MANAGEMENT OF WATERSHED-LAKE INTERACTIONS IN … · CONTENT • Green economy and watershed...

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MANAGEMENT OF WATERSHED-LAKE

INTERACTIONS IN MOUNTAIN REGIONS

AFFECTED BY ACID ATMOSPHERIC DEPOSITION

Josef Krecek

Department of Hydrology

Czech Technical University in Prague

2nd European Forest Week The joint meeting of the FAO European Forestry Commission and the UNECE Committee on Forests

Rovaniemi, Finland, 9–13th December 2013

CONTENT

• Green economy and watershed approach

• Watershed-lake interactions in mountain regions of central

Europe

• Key-study in the Jizera Mountains (Czech Republic)

- Impacts of the acid atmospheric deposition

- Restoration of catchments and lakes

- Forest zonation and ecosystem services

- Future risks

• Conclusions

MANAGEMENT OF WATERSHED-LAKE INTERACTIONS IN MOUNTAIN REGIONS

GREEN ECONOMY AND WATERSHED

APPROACH

Green Economy: an alternative vision for growth and

development; one that can generate growth and improvements

in people’s lives in ways consistent with sustainable

development (MANISH BAPNA, 2011).

Catchment outflow (water quality, water yield, run-off timing) is

a measure of ecological stability and sustainabile development

within a watershed.

New catchment value in the multi-resource management and

watershed – lake interactions.

GAIA THEORY AND BIODIVERSITY

LOVELOCK, J.E. (1993): Self-regulating concept of the world

DAISY-WORLD MODEL: The regulating capacity of the

ecosystem increases with biodiversity

ACID ATMOSPHERIC LOAD

UNEP (2005)

Schöpp et al. (2003)

European emissions prognosed Risk of acidification in Europe

1) Extreme acid atmospheric deposition in the 1980s

2) In the 1990s, drop in emmissions and decreasing the acid load

3) Reforestation, and stabilisation of headwater catchments

4) Recovery of aquatic ecosystems

5) Climate change impacts

ECOSYSTEM SERVICES IN A MOUNTAIN

CATCHMENT

Supporting infiltration

Control of erosion

Additional precipitation

Riparian buffer zones

Differentiation of practices in

forest stands respecting

catchment morphology

and the environment.

Four typical forest stands

in a mountain watershed:

CONTENT

• Green economy and watershed approach

• Watershed-lake interactions in mountain regions of central

Europe

• Key-study in the Jizera Mountains (Czech Republic)

- Impacts of the acid atmospheric deposition

- Restoration of catchments and lakes

- Forest zonation and ecosystem services

- Future risks

• Conclusions

MANAGEMENT OF WATERSHED-LAKE INTERACTIONS IN MOUNTAIN REGIONS

Central Europe (48-51 N, 12-19 E), Temperate climate: Dfb (humid

continental), Dfc (sub-arctic).

Elevation range from 115 to 1,602 m

Forest land: 34 %

Mountain forests: 18,550 km2 (70 % of forested area)

Native species are Common beech (Fagus sylvatica), Common silver fir (Abies alba), and Norway spruce (Picea abies), but,

dominate even – age spruce plantations 84 % Mean rotation period 115 years Annual harvest of timber 6 m3/ha Natural regeneration 18 % of the artificial one Ownership of mountain forests: State (61 %), private (23 %), and municipal (16 %) Priorities: Commercial (75 %) and protective forests (25 %).

Water supply by surface waters 80 %, control of 60,000 km of streams

CZECH REPUBLIC FACT SHEET

THE JIZERA MOUNTAINS

B, J, JD, O, S … focused spots

50o 40’ – 50o 40’ N

15o 08’ – 15o 24’ E

Elevation: 300 – 1,124 m

Area: 350 km2

Forest land: 83 %

(spruce plantations: 90 %)

‘Black Triangle’

CATCHMENT HYDROLOGY

1) J (Jizerka basin, 102 ha): clear-cut and reforestation.

2) O (Oldrichov basin, 23 ha): semi-native beech stands.

LAKE CHEMISTRY AND BIOLOGY

• In situ temperature, pH,

conductivity and

dissolved oxygen

• Secchi depth

• Sampling water and

ANNUAL CONTENT OF SO2 IN THE AIR

90Jizerka

Hejnice

Open-field SO4 - deposition decreased

from 8.6 (1986 - 1989) to 2.3 (2000 – 2008) (g/m2 year)

CONSEQUENCES OBSERVED in 1980-2000

Decline of the water environment:

• Low water-pH (from 4 to 5)

• Low hardness (Ca, Mg)

• High content of Al (1 – 2 mg/l)

Public health limits (WHO, 2004):

pH: 6.5–9.5

Maximum content of Al: 0.1 mg/l

Biota reduced:

• The number of species in plankton and

benthic communities reduced

• Changes in zooplankton to prevailing rotifers

• The fish became extinct already in the 1960s

Catchment deterioration:

• Forest die-back and clear-cut.

• From Picea abies to Junco effusi-Calamagrostietum villosae community

INCREASED DRAINAGE NETWORK

Risk of channel run-off:

Original drainage

Deep erosion rills

Shallow erosion rills

Clear-cut of spruce

plantations with

skidding timber by

wheeled tractors.

Drainage network

increased

from 1.5 to 6.6 km/km2

Exceeded the max

potential channel

length of the DM

analysis by 50 %.

Increased risk of direct

run-off, floods, rill

erosion and

sedimentation.

EVAPOTRANSPIRATION LOSS

• Mature spruce stand:

Interception I = 0.3 PG

Throughfall Th = 0.7 PG

S-load: 200 % of the open-field

•Grass cover:

Interception I = 0.16 PG

Throughfall Th = 0.84 PG

S-load: two times higher than the open-field

(PG …gross precipitation)

ADDITIONAL ACID DEPOSITION

Fog-water income (pH: 3.1 – 4.5) rises with afforestation

FOG-WATER EVIDENCE

880 900 920 940 960 980

nadmořská výška [m n. m.]

Teplé období Chladné období Celé obdobíElevation (m)

1980 1985 1990 1995 2000 2005

7Reservoirs

1 2 3 4 5 6 7 8 9 10 11 12

pH IN WATER RESERVOIRS

RESTOCKING THE FISH

• Acidity tolerant:

Brook char (Salvelinus fontinalis)

• Native:

Brown trout (Salmo trutta morpha fario)

Minnow (Phoxinus phoxinus)

BENTHIC MACROINVERTEBRATES

• From „strongly acidified“ (pH: 4.07 – 4.57, R-Al: 448 – 1913 ug/l) to „moderately acidified“ (pH: 5.18 – 6.38, R-Al: 52 – 261 ug/l) streams.

• Sampling in 100 m long stretch with uniform stream characteristics.

• The largest biotic difference detected by PCA was in the presence of caddisflies.

Taxa/Site Strongly acidified Moderately acidified

Turbellaria 1

Nematoda 1

Oligochaeta 2 4

Mollusca

Hydracarina 1

Crustacea 1

Ephemeroptera 3

Odonata

Plecoptera 7 20

Megaloptera 1 1

Heteroptera 2 1

Trichoptera 5 17

Diptera excl. Chironomidae 8 10

Chironomidae 4 5

Coleoptera 3 6

TOTAL 33 68

Taxanomic

richness

4 4,5 5 5,5 6

March May July August November

4 4,5 5 5,5 6 6,5 7

March May July August November

Toxic Al NontoxicAl

November 1996 May 1997

LakepH=6.0

LakepH=4.8

InflowpH=5.1

InflowpH=6.0 Level of

toxicity

SEASONAL ACIDIFICATION

WATERSHED RESTORATION

2004 2012

Rresults of both, reforestation efforts and the natural regeneration

(Fig.: Watershed of the Souš Reservoir)

PREDICTION OF THE CLIMATE CHANGE

IMPACTS: 2071-2100

• Runoff reduction: 10 – 40 %.

• Seasonal changes:

drop (20 – 90 %) in the summer,

and increase (30 – 50 %) in the winter.

• Snow cover reduced (30 %).

• Spruce stands endangered (50 %).

J F M A M J J A S O N D

LYS 1967-1990

RCAO-HA2

RCAO-HB2

RCAO-EA2

RCAO-EB2

1961-1990

-100-80-60-40-20

020406080

100120140160

RCAO-HA2RCAO-HB2RCAO-EA2RCAO-EB2

RCAO-HA2

RCAO-HB2

RCAO-EA2

RCAO-EB2

CONCLUSIONS

• Mountain watersheds of central Europe are affected by a long-lasting acid atmospheric deposition.

• The traditional concept of “protective forests” in mountain catchments can lead to misinterpretations of the green economy there.

• Ecosystem services in mountain regions should control the acid atmospheric load and support the biodiversity in both terrestrial and aquatic ecosystems.

• The watershed concept seems to be an important tool indicating the sustainable development.

• The restoration of mountain watersheds affected by acidification should find a compromise between regrowth of forests and recovery of biota in streams and lakes.

• Future risks: nitrogen emissions and climate change impacts.

ACKNOWLEDGEMENTS

The project has been sponsored by:

- Earthwatch Institute (1991-2013),

- Grant Agency of the Czech Republic (2008-2013),

- Czech Technical University in Prague (2010-2013).

Thank you!

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