An ecosystem is greater than the sum of its parts.

-Eugene P. Odum

But what are its parts?


Components of Ecosystem Integrity

Component Description

Hydrogeomorphology Physical processes governing geologic setting, climate,

hydrologic cycling, and watershed land use with

implications for channel morphology, sediment regimes,

channel hydraulics, and hydrologic connectivity

Biogeochemistry Chemical processes driving the concentration, fate, and

transport of nutrients, contaminants, and other

constituents

Biological Systems Reproduction, survival, and movement of living

components of an ecosystem

Socio-economics Instrumental value of ecosystems to humans

Cultural-personal values Intrinsic value of ecosystems to humans and resulting

influence of humans on ecosystems

Described further in EMRRP-EBA-04 and EMRRP-EBA-16. See also alternative view in EMRRP-SR-52


Temporal Variability

Ecosystems are noisy places, often on developmental trajectories

What natural disturbances govern ecosystem structure and function?

► Pulses: discrete events (e.g., floods)

► Presses: slowly escalating events (e.g., droughts)

► Ramps: slowly changing conditions (e.g., sea level rise)

What is the disturbance regime?

► i.e., magnitude, frequency, duration, timing, and rate of change (sensu, Poff et al. 1997)

Is the system “stationary”? Are disturbance regimes changing?


Spatial Considerations

Composition

Configuration

Connectivity

Location


Measuring ecological outcomes


A few definitions…

Structure: “refers to both the composition of the

ecosystem (i.e., its various parts) and the physical and

biological organization defining how those parts are

organized”

Function: “describes a process that takes place in an

ecosystem as a result of the interactions of plants,

animals, and other organisms in the ecosystem with

each other or their environment”

► Comprised of numerous ongoing processes

Structure < Process < Function

Definitions: NRC Report on Ecosystem Services (Heal et al. 2005)


Structure v. Function

Structure Function

What ecosystems look like What ecosystems do

A snapshot in time Usually a rate

Restoration emphasizes form Restoration emphasizes process

Emphasize the static condition Focus on dynamism

Indicates something is wrong Indicates why it is wrong

Varies in time and space Varies in time and space

Necessary for restoring a

healthy ecosystem

Necessary and sufficient for restoring

a healthy ecosystem

After Amy Rosemond (UGA)


Two competing approaches

After Bradshaw (1996)

Structure

Fu

nctio

n

Original / Restored

Degraded


Ecosystem Services

Millennium Ecosystem

Assessment (2005)

“the benefits people obtain

from ecosystems”

Structure and function can

influence, but are not

necessarily services

Figure: MEA (2005)


Connecting Structure, Function,

and Services

Figure: Carpenter et al. (2009), Palmer and Filoso (2009)


Ecosystem Services in the Corps

Services are not new to USACE

A USACE-centric definition

► Ecosystem goods and services are socially valued aspects or outputs

of ecosystems that depend on self-regulating or managed ecosystem

structures and processes.

See also: Murray et al. (2013), Tazik et al. (2013)

1. Management

Activity

2. Ecological

Outcomes

3. Ecosystem

Goods &

Services

4. Social

Benefits

A. Response

Function

B. Ecoservice

Production Function

C. Benefit/Damage

Function


A few examples…

Structure Process/Function Services

Fish habitat Population survival rate Commercial fishing yield

Channel width Bank erosion rate Land gain / loss

Nitrate concentration Nutrient uptake and

transformation rates

Reduced water treatment

cost

Wetland plant density or

configuration

Storm surge attenuation Reduced flood damage

Population abundance of

salmon (i.e., run size)

Reproductive or survival

rates

Subsistence fishing harvest

Biodiversity Adaptation or speciation

rates

Heritage value for future

generations

Watershed connectivity Sediment flux or delivery Maintenance of wetland

elevation under SLR

After Palmer and Febria (2012)


Defining “success” in restoration


Three general views on success

Relative to a

reference ecosystem

Relative to project

objectives

► Structure

► Function

► Goods and services

► Legal mandates?

Benefit-cost analysis


Reference-Based Success

Creating a

benchmark for

success

► On-site analog

► Off-site analog

► Historical

► Virtual

► Regional

Miller et al. (2012, EMRRP-EBA-12), Pruitt et al. (2013, EMRRP-EBA-11)


Objective Setting for Ecosystem Restoration

Setting good objectives

Developing metrics corresponding to objectives

Comparing and combining metrics to facilitate

decision making

General Goals Specific Objectives Metrics

Provide for municipal

water supply

Maximize water

withdrawal

Average annual withdrawal

rate

Maintain a healthy

river ecosystem

Minimize difference

between unaltered and

altered hydrographs

7 Discharge metrics

normalized from 0 to 1 and

averaged

McKay et al. (2012, EMRRP-EBA-16)


Benefit-Cost Analysis:

An Economist’s Paradise

Benefit - Cost Ratio:

► Ratio of Benefits to Costs: r = B / C

► r > 1 means more benefits than costs

Net Value:

► Benefits minus costs: NV = B - C

► NV > 0 means more benefits than costs

Internal Rate of Return (irr):

► Discount rate that makes B(irr) = C

► irr > market rate is a good investment

► “Time value of money”

Costs ($) Benefits ($)

Land Purchase Recreational kayaking

Project

Planning

Reduced water

treatment

Construction Increased property

value

Monitoring Recreational fishing


When is “success” achieved?

How long until

success is achieved?

What is the “rate of

return”?

How long is a

sponsor willing to

wait?


Ecosystems are variable

How often is success achieved?

Does it have to be all of the time?


Final Thoughts


Take-away points

Structure is NOT function. Function is NOT service.

Models are useful tools for forecasting potential

trajectories of the structural and functional

components of ecosystems.

HOWEVER, what is being modeled is dictated by

the project’s scope and objectives!

► Modeling approaches are adapted to projects, not the

other way around


Extra Slides


References for Further Reading Functions

► Beechie et al. 2010. Process-based principles for restoring river ecosystems. Bioscience, 60 (3), 209-222.

► Fischenich. 2006. Functional objectives for stream restoration. ERDC TN-EMRRP SR-52.

► Palmer and Febria. 2012. The heartbeat of ecosystems. Science, 336.

► McKay et al. 2012. Ecosystem restoration objectives and metrics. ERDC TN-EMRRP-EBA-16.

Ecosystem Services ► Heal et al. 2005. Valuing ecosystem services. National Academies of Science.

► Palmer and Filoso. 2009. Restoration of ecosystem services for environmental markets. Science, 325.

► Carpenter et al. 2009. Science for managing ecosystem services: Beyond the Millenium Ecosystem Assessment.

PNAS, 106 (5), 1305-1312.

► Murray, Cushing, Wainger, and Tazik. 2013. Incorporating ecosystem goods and services in environmental planning –

Definitions, classification and operational approaches. ERDC TN-EMRRP-ER-18.

► Tazik, Cushing, Murray, and Wainger. 2013. Incorporating ecosystem goods and services in environmental planning.

ERDC/EL TR-13-17.

Restoration and Conservation ► Bradshaw. 1996. Underlying principles of restoration. Canadian Journal of Fisheries and Aquatic Sciences, 53, 3-9.

► Ehrenfeld. 2000. Defining the limits of restoration: The need for realistic goals. Restoration Ecology, 8 (1), 2-9.

► Society for Ecological Restoration (SER). 2004. International Primer on Ecological Restoration.

► Palmer et al. 2005. Standards for ecologically successful river restoration. Journal of Applied Ecology, 42, 208-217.

► Clewell. 2009. Intent of ecological restoration, its circumscription, and its standards. Ecological Restoration, 27 (1).

► Fischenich et al. 2013. Science-based framework for environmental benefits assessment. ERDC/EL TR-13-4.

http://www.nap.edu/openbook.php?isbn=030909318X

http://www.ser.org/resources/resources-detail-view/ser-international-primer-on-ecological-restoration


Trajectories / Dynamism


Ecosystems are

resilient! Resilience: The ability

to bounce back

Of what? To what?

Attribute Recovery Resistance Adaptive

capacity Commonly

referred to as:

Engineering Resilience Ecological Resilience Community Resilience

Definition Speed or rate of system

recovery after

disturbance

Magnitude of disturbance

that can be absorbed without

flipping into an alternative

state

Ability to preempt and

avoid major mishaps in

institutions

Emphasis Efficiency, constancy,

predictability, stability

Persistence, change,

unpredictability, thresholds

Monitoring,

measurement,

management, and

operation

Schultz et al. (2012)


Sustainability

“Development that meets the

needs of the present without

compromising the ability of

future generations to meet

their own needs”

► World Commission on

Environment and Development.

1987. Our common future.

(“Brundtland Report”)

Will the process continue

without intervention?


Some challenges to executing

ecosystem goods and services

All services are not monetized. Value is not cost.

Ecosystem services vary over space and time with

respect to production, demand, and social values.

► No user, no service. Who and where is the beneficiary?

► What will societal values be in 40 years?

Use (e.g., commercial fishing) v. non-use (e.g.,

existence value of fish)

Intermediate (e.g., water purification) v. final (e.g., safe

drinking water, recreational fishing opportunity) services

► Final services help avoid “double-counting”

See also: Murray et al. (2013), Tazik et al. (2013)


A brief history of restoration (1/2) Habitat enhancement (ca. 1970s)

Habitat diversity (ca. 1980s)

Natural design templates (ca. 1990s)

Process- and function-based restoration (ca. 2000s)

Ecosystem service restoration (?)


A brief history of restoration (2/2)

Mace (2014)


Restoration of what?

Species / populations?

Habitat?

Communities?

Water or soil quality?

Ecosystems?

Implies biotic and abiotic

“Systems” indicates

functions or interactions

Our ultimate aim should be the restoration of the

whole ecosystem, even if we sometimes emphasize

some particular component or attribute. Bradshaw (1996)


Standards for ecologically

successful river restoration

1. Guiding image of dynamic state

2. Ecosystems are improved

3. Resilience is increased

4. No lasting harm

5. Ecological assessment is completed

6. (Hypotheses or conceptual model

guide restoration)

Palmer et al. (2005) and Jansson et al. (2005)


Attributes of restored ecosystems

1. Characteristic assemblage of species observed in reference system

2. Contains indigenous species to the greatest practicable extent

3. All functional groups are present or can colonize

4. Physical environment capable of sustaining reproducing populations

of species necessary for community stability and development

5. Normal function for stage of ecological development

6. Suitably integrated into the landscape

7. Potential threats from surrounding landscape eliminated or reduced

8. Sufficiently resilient to endure normal periodic stress (i.e., disturbance)

9. Self-sustaining

Adapted from SER (2004)


Future Directions:

Shifting from structure to function

Moving beyond habitat

► Populations: abundance, survival, recruitment, movement,…

► Communities: food webs, energetics,…

► Ecosystems: decomposition, nutrient uptake, metabolism,…

► Landscape: structure, particle tracking, metapopulations, gene flow

Figures: Peterson et al. (2011), Cross et al. (2011), Freeman et al. (2012)


Future Directions:

Multiple endpoints

and methods Getting away from single species

(or outcome) restoration. Moving

toward multi-metric decision

making.

Combining outcomes and

incorporating values will be the

massive challenge (MCDA and

SDM might be key tools)

Why select a model when many

can be applied simultaneously?

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