Collecting in situ data for assessing changes in habitat quality over time

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Collecting in situ data for assessing

changes in habitat quality over time

Maud Raman, Toon Westra, Patrik Oosterlynck, Floris Vanderhaeghe & Gerald Louette

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Localisation of Flanders, Northern Belgium

Natura-2000 research in N-Belgium

A monitoring network for vegetation quality

Synergies between networks and surveys

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Flanders – Northern Belgium

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66000 hectares Natura 2000 habitat types (4,8% of Flanders)

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Natura-2000 research in Northern Belgium

Su rv e ys Biotic characterisation of habitattypes Abiotic characterisation of habitattypes Defining tresholds to preserve a favourite conservation status HabNorm Vegetation monitoring

Monitoring natural environment

Mon

it

oring

Monitoring the conservation status

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Assessing the conservation status of a

habitat type

Criterion Favourable or unfavourable conservation status

Range F/UF

Area F/UF

Structures and functions (quality) F/UF Future prospects F/UF

Overall conclusion F/UF

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Natura 2000 habitats in Flanders –

conservation status

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Monitoring the conservation status – Optimalisation

habitatmap

What? Identification and mapping of Natura 2000 habitat (sub)types in N-Belgium

How? Using field keys to improve the repeatability When? 12 year monitoring cycle

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What? Monitoring the habitat quality: a set of habitat type specific indicators for overall quality (vegetation-structure-disturbance)

How?

• _{Measuring the vegetation in permanent plots}

• _{Using tables with habitat characteristics and evaluation}

matrices

When? 12 year monitoring cycle Aim?

• Reports to the Flemish government

 Quantitative information

 _{Monitoring the N2000 program}

• Reports to the European Commission

 Qualitative information

 _{Structures and functions, future prospects, threats}

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For each habitat (sub)type/biogeographic region/Flanders:

STATE

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What?

• Monitoring state and trends of the natural environment of N2000

habitat (sub)types

• _{Monitoring state and trends of environmental pressures}

How?

• _{Measuring environmental factors (permanent stations/marked}

sites)

• Designing networks for air/groundwater/surface water/soil

• _{Using sampling protocols}

Aim?

• Reports to the Flemish government

 Quantitative information

 Monitoring the N2000 program, prioritizing actions in environmental

policy

• _{Information to be used in Appropriate Assessments}

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STATE Environmental factor TREND time past/present P RE SENT PAST -FUTURE + x year

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Habnorm

What?

• _{Defining abiotic en biotic characteristics of N2000 habitat}

(sub)types

• Setting tresholds for abiotic factors in relation to environmental

pressures to preserve a favourite conservation status How?

• _{Measuring the vegetation and site conditions}

• _{Designing surveys for each habitat (sub)type}

• _{Using sampling protocols}

Aim?

• _{Creating a reference framework (defining reference conditions}

for each N2000 habitat)

 _{in order to assess the impact of a plan on N2000 habitats in SAC in}

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STATE

Environmental factor

P

RE

SENT

For each habitat (sub)type, considering steering environmental factors

Tolerance 1

Tolerance 2

Environmental factor/environmental gradiënt

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Selection of indicators

Art 17: specific functions, structures, typical species -> habitat quality

Biodiversitymodel Noss -> hierarchical organisation

Composition Structure Function

Landscape/Biogeographic

region forest habitats, y-diversity perimeter/area index connectivity index

Ecosystem/Community phenology in growth classes , α-diversity, β-diversity

vertical structure, minimal structure area, type of

management

deadwood, encroachment, ruderalisation

Population/Species typical species, invasive species, typical fauna

minimal population size typical

species metapopulation characteristics, Genetic allelic diversity heterozygosity inbreeding

Indicators

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Measurability

Proven and quantifiable ecological relation with relevant processes; Applicable for many habitat types;

Sensitive;

Simple, cost efficient, repeatable measuring;

Robust for seasonal or other climatical variation; No correlation with other indicators

Categories used in Flanders: structure, disturbance (cf. function) en vegetation (cf. composition)

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Criteriu

m Target value Opmerkingen Referenties

≥ 4 ≥ 10%

Anonymous (2004b); Schaminée et al. (1996); Ministerie van LNV (2006a)

10%-30% Hennekens et al. (2001); expert _judgement

≤10% Hennekens et al. (2001); expert _judgement

≤ 50% expert judgement

≤10% expert judgement; Anoniem (2004a)

≤ 10% with a few exceptions Anonymous (2004a);expert judgement

≤ 10% with a few exceptions expert judgement

≤ 10% expert judgement

≤ 30% Dorland et al. (2011); expert _judgement

≤ 30% respecting natural gradiënts

of moisture

≤ 30% respecting natural gradiënts _{of moisture}

B. Evaluation matrix

Favourable state

Vegetation

number of typical

species the presence of all possible typical

species of the habitat type (cover as in reference conditions)

conserving the frequency and cover of quality indicating mosses, lichens and fungi

analysis of vegetation data; deels naar Anonymous (2004b); Hennekens et al. (2001) cover of typical species eutrophication grass encroachment encroachment incl. ruderalisation Habitat structure

life forms 3 life forms present mos layer Disturbance mosses rewetting dessication forest encroachment encroachment by blackberries litter at most occasionally

value of indicator is comparable with these of reference conditions

at most occasionally

value of indicator is comparable with these of reference conditions value of indicator is comparable with

these of reference conditions at most occasionally at most occasionally at most occasionally

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Measuring technique

Two plots centered at each sampling location

• _{Circular plot (with 18 m radius): vegetation structure}

• Square plot (16 x 16 m forest habitats - 3 x 3 meter other

terrestrial habitats): species composition and cover

For aquatic habitats different sampling units were used

• _{Standing waters habitats}

-> the entire water body

• _{Stream habitats:}

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Plot dimensions

Scale at which vegetation quality components occur versus acceptable accuracy

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Simplified Londo-scale

Scale Cover (%) 0.1 <1 0.2 1-3 0.4 3-5 7 5-10 12 10-15 20 15-25 30 25-35 40 35-45 50 45-55 60 55-65 70 65-75 80 75-85 90 85-100

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Design monitoring scheme

Habitat map = sample frame

Spatially balanced random sampling : the Generalized Random-Tessellation Stratified method

Separate sample for each habitat (sub)type, except for scarce habitat types (<10 ha) -> habitat quality assessed in combination with habitat mapping

Special Areas of Conservation are monitored in more detail Total monitoring effort:

• _{around 5000 sampling stations for 49 habitat (sub)types}

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D e te ct ab le p e rce n tag e ‘b ad ’ Sample size Unfavourable Unknown Unfavourable inadequate

Proportion of habitat with UF (local) quality is estimated

Overall quality of a habitat is unfavourable if >= 25% of habitat is UF Line grey/red gives the minimal amount of sample units to detect a difference with the 25%-norm

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Sample size Unfavourable Favourable

Negative Positive Minimal detectable difference with reference to 25 %

Sample size = 170:

• _{35% of the sample units should be in UF condition to detect a difference}

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Choise of sample size

 _{Habitattypes and subtypes (scale of Flanders)  170}

 _{Habitattypes within network of SAC  80}

 _{Finite correction factor  decrease sample size for habitats}

with smaller areas

Sampling units (including existing sampling units)

 _{Terrestial habitats = 4000 sampling units}

 _{Standing water bodies = 300 sampling units}

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Synergies with existing monitoring

programs in Flanders

Several operational monitoring programs with useful data on a regional scale

• Forest Inventory of Flanders, the monitoring programs of the

Scheldt estuary , the inventory of coastal dunes...

We want to achieve maximum synergy:

• _{harmonizing measuring techniques}

• by making use of existing sampling units

• _{if needed, add extra sampling units to reach the desired}

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Discussion

Dimensions: scale at which vegetation quality components

occur versus processes?

Use of species-area curves?

Plot dimensions versus indicators for acidification,

eutriphication, …?

Habitat type definition

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A framework for

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Scale

Aim

Vegetation composition

Habitat

quality Climate Soil

Groundwater /Moisture

Surface water

Predicting the occurence and variation of N2000 habitat types across a long climatic gradient

Observing trends of vegetation characteristics and climatic factors over time

Predicting the occurence and variation of N2000 habitat types using environmental data

Observing trends of vegetation characteristics and environmental factors over time

Modelling the occurence and variation of N2000 habitat types in Flanders

Assessing the habitat quality over time in Flandere

Europe x x

Atlantic lowland (Belgium with surrounding

countries)

Flanders, N-Belgium x x x x x

x x x x x

Collecting in situ data for assessing changes in habitat quality over time