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Topic: How do ecosystem dynamics influence the value of water relevant for the third step of water accounting: ‘recording the
productivity resulting from water consumption in river basins’ (http://www.wateraccounting.com/)
Ecosystem dynamics and values Case studies Ecosystem scale
Water Management in De Wieden Water in the Ferlo, Senegal, a semi-arid ecosystem
Case study Landscape Scale: Ecosystem Services in the Gelderse Valley
Implications for Water Accounting
Ecosystem dynamics and values: ecosystem services
Ecosystem services = the benefits provided by ecosystems (MA, 2003)
Step 2. Assessment of ecosystem
services in bio-physical terms
Step 3. Valuation using monetary, or
other, indicators
Step 4. Aggregation or comparison
of the different values
Step 1. Specification of the boundaries
of the system to be valued
Provisioning services Regulating services Cultural services
Direct use values Indirect use values Option values Non-use values
Ecosystem
Total value
Ecosystem Services in a dynamic context
Consumption
Production
Pressures
Management Ecosystem
services
Ecosystem dynamics
Dispersion,transformation
Waste treatment
Aquatic
ecosystem
Case 1. Ecosystem services in De Wieden
The De Wieden wetland (NLs) is one of the largest lowland peatland mashes in Western Europe, in total around 6000 ha.
It is a Ramsar wetland, a Natura 2000 site, and of principal importance for nature conservation in the Netherlands
What are the key ecosystem services supplied by the Weiden, what is their economic value, and how are they influenced by water quality management ?
Model to analyse impacts of nutrient pollution control
impacts
costs
without biomanipulation with biomanipulation
benefits
P-loading
P-concentration
Turbidity
Algae growth
Macrophyte growth
Eutrophication control measures
Lake clearness
Net benefits of eutrophication control
Benefits of clear water
Constructing the abatement curve (2)
y = 0.134x2 + 1.32x
0
5
10
15
20
25
30
35
0 5 10 15
Reduction in total-P loading (ton P/year)
Total costs (mln euro)
Functional relations in the model – an example
Relation between nutrient concentrations and algae growth
y = 150x
0
10
20
30
0 0.02 0.04 0.06 0.08 0.1
Concentration total-P (mg/l)
Chl
orop
hyll
a (u
g/l)
Impacts of reduced nutrient loading on ecosystem
services supply
Fisheries Neutral: eel is relatively insensitive to turbidity and nutrient concentrations
Reed harvesting Neutral
Recreation Enhanced value for swimmers and people on boats
Nature conservation All threatened (red-list) species would benefit, none would suffer
Results (2)
NPV of eutrophication control - for incremental benefits of 1 mln euro/year
-20-15-10-505
10
0 2 4 6 8 10
Reduction in P-loading
NP
V (
mln
eur
o) .
Case study 2: The Ferlo (Senegal)
In the Ferlo, livestock grazing is the main source of income; but sustained, heavy grazing pressures have an impact on the vegetation. This impact depends to a large extent on the annual rainfall.
Question: how does rainwater availability influence livestock production ?
The Ferlo - the model
Rain-use efficiency
Effective rain
Grass production
Livestock production
Animal feed consumption
Income
Stocking density
Livestock prices
Source: Weikard and Hein, in press, Hein and Weikard, 2008, Hein, 2006
Case 3: Ecosystem Services Supply at the Scale of the
Landscape the Gelderse Valley, the Netherlands
7 Ecosystem services: arable agriculture, intensive livestock holding, tourism, leisure cycling, residential areas, plant habitat, water extraction.
Main aim: how can ecosystem services be identified in the landscape
:
Allocating values to ecosystem services in the landscape
1. Delineation: Landscape functions are directly observable from the land cover or are defined by policy regulations. Arable land, intensive livestock holdings, residential,
drinking water extraction zones 2. No or partial delineation: Non-directly observable
landscape functions without strict delineations. Tourism, leisure cycling, plant habitat
Maps depicting the value of ecosystem service supply
Source: Willemen et al., 2008, Willemen et al., 2010
Implications for water accounting (1)
Ecosystem service approach has the advantage of allowing comprehensive analysis of benefits provided by land / water
But ecosystem service supply is dynamic, and current benefits does not necessarily represent the maximum or sustainable benefits that can be supplied. Current supply Maximum sustainable biological harvest Efficient harvest Sustainable harvest vis-à-vis natural reference situation
Implications for water accounting (2)
Different approaches needed to quantify ecosystem services at different scales, in particular for regulation services.