Prof. Dr. Gerhard Wiegleb

BTU Cottbus, Germany

Restoration of heavily disturbed

landscapes – the lignite post mining

landscape around Cottbus

Vilm, July 2012

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Contents

Principles of ecological restoration

• Goal functions and reference states, aim conflicts, types of

landscapes to be restored

Case study: Open cast lignite mining landscape in Lower Lusatia,

East Germany

• Legal and economic framework

• Own research results

Conclusions

• General principles of restoration, the human factor, the role of

scientists, necessity for information exchange

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Principles of ecological restoration

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Definition of Ecological Restoration

• Ecological Restoration is an attempt to guide damaged ecosystems to a previous, healthier, more natural, or any other desired condition (adapted from SER Primer on Ecological Restoration*).

• The prefix “Re-“ does not necessarily imply a historic state.

• “Attempt“ indicates that restoration can fail because of many uncertainties in the restoration process.

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* http://www.ser.org/content/ecological_restoration_primer.asp

Examples of ecological restoration

Ecosystems are embedded in landscapes: mosaics of two or more ecosystems that exchange organisms, energy, water and nutrients (on a large-scale)

• Rehabilitation of river courses and flood plains

• Restoration of soil degradation caused by desertification, salinization etc.

• Reclamation of degradation and devastation caused by mining

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http://www.cpre.org.uk/what-we-do/energy-and-waste/quarrying-

and-mining/the-issues

http://rainbowfish.angfaqld.org.au/Habit

at.htm

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0

“Landscaping”

Regional planning

EIA/SEA Directive

Landscape and urban planning

Agricultural and forest

planning

Precautionary

approach

Protective

Approach

Restorative

approach Ecological restoration

Instruments

Habitats Directive

Conservation law

- Species protection

- Habitat protection

- Protected areas

Indicators

- Macrophytes

- EU birds

- Area size

- etc.

Sustainable use

Conservation

Strategies

Environmental Liability Directive

Habitats Directive

“EIA”

Red = EU legislation

Ecological restoration (textbook approach)

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Renaturalization (incl.

“extensification”)

Restoration (“restitution”,

“sanitation“, “regeneration”)

Rehabilitation

(“revitalization“)

Self-sustaining

rehabilitation

Reclamation

(“remediation“)

Reconstruction

Reintroduction

What else? Creation?

Species composition

Biomass/nutrient

content

No action

natural

Increasing

ecological

integrity?

Source: modified from A.D.Bradshaw, www.beloit.edu

Ecological restoration (refined approach)

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Biotic integrity (species, habitats)

Abiotic integrity

(functions, processes)

Original state

(natural or

cultural)

Disturbed state

Ecological trajectory: Developmental pathway of an ecosystem e.g.

from an unrestored to a desired state of recovery

Ecological restoration - a dynamic model

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Time

Desired ecological functions

Ecosystem of natural

or cultural landscape

More or less

degraded system

Damage,

degradation

Restoration

Further

degradation

Unsuccessful

restoration

Threshold for success

Ecological restoration in Europe

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Type Ecosystem type Aim

Restoration of

natural landscapes

Rivers, lakes, bogs

and fens, salt

marshes, forests

Reduction or

minimization of

land-use

Restoration of

cultural landscapes

Wet grassland,

heathland, arid

grassland,

hedgerows, also

some forest types

Continuation or

reintroduction of

historic land-use or

its simulation

Restoration of

heavily disturbed

landscapes

Mining areas,

military areas,

quarries, urban and

industrial waste

land

Obvious damage

has to be repaired.

Desired states are

being initialized or

reconstructed

Aim conflicts within ecological restoration

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• Examples: natural beech forest vs. urban areas

Close-to-naturalness Biodiversity

Some natural habitats in Central Europe originally

have been less diverse than anthropogenically

disturbed ones

Conflict

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Biodiversity and Naturalness

Species no.

Taxon

In Central

Europe

In beech

forests

In cities

Mammals

98

27

22

Birds

400

70

200

Reptils

14

5

4

Amphibia

19

7

10

Snails and

slugs

490

70

55

Spiders

2,280

560

680

Crayfish

900

26

8

Myriapods

200

60

25

Beetles

6,800

1,500

1,190

Butterflies /

moths

3,000

1,300

1,880

Hymen-

opterans

10,000

700

1,110

Dipterans

6,000

1,080

240

Other insects

3,000

580

800

The assumed price of

biodiversity gain?!

The sustainability triangle

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Economic

dimension Social

dimension

Ecological

dimension

Willingness-to-pay

Reference

states

Ecosystem

services

Human

population

Restoration is often falsely regarded as a technical process only. However,

the human dimension has to be taken into account as well.

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Naturalness and Wildness

Naturalness can be decomposed into two concepts:

• Wildness – freedom from human control and

manipulation (actualistic)

• Naturalness s. str. – native species, patterns, and

processes (historic)

Source: http://leopold.wilderness.net

Restoration of lignite post mining

landscapes in Lower Lusatia

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Brandenburg University of Technology Cottbus (BTU)

Map of Germany

Medium mountains

Alps

Glacial lowland

Luckau

Berlin

Germany

Cottbus

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Overview of the landscape

Military training area

Lignite mine After Pilarski

Distribution of mining areas

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• 800 km2 devastated

• 2500 km affected by

lowering of ground

water

• 18 mines closed

down (yellow)

• 5 mines active

(brownish)

• 2 mines to be

extended and 3

mines to be opend

up (red)

History of lignite mining in Lusatia

• Mining started around 1789, below ground mining in the 19th century.

• Since 1900 open cast mining was favoured, both for economic reasons and

for avoiding casualties. Shafts often collapsed because of the loose sandy

substrate.

• In 1924 the first conveyor belt bridge was introduced in the mine site

Plessa (55 km southwest of Cottbus). Conveyor belt bridges were combined

with shovel excavators since 1934, later also with bucket-wheel excavators.

• First attempts for restoration were made around 1930 (afforestation with

Scots Pine).

• Since 1960 mining was intensified because of the energy shortage in East

Germany. Since 1973 60-m conveyor belt bridges were used.

• A legal obligation for reclamation existed but could not follow the excavation.

After 1989 and the closing down of many mines the German state became

the owner of many unreclaimed mines and had to carry the financial burden

of reclamation.

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Mining technology and obvious damage

21 http://www.lausitzer-braunkohle.de/feld_welzow_1.php

Active mines Cottbus-Nord

(above) and Nochten (below)

Damage in the adjacent areas because

of groundwater lowering

http://de.wikipedia.org/w/index.php?title=Datei:Tagebau_Nochten,_K

W_Boxberg.jpg&filetimestamp=20080920182845

The environmental impact of open cast mining

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The main impacts are

- Destruction of land (= devastation) including fauna

and flora

- Lowering of groundwater level up to 100 m, creating

completely new hydrological conditions

- Creatings dangers in former of landslides or

solifluction of lose sediments

- Changing the mesoclimate of the region (already the

dryest region in Germany)

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Seeding of grasses for erosion

control

Starting conditions

Afforestations with Red Oak

Standard reclamation measures

Natural succession in terrestrial habitats (from open

land to forest)

P. Denkinger

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http://www.schlabendorfer-

felder.de/sammeln/lokale_akteure/vegetation/vegetation_einfuehr

ung.htm

From dryland to wetland

Upwelling ground water after wet summers since 2009

Process of Ecological Restoration

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Restoration Goal possible, sustainable, local needs, reasonable cost

Restoration Objectives Ecosystem attributes, priorities

Measurable Success Criteria What criteria over what time scale?

Topsoil Retained (e.g. strip mining):

• Clearing Existing Vegatation • Topsoil Handling • Earthworks

Re-vegetation

Nutrient accumulation and cycling

Indigenous volunteer species

Topsoil Lost/Buried (e.g. tailings dams)

• Assessment of Wastes/Sites • Site Preparation

Adaptive Management Replanting, fire/pest management

Monitoring

Assessment of Success Criteria

Measurement, feedback to proceding stage

Aims of mining restoration

Reclamation aims according to German mining legislation are simple and

legally binding.

• Restoration of the previous state with respect to landuse, usually

forestry and agriculture

• Danger prevention, in particular prevention of land slides and

solifluction of the lose sediments, avoiding disturbance by wind erosion

• Reintegration of the mining areas into the regional water household,

with respect to water quality and ground water level

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Comparison of restoration of different ecosystem types

River Peat land Mining area

Legal obligations Direct, EU Water

Framework

Directive

Indirect, EU

Habitats and

Birds Directive

Direct, national

mining law

Economic need Obvious because

of damage to

cities and cultural

goods

Remote, benefit

of ecosystem

services not

quantified

Unclear on the

long term

Goals Clearly defined to

be specified on a

case-based basis

Simple: peat

depths, water

level, no

eutrophication

Set by mining law

but in contrast to

nature

conservation law

Instruments Multiple, from EIA

to EU programs

Multiple, mostly

from agricultural

planning

Classical

reclamation

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Own research

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Habitat types

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Analysis of change

based on remote

sensing data Antwi 2007

M. Pilarski U. Nocker

1995 2000

Total Land Area 5598,81 5619,91

Number of patches 4938,00 10472,00

Mean Patch Size 1,13 0,54

Edge Density 308,76 451,82

Mean Shape Index 1,38 1,31

Shannon Diversity Index 1,79 2,18

Shannon Eveness Index 0,75 0,81

Development of landscape

heterogeneity 1995 and 2000

31 Landscape is getting more heterogenous

Antwi 2007

Landscape characteristics - time lag effects

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Shannon Diversity Index

1.5

1.6

1.7

1.8

1.9

2

2.1

2.2

1888 1991 1995 1998 2000 2003

Year

Nu

mb

er

Nord (SDI) Süd (SDI)

Peak 18 years after closing

Still increasing 15

years after closing

despite all

reclamation effort!

Antwi 2007

Chronosequence of Plant Species In Open Areas

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Chronosequence of Arthropod Species No.

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age (years)

Invertebrate animals come very fast as well

Ln S

Capture of diaspores

Diaspores come very fast

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Highly acidic?

Possible obstacles?

Production limitation due to sediment inhomogeneity

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pH > 4 pH > 4 pH < 4 pH < 4

Planted Scots Pines do not grow (filter effect of low pH):

good or bad depends on the viewpoint

Acid mining lakes

38 pH = 2.0, leading to die back of trees after upwelling of acid groundwater

Sooner or later later the free sulfuric acid appears in the surface waters

Avifauna of mining lakes

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Habitat type Site characterisation Bird species

Large rest-holes Deep water, steep slopes, sparse aquatic and riparian vegetation, mostly acidic, pH 2.1–4.5, rarely neutral

Black-headed Gull (Larus ridibundus) Mediterranean Gull (Larus melanocephalus)

Herring Gull (Larus argentatus) Eastern Yellow-legged Gull (Larus cachinnans)

Western Yellow-legged Gull (Larus michahellis) Common Gull (Larus canus) Common Tern (Sterna hirundo)

Small water

bodies

Shallow water, partly temporary, with aquatic vegetation and reed belts, mostly neutral, pH 5-7

Marsh Harrier (Circus aeruginosus) Great Reed Warbler (Acrocephalus arundinaceus)

European Crane (Grus grus)

Streams Often only temporary, partly filled with iron-rich, acidic mining water

No specialized avifauna

From Blaschke et al. 2000

Characteristics of mining water

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Mining waters are

- Acid

- Turbid

- Iron-rich

Before they are released into the surface water system, they

must be purified by artifical wetlands (= former rest lakes

which are used as natural sewage plants)

- Turbidity and iron can be removed by sedimentation

- Acidity can be removed by neutralization with limestone or

organic waste (!)

- But not for „ecological reasons“ (see the „defense of the

plume moth“, J. Dahl)

Outlook and conclusions

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Types of restoration projects

• Top-down activities, government induced, run by experts only (the bog landscape project, at least in the beginning)

• Top-down approach including participation of various groups such as local administration, people, NGOs, private sector etc. (the ordinary post mining case)

• Model projects proposed by scientists

• Bottom-up activities triggered by the local community (mostly small-scale, but see following example)

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A positive example: “Kolonisten gesucht“ (“Colonists

wanted“)

43 http://www.schlabendorfer-

felder.de/auswerten/download/subicon_steckbriefe_2010_ebook.pdf

Landscape workshop Schlabendorfer Felder

• Knowledge transfer between science and practice

• Embedding biodiversity discourses into discourses about regional development

• Environmental education by ecological research

• By exhibitions

Wiegleb - Anders - Rißmann

www.schlabendorfer-felder.de

Transparenz, Systematik,

Dokumentation

Sammeln: Werkstattausstellung Auswerten: Workshops und

Pleinaire Verknüpfen:

Abschlussausstellung 19.6.10

… and publications

Nature conservation: fixed guiding principles vs. „look,

what is possible“

Natural dynamics vs. management to keep areas open

Natural dynamics is related to social dynamics

Ecologists must accept a new role: from expert judgment to service and

partnership

Wiegleb - Anders - Rißmann

Critical dialogue between

scientists and practitioneers

Forestry: New forest images, new chances

• Flexibility is also required from

all landusers

• Foresters in Central Europe are

used to strict separation of

forest and open areas since

1850

• The new situations allows

succession forest which grow

without interference by

foresters.

Wiegleb - Anders - Rißmann

Conclusion from the mining example

• Still, after 20 years restoration aims remain controversial.

• The focus on restoring agriculture areas and forests is unbroken. It

took a long time until the local population recognized the potential

of their new landscapes. The process of decision making is now

more relaxed (see Landscape Workshop, www.schlabendorfer-

felder.de )

• Around 25 % of the reclaimed land is now reserved for nature

conservation (Natura 2000 areas according to EU Habitats

Directive, Specially Protected Aareas according to EU Birds

Directive, protected areas according to national legislation)

• Rethinking was triggered by external actors with a lot of money,

who bought “waste land“ and started to implement nature

conservation projects (Heinz Sielmann Foundation, NABU)

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Personal statements

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The role of scientists in restoration

• We must consider the fundamental roles of actors, stakeholders, public vs. experts, half-experts, laymen etc.

Scientists may take different roles in the restoration process:

• As advisors (experts on the political level)

• As party involved (in regional model projects, as participant in discussion on restoration aims)

• As scientists only (carrying out research on an interesting object)

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Summary

• Restoration may be driven by many motives, e.g.

legal, cultural, ethical, and economic ones.

• Still, there would be no restoration without non-

scientific motives, but the will be no successful

restoration without scientific knowledge

• Our credo is that good ecological science will

eventually lead to good ecological restoration.

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Thank you for your attention!

• I thank Dr. U. Bröring (Cottbus), P. Denkinger (Hamburg), Dr. M. Pilarski

(Potsdam), Dr. K. Anders (Müncheberg), Dr. E. Antwi (Tokyo) and Dr. T.

Peschel (Berlin) for valuable contributions to the work.

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