Ecological Modelling

The Bridge between Ecology and Lake
Management: Ecological Modelling, -
Economics,
-Engineering and -Indicators
By Sven Erik Jørgensen, Copenhagen
University, Institute A, Environmental
Chemistry, University Park 2, 2100
Copenhagen Ø. sej@farma.ku.dk
msijapan@hotmail.com

1962:
• “The Silent Spring” by Rachel
Carson started the first green
wave

1970:
The idea: Zero Discharge 1985 was
introduced in USA, but was
impossible to realize due to the
economy- The solution to the
problem was the application of
ecological models. The needs for
an ecological approach in
environmental management
became clear.

Urbanization
IMPACT Ecosystem
Industrialization
Selection of
environmental
technology
Reduction of
impact by environmental
technology
Ecological
model of the
changes causet
by the
impact

ENVIRONMENTAL
TECHNOLOGY
ECOLOGICAL
MODELLING
MAN
ECOSYSTEMS
CLEANER
TECHNOLOGY,
SUSTAINABLE
DEVELOPMENT
ENVIRONMENTAL
LEGISLATION
GLOBAL PROBLEMS:
GREEN HOUSE EFFECT
OZONE LAYER
RAIN FOREST
(ACID RAIN)
ECOLOGICAL
ENGINEERING/
ECOTECHNOLOGY

1. Different scale dependent on purpose
2. Different types dependent on the purpose
Geology, railroad, aeroplan, marine maps.....
3. A map cannot contain all information,
details
4. A map is a simplification of reality which
is useful in a given context.

Streeter- Phelps
Lotka-Volterra
1920
1950
Population dynamics
River models
Eutrophication models
Complex river models
1970
1975
Fixed modeling procedure
Balanced complexity
More ecology
1980
Ecotoxicological models
More case studies
Validation of prognoses
1990
Structurally dynamic models
Ecological constraints
New mathematical tools, included
machine learning
2000

Advantages of Modelling:
• Models are synthesis of all what we
know- observations, theoretical
knowledge, knowledge about rates and
sizes, knowledge about food items etc.
• Models are tools to overview complex
systems
• Models make it possible to quantify by
the use of mathematical formulations and
computers

Man made impact
Control function
(forcing function)
Natural forcing
function
The ecosystem described
by the use of state variables
THE MODEL GIVES THE RELATIONSHIP
BETWEEN FORCING FUNCTIONS AND
STATE VARIABLES.

Bio-geo-chemical models
5: >100 models, 4: 25-99 models, 3: 10-25 models,
2: 4-9 models, 1: 1-2 models, 0: No models
• Ecosystem
# of models
• Rivers, lakes, lagoons, estuaries 5
• Wetlands, agricultural land 5
• Forests, fjords, bays 5
• Open sea, national parks, grassland 4
• Savanna, mountain land 2
• Desert, artic/anartic system 1
• Mountain land above timberline 0

Bio-geo-chemical models
5: >100 models, 4: 25-99 models, 3: 10-25 models,
2: 4-9 models, 1: 1-2 models, 0: No models
Problems
# of models
Oxygen depletion, eutrophication 5
Pesticides, acid rain, groundwater pollution 5
Global warming, ERA (toxic substances) 5
Heavy metals, ozone layer, endangered sp. 4
Health / pollution 3
Endocrine disruptors, microclimate 2

A wide range of lake models have
been developed to find possible
solutions for
• the eutrophication, several hundred models
• the acidification, more than 100 models
• Over-fishing, more than 50 models
• the discharge of toxic substances, more than 100 models
• siltation, more than 25 models
• oxygen depletion, several hundred models
• and
• Salinization, ore than 10 models
• These models have been extensively used in lake
management.

Galilei: measure everything
and what is not measurable
make measurable

Galilei modified: model everything
and, what is not modelable make
modelable

The Ramification of Ecological
Modelling
• Ecological Modelling
2004 Ecological
Complexity
1992 Ecological
Engineering
2006 Ecological
Informatics
2000 Ecological
Indicators
1986 Ecological
Economy
1975 Ecological Modelling

Development: Previously Ecological Modelling
published other topics in applied ecology. Now they
are published in separate journals and Ecological
Modelling is only publishing Ecological Models and
Ecosystem Theory
• Ecological Modelling 1975: 320 pages
• 1988 Ecological Economics
• 1991 Ecological Engineering
•
• 2000 Ecological Indicators
•
• 2004 Ecological Complexity
• 2006 Ecological Informatics
•
• Ecological Modelling 2009: 4000 pages
• Citation index 2008: 2.18

Development: number of papers
Stabilized around 380 papers /
year 2008
2008
3 5 0
3 0 0
Number of papers / year
2 5 0
2 0 0
1 5 0
1 0 0
5 0
0
1 9 8 4 1 9 8 6 1 9 8 8 1 9 9 0 1 9 9 2 1 9 9 4 1 9 9 6 1 9 9 8 2 0 0 0 2 0 0 2 2 0 0 4 2 0 0 6
Y e a r

Ecological Modelling:
• 380 papers per year and 4000 pages
• Citation index has increased to
• 2.18
• It is also going excellently for the other
journals Ecological Economics,
Ecological Engineering, Ecological
Indicators, Ecological Complexity and
Ecological Informatics

Ecological Economics
• Models are used heavily and
also published from time to
time in Ecological Modelling

What is ecological engineering
• Design of sustainable ecosystems that
integrate human society with its natural
environment to the benefit of both.
• Notice that it is engineering in ecosystems,
which implies that it is based on design
principles and ecology

Type 3: ecosystems are recovered
Environment / ecosystems / surrounding
nature
Type 1: ecostems
are
used to treat
waste
Society
Type 2: ecosystems
are constructed to
treat waste
Type 4: ecologically sound planning
of the use of ecosystems

Subdisciplines of Ecological
Engineering:
• Ecotechnology≈ ecological engineering
• Ecohydrology: the use of hydrology to improve
ecological conditions of ecosystem or the use of
ecology to influence the hydrology
• Phytoremediation: use of plants to remove
pollutants for instance removal of toxic
substances by plants
• Phytotechnology: use of plants in ecotechnology

CONSTRUCTED
WETLAND
WITHDRAWAL OF WATER
WATER TREATMENT
LAKE
REMOVAL OF PHOSPHO-
RUS BY PRECIPITATION
BEFORE DISCHARGE
STREAM
STREAM
HYPOLIMNION WATER IS
REMOVED BY SIPHONING

Adsorption of Pe,
HM, P, OM, N
Decomposition
of Pe, OM
Denitrification
N
Uptake by plants of
Pe, HM, P, N
Pesticides (Pe)
Input
Heavy metals (HM)
Phosphorus (P)
Organic matter (OM)
Nitrogen
compounds (N)
Transport to
limnetic zone
Transition zone (ecotone)

Several lake restoration methods have
been developed and used to recover
lakes:
• Aeration in lakes by air and oxygen
• Biomanipulation
• Precipitation of phosphorus directly in the lake
• Neutralization of acids in the lakes
• Use of wetlands for the removal of pollutants.
• Siphoning of bottom water (often anaerobic and with a
high phosphorus concentration)
• Removal of the sediment (often with high
concentrations of phosphorus and toxic substances)
• Management of the lake hydrology by shorter retention
time during the spring and summer or by decreasing
the annual retention time.
• Introduction of plant eating fish species

Epilimnion
Hypolimnion
Thermocline
Column with activated
aluminium oxide

Ecosystem Theory
• Environmental Management of ecosystems
requires that we know the system that we
want to manage and it is furthermore
important to know the system properties of
the systems that we want to model
• Ecological Modelling is publishing many
system ecological papers, but Ecological
Complexity is an important supplement for
publication of ecosystem theory

Recently at a brainstorming meeting on
the Danish Island Møn, it was possible to
“hang” 10 basic laws, proposed by SEJ
on 5 ecosystem properties:

Recently at a brainstorming meeting on the
Danish Island Møn, it was possible to
“hang” these 10 laws on 5 ecosystem
properties:

We do have an ecosystem theory! Why
do we not apply this theory more
widely inlake ecology and lake
management?
• It should be applied to explain
ecological observations and used
as tool in ecological modelling,
engineering and for the assessment
of ecosystem health by the use of
ecological indicators!!

The Application of
Ecological Indicators to
assess Ecosystem Health
Ecological Indicators are used
increasingly as an environmental
management tool – often as a
supplement to ecological modelling
It is also supplemented by assessment
of ecosystem services

Important book:
• Jørgensen, S.E., Robert
Costanza and Xu Fuliu
Handbook of Ecolgical Indicators
for the Assessment of
Ecosystem Health, crc, Lewis
Publ. 2004. Second edition 2010

Do you know the disease?
• The disease may define the
indicator, for instance PCB
pollution in the Great Lakes
• Invasion by zebra mussels
• (Lake Erie)

What should ecological
indicators cover?
• l) homeostasis;
• 2) absence of disease,
• 3) diversity or complexity;
• 4) stability or resilience;
• 5) vigor or scope for growth
• 6) balance between system
components

Two methods may be
applied:
• By Direct Measurements /
Observations Method
• By the Application of Models,
for instance ECOPATH or a
bio-geochemical model

Classification of Ecological
Indicators and their application in
lake management
• Reductionistic (single) indicators - like for
instance PCB (Great Lake)
• Species present / absent (many lakes)
• Semiholistic indicators: f.inst. Odum’s
attributes (many lakes)
• Holistic indicators - biodiversity /
ecological network (For instance the East-
African lakes)
• “Super-holistic” - thermodynamic
indicators, such as emergy, exergy and
the ratio exergy/ emergy (several lakes)

Conclusions I:
Due to ecological modelling,
ecological economics,
ecological engineering
and use of
ecological indicators,
we have to day lake
management based on
a solid ecological
Knowledge - fortunately

Conclusions II:
The lake management
would probably have been
more technological and
less ecological to day if
we would not have had
the sub-disciplines in
applied ecology to enhance
the ecological considerations
in lake management

Thank you for your attention