BROADER ENVIRONMENTAL COSTS? â USE AN ECOSYSTEM SERVICES APPROACH. ⢠Loss of ecosystem services from landslides? â¢
SOIL'S ROLE IN RESTORING ECOSYSTEM SERVICES
AN ECOSYSTEM SERVICES APPROACH TO THE EVALUATION OF SOIL CONSERVATION POLICY IN NEW ZEALAND HILL COUNTRY
Estelle Dominati, Alec Mackay,
March 2014
SOILS: A FINITE RESOURCE GETTING SCARCER EVERYDAY Misconception: NZ is blessed with large areas of versatile and elite soils → 5.2 % High class soils (LUC 1&2 – 14.4% if add LUC 3)
Challenging Government Goals: • Double exports earning by 2025 • Cut emissions to the environment by half • Increase well-being of kiwis Greater demands on the environment High demand for a holistic value for Land: Assess the multi-functionality of land to achieve sustainability.
Ecosystem services approach future of resource management Ecosystem services = “direct and indirect contributions of ecosystems to human well-being” (TEEB, 2010)
Hawke’s Bay coastal zone
SOIL CONSERVATION Damage from April 2011 storm: 43 km2 (4300 ha) of bare ground from a total area of 5900 km2
GNS science, Jones et al., 2011
LOCALISATION OF DAMAGE Land Use Capability class
1
2
3
4
5
6
Area in Sheep & Beef
1,661
6,100
39,467
20,026
3,764
207,979 65,588
Area lost to erosion
4.7
24.4
109.7
54.3
25.5
Bare ground (% of total land 0.3% in that LUC)
0.4%
0.3%
0.3%
Bare ground (% of total area 0.1% lost)
0.6%
2.6%
1.3%
7
8
other
Total
3,985
1,624
348,569
2,156.7 1,341.3 503.8
2.9
4,220
0.7%
1.0%
0.2%
NA
0.6%
51.1% 31.8% 11.9% 0.1%
2.0%
94.8%
12.6%
100%
SOIL CONSERVATION COSTS OF THE APRIL 2011 STORM TO HAWKE’S BAY REGIONAL COUNCIL: NZ$ 39 million = infrastructure, land, personal and commercial damage claims
BROADER ENVIRONMENTAL COSTS? USE AN ECOSYSTEM SERVICES APPROACH • • • •
Loss of ecosystem services from landslides? Recovery of the provision of ES ? Impact on the provision of ES of Soil Conservation practices Cost Benefit Analysis of an investment in soil conservation (wide-spaced trees)
SOIL NATURAL CAPITAL Soil Degradation
Degradation Processes •Erosion •Compaction
Inherent Properties
SOIL ECOSYSTEM SERVICES Cultural Services Self-actualisation Needs
•Depth •Clay types •Texture •Wetness class
Esteem needs
Regulating Services Social needs
Supporting Processes •Nutrient cycling •Water cycling •Soil biological activity
Human Needs
Manageable Properties •Mp •OM •N and P •pH
Provisioning Services
Safety and security needs
Physiological needs
Soil Formation and Maintenance External Drivers Natural & Anthropogenic Climate, Land use Dominati E, Patterson M, Mackay A (2010) A framework for classifying and quantifying the natural capital and ecosystem services of soils. Ecological Economics, 69(9), 1858-1868.
Key: Stocks Flows Processes Drivers
IMPLEMENTATION OF THE FRAMEWORK 1
MODELLING OF SOIL RECOVERY AND SOIL CHANGE WITH MANAGEMENT: • Typical Sheep and Beef farm of Hawke’s Bay
• Follow soil properties recovery after erosion, • Follow soil properties of pasture planted with wide-spaced poplars 2
QUANTIFICATION OF THE SOILS SERVICES : • Flows /ha/yr • proxies to measure each service = focus on part played by the ecosystem • Use of OVERSEER® nutrient budget to calculate proxies
3
ECONOMIC VALUATION OF ES: Economic value of each soil service in NZ$/ha/yr. Techniques used: Market prices, Replacement costs, Provision costs, Defensive expenditures
FARM CHARACTERISTICS AND SOIL PROPERTIES Land Use Capability classes Stocking rate (SU/ha) Area (ha) Soil type Olsen P Anion Storage Capacity N fertiliser applied (kgN/ha/yr) P fertiliser applied (kgP/ha/yr)
Block 1
Block 2
1-5
6-8
13 255 (45%) Waimarama sandy loam (sedimentary, brown) 25 43
8 315 (55%)
20
0
20
15
Wanstead clay loam (recent, pallic) 16 21
Analysis done on Block 2 = 95% of damage and 100% of conservation
ECOSYSTEM SERVICES FROM SOIL AND TREES PROVISIONING SERVICES: • • • • •
Provision of food (pasture quantity and quality) Provision of food: Tree foliage Provision of fibre: Wood Provision of physical support to human infrastructures and animals Provision of shade and shelter to farms animals from trees
REGULATING SERVICES: • • • • • • •
Filtering of nutrients (N and P) and contaminants Flood mitigation Recycling of wastes and detoxification Carbon storage in soil Carbon storage in trees Regulation of N2O and CH4 emissions Biological control of pests and diseases
CULTURAL SERVICES: • • • •
Aesthetic experience Recreation Cultural uses Spiritual enrichment (Earth sacredness)
FODDER FROM TREES 1 QUANTIFICATION: • Estimate the amount of foliage dry matter depending on tree age and density (stems per hectare) Kg DM/ha
2 VALUATION: • Use the market price of pasture dry matter ($0.14/kgDM) Value of fodder from trees (NZ$/ha/yr)
FLOOD MITIGATION 1 QUANTIFICATION: • Quantify the service with OVERSEER : Water stored by the soil (mm/ha/yr)
Rainfall (RF) - Runoff (RO)
RF
RO
2 VALUATION: • Use the provision cost method. • Calculate the maximum amount of water stored by the soil for 7 consecutive days • Calculate the size and annualised costs of dams needed to stored that water on farm. Value of flood mitigation (NZ$/ha/yr)
Flood mitigation service
METHODOLOGY Three situations over time: • Uneroded soil: actual management • Eroded soil: follow ES provision during soil recovery
• Wide spaced trees: what happens to ES under wide spaced poplars
Soil Properties & Soil Change over time
Provision of Ecosystem Services
Value of Ecosystem Services
RECOVERY OF SOIL PROPERTIES
Pasture production semipermanently reduced by 20%
Rosser B.J., Ross C.W. (2011) Recovery of pasture production and soil properties on soil slip scars in erodible siltstone hill country, Wairarapa, New Zealand. New Zealand Journal of Agricultural Research 54:23-44.
TRENDS OF RECOVERY OF ES AFTER EROSION – NO TREES 200% 180% Food Quantity
160%
% of uneroded level
140%
Flood mitigation
120% 100%
Filtering of nutrients and contaminants
80% Net Carbon accumulation (10-100 cm)
60% 40%
Regulation of pests and diseases populations
20% 0% 0
20
40
60 80 Years after the erosion event
100
120
Results of the Economic Valuation & Cost-Benefit Analysis
VALUE OF ES BEFORE AND AFTER EROSION – NO TREES 6000
Total value
Block 1 Block 2
5000
Eroded block 2 20 years after 50 years after
$/ha/yr
4000
3000
2000
1000
0 Total value ($/ha/yr)
Provisionning services
Regulating services
Value of the flows of Ecosystem services NOT the Natural Capital stocks Value of regulating services is greater than value of the provisioning services Recovery non linear: rapid between years 1-20, then slows down
VALUE OF ES – WITH AND WITHOUT TREES 6000 Block 1 Block 2 5000
Blok 2 Eroded (Y0)
Above standard pasture
Trees (Y10) Trees (Y20)
$/ha/yr
4000
3000
Above eroded levels
2000
1000
0 Total value ($/ha/yr)
Provisionning services
Regulating services
NET PRESENT VALUE OVER 20 YEARS ($/ha) 30% less than B1 $90,000
Extra 10% with trees $80,000
56% permanently lost with erosion
$70,000
NPV in $/ha
$60,000 $50,000
Uneroded pasture Block 1
$40,000
Uneroded pasture Block 2 Trees on Block 2
$30,000 Eroded Block 2 recovering
$20,000 $10,000 $3%
5% Discount rate
10%
$1 in soil conservation $68 NPV added services + avoided costs
BENEFIT COSTS ANALYSIS Four scenarios for Block 2: • Option1: Trees not harvested - Services not considered
• Option 2: Trees harvested - Services not considered • Option 3: Trees not harvested - Services considered • Option 4: Trees harvested - Services considered Method: • For each scenario, look at costs and revenues for each year
• The value of ES (net Δ) is a benefit, usually NOT considered in BCA • Calculate the NPV over 20 years (4 discount rates)
BCA OF 4 MANAGEMENT OPTIONS, FOR 4 DISCOUNT RATES 12000
Option1 = Trees not harvested - Services not considered Option 2 = Trees harvested - Services not considered
Net present value /ha over 20 years
10000
Option 3 = Trees not harvested - Services considered Option 4 = Trees harvested - Services considered
8000
6000
4000
2000
0
-2000 0%
3%
5% Discount rate
10%
CONCLUSIONS The Ecosystem Services approach can: • Give new insights into the current use of our natural resources • Focus on performance of the ecosystem under specific combination of land use and management • Holistic approach to the value of land including trade-offs between social, economic and environmental aspects • Guide future investments in Ecological Infrastructure for policy (incentives?)
In New Zealand: • NC/ES used for a NEA for environmental reporting • Include ES in regional plans • Use NC approach for limit setting for NO3- leaching
Thank you!
