remote sensing, social and economical data to understand agricultural land cover dynamics in eastern...
DESCRIPTION
Cécile BILLARDPresentation for the conference on Taking stock of smallholders and community forestryMontpellier FranceMarch 24-26, 2010TRANSCRIPT
Remote sensing, social and economical data to understand agricultural land cover dynamics in eastern Amazonia
Taking stock of smallholder and community forestry: Where do we go from here?
Picture 4
24 - 26 March 2010, Montpellier, France
by Cécile BILLARDMsc. Degree in Forest Ecology and ManagementUniversity of Freiburg, Germany
Introduction
Framework: the AMAZ-ES Project (Biodiversity of Amazonian Landscape, Socio-economic drivers and Production of ecosystem goods and services)
Transdisciplinary project supported by the French National Agency for Research (ANR)
French-Colombian-Brazilian partners (sociology, economy, agronomy, ecology & modelling)
2 countries, 6 communities, 300 households Amazonian basin VS. Different socio-economical contexts Colonisation VS. Demographic pressure
How do national & regional policies affect ecosystems ?
Research issue Modelling the interactions between society and the environment Developing tools adapted to modelling complex systems
2
Location State of Para, Brazil Community of Palmares II
Community of Landless Rural Workers Context of settlement:
Previous fazenda invaded by MST (90’s) Eldorado dos Carajás massacre in 1996 Official settlement of 517 families in 1997 Expropriated land of 15 850 ha
Context of forest margin colonization
An equal distribution of land Lots of 25ha each (1000 x 250 m) Small scale & diversified agriculture : crops, pastures, fallows, homegardens
Study area
3
Objectives & hypotheses
Objectives
To assess & explain the landscape dynamics over time To describe the current land cover To quantify agricultural & forest changes
To identify these changes at the household-level
To test the influence of social and economical factors on land use changes
Main Hypotheses Specific social & economical characteristics of local people influence land
use decision at the household-level
4
Satellite imagery of years 1986, 1992, 2001 & 2007 Field survey (modelling team) to determine each landscape
element in 2007
Spatio-temporal analysis of land use and land use changes
Supervised classification of the 4 images to quantify & describe the actual land cover and the land use changes since 1986
Landscape analysis: typology of the lanscape elements (field & remote sensing) & Model of the dynamic of succession over time
Typology of land use changes at the household-level (land register)
Grouping farms with similar pattern (PCA & Cluster dendrogram)
Material & methods
5
Socio-economical data collected at the household-level Field survey (sociology team) in 2007 Collection of quantitative (age of the household’s chief, …) and
qualitative (level of study, …) datas: 51 households
Socio-economical analysis General and detailed (for each type) description of the households,
based on socio-economical variables
Material & methods
6
Cadastral map of Palmares (land register) 3 Sub-windows of 17 households To cross land use changes and socio-economical
parameters
Statistical analysis Sample of 44 households Quantitative (economical variables social indicators,
land use, land use changes) and qualitative (social indicators) variables
Correlation analysis: to quantify the influence of these variables on land use changes and deforestation
Material & methods
7
Relationship between land use changes and socio-economical parameters
Focus on recent land use changes 2001-2007Focus on deforestation rates
Results of classifications
8
1986 20011992 2007
Gain in precision & complexity over time
Landscape analysis
9
Composition of agricultural lot in 2007:
- 50% forested- 16% fallows- 15% multi-stratified plantations- 11% pastures- 8% bare lands
Deforestation rates: 45% of each forested lot was converted into non forest areas between 1986-2007
Most of the changes occured between 2001-2007
Land use change at the sub-windows’ scale
Typologie of the farmer’s land use over time
10
6. Dynamic of regrowth
4. Dynamic of forest conversion into multi-stratified plantations (and pastures)
5. Active dynamic of forest burning (advanced stage)
2. Recent dynamic of forest burning (first stage of forest degradation)
7. Active dynamic of forest conversion into a mosaic of plantations, fallows and pastures
3. Development of agricultural practices(low impact on forests)
Axis 1
Axe
2
Axe 1 PASTUREFOREST
Axe
2BU
RNED
FO
RES
TS
1. Recent dynamic of agricultural progression(forest degradation)
PLA
NTA
TIO
NS
Identification of 7 dynamics of land use changes
11
Type 6: Dynamic of regrowth traducing pasture and bare lands abandon and the progression of multi-stratified plantations
Type 1: Recent dynamic of agricultural progression, especially pastures and multi-stratified plantations, at the detriment of the forest which was already exploited
Description of the types
Recent land use changes (2001-2007) at the household-level
12
Results of the correlation analysis
Household features influencing land-use decisions
Negative correlation AMOUNT OF INCOMES
deforestation rates & forest cover changes LEVEL OF STUDY
pasture cover PRODUCTIVE CAPITAL FOR CATTLE RANCHING DURATION OF STAY
Bare and/or burned lands cover
Positive correlation AMOUNT OF CREDIT
fallow cover (especially with non-refundable credits)
13
Understanding of social, economical & political drivers and their influence on land use decisions of smallholders Specific parameters do influence land use decisions Time effect of household trajectories (life cycle)
New insight provides a reliable basis for drawing up local and regional sustainable management policies
for a more sustainable resources management need for forest margin consolidation and remaining forest
conservation
Conclusion
14
THANKS for your attention!
For more information:
Cécile BILLARDMsc. Degree in Forest Ecology & ManagementUniversity of Freiburg – [email protected]
Valéry GONDCIRAD – ES, UPR 105 Biens et services des écosystèmes forestiers tropicauxCampus de Baillarguet TA C-105/D-21434398 Montpellier Cedex 5Tel : (33) 4 67 59 37 87Projet : http://www.coforchange.eu/
15
Typology of land use changes
Determination of 4 main dynamics -Empirical model-
A dynamic of deforestation and forest degradation, especially by burning
A dynamic of land exploitation by burning
A dynamic driven by the development of agricultural activities
A dynamic of secondary growth or natural regeneration
16