from trend to one-time pairwise testing: statistical and economic optimization in the evaluation of...
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From trend to one-time pairwise testingstatistical and economic optimization in the evaluation of intervention effects in seasonal environments
Jan H. Wanink & Ronald Bijkerk
Koeman en Bijkerk bvEcological Research and ConsultancyP.O. Box 111, 9750 AC Haren, The [email protected]
OVERVIEW
CASE STUDIES FROM DITCHES AND CANALS
● agricultural buffer strips ● natural banks
● mammal ladders
CONCLUSIONS
WHY USE THE ALTERNATIVE?
BACKGROUND
agricultural buffer strips
CASE STUDIES FROM DITCHES AND CANALS
natural banksmammal ladders
Jan H. Wanink & Ronald Bijkerk
INTECOL 2013
London, UKAugust 20, 2013
Conservation management and policy
From time-series to one-time pairwise testingstatistical and economic optimization in the evaluation of intervention effects in seasonal environments
PROBLEM DEFINITION
TRADITIONAL METHOD
ALTERNATIVE METHOD
BACKGROUND
PROBLEM DEFINITION
CONCLUSIONS
TRADITIONAL METHOD
ALTERNATIVE METHOD
WHY USE THE ALTERNATIVE?
OVERVIEW
CONCLUSIONS
WHY USE THE ALTERNATIVE?
BACKGROUND
agricultural buffer strips
CASE STUDIES FROM DITCHES AND CANALS
natural banksmammal ladders
BACKGROUND
Jan H. Wanink & Ronald Bijkerk
INTECOL 2013
London, UKAugust 20, 2013
Conservation management and policy
From time-series to one-time pairwise testingstatistical and economic optimization in the evaluation of intervention effects in seasonal environments
PROBLEM DEFINITION
TRADITIONAL METHOD
ALTERNATIVE METHOD
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
OVERVIEW
CONCLUSIONS
WHY USE THE ALTERNATIVE?
BACKGROUND
agricultural buffer strips
CASE STUDIES FROM DITCHES AND CANALS
natural banksmammal ladders
PROBLEM DEFINITION
Jan H. Wanink & Ronald Bijkerk
INTECOL 2013
London, UKAugust 20, 2013
Conservation management and policy
From time-series to one-time pairwise testingstatistical and economic optimization in the evaluation of intervention effects in seasonal environments
PROBLEM DEFINITION
TRADITIONAL METHOD
ALTERNATIVE METHOD
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
OVERVIEW
CONCLUSIONS
WHY USE THE ALTERNATIVE?
BACKGROUND
agricultural buffer strips
CASE STUDIES FROM DITCHES AND CANALS
natural banksmammal ladders
TRADITIONAL METHOD
Jan H. Wanink & Ronald Bijkerk
INTECOL 2013
London, UKAugust 20, 2013
Conservation management and policy
From time-series to one-time pairwise testingstatistical and economic optimization in the evaluation of intervention effects in seasonal environments
PROBLEM DEFINITION
TRADITIONAL METHOD
ALTERNATIVE METHOD
Common practice: monitoring for at least five years, after which intervention effects are evaluated using trend analysis
OVERVIEW
CONCLUSIONS
WHY USE THE ALTERNATIVE?
BACKGROUND
agricultural buffer strips
CASE STUDIES FROM DITCHES AND CANALS
natural banksmammal ladders
ALTERNATIVE METHOD
Jan H. Wanink & Ronald Bijkerk
INTECOL 2013
London, UKAugust 20, 2013
Conservation management and policy
From time-series to one-time pairwise testingstatistical and economic optimization in the evaluation of intervention effects in seasonal environments
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
The results are tested with pairwise statistical tests
OVERVIEW
CONCLUSIONS
WHY USE THE ALTERNATIVE?
BACKGROUND
agricultural buffer strips
CASE STUDIES FROM DITCHES AND CANALS
natural banksmammal ladders
WHY USE THE ALTERNATIVE METHOD?
Jan H. Wanink & Ronald Bijkerk
INTECOL 2013
London, UKAugust 20, 2013
Conservation management and policy
From time-series to one-time pairwise testingstatistical and economic optimization in the evaluation of intervention effects in seasonal environments
PROBLEM DEFINITION
TRADITIONAL METHOD
ALTERNATIVE METHOD
1) No seasonal distortion of the data >> statistical significance of intervention effects can be determined more easily
OVERVIEW
CONCLUSIONS
WHY USE THE ALTERNATIVE?
BACKGROUND
agricultural buffer strips
CASE STUDIES FROM DITCHES AND CANALS
natural banksmammal ladders
WHY USE THE ALTERNATIVE METHOD?
Jan H. Wanink & Ronald Bijkerk
INTECOL 2013
London, UKAugust 20, 2013
Conservation management and policy
From time-series to one-time pairwise testingstatistical and economic optimization in the evaluation of intervention effects in seasonal environments
PROBLEM DEFINITION
TRADITIONAL METHOD
ALTERNATIVE METHOD
2) Lower number of samples to analyse >> cheaper
Traditional Alternative
Number of stations 10 200
Sampling frequency per year 9 0.2
Number of sampling years 5 5
Number of analyses (x € or £) 450 200
OVERVIEW
CONCLUSIONS
WHY USE THE ALTERNATIVE?
BACKGROUND
agricultural buffer strips
CASE STUDIES FROM DITCHES AND CANALS
natural banksmammal ladders
CASE SUDIES FROM DITCHES AND CANALS
Jan H. Wanink & Ronald Bijkerk
INTECOL 2013
London, UKAugust 20, 2013
Conservation management and policy
From time-series to one-time pairwise testingstatistical and economic optimization in the evaluation of intervention effects in seasonal environments
PROBLEM DEFINITION
TRADITIONAL METHOD
ALTERNATIVE METHOD
OVERVIEW
CONCLUSIONS
WHY USE THE ALTERNATIVE?
BACKGROUND
agricultural buffer strips
CASE STUDIES FROM DITCHES AND CANALS
natural banksmammal ladders
CASE SUDIES FROM DITCHES AND CANALS
Jan H. Wanink & Ronald Bijkerk
INTECOL 2013
London, UKAugust 20, 2013
Conservation management and policy
From time-series to one-time pairwise testingstatistical and economic optimization in the evaluation of intervention effects in seasonal environments
PROBLEM DEFINITION
TRADITIONAL METHOD
ALTERNATIVE METHOD
1) agricultural buffer strips2) natural banks1) mammal ladders
OVERVIEW
CONCLUSIONS
WHY USE THE ALTERNATIVE?
BACKGROUND
agricultural buffer strips
CASE STUDIES FROM DITCHES AND CANALS
natural banksmammal ladders
1) agricultural buffer strips
Jan H. Wanink & Ronald Bijkerk
INTECOL 2013
London, UKAugust 20, 2013
Conservation management and policy
From time-series to one-time pairwise testingstatistical and economic optimization in the evaluation of intervention effects in seasonal environments
PROBLEM DEFINITION
TRADITIONAL METHOD
ALTERNATIVE METHOD
Poster B2.38 ̶ Wednesday August 21, 18:15 – 19:30Testing for effects of agricultural buffer strips on the ecological quality of adjacent surface waters
OVERVIEW
CONCLUSIONS
WHY USE THE ALTERNATIVE?
BACKGROUND
agricultural buffer strips
CASE STUDIES FROM DITCHES AND CANALS
natural banksmammal ladders
Jan H. Wanink & Ronald Bijkerk
INTECOL 2013
London, UKAugust 20, 2013
Conservation management and policy
From time-series to one-time pairwise testingstatistical and economic optimization in the evaluation of intervention effects in seasonal environments
PROBLEM DEFINITION
TRADITIONAL METHOD
ALTERNATIVE METHOD
Buffer strips between farmland and adjacent watercourses1) agricultural buffer strips
Fertilization and spraying of the strips prohibited
OVERVIEW
CONCLUSIONS
WHY USE THE ALTERNATIVE?
BACKGROUND
agricultural buffer strips
CASE STUDIES FROM DITCHES AND CANALS
natural banksmammal ladders
Jan H. Wanink & Ronald Bijkerk
INTECOL 2013
London, UKAugust 20, 2013
Conservation management and policy
From time-series to one-time pairwise testingstatistical and economic optimization in the evaluation of intervention effects in seasonal environments
PROBLEM DEFINITION
TRADITIONAL METHOD
ALTERNATIVE METHOD
51 paired sampling stations
1) agricultural buffer strips
Sampled after 2 – 3 years
OVERVIEW
CONCLUSIONS
WHY USE THE ALTERNATIVE?
BACKGROUND
agricultural buffer strips
CASE STUDIES FROM DITCHES AND CANALS
natural banksmammal ladders
Jan H. Wanink & Ronald Bijkerk
INTECOL 2013
London, UKAugust 20, 2013
Conservation management and policy
From time-series to one-time pairwise testingstatistical and economic optimization in the evaluation of intervention effects in seasonal environments
PROBLEM DEFINITION
TRADITIONAL METHOD
ALTERNATIVE METHOD
Lower concentrations of N-compounds at A-stations
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
1) agricultural buffer strips
OVERVIEW
CONCLUSIONS
WHY USE THE ALTERNATIVE?
BACKGROUND
agricultural buffer strips
CASE STUDIES FROM DITCHES AND CANALS
natural banksmammal ladders
Jan H. Wanink & Ronald Bijkerk
INTECOL 2013
London, UKAugust 20, 2013
Conservation management and policy
From time-series to one-time pairwise testingstatistical and economic optimization in the evaluation of intervention effects in seasonal environments
PROBLEM DEFINITION
TRADITIONAL METHOD
ALTERNATIVE METHOD
2) natural banksConstruction of natural banks along canals(intervention measure to meet ecological standards WFD)
OVERVIEW
CONCLUSIONS
WHY USE THE ALTERNATIVE?
BACKGROUND
agricultural buffer strips
CASE STUDIES FROM DITCHES AND CANALS
natural banksmammal ladders
Jan H. Wanink & Ronald Bijkerk
INTECOL 2013
London, UKAugust 20, 2013
Conservation management and policy
From time-series to one-time pairwise testingstatistical and economic optimization in the evaluation of intervention effects in seasonal environments
PROBLEM DEFINITION
TRADITIONAL METHOD
ALTERNATIVE METHOD
2) natural banksTesting effects on macro-invertebrates
OVERVIEW
CONCLUSIONS
WHY USE THE ALTERNATIVE?
BACKGROUND
agricultural buffer strips
CASE STUDIES FROM DITCHES AND CANALS
natural banksmammal ladders
Jan H. Wanink & Ronald Bijkerk
INTECOL 2013
London, UKAugust 20, 2013
Conservation management and policy
From time-series to one-time pairwise testingstatistical and economic optimization in the evaluation of intervention effects in seasonal environments
PROBLEM DEFINITION
TRADITIONAL METHOD
ALTERNATIVE METHOD
2) natural banks
Stations n Δ %DN Δ %P Δ EQR
Cluster 1 9 - 7 11 0.2
Cluster 2 4 - 8 6 0.1
Significant effects found for cluster 1Sample size of cluster 2 too small Power analysis used to predict optimal sample sizes
Tested parameters (WFD metrics)DN = Dominant Negative indicator species
P = Positive indicator speciesEQR = Ecological Quality Ratio
OVERVIEW
CONCLUSIONS
WHY USE THE ALTERNATIVE?
BACKGROUND
agricultural buffer strips
CASE STUDIES FROM DITCHES AND CANALS
natural banksmammal ladders
Jan H. Wanink & Ronald Bijkerk
INTECOL 2013
London, UKAugust 20, 2013
Conservation management and policy
From time-series to one-time pairwise testingstatistical and economic optimization in the evaluation of intervention effects in seasonal environments
PROBLEM DEFINITION
TRADITIONAL METHOD
ALTERNATIVE METHOD
3) mammal laddersSloping escape routes for mammals trapped in a canalTwo ladders per location, at opposite sides of the canalExpected additional function: fish habitat
OVERVIEW
CONCLUSIONS
WHY USE THE ALTERNATIVE?
BACKGROUND
agricultural buffer strips
CASE STUDIES FROM DITCHES AND CANALS
natural banksmammal ladders
Jan H. Wanink & Ronald Bijkerk
INTECOL 2013
London, UKAugust 20, 2013
Conservation management and policy
From time-series to one-time pairwise testingstatistical and economic optimization in the evaluation of intervention effects in seasonal environments
PROBLEM DEFINITION
TRADITIONAL METHOD
ALTERNATIVE METHOD
3) mammal laddersOne year after construction: testing by electrofishingAt 10 locations: 20 m inside and 20 m outside the two ladders
OVERVIEW
CONCLUSIONS
WHY USE THE ALTERNATIVE?
BACKGROUND
agricultural buffer strips
CASE STUDIES FROM DITCHES AND CANALS
natural banksmammal ladders
Jan H. Wanink & Ronald Bijkerk
INTECOL 2013
London, UKAugust 20, 2013
Conservation management and policy
From time-series to one-time pairwise testingstatistical and economic optimization in the evaluation of intervention effects in seasonal environments
PROBLEM DEFINITION
TRADITIONAL METHOD
ALTERNATIVE METHOD
3) mammal ladders
bad poor moderate good high
WFD classifications, based on Ecological Quality Ratio (EQR)
EQR higher inside at 8 out of 10 locations (L)Mean difference: 0.13 (13% of metric width) Inside scores one class higher (good) than outside (moderate)
EQR L-avg p L-1 L-2 L-3 L-4 L-5 L-6 L-7 L-8 L-9 L-10
inside 0.68 <0.05 0.65 0.63 0.71 0.55 0.77 0.77 0.80 0.56 0.73 0.69
outside 0.55 0.33 0.72 0.49 0.62 0.59 0.59 0.70 0.33 0.70 0.44
OVERVIEW
CONCLUSIONS
WHY USE THE ALTERNATIVE?
BACKGROUND
agricultural buffer strips
CASE STUDIES FROM DITCHES AND CANALS
natural banksmammal ladders
CONCLUSIONS
Jan H. Wanink & Ronald Bijkerk
INTECOL 2013
London, UKAugust 20, 2013
Conservation management and policy
From time-series to one-time pairwise testingstatistical and economic optimization in the evaluation of intervention effects in seasonal environments
PROBLEM DEFINITION
TRADITIONAL METHOD
ALTERNATIVE METHOD
Pairwise sampling and testing to evaluate intervention effects is:● effective● relatively cheap
Effects on fast responding parameters can be shown quickly
Preferably, sampling design should precede the measures