1 INTRODUCTION ................................................. 1
1.1 Problem background ...................................... 1
1.2 Objective of the thesis ................................. 5
1.3 Structure of the thesis ................................. 7
2 BIOLOGICAL INVASIONS AS ECOLOGICAL PHENOMENON ............... 11
2.1 Terms and definitions .................................. 11
2.2 The invasion process and causing factors ............... 14
2.2.1 Phases of the invasion process .................. 14
2.2.2 Factors influencing the invasion process ........ 15
2.3 The scope of impacts of biological invasions ........... 22
2.3.1 Ecological impacts .............................. 23
2.3.2 Societal impacts ................................ 26
2.3.3 Irreversibility during the invasion process ..... 27
2.4 Management options of biological invasions ............. 28
3 UNCERTAINTY LINKED TO BIOLOGICAL INVASIONS .................. 31
3.1 A taxonomy of uncertainty .............................. 32
3.2 Uncertainty regarding biological invasions impacts ..... 36
3.2.1 Preparatory considerations ...................... 36
3.2.2 Uncertainty regarding the time dimension ........ 38
3.2.3 Uncertainty regarding the impact dimension ...... 40
3.3 Sources of uncertainty of biological invasions ......... 42
3.4 Uncertainty regarding the management of invasive
species ................................................ 44
3.4.1 Uncertainty regarding the ecological
effectiveness of prevention and eradication
strategies ...................................... 46
3.4.2 Uncertainty regarding the ecological
effectiveness of control and adaptation
strategies ...................................... 47
3.5 Dealing with uncertainty linked to biological
invasions .............................................. 48
3.5.1 General recommendations ......................... 49
3.5.2 Specific suggestions for biological invasions ... 54
3.5.3 Conclusions from the analysis of uncertainty .... 57
4 ECONOMIC VALUATION: FOUNDATIONS AND APPLICATION TO
BIOLOGICAL INVASIONS ........................................ 60
4.1 Welfare economic aspects of biological invasions ....... 60
4.1.1 Individual preferences as source of economic
value ........................................... 60
4.1.2 Private and public goods ........................ 61
4.1.3 The public good character of biological
invasions ....................................... 63
4.2 The role of economic assessments of biological
invasions .............................................. 64
4.2.1 Costs and benefits of biological invasions ...... 65
4.2.2 Assessments of costs and benefits ............... 66
4.2.3 Economic impact assessment: assessing gross
costs ........................................... 67
4.2.4 Decision aid: net benefits of management
options ......................................... 70
4.2.5 Comparison of economic impact assessment and
decision aid .................................... 71
4.3 Cost-benefit analysis as tool for decision aid ......... 72
4.3.1 Purpose of a cost-benefit analysis .............. 73
4.3.2 Stages of practical cost-benefit analysis ....... 74
4.4 Environmental economic valuation techniques ............ 76
4.4.1 Revealed preferences methods .................... 77
4.4.2 Stated preferences methods ...................... 79
4.5 The Total Economic Value ............................... 81
4.5.1 The idea of the Total Economic Value ............ 81
4.5.2 The TEV applied to biological invasions ......... 83
4.5.3 Limits of the TEV ............................... 85
4.6 Critiques of the welfare economic valuation of
biological invasions ................................... 89
4.6.1 General criticism of welfare economic
valuation of the environment .................... 89
4.6.2 Challenges for an economic valuation of
biological invasions ............................ 91
4.6.3 Challenges for ecological-economic assessments
of biological invasions ......................... 94
5 SURVEY OF CURRENT STUDIES ON THE ECONOMICS OF BIOLOGICAL
INVASIONS ................................................... 97
5.1 Introductory remarks ................................... 97
5.2 Cornerstones of the review ............................. 98
5.3 Overview of the literature ............................ 100
5.3.1 General character of the studies ............... 102
5.3.2 Evaluated strategies ........................... 105
5.4 In-depth analysis of selected studies ................. 105
5.5 Studies addressing the scope- and the uncertainty-
problem ............................................... 115
5.5.1 Scope of impacts to be considered .............. 115
5.5.2 The role of uncertainty ........................ 117
5.6 Conclusions from the survey ........................... 117
6 ENHANCING ECONOMIC ASSESSMENTS WITH THE CONCEPT OF
ECOSYSTEM SERVICES ......................................... 121
6.1 The concept of ecosystem services ..................... 121
6.1.1 Origins of the concept ......................... 122
6.1.2 Current relevance .............................. 124
6.1.3 The classification of ecosystem services ....... 126
6.1.4 The status of biodiversity in the concept
of ecosystem services .......................... 130
6.2 Impacts of biological invasions on ecosystem
services .............................................. 132
6.3 Advantages of the concept of ecosystem services for
economic assessments of biological invasions .......... 141
6.3.1 The concept of ecosystem services
contributing to the scope-problem .............. 142
6.3.2 The concept of ecosystem services
contributing to the uncertainty-problem ........ 145
6.3.3 Addressing stakeholders for affected
ecosystem services ............................. 148
6.4 Conclusions: the suitability of ecosystem services
for economic assessments of biological invasions ...... 156
7 BIOLOGICAL INVASIONS IN GERMANY AND THE CASE STUDY OF
AMBROSIA ARTEMISUFOLIA ..................................... 161
7.1 Impacts of invasive species on ecosystem services
in Germany ............................................ 161
7.1.1 The special situation due to Germanys
evolutionary history ........................... 161
7.1.2 Examples of invasive species changing
ecosystem services in Germany .................. 162
7.2 The case of Ambrosia artemisiifolia in Germany ........ 166
7.2.1 Characteristics of the Ambrosia-problem in
Germany ........................................ 166
7.2.2 Contributions to the scope-problem: ecosystem
services used as analysis structure for
impacts of Ambrosia ............................ 169
7.2.3 Management options for Ambrosia ................ 174
7.2.4 Contributions to the uncertainty-problem:
structuring incomplete knowledge with the
concept of ecosystem services .................. 178
7.2.5 Identification of stakeholders involved in
the Ambrosia-problem ........................... 185
7.3 Conclusions from the case study: a physical
assessment of Ambrosia with the concept of ecosystem
services .............................................. 194
8 FINAL CONCLUSIONS AND RECOMMENDATIONS FOR FURTHER
RESEARCH ................................................... 199
8.1 Summary of main findings .............................. 199
8.2 Implications of the findings for economic analyses .... 203
8.3 Remaining problems and recommendations for further
research .............................................. 207
9 SUMMARY (ENGLISH AND GERMAN) ............................... 211
10 LITERATURE ................................................. 219
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