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From trend to one-time pairwise testing
statistical and economic optimization in the evaluation of intervention effects in...
Jan H. Wanink & Ronald Bijkerk

INTECOL 2013
Conservation management and policy
London, UK
August 20, 2013

From time-seri...
Jan H. Wanink & Ronald Bijkerk

INTECOL 2013
Conservation management and policy
London, UK
August 20, 2013

From time-seri...
Jan H. Wanink & Ronald Bijkerk

INTECOL 2013
Conservation management and policy
London, UK
August 20, 2013

From time-seri...
Jan H. Wanink & Ronald Bijkerk

INTECOL 2013
Conservation management and policy
London, UK
August 20, 2013

From time-seri...
Jan H. Wanink & Ronald Bijkerk

INTECOL 2013
Conservation management and policy
London, UK
August 20, 2013

From time-seri...
Jan H. Wanink & Ronald Bijkerk

INTECOL 2013
Conservation management and policy
London, UK
August 20, 2013

From time-seri...
Jan H. Wanink & Ronald Bijkerk

INTECOL 2013
Conservation management and policy
London, UK
August 20, 2013

From time-seri...
Jan H. Wanink & Ronald Bijkerk

INTECOL 2013
Conservation management and policy
London, UK
August 20, 2013

From time-seri...
Jan H. Wanink & Ronald Bijkerk

INTECOL 2013
Conservation management and policy
London, UK
August 20, 2013

From time-seri...
Jan H. Wanink & Ronald Bijkerk

INTECOL 2013
Conservation management and policy
London, UK
August 20, 2013

From time-seri...
Jan H. Wanink & Ronald Bijkerk

INTECOL 2013
Conservation management and policy
London, UK
August 20, 2013

From time-seri...
Jan H. Wanink & Ronald Bijkerk

INTECOL 2013
Conservation management and policy
London, UK
August 20, 2013

From time-seri...
INTECOL 2013
Conservation management and policy
London, UK
August 20, 2013

Jan H. Wanink & Ronald Bijkerk

From time-seri...
Jan H. Wanink & Ronald Bijkerk

INTECOL 2013
Conservation management and policy
London, UK
August 20, 2013

From time-seri...
Jan H. Wanink & Ronald Bijkerk

INTECOL 2013
Conservation management and policy
London, UK
August 20, 2013

From time-seri...
INTECOL 2013
Conservation management and policy
London, UK
August 20, 2013

Jan H. Wanink & Ronald Bijkerk

From time-seri...
Jan H. Wanink & Ronald Bijkerk

INTECOL 2013
Conservation management and policy
London, UK
August 20, 2013

From time-seri...
Jan H. Wanink & Ronald Bijkerk

INTECOL 2013
Conservation management and policy
London, UK
August 20, 2013

From time-seri...
INTECOL 2013
Conservation management and policy
London, UK
August 20, 2013

Jan H. Wanink & Ronald Bijkerk

From time-seri...
Jan H. Wanink & Ronald Bijkerk

INTECOL 2013
Conservation management and policy
London, UK
August 20, 2013

From time-seri...
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From trend to one-time pairwise testing: statistical and economic optimization in the evaluation of intervention effects in seasonal environments

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Oral presentation at INTECOL 2013, London.

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From trend to one-time pairwise testing: statistical and economic optimization in the evaluation of intervention effects in seasonal environments

  1. 1. From trend to one-time pairwise testing statistical and economic optimization in the evaluation of intervention effects in seasonal environments Jan H. Wanink & Ronald Bijkerk Koeman en Bijkerk bv Ecological Research and Consultancy P.O. Box 111, 9750 AC Haren, The Netherlands j.h.wanink@koemanenbijkerk.nl
  2. 2. Jan H. Wanink & Ronald Bijkerk INTECOL 2013 Conservation management and policy London, UK August 20, 2013 From time-series to one-time pairwise testing statistical and economic optimization in the evaluation of intervention effects in seasonal environments OVERVIEW BACKGROUND PROBLEM DEFINITION TRADITIONAL METHOD ALTERNATIVE METHOD WHY USE THE ALTERNATIVE? BACKGROUND TRADITIONAL METHOD PROBLEM DEFINITION ALTERNATIVE METHOD WHY USE THE ALTERNATIVE? CASE STUDIES FROM DITCHES AND CANALS agricultural buffer strips natural banks mammal ladders CASE STUDIES FROM DITCHES AND CANALS agricultural buffer strips natural banks mammal ladders CONCLUSIONS CONCLUSIONS
  3. 3. Jan H. Wanink & Ronald Bijkerk INTECOL 2013 Conservation management and policy London, UK August 20, 2013 From time-series to one-time pairwise testing statistical and economic optimization in the evaluation of intervention effects in seasonal environments OVERVIEW BACKGROUND PROBLEM DEFINITION TRADITIONAL METHOD ALTERNATIVE METHOD WHY USE THE ALTERNATIVE? CASE STUDIES FROM DITCHES AND CANALS agricultural buffer strips natural banks mammal ladders CONCLUSIONS BACKGROUND Environment managers increasingly have to take intervention measures to meet ecological standards requested by, for instance, the European Water Framework Directive Such intervention measures often come with the obligation to monitor for their effects
  4. 4. Jan H. Wanink & Ronald Bijkerk INTECOL 2013 Conservation management and policy London, UK August 20, 2013 From time-series to one-time pairwise testing statistical and economic optimization in the evaluation of intervention effects in seasonal environments OVERVIEW BACKGROUND PROBLEM DEFINITION TRADITIONAL METHOD ALTERNATIVE METHOD WHY USE THE ALTERNATIVE? CASE STUDIES FROM DITCHES AND CANALS agricultural buffer strips natural banks mammal ladders CONCLUSIONS PROBLEM DEFINITION Determination of statistically significant trends in response parameters is commonly inhibited by large seasonal fluctuations in the tested parameters Using trend analysis, one can detect significant intervention effects after several years only, hence making monitoring expensive
  5. 5. Jan H. Wanink & Ronald Bijkerk INTECOL 2013 Conservation management and policy London, UK August 20, 2013 From time-series to one-time pairwise testing statistical and economic optimization in the evaluation of intervention effects in seasonal environments OVERVIEW BACKGROUND PROBLEM DEFINITION TRADITIONAL METHOD ALTERNATIVE METHOD WHY USE THE ALTERNATIVE? CASE STUDIES FROM DITCHES AND CANALS agricultural buffer strips natural banks mammal ladders CONCLUSIONS TRADITIONAL METHOD Common practice: monitoring for at least five years, after which intervention effects are evaluated using trend analysis
  6. 6. Jan H. Wanink & Ronald Bijkerk INTECOL 2013 Conservation management and policy London, UK August 20, 2013 From time-series to one-time pairwise testing statistical and economic optimization in the evaluation of intervention effects in seasonal environments OVERVIEW BACKGROUND PROBLEM DEFINITION TRADITIONAL METHOD ALTERNATIVE METHOD Some years after the intervention measure: one-time sampling of many paired stations Only one station of each pair is subjected to the measure under study ALTERNATIVE METHOD The results are tested with pairwise statistical tests WHY USE THE ALTERNATIVE? CASE STUDIES FROM DITCHES AND CANALS agricultural buffer strips natural banks mammal ladders CONCLUSIONS
  7. 7. Jan H. Wanink & Ronald Bijkerk INTECOL 2013 Conservation management and policy London, UK August 20, 2013 From time-series to one-time pairwise testing statistical and economic optimization in the evaluation of intervention effects in seasonal environments OVERVIEW BACKGROUND PROBLEM DEFINITION TRADITIONAL METHOD ALTERNATIVE METHOD WHY USE THE ALTERNATIVE? CASE STUDIES FROM DITCHES AND CANALS agricultural buffer strips natural banks mammal ladders CONCLUSIONS WHY USE THE ALTERNATIVE METHOD? 1) No seasonal distortion of the data >> statistical significance of intervention effects can be determined more easily
  8. 8. Jan H. Wanink & Ronald Bijkerk INTECOL 2013 Conservation management and policy London, UK August 20, 2013 From time-series to one-time pairwise testing statistical and economic optimization in the evaluation of intervention effects in seasonal environments OVERVIEW BACKGROUND WHY USE THE ALTERNATIVE METHOD? 2) Lower number of samples to analyse >> cheaper PROBLEM DEFINITION TRADITIONAL METHOD Traditional Alternative Number of stations 10 200 Sampling frequency per year 9 0.2 Number of sampling years 5 5 450 200 ALTERNATIVE METHOD WHY USE THE ALTERNATIVE? CASE STUDIES FROM DITCHES AND CANALS agricultural buffer strips natural banks mammal ladders CONCLUSIONS Number of analyses (x € or £)
  9. 9. Jan H. Wanink & Ronald Bijkerk INTECOL 2013 Conservation management and policy London, UK August 20, 2013 From time-series to one-time pairwise testing statistical and economic optimization in the evaluation of intervention effects in seasonal environments OVERVIEW BACKGROUND PROBLEM DEFINITION TRADITIONAL METHOD ALTERNATIVE METHOD WHY USE THE ALTERNATIVE? CASE STUDIES FROM DITCHES AND CANALS agricultural buffer strips natural banks mammal ladders CONCLUSIONS CASE SUDIES FROM DITCHES AND CANALS
  10. 10. Jan H. Wanink & Ronald Bijkerk INTECOL 2013 Conservation management and policy London, UK August 20, 2013 From time-series to one-time pairwise testing statistical and economic optimization in the evaluation of intervention effects in seasonal environments OVERVIEW CASE SUDIES FROM DITCHES AND CANALS 1) agricultural buffer strips BACKGROUND PROBLEM DEFINITION TRADITIONAL METHOD ALTERNATIVE METHOD WHY USE THE ALTERNATIVE? CASE STUDIES FROM DITCHES AND CANALS agricultural buffer strips natural banks mammal ladders CONCLUSIONS 2) natural banks 1) mammal ladders
  11. 11. Jan H. Wanink & Ronald Bijkerk INTECOL 2013 Conservation management and policy London, UK August 20, 2013 From time-series to one-time pairwise testing statistical and economic optimization in the evaluation of intervention effects in seasonal environments OVERVIEW BACKGROUND PROBLEM DEFINITION TRADITIONAL METHOD ALTERNATIVE METHOD WHY USE THE ALTERNATIVE? CASE STUDIES FROM DITCHES AND CANALS agricultural buffer strips natural banks mammal ladders CONCLUSIONS 1) agricultural buffer strips Poster B2.38 ̶ Wednesday August 21, 18:15 – 19:30 Testing for effects of agricultural buffer strips on the ecological quality of adjacent surface waters
  12. 12. Jan H. Wanink & Ronald Bijkerk INTECOL 2013 Conservation management and policy London, UK August 20, 2013 From time-series to one-time pairwise testing statistical and economic optimization in the evaluation of intervention effects in seasonal environments OVERVIEW 1) agricultural buffer strips Buffer strips between farmland and adjacent watercourses BACKGROUND PROBLEM DEFINITION TRADITIONAL METHOD ALTERNATIVE METHOD WHY USE THE ALTERNATIVE? CASE STUDIES FROM DITCHES AND CANALS agricultural buffer strips natural banks mammal ladders CONCLUSIONS Fertilization and spraying of the strips prohibited
  13. 13. Jan H. Wanink & Ronald Bijkerk INTECOL 2013 Conservation management and policy London, UK August 20, 2013 From time-series to one-time pairwise testing statistical and economic optimization in the evaluation of intervention effects in seasonal environments OVERVIEW BACKGROUND 1) agricultural buffer strips 51 paired sampling stations Sampled after 2 – 3 years PROBLEM DEFINITION TRADITIONAL METHOD ALTERNATIVE METHOD WHY USE THE ALTERNATIVE? CASE STUDIES FROM DITCHES AND CANALS agricultural buffer strips natural banks mammal ladders CONCLUSIONS
  14. 14. INTECOL 2013 Conservation management and policy London, UK August 20, 2013 Jan H. Wanink & Ronald Bijkerk From time-series to one-time pairwise testing statistical and economic optimization in the evaluation of intervention effects in seasonal environments OVERVIEW BACKGROUND 1) agricultural buffer strips Lower concentrations of N-compounds at A-stations PROBLEM DEFINITION TRADITIONAL METHOD Variable H1 t n p Total P A<B 1.08 41 0.8573 Total N A<B - 2.42 50 0.0095 Ammonia A<B - 2.21 37 0.0169 Nitrate A<B - 2.18 40 0.0175 ALTERNATIVE METHOD WHY USE THE ALTERNATIVE? CASE STUDIES FROM DITCHES AND CANALS agricultural buffer strips natural banks mammal ladders CONCLUSIONS
  15. 15. Jan H. Wanink & Ronald Bijkerk INTECOL 2013 Conservation management and policy London, UK August 20, 2013 From time-series to one-time pairwise testing statistical and economic optimization in the evaluation of intervention effects in seasonal environments OVERVIEW 2) natural banks Construction of natural banks along canals BACKGROUND PROBLEM DEFINITION TRADITIONAL METHOD ALTERNATIVE METHOD WHY USE THE ALTERNATIVE? CASE STUDIES FROM DITCHES AND CANALS agricultural buffer strips natural banks mammal ladders CONCLUSIONS (intervention measure to meet ecological standards WFD)
  16. 16. Jan H. Wanink & Ronald Bijkerk INTECOL 2013 Conservation management and policy London, UK August 20, 2013 From time-series to one-time pairwise testing statistical and economic optimization in the evaluation of intervention effects in seasonal environments OVERVIEW BACKGROUND PROBLEM DEFINITION TRADITIONAL METHOD ALTERNATIVE METHOD WHY USE THE ALTERNATIVE? CASE STUDIES FROM DITCHES AND CANALS agricultural buffer strips natural banks mammal ladders CONCLUSIONS 2) natural banks Testing effects on macroinvertebrates
  17. 17. INTECOL 2013 Conservation management and policy London, UK August 20, 2013 Jan H. Wanink & Ronald Bijkerk From time-series to one-time pairwise testing statistical and economic optimization in the evaluation of intervention effects in seasonal environments OVERVIEW 2) natural banks Significant effects found for cluster 1 BACKGROUND PROBLEM DEFINITION Sample size of cluster 2 too small Power analysis used to predict optimal sample sizes TRADITIONAL METHOD Tested parameters (WFD metrics) DN = Dominant Negative indicator species P = Positive indicator species EQR = Ecological Quality Ratio ALTERNATIVE METHOD WHY USE THE ALTERNATIVE? Stations n Δ %DN Δ %P Δ EQR Cluster 1 9 -7 11 0.2 Cluster 2 4 -8 6 0.1 CASE STUDIES FROM DITCHES AND CANALS agricultural buffer strips natural banks mammal ladders CONCLUSIONS
  18. 18. Jan H. Wanink & Ronald Bijkerk INTECOL 2013 Conservation management and policy London, UK August 20, 2013 From time-series to one-time pairwise testing statistical and economic optimization in the evaluation of intervention effects in seasonal environments OVERVIEW 3) mammal ladders Sloping escape routes for mammals trapped in a canal BACKGROUND PROBLEM DEFINITION TRADITIONAL METHOD ALTERNATIVE METHOD WHY USE THE ALTERNATIVE? CASE STUDIES FROM DITCHES AND CANALS agricultural buffer strips natural banks mammal ladders CONCLUSIONS Two ladders per location, at opposite sides of the canal Expected additional function: fish habitat
  19. 19. Jan H. Wanink & Ronald Bijkerk INTECOL 2013 Conservation management and policy London, UK August 20, 2013 From time-series to one-time pairwise testing statistical and economic optimization in the evaluation of intervention effects in seasonal environments OVERVIEW 3) mammal ladders One year after construction: testing by electrofishing BACKGROUND PROBLEM DEFINITION TRADITIONAL METHOD ALTERNATIVE METHOD WHY USE THE ALTERNATIVE? CASE STUDIES FROM DITCHES AND CANALS agricultural buffer strips natural banks mammal ladders CONCLUSIONS At 10 locations: 20 m inside and 20 m outside the two ladders
  20. 20. INTECOL 2013 Conservation management and policy London, UK August 20, 2013 Jan H. Wanink & Ronald Bijkerk From time-series to one-time pairwise testing statistical and economic optimization in the evaluation of intervention effects in seasonal environments OVERVIEW 3) mammal ladders EQR higher inside at 8 out of 10 locations (L) BACKGROUND PROBLEM DEFINITION Mean difference: 0.13 (13% of metric width) Inside scores one class higher (good) than outside (moderate) TRADITIONAL METHOD WFD classifications, based on Ecological Quality Ratio (EQR) ALTERNATIVE METHOD bad poor moderate good high WHY USE THE ALTERNATIVE? EQR L-avg p inside 0.68 <0.05 outside 0.55 L-1 L-2 L-3 L-4 L-5 L-6 L-7 L-8 L-9 L-10 CASE STUDIES FROM DITCHES AND CANALS agricultural buffer strips natural banks 0.65 0.63 0.71 0.55 0.77 0.77 0.80 0.56 0.73 0.69 mammal ladders CONCLUSIONS 0.33 0.72 0.49 0.62 0.59 0.59 0.70 0.33 0.70 0.44
  21. 21. Jan H. Wanink & Ronald Bijkerk INTECOL 2013 Conservation management and policy London, UK August 20, 2013 From time-series to one-time pairwise testing statistical and economic optimization in the evaluation of intervention effects in seasonal environments OVERVIEW CONCLUSIONS BACKGROUND Pairwise sampling and testing to evaluate intervention effects is: PROBLEM DEFINITION TRADITIONAL METHOD ALTERNATIVE METHOD ● effective ● relatively cheap Effects on fast responding parameters can be shown quickly WHY USE THE ALTERNATIVE? CASE STUDIES FROM DITCHES AND CANALS agricultural buffer strips natural banks mammal ladders CONCLUSIONS Preferably, sampling design should precede the measures

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