Ledru Marie-Pierre, Jeske-Pieruschka V., Bremond L., Develle A. L., Sabatier P., Martins E. S. P. R., de Freitas M. R. D., Fontenele D. P., Arnaud F., Favier C., Barroso F. R. G., Araujo F. S. (2020). When archives are missing, deciphering the effects of public policies and climate variability on the Brazilian semi-arid region using sediment core studies. Science of the Total Environment, 723, 137989 [16 p.]. ISSN 0048-9697.
Titre du document
When archives are missing, deciphering the effects of public policies and climate variability on the Brazilian semi-arid region using sediment core studies
Année de publication
2020
Auteurs
Ledru Marie-Pierre, Jeske-Pieruschka V., Bremond L., Develle A. L., Sabatier P., Martins E. S. P. R., de Freitas M. R. D., Fontenele D. P., Arnaud F., Favier C., Barroso F. R. G., Araujo F. S.
Source
Science of the Total Environment, 2020,
723, 137989 [16 p.] ISSN 0048-9697
The northeastern region of Brazil is the most densely populated and biodiverse semi-arid regions of the planet. Effects of the natural climate variability and colonization on the landscape have been described since the beginning of the 16th century but little is known about their effects on natural resources. Climate projections predict temperatures above 40 degrees C and an increase in the number and duration of droughts at the end of the 21st century with strong societal impacts. Here, we analyze the influence of public policies, human activities and natural climate variability on the environment over the last 60 years. Our study is based on sedimentological and environmental reconstructions from two sediment cores collected in two dam lakes on the river Acarau in the State of Ceara. Multiproxy analyses of both cores (inorganic geochemistry, pollen, charcoal, remote sensing) at an annual resolution showed that 1) at interannual scale composition and distribution of the dry forest (known as Caatinga) were not affected by the alternance of drought and high moisture episodes; 2) at decadal scale human activities such as agriculture were reflected by changes in vegetation cover and fishery by progressive changes in lake trophic status; 3) public policies were able to promote changes in the landscape e.g., land colonization with the regression of the dry forest and irrigation plan able to amplify the deforestation and change the floristic composition. Thanks to paleo-science approach, our environmental diagnosis should help future decision-making and provide guidelines for preservation of resources and wellbeing of the inhabitants.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020]
;
Sciences du milieu [021]
;
Sciences du monde végétal [076]
;
Etudes, transformation, conservation du milieu naturel [082]
Description Géographique
BRESIL ; ZONE SEMIARIDE
Localisation
Fonds IRD [F B010078074]
Identifiant IRD
fdi:010078074
