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 Netherlandsj.h.wanink@koemanenbijkerk.nl

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

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