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)
SO2
NO2
NH4
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
O
B
JD
S
J
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
biota
ANNUAL CONTENT OF SO2 IN THE AIR
19
70
19
75
19
80
19
85
19
90
19
95
20
00
20
05
0
10
20
30
40
50
60
70
80
90Jizerka
Hejnice
Limit
Year
SO
2 (
g/m
3)
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
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
880 900 920 940 960 980
zach
yce
né
mn
ožs
tví
[ml]
nadmořská výška [m n. m.]
Teplé období Chladné období Celé obdobíElevation (m)
ml
1980 1985 1990 1995 2000 2005
3
4
5
6
7Reservoirs
Limit
Year
pH
1 2 3 4 5 6 7 8 9 10 11 12
3
4
5
6
7
1995
Limit
1985
Month
pH
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
0
2
4
6
8
10
depth
(m
)
4 4,5 5 5,5 6
pH
March May July August November
0
2
4
6
8
10
12
14
16
depth
(m
)
4 4,5 5 5,5 6 6,5 7
pH
March May July August November
0
100
200
300
400
500
600
700
Alu
min
ium
(ug
/l)
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 %).
0
2
4
6
8
10
12
14
J F M A M J J A S O N D
Flo
w [
l.s-1
]
LYS 1967-1990
RCAO-HA2
RCAO-HB2
RCAO-EA2
RCAO-EB2
1961-1990
-100-80-60-40-20
020406080
100120140160
J F M A M J J A S O N D
Runo
ff c
hang
e [%
]
RCAO-HA2RCAO-HB2RCAO-EA2RCAO-EB2
-100
-80
-60
-40
-20
0
20
40
60
80
100
120
J F M A M J J A S O N D
Runo
ff c
hang
e [%
]
RCAO-HA2
RCAO-HB2
RCAO-EA2
RCAO-EB2
LYS
PLB
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!