jesper fredshavn, neri, denmarkreference values /..1 future reference values for structure and...

/..1Jesper Fredshavn, NERI, Denmark Reference values

Future Reference Values

for Structure and Functionin the Habitat Directive Nature Types

Dr. Jesper Fredshavn

NERI, Aarhus University, DenmarkApril 26, 2007


Reference values

Setting reference values has scientific

as well as political aspects

”how high will you fly”

”how low can you go”


The process of future reference values

Select relevant indicators Monitor indicators

Select a reference set of areas with favourable condition Compare variation range of reference set with entire

monitoring set Set criterias of individual indicators Set importance of different indicators

Produce reference value of structure and function from the weighted average of indicators of the reference set


Scientific Criteria for Favourable Conservation Status in Denmark

Technical Report from NERI - 462 pp in a Danish version

Criteria for 51 habitats

Criteria for 36 species

Criteria for 75 birds

A draft version with 7 habitats, 4 species and 4 birds in English


Table 3.29. Criteria for favourable conservation status on local/site level for the habitat type 4030. Indicators marked with (P) are pressure indicators.

Type 4030 Property Unit of measurement Criteria Comments

Area Area (hectares) Number of hectares Stable or increasing

Structure and function Naturally low nutrient level Nitrogen deposition (kg/N/hectare/year)

Not exceeding the critical load Critical load 10-20 kg/N/year, UNECE 2003

Naturally low nutrient level C/N relation in upper layer of peat Within the expected variation of the natural habitat type in Denmark. Stable or improving

Should be >30

Naturally low nutrient level Nutrition content in year-shoot of dwarf bushes

Within the expected variation of the natural habitat type in Denmark. Stable or improving

Should be <14 mg/g

Naturally low nutrient level Frequency and intensity of the heather’s leaf-beetle

Not exceeding one large attack each 15 years

Natural part of the dynamic of the heath, but increased frequency may indicate increased N-content in parts of the plant

Acidity pH The pH must be stable and not considerably lower than the natural acidity of the locality.

If no historical information is available, the natural pH can be predicted by model

Open vegetation Coverage of Mountain pine, Spruce, Aspen, Oak, Birch, and Juniper

Stable or decreasing Should be <10%. Sparse occurrence of trees may be acceptable out of consideration for animals and birds

Vegetation dynamics Coverage /frequency of heather (dwarf bushes) in the pioneer stage

Within the expected variation of the natural habitat type in Denmark. Stable or improving

Should be about 10% of the heather/ dwarf bush area. Dynamic is favourable where the heath’s other plant communities and fauna shift with the stages of the heather’s life cycle

Regeneration (heather/ dwarf bushes)

Coverage of bare soil Within the expected variation of the natural habitat type in Denmark. Stable or improving

Preferably >20% at intervals of some years. Important for establishing of lichen/ mosses, herbs, the sedge family, and for heat-demanding insects

Invasive species Coverage/ frequency of Campylopus introflexus and the other cryptogames

Stable or decreasing Should be <5%, but not more than 10% of the cryptogame community’s total frequency. The moss is invasive and an aggressive competitor to the heather’s lichen-species

Species composition of plants

Deviation from the species composition of the habitat type in reference condition

The deviation is within the expected variation of the natural habitat type in Denmark

The species composition is a diversity indicator of changes in the environment factors

Characteristic species Population of characteristic species

Index of populations of characteristic species present

Long-term maintenance on a stable or increasing level

Variations are natural. In special cases declines may be acceptable /targeted.


Monitoring: Intensive sampling stations

201 Sampling stations, monitored yearly

Detailed data on year-to-year fluctuations

in Natura 2000 areas

6-19 stations pr habitat type

(tot. 201 stations covering 18 hab. types)

40 random sampling sites pr station (5-10 ha)

•Area: changes in sampling sites with hab. type

•Structure/function: registration of vegetation and geo/chemical indicators

•Species: sampling site and 5 m circle


Monitoring: Extensive sampling stations

761 Sampling stations, monitored 6-years cycle

Specific data on conservation status and trends

50% in N2000 – 50% outside N2000

9-92 stations pr habitat type

(tot. 761 stations covering 16 hab. types)

40 random sampling sites pr station (5-10 ha)

•Area: changes in sampling sites with hab. type

•Structure/function: registration of vegetation and geo/chemical indicators

•Species: sampling site and 5 m circle


Indicators - function and structure

5 m

Observations in the 5 m circle:Vegetation heightPct. cover of woody speciesPct. cover of herbivoriBog structure

Observations in the sample plots:pH in soil/waterConductivityC/N - ratioPhosphorousNitrate in soil/waterN in shoots, mosses and lichens

Observations on the station:Pct. cover of invasive speciesPct. cover of rare typical spec.


The 201 intensive sampling stations

Monitoring stations

Main nature types

MeadowHeath landCalc. FensDunesAcid fensGrasslandSalt meadow


Sampling Stations

Sampling stations are each designated for one habitat type

The stations cover the habitat type broadly and often include several habitat types in a mosaic

Random sampling sites are used to :

• detect changes in area covered by each habitat type

• sampling of structure and function indicators


Mapping of Danish habitat types

Complete mapping of all 254 Natura 2000 areas

and sampled data outside Natura 2000 areas

• Stratified Network of Monitoring Stations based on size and quality of the areas

• Natura 2000 Management Plans

Biological status assessment -

• Area: GIS data, field verification

• Structure/function: Visual, measurable field indicators

• Species: 5 m documentation circle


Mapping the area of habitat types

Natura 2000 Designated

Area

Basic mapping of

Habitat types

(ortho photo interpretation &

field mapping)


Structural indicators in the mapping

Vegetation structure Hydrology and coastal protection Grassing and nature management Eutrofication and pesticide spraying Habitat type specific structures

The structural indicators reflects the pressures on the habitat types

All habitat types are evaluated from the same indicators, but the scoring and weighting of the indicators vary from habitat type to habitat type


Vegetation structure

1. Vegetation StructureCategories

1. 2. 3. 4. 5.Evaluation

Percent area without vegetation cover0-5% 5-10% 10-30% 30-75% 75-100%Percent area with grass/herb vegetation below 15 cm0-5% 5-10% 10-30% 30-75% 75-100%Percent area with grass/herb vegetation 15-50 cm0-5% 5-10% 10-30% 30-75% 75-100%Percent area with grass/herb vegetation above 50 cm0-5% 5-10% 10-30% 30-75% 75-100%Percent area with dwarf bush formation0-5% 5-10% 10-30% 30-75% 75-100%Percent area with tree cover (canope)0% 1-10% 10-25% 25-50% 50-100%Percent area with invasive species0% 1-10% 10-25% 25-50% 50-100%


Hydrology and coastal protection

2. Hydrology og coastal protectionCategories


Drainage and water catchment (bogs, mires and fens)No drainageand watercatchment

No vegetationchanges fromdrainage orwatercatchment

Drainage withsummerdesiccationand initialovergrowth

Generallydesiccatedand overgrownwith talldrylandspecies

Completedesiccationand withdrylandcharacter

Streams and watercourseNatural streamswithoutmanagement

Naturalstreams.Managementis not affectingvegetation

Someregulation ofstreams andsome streamplant cutting

Streamsregulated andwith annualcutting

All streamsin pipes

Coastal protection (coastal habitats)No coastalprotection

Coastalprotection butwith naturaldynamics andvegetationzonation

Coastalprotection withsignificantinfluence onnaturaldynamics andvegetationzonation

Strong coastalprotection withfresh waterdominatedvegetation andonly littlezonation

Fresh watervegetationwith no saltinfluence


Agriculture and Nature management

3. Grassing and nature managementCategories


Percent area with grassing and/or hay cutting0-5% 5-10% 10-30% 30-75% 75-100%

4. Agricultural pressuresCategories

1. 2. 3. 4. 5.Percent area with significant effects from agricultural spraying and manuring0% 1-10% 10-25% 25-50% 50-100%

5. Habitat specific structuresCategories of positive and negative structures

1: abundant 2: sparse/rudimentary 3: not presentHabitat type Structure

6230 Nardus grassland Large stones, ant’s nests, steep slopes. Scattered trees andbusheseutroficated and dominated by Lolium per., Elytrigia rep.,Cirsium arv., Cerastium and Poa ann.


Species indicators

5 m

Documentation from a circle of 5 m radius

Species composition of vascular plants

The circle is placed in a homogenous area characteristic of the habitat type


Biological Status Classes

5 quality classes for Biological Status cf. the 5 class frame used by the Water Framework Directive

I High nature status

II Good nature status

III Moderate nature status

IV Poor nature status

V Bad nature status

I & II represents the Habitat Directive’s demands for FCS


Indicators

Status class I II III IV V

score 1,0 - 0,8 0,8 - 0,6 0,6 - 0,4 0,4 - 0,2 0,2 - 0,0

The Biological Status assessment is based on the evaluation of a set of indicators.

The Biological Status is assessed on a reference scale between 0 and 1, where 1 is the optimal condition without any negative pressures and 0 is the worst possible condition

Each indicator is evaluated separately and given a score between 0 and 1, and the biological status is then calculated from the weighted scores of the indicators



1. 2. 3. 4. 5.

Eva

lua

tio

n

Percent area without vegetation cover0-5% 5-10% 10-30% 30-75% 75-100%Percent area with grass/herb vegetation below 15 cm0-5% 5-10% 10-30% 30-75% 75-100%Percent area with grass/herb vegetation 15-50 cm0-5% 5-10% 10-30% 30-75% 75-100%Percent area with grass/herb vegetation 50 cm0-5% 5-10% 10-30% 30-75% 75-100%Percent area with dwarf bush formation0-5% 5-10% 10-30% 30-75% 75-100%Percent area with tree cover (canope)0% 1-10% 10-25% 25-50% 50-100%Percent area with invasive species0% 1-10% 10-25% 25-50% 50-100%

Calculation of Structural Index


1. 2. 3. 4. 5.

Eva

lua

tio

n

Percent area without vegetation cover0-5% 5-10% 10-30% 30-75% 75-100%

1

Percent area with grass/herb vegetation below 15 cm0-5% 5-10% 10-30% 30-75% 75-100%

3

Percent area with grass/herb vegetation 15-50 cm0-5% 5-10% 10-30% 30-75% 75-100%

4

Percent area with grass/herb vegetation 50 cm0-5% 5-10% 10-30% 30-75% 75-100%

1

Percent area with dwarf bush formation0-5% 5-10% 10-30% 30-75% 75-100%

2

Percent area with tree cover (canope)0% 1-10% 10-25% 25-50% 50-100%

2

Percent area with invasive species0% 1-10% 10-25% 25-50% 50-100%

1


Calculation of Structural Index


1. 2. 3. 4. 5.

Eva

lua

tio

n

Sco

re

Percent area without vegetation cover0-5% 1.00 5-10% 0.60 10-30% 0.40 30-75% 0.10 75-100%0.00

1 1.00

Percent area with grass/herb vegetation below 15 cm0-5% 0.00 5-10% 0.10 10-30% 0.40 30-75% 0.60 75-100%1.00

3 0.40

Percent area with grass/herb vegetation 15-50 cm0-5% 0.30 5-10% 0.60 10-30% 1.00 30-75% 0.60 75-100%0.30

4 0.60

Percent area with grass/herb vegetation 50 cm0-5% 1.00 5-10% 0.60 10-30% 0.40 30-75% 0.10 75-100%0.00

1 1.00

Percent area with dwarf bush formation0-5% 0.30 5-10% 0.60 10-30% 1.00 30-75% 0.60 75-100%0.30

2 0.60

Percent area with tree cover (canope)0% 0.80 1-10% 1.00 10-25% 0.60 25-50% 0.30 50-100%0.00

2 1.00

Percent area with invasive species0% 1.00 1-10% 0.60 10-25% 0.40 25-50% 0.10 50-100%0.00

1 1.00

1. Vegetation Structure 0.40Categories

1. 2. 3. 4. 5.

Eva

lua

tio

n

Sco

re

Wei

gh

t

Percent area without vegetation cover0-5% 5-10% 10-30% 30-75% 75-100%

1 1.00 0.05

Percent area with grass/herb vegetation below 15 cm0-5% 5-10% 10-30% 30-75% 75-100%

3 0.40 0.20

Percent area with grass/herb vegetation 15-50 cm0-5% 5-10% 10-30% 30-75% 75-100%

4 0.60 0.20

Percent area with grass/herb vegetation 50 cm0-5% 5-10% 10-30% 30-75% 75-100%

1 1.00 0.20

Percent area with dwarf bush formation0-5% 5-10% 10-30% 30-75% 75-100%

2 0.60 0.05

Percent area with tree cover (canope)0% 1-10% 10-25% 25-50% 50-100%

2 1.00 0.20

Percent area with invasive species0% 1-10% 10-25% 25-50% 50-100%

1 1.00 0.10


Species scores

The species are assigned scores from 1 to 7 based on how they react on increased antropogenic pressures:

-1 = Problem species

1 = Very tolerant

3 = Indifferent

7 = Very susceptible

The species are related to Main Habitat types: 21, coastal dunes; 40, heath land; 62, grass land; 64, meadow; 91, forests etc.

MainNature type Score Danish name Scientific name

62 -1 kløver, hvid- Trifolium repens62 -1 kvik, almindelig Elytrigia repens ssp. repens62 1 hundegræs, almindelig Dactylis glomerata62 1 kløver, rød- Trifolium pratense62 2 gåsemad, almindelig Arabidopsis thaliana62 2 gåsepotentil Argentina anserina62 3 hønsetarm, storblomstret Cerastium arvense62 3 kamgræs, almindelig Cynosurus cristatus62 4 enghavre, dunet Helictotrichon pubescens62 4 flipkrave Teesdalia nudicaulis62 5 djævelsbid Succisa pratensis62 5 evighedsblomst, gul Helichrysum arenarium62 6 kobjælde, opret Anemone pulsatilla62 6 kohvede, blåtoppet Melampyrum nemorosum62 7 guldblomme Arnica montana62 7 gøgeurt, bakke- Orchis ustulata


Species Index vs Structural IndexDry grassland

0.00

0.20

0.40

0.60

0.80

1.00

0.00 0.20 0.40 0.60 0.80 1.00

6120

6210

6230

Ecological inertia

Newly established natural

areas are characterised by

high structural indices,

but for many years

they maintain a low

species diversity

Disturbed and destroyed

habitats can for many years

still maintain relicts of the

original and rare species,

but eventually the species

will disappear


Mapping results

The mapped areas with habitat types in the Danish NATURA 2000 areas are generally small and of good or low quality.

Areas of low biological quality are expected not to meet the demands of favourable conservation status

smallmedium

large

high

good

low

0

200

400

600

800

1000

1200

1400

1600

1800

number

Area size

Biol. quality

Distribution of areas with habitat types in Danish NATURA 2000 areas on size and quality


Mean values of the indicators of calcareous grassland

0,00

0,50

1,00

1,50

2,00

2,50

3,00

3,50

4,00ve

g_n

o

veg_

low

veg_

med

veg_

hig

h

veg_

bus

h

veg_

tree

veg_

inva

s

hyd_

dra

in

hyd_

stre

am

hyd_

coas

t

Gra

zing

Eut

roph

Ha

b_po

sitiv

e

Ha

b_ne

gativ

e

Full set 6210

Favourable set

Unfavourable set


Mean values of the indicators of alkaline fens

0,00

0,50

1,00

1,50

2,00

2,50

3,00

3,50

4,00

4,50ve

g_n

o

veg_

low

veg_

med

veg_

hig

h

veg_

bus

h

veg_

tree

veg_

inva

s

hyd_

dra

in

hyd_

stre

am

hyd_

coas

t

Gra

zing

Eut

roph

Ha

b_po

sitiv

e

Ha

b_ne

gativ

e

Full set 7230

Favourable set

Unfavourable set


Mean values of the indicators of salt meadows

0,00

0,50

1,00

1,50

2,00

2,50

3,00

3,50

4,00ve

g_n

o

veg_

low

veg_

med

veg_

hig

h

veg_

bus

h

veg_

tree

veg_

inva

s

hyd_

dra

in

hyd_

stre

am

hyd_

coas

t

Gra

zing

Eut

roph

Ha

b_po

sitiv

e

Ha

b_ne

gativ

e

Full set 1330

Favourable set

Unfavourable set


No of species

0,00

5,00

10,00

15,00

20,00

25,00

30,00

35,00

1330 6210 7230

no

of

spec

ies

Full set

Favourable set

Unfavourable set


Reference set of alkaline fens, 7230

Eutrophication

hydr

olog

y


Reference value

Status class I II III IV V

score 1,0 - 0,8 0,8 - 0,6 0,6 - 0,4 0,4 - 0,2 0,2 - 0,0

The Biological Status is calculated from the weighted scores of the mapping indicators

A reference set of high and good nature status would reproduce 0,6 as the reference value

An index calculated from the weighted scores of the monitoring indicators, and the selection of a reference set, would produce a national reference value of structure and function


The process of future reference values

Select relevant indicators

Select a reference set of areas with favourable condition

Produce reference values of structure and function


Mapping:1.000.000 Euro’s = 16 man years over a 2 years period

254 N2000 areas with a total of 5.700 sites or appr.

16x1400 hours/ 5.700 sites = 4,0 hours/site

Monitoring:201 intensive sampling stations:

1.000.000 Euro/year = 5.000 Euro/Sampling station

761 extensive sampling stations: 800.000 Euro/year = 1.000 Euro/Sampling station

How expensive is it?

Cost calculations


Thank you for your attention

jesper fredshavn, neri, denmarkreference values /..1 future reference values for structure and...

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