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Desurvey: W.P.1.3.3 John B. Thornes (K.c.l ). Desurvey Mission. - PowerPoint PPT Presentation
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Desurvey: W.P.1.3.3
John B. Thornes (K.c.l)• W.P.Specific Objective• …to provide a generic
desertification model that can be readily applied to desertification scenarios (identified from the PIK syndrome approach) as applied to the European bio-physical and socio-economic environments
• Stressing:• ……. The interaction between the
socio-economic and bio-physical drivers and….
• ……….Sustainable renewable resources model of Gutierrez and adapted for desertification by Puigdefabrigas for desertification.
Develop a surveillance system that to assess and diagnose desertification. Contribute to strengthen the necessary scientific knowledge for the future orientation of the sustainable Development Strategy and the 6th Environment Action Programme
Lagadas County Pilot Site, Greece bypermission of V. Papanastasis
Desurvey Mission
• Requirements
• Interface
• Machine
• Requirements• Multiscaling• Ease of parameterisation• Readily available data sources• Policy-implementation
• Interface• Computer-based• different scales• different land-uses
• Machine• PC platform• Object –oriented implementation• Graphic output
Syndromes for AlentejoTable 1.3.3.(2)
syndrome Symptoms Interacting variables
SAHELPre-1890 Rural poverty and population pressure drives farmers to overuse marginal land
Climate, productivity and population
ARAL SEA(1940-1960) Bad management or failure of centrally planned,large scale projects involving deliberate reshaping of the natural environment
Govt. policy on wheat.Wheat productionLand degradation
DUST BOWL1960-1990 Industrialised farming inWheat campaign
Vegetation cover, soil erosion, population densities
SAHEL(AGAIN)(1980-2000)
Overuse of marginal land E.U. subsidies, extensification of agriculture, new farming ‘intakes’ from commons.
RURAL EXODUS(200-) Abandonment of traditional agricultural practices
Abandonment of land, population changes,
A group of signs and symptoms which, when present together allow the description and naming of a particular disease
Regev-Gutierrez
• U. Regev and A. Gutierrez have developed a new economic-ecology paradigm
• Based on the multi-level food chain, with resources at bottom, and human harvesting at top.
• It is constrained by objective functions(such as private maximization of gain, or community sustainability.
• The result is contained in a stability analysis
Resources-Rain/sunshin-nutrients
VegetationVegetation
GrazersGrazers
Harvesters
Source
Production
Consumption
alpha coefficient according to alpha= 1-exp(-b*m), with b=0.023
0
0.2
0.4
0.6
0.8
1
1.2
0 200 400 600 800
Series1
Logistic growth for level i minus respiration
Take-off by predator at level i+1
α coefficient (y) against biomass
Baumgartner-Gutierrez equation for mass change at level i
Xi is mass at i th level exponent is ratio of supply at next lower level (i-1) to demand at this level
Ci is conversion of demand (di) at ith level u i is respiration demand at level i
Respiration term
Gutierrez-Baumgartner fnct of growth relative to different supply/demand ratios
0
0.2
0.4
0.6
0.8
1
1.2
0 100 200 300 400 500
supply for constant demand
(1-e
xp(s
uppl
y/de
man
d)
D=40 D=50 D=80 D=90
Herbivore isocline vs M1,M2,M3From Gutierrez(1996) Fig. 8.1
Gutierrez, A.P.(1996) Applied Population Ecology, A Supply-Demand Approach. Wiley
Herbivore isocline (M2)vs M1
From Gutierrez(1996)Fig8.1)
α is apparency of trophic level to its consumer (how easy it is to get food)
θ2D2 is converted demand from this level
M1 is plant (resource in this case)
M2 a herbivore
M3 a predator
Resource-soil
Producer
Consumer
Soil erosion model
Landdegradation
climateclimate
Modified erosion
topography
Plant growth model
Economic ecology model
Baumgartner-Gutierrez equation for mass change of vegetation
dM1/dt={θ1(1-e-λ1)D1 -r1M1b1}M1 Metabolic pool equation plants -(1-e-λ2)D2M2 Loss to herbivores in level above
λ1=α1M0/D1M1 ratio of supply of resource to Demand from plants
λ2 = α2M2D3/D3M3 ratio of supply of herbivores to Demand from predators
M1=vegetation M2=herbivores M3=carnivoresM0=rain
α=accessibility
Θ=conversion factor
Appendix I