Isabelle Tritsch | CIRAD - Academia.edu (original) (raw)

Papers by Isabelle Tritsch

Echogéo, 2017

L’Amazonie a amorcé depuis quelques années une baisse de la déforestation couplée à un développem... more L’Amazonie a amorcé depuis quelques années une baisse de la déforestation couplée à un développement économique. Le processus est cependant inégal. Si les grands et moyens producteurs font évoluer leurs systèmes de production vers l’intensification et la diversification dans les espaces déjà ouverts, délaissant en apparence les stratégies d’expansion, l’agriculture familiale reste à l’écart du découplage entre production et déforestation. Dans cet article, les engagements des pouvoirs publics et des filières, leurs effets en matière de déforestation et les inégalités d’adaptation sont analysés à l’échelle de l’Amazonie Légale et à celle d’une municipalité considérée comme un modèle car à l’initiative d’une démarche de Município Verde : Paragominas, en Amazonie orientale.

Agricultural landscapes of the Southern Brazilian Amazon are the result of eighty years of govern... more Agricultural landscapes of the Southern Brazilian Amazon are the result of eighty years of governmental policies to install a powerful agricultural sector. Yet, this rapid expansion raised important environmental considerations especially with regard to deforestation. The agricultural frontier is thus now facing a huge challenge: to combine socio-economic development with environmental conservation in a context of frontier expansion. Based on a conceptual model of the agricultural frontier, we review historical changes in environmental and development policies in the Brazilian state of Mato Grosso and emphasize their ambivalent trend to both encourage and control the progress of the frontier. We then extend this model with an integration stage where environmental governance and economic development evolve from competing to complementary concepts. At this stage, the efforts to slow down deforestation are accompanied with programs to promote new agricultural practices and support industrialization. Finally, we put into perspective this recent evolution with regards to the underlying reasons for changing the agricultural model, thus considering the agricultural frontier to be at a tipping point where first positive results need to be confirmed in spite of an unstable economic and political situation.

Espace Populations Societes Space Populations Societies, Jan 12, 2015

Highlights - We emphasize the end of the boom-and-bust development pattern in the Brazilian Amazo... more Highlights
- We emphasize the end of the boom-and-bust development pattern in the Brazilian Amazon.
- Deforestation and socio-economic development follow an inverted U-shape relationship.
- Household incomes are greater in stabilized areas than in areas undergoing deforestation.
- Environmental governance efforts fostered the emergence of EKC.

Abstract
Socio-economic development in the Brazilian Amazon is currently reaching national averages although deforestation activity has been declining for a decade. As a consequence, recent studies rejected the widely agreed boom-and-bust development hypothesis that deforestation first generates an economic boom, which is then followed by a collapse as forest resources are depleted. Here, we confirm these studies that there is no boom-bust cycle and suggest that a new pattern of relationship between deforestation and socio-economic development has emerged following an environmental Kuznets curve (EKC). In this scenario, environmental degradation increases in the early stages of economic development and decreases in later stages as the economy develops and wellbeing increases. To validate this assumption, we conducted the first sub-municipal analysis of socio-economic development and deforestation in the Brazilian Amazon for the 2000–2010 period. Our results confirm the emergence of an EKC relationship with a turning point beyond which socio-economic growth does not appear anymore to be a driver of deforestation. We also emphasize that areas subjected to active deforestation in 2010 present lower socio-economic indicators than stabilized areas, pointing to the precarious socio-economic situation of areas still undergoing active deforestation. We put these results in perspective by considering Brazilian efforts to ensure a transition in environmental governance with the objective of promoting land use sustainability through control of deforestation at the same time as supporting socio-economic development.

Highlights - Low overall relations between population density and deforestation. - One third of A... more Highlights
- Low overall relations between population density and deforestation.
- One third of Amazon deforestation is associated with only 1.5% of the population.
- In contrast, 13% of the rural population live in preserved forests.
- ‘Discrete urbanization’ of rural areas: multiplication of small towns.

This paper provides the first analysis at the sub-municipality scale of the relationships between population densities and deforestation in the Brazilian Amazon between 2000 and 2010. We use the database on deforestation published by the Brazilian space research center (INPE) and the population census data released by the federal geographical and statistical agency IBGE at their finest scale: the census tract level. By crossing the population density and deforestation variables, we identify ten human settlement patterns in the Amazon. There are low-low and high-high classes of population density and deforestation , but also low-high and high-low classes. This analysis helps understand the low overall relations in the Amazon for population and deforestation. We emphasize the expansion of large-scale agriculture and cattle ranching as causing the depopulation of rural areas while in many regions of the Amazon quite strong population densities coexist with relatively low extents of deforestation. Such findings stress the need to implement case-specific public policies in these regions in order to encourage human presence compatible with the conservation of forest cover and biodiversity. We also confirm the importance of the Amazon urbanization process, including the 'discrete urbanization' of rural areas, and the need to better recognize the distinct social and environmental problems of urban areas.

Resumo-Dinâmica da população e do desmatamento na Amazônia brasileira entre 2000 e 2010: uma visã... more Resumo-Dinâmica da população e do desmatamento na Amazônia brasileira entre 2000 e 2010: uma visão baseada nos dados espaciais e estatísticas brasileiras. O Brasil tem dados precisos sobre as áreas desflorestadas anualmente através do seu programa PRODES (Monitoramento da Floresta Amazônica Brasileira por Satélite) do INPE (Instituto Nacional de Pesquisas Espaciais) com base na análise de imagens de satélite Landsat. Além disso, ele monitora a sua população e suas condições socioeconômicas com a realização decenal de censos da totalidade da população brasileira pelo Instituto Brasileiro de Geografia e Estatística (IBGE). Presentamos aqui uma metodologia inovadora para cruzar os dados espaciais do PRODES e os dados sociais do censo demográfico, isso apesar das diferentes escalas geográficas utilizadas, usando uma grade de mais de 50.000 células de 100 km². Com estes novos dados, mostramos a complexidade das dinâmicas populacionais e de desmatamento modelando hoje a Amazônia brasileir...

La conservation des forêts tropicales par les populations traditionnelles est un thème en débat d... more La conservation des forêts tropicales par les populations traditionnelles est un thème en débat depuis les années 90, lorsque les premières zones dévolues à des populations agro-extractivistes ont été créées. La viabilité écologique et économique de ces zones est remise en question face à l’augmentation de leur déboisement, conséquence de la faible valeur attribuée aux produits issus de l’extractivisme et à l’évolution des modes de vie des populations agro-extractivistes. Pour maintenir ces systèmes de production dans des dynamiques compatibles avec la conservation de la forêt, il est nécessaire de valoriser les produits forestiers. Le PAE Chico Mendes dans l’Acre est une communauté symbole pour la conservation de la forêt par les populations traditionnelles. De nombreuses politiques publiques et programmes de valorisation forestière y ont été mis en place, dont un programme pilote de production communautaire de bois éco-certifié FSC®. Cette étude s’interroge d’une part sur les syst...

Dynamics of population and deforestation in the Brazilian Amazon between 2000 and 2010: a differe... more Dynamics of population and deforestation in the Brazilian Amazon between 2000 and 2010: a different view based on spatial and statistical public data. Brazil has accurate data on the forested surfaces annually cleared through its PRODES program (Monitoramento da floresta Amazônica Brasileira por Satellite) implemented by INPE (Instituto Nacional de Pesquisas Espaciais) and based on the analysis of Landsat satellite images. In addition, Brazil monitors its population and its socio-economic conditions with the realization of decennial full censuses of the Brazilian population by the IBGE (Instituto Brasileiro de Geografia e Estatística). Here we propose an innovative methodology crossing the deforestation data from the PRODES and the social data from the IBGE census’ despite the different geographical ladders they used, using a grid of more than 50,000 cells of 100 km². With the finesse of this new data, we show the complexity of population and deforestation dynamics shaping today the...

Les populations amérindiennes expérimentent depuis plusieurs décennies des changements sociaux-éc... more Les populations amérindiennes expérimentent depuis plusieurs décennies des changements sociaux-économiques et territoriaux importants, dans un contexte d’augmentation démographique forte. Nous nous intéressons à l’adaptation des systèmes d’occupation du territoire et d’exploitation des ressources naturelles des amérindiens de Guyane face aux contraintes exercées sur leur territoire et leur mode de vie. Quelle résilience des systèmes amérindiens d’utilisation du territoire et de ses ressources naturelles ? La concentration de l’habitat amérindien autour du bourg de Camopi, liée à l’implantation des infrastructures de type dispensaire et école, et à la promotion de l’habitat sédentaire, génère une pénurie des ressources naturelles et un mal-être social. Le système s’adapte par un éclatement de l’habitat en villages périphériques et par une extension des terroirs agricoles le long des fleuves, afin de retrouver de l’espace. Ces villages reproduisent un modèle d’organisation spatiale se...

Bois et Forets des Tropiques

Amerindian populations have been experiencing major socio-economic changes for several decades, i... more Amerindian populations have been experiencing major socio-economic changes for several decades, in a context of rapid demographic growth. This article addresses the ways in which the Amerindian populations of French Guiana have adapted their land use and natural resource management systems to cope with the pressures exerted on their lands and lifestyles. The aim was to investigate the resilience of their systems for land and natural resource use. The concentration of Amerindian habitats around the town of Camopi, which is linked to the availability of health and school infrastructure and to efforts to promote a sedentary lifestyle, is a factor of increasing natural resource scarcity and social alienation. The system is adapting by fragmenting the Amerindian habitat into peripheral villages and extending farmlands along rivers to access to more space. These villages replicate patterns of spatial organisation that are similar to those found in traditional Wayãpi and Teko villages, exc...

Confins, 2012

Deux peuples amérindiens de langue tupi-guarani, les Teko et les Wayãpi, vivent sur le territoire... more Deux peuples amérindiens de langue tupi-guarani, les Teko et les Wayãpi, vivent sur le territoire de Camopi, commune de Guyane française. Dans cet article 1 nous nous attachons à retracer la construction historique de leurs territoires actuels, en montrant quand et comment ils se les ont appropriés. Nous explicitons également comment ces territoires sont devenus une commune de la République française. Dans une deuxième partie, nous présentons comment ces peuples s'adaptent aux changements contemporains induits par l'orpaillage illégal ayant lieu sur leur territoire et par le recrû démographique sans précédent qu'ils connaissent. Enfin, après avoir montré l'échec des politiques de regroupement que l'État français leur a imposé depuis 40 ans, nous concluons sur l'importance identitaire de leurs revendications socio-culturelles et territoriales contemporaines.

Á partir de l’exemple de la vallée du Trombetas (Pará), nous analysons l’évolution des pratiques ... more Á partir de l’exemple de la vallée du Trombetas (Pará), nous analysons l’évolution des pratiques migratoires des populations forestières d’Amazonie et leurs interactions avec certains phénomènes démographiques : décohabitation, primo-fécondité et primo-nuptialité.
Aujourd’hui, la plupart des familles réussissent à fréquenter la ville de façon régulière grâce à des systèmes de mobilités articulant dispersion résidentielle et complémentarité des fonctions au sein du ménage. Chez les jeunes filles, la mobilité rurale-urbaine est fréquemment motivée par l’accès aux services scolaires et s’accompagne d’une décohabitation précoce. Parallèlement, on observe un rajeunissement de la fécondité.

Synthèse de terrain du projet DURAMAZ. Le texte répond aux neuf questions définies par le projet ... more Synthèse de terrain du projet DURAMAZ. Le texte répond aux neuf questions définies par le projet DURAMAZ pour le site d'étude du Projet de Assentamento Agro-extrativista (PAE) Chico Mendes.

The goal of this article is to understand the contemporary transformations of indigenous territor... more The goal of this article is to understand the contemporary transformations of indigenous territories in relation to several factors, including urbanisation, population growth, economic development and conservation policies. Using socioeconomic , governance and land use data, we explain the current territorial reorganisations of the Wayãpi and Teko indigenous peoples. We demonstrate the existence of an emerging 'multi-sited' land use system that allows these indigenous peoples to benefit from resources in both urban and forest areas and ensures sovereignty over the territory. We emphasise the role of the delimitation of protected areas in catalysing identity claims and the process of land use reformulation.

Conference Presentations by Isabelle Tritsch

13th Congress of the International Society of Ethnobiology - Session 12 "Environmental norms, mob... more 13th Congress of the International Society of Ethnobiology - Session 12 "Environmental norms, mobility and biodiversity management in Amazonia"

Indicators to monitor forest degradation and logging impacts in the Brazilian Amazon

We studied the trajectories of forest degradation in the municipality of Paragominas – PA in the ... more We studied the trajectories of forest degradation in the municipality of Paragominas – PA in the eastern Brazilian Amazon between 1995 and 2009, with a focus on the forestry company Cikel (400 000 ha certified by FSC since 2001).
First, we developed a semi-automatic remote sensing methodology to detect forest degradation using multi-temporal Landsat images (spatial resolution of 30m) covering the 1995-2009 period. This method included two steps: 1) Identification of logging tracks and log landings using an algorithm of Bourbier et al. (2013). This algorithm uses spectral indices and morphological filters to strengthen the spectral contrasts between bare soil and forest cover. 2) Identification of logging gaps - which are characterized by senescent vegetation due to trees fall - using a Spectral Mixture Analysis carried out in CLASlite (Asner et al., 2009) and a fraction index (Souza et al., 2013). So, we obtained annual maps identifying these three major impacts.
Secondly, we calculated annual landscape metrics of forest degradation using the R package "SpatialEco". Then, we calculated indicators which synthetize information about logging impacts and logging frequencies over the period from these annual degradation metrics. Finally, we selected a set of 6 indicators and statistically analyzed the trajectories of degradation occurring in Paragominas using ACP and CAH.

Our results emphasize four major degradation trajectories from well managed forests to highly-logged forests. They clearly show a difference between legal and illegal logging in terms of forest degradation. Moreover, they indicate that impacts of FSC certification on forest degradation were positive. Degradation was statistically lower in the certified logged plots compared to the uncertified plots. These set of indicators are adequate to monitor forest degradation through space and provide guidance to policy-makers for a better management of forest resources.

Echogéo, 2017

Espace Populations Societes Space Populations Societies, Jan 12, 2015

Bois et Forets des Tropiques

Confins, 2012

Indicators to monitor forest degradation and logging impacts in the Brazilian Amazon

Demographic pressure is often viewed as the principal determinant of tropical deforestation. Howe... more Demographic pressure is often viewed as the principal determinant of tropical deforestation. However, with the actual trend of rural-urban migrations and the expansion of large-scale cropping in the tropics, the relation between human settlement patterns and deforestation is unclear. This research investigates the variation in population settlement across the Brazilian Amazon between 2000 and 2010 and how it is related to deforestation. The basis of our analysis are the high resolution geographic database on deforestation released by the Brazilian space research center (INPE) and population census data at block level released by the Brazilian geographical and statistical agency IBGE. We propose an innovative methodology to cross these data despite their different geographical ladders using a grid of more than 50,000 quadrats of 100 km² covering the entire Brazilian Amazon. We show the importance of rural depopulation both in the agriculture/forest frontier and in the riverine road-less regions and the important growth of regional towns. In the frontier, rural depopulation is not associated with lower deforestation rates what give rise to what one can call “deforested desert”: quadrats with very low population density and high deforestation rates. At the opposite, we show the still important number of people living in forest without causing deforestation. This radiography of deforestation and population settlement demonstrates the complexity of the processes shaping the Brazilian Amazon and the need to better considerate the current human settlement pattern when implanting public policies.