Introduction Ecological---Economic Economic … Economic relationships and the sustainable...

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*Institute for Agricultural Policy & Market Research // JL University of Giessen // Germany // [email protected] Ecological Ecological Ecological Ecological-Economic Economic Economic Economic relationships relationships relationships relationships and the and the and the and the sustainable management of sustainable management of sustainable management of sustainable management of rangelands. rangelands. rangelands. rangelands. A case of Bio A case of Bio A case of Bio A case of Bio-economic economic economic economic modeling modeling modeling modeling in in in in Namibia Namibia Namibia Namibia Stephanie Domptail* Rangelands are present on arid and semi arid climates and are a most important source of livelihood in Saharan and sub-Saharan Africa. Degradation of rangelands world wide and in Namibia has been thematized as it is clearly linked to farmers’ and rural livelihoods. Rangelands management is the result of both ecological and economic pressures, and their interaction. Our work is part of the biodiversity project BIOTA Africa. It aims at providing more understanding of the dynamics and feedbacks existing between the ecological and the economic subsystems considering the ranching activity. Introduction Qualitative analysis Vulnerability approach: Identify points of pressure which constraint farmers in their land use Method: Text analysis Data: Text data of expert interviews and farmers interviews How do ecological and economic dynamics integrate in the making of strategies for rangeland management ? Bio-economic model enables the assessment of ecological, economic and some institutional parameters on land use decision making using scenario analysis. Main results are that expectations of farmers over the ecological and economic pattern of pressure, as well as farmers’ objectives are key element in stocking strategies. However, a further qualitative analysis can reveal complementary information on the constraints imposed by the environment on farmers’ strategies. Quantitative analysis Environmental / ecological economic approach: Model system and identify key parameters and relationships in system for decision making upon land use Method: Bio-economic modeling: depicts STRATEGIES which INTEGRATE the ecological consequences of farm management in the calculation of the optimal land use strategy under STOCHASTIC conditions Data: Model parameterized using interview data. Produced data describe land use strategies under different conditions (sensitivity analysis) and scenarios Outlook How do external ecological, economic and institutional constraints affect this dynamic ? Picture 2006 Variable costs Stocking density Fixed costs Biomass (grass/bush) Lamb sales Income Rainfall Rangeland condition/state Decision making Ecological feedback Economic feedback Farm scale Landscape scale Ecological Economic Institutional Environment Case study: Typical commercial ranch Arid southern Namibia (rainfall 150 mm a year) Farming system : Interviews with about 25 commercial farmers Rangeland condition: represented with State-and- Transition model: 6 different rangeland ecological states http://encarta.msn.com/map_ 701514947/namibia.html State 1: high cover – grass dominated State 2: high cover – bush range State 3: bare land State 4: sparse vegetation State 5: bush dominated State 6: dominated by annuals grasses

Transcript of Introduction Ecological---Economic Economic … Economic relationships and the sustainable...

*Institute for Agricultural Policy & Market Research // JL University of Giessen // Germany //

[email protected]

EcologicalEcologicalEcologicalEcological----Economic Economic Economic Economic relationships relationships relationships relationships and the and the and the and the sustainable management of sustainable management of sustainable management of sustainable management of rangelands. rangelands. rangelands. rangelands.

A case of BioA case of BioA case of BioA case of Bio----economic economic economic economic modelingmodelingmodelingmodeling in in in in NamibiaNamibiaNamibiaNamibia

Stephanie Domptail*

Rangelands are present on arid and semi arid climates and are a most important source of livelihood in Saharan and sub-Saharan

Africa. Degradation of rangelands world wide and in Namibia has

been thematized as it is clearly linked to farmers’ and rural livelihoods.

Rangelands management is the result of both ecological and

economic pressures, and their interaction. Our work is part of the

biodiversity project BIOTA Africa. It aims at providing more understanding of the dynamics and feedbacks existing between

the ecological and the economic subsystems considering the ranching activity.

Introduction

Qualitative analysis

Vulnerability approach: Identify points of pressure which constraint farmers in their land use

Method: Text analysis

Data: Text data of expert interviews and farmers interviews

⇒ How do ecological and

economic dynamics integrate in

the making of strategies for

rangeland management ?

Bio-economic model enables the assessment of ecological, economic and some institutional parameters on land use decision making using scenario analysis. Main results are that expectations of farmers over the ecological and economic pattern of

pressure, as well as farmers’ objectives are key element in stocking strategies.

However, a further qualitative analysis can reveal complementary information on the constraints imposed by the environment on

farmers’ strategies.

Quantitative analysis

Environmental / ecological economic approach: Model system and identify key parameters and relationships in system for decision making upon land use

Method: Bio-economic modeling: depicts STRATEGIES which INTEGRATE the ecological consequences of farm management in the calculation of the optimal land use strategy under STOCHASTIC conditions

Data: Model parameterized using interview data. Produced data describe land use strategies under different conditions (sensitivity analysis) and scenarios

Outlook

⇒ How do external ecological,

economic and institutional

constraints affect this dynamic ?

Picture 2006

Variable costs

Stocking density

Fixed costs

Biomass

(grass/bush)

Lamb sales

Income

RainfallRangeland

condition/state

Decision making

Ecological feedback

Economic feedback

Farm scale

Landscape scale

EcologicalEconomic

Institutional

Environment

Case study: Typical

commercial ranch

Arid southern Namibia (rainfall 150 mm a year)

Farming system: Interviews with

about 25 commercial farmers

Rangeland condition:represented with State-and-

Transition model: 6 different rangeland ecological states

http://encarta.msn.com/map_

701514947/namibia.html

State 1: high cover – grass dominated

State 2: high cover – bush range

State 3: bare land State 4: sparse vegetation State 5: bush dominated State 6: dominated by annuals grasses