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HOW STRONG IS THE RELATIONSHIP BETWEEN RAINFALL VARIABILITY AND CAATINGA PRODUCTIVITY? A CASE STUDY UNDER A CHANGING
Cleber Salimon1, Liana Anderson2
1Universidade Estadual da Paraíba, Rua Horácio Trajano, s/n, 58071-160 João Pessoa, PB, Brazil.
Anais Da Academia Brasileira De Ciencias
|May 25, 2017
Summary
Rainfall significantly impacts vegetation in Brazil. Reduced rainfall by 65% in dry years led to a 25% drop in plant productivity, highlighting ecosystem vulnerability.
Area of Science:
- Ecology
- Environmental Science
- Climate Science
Background:
- Semiarid tropical Brazil's vegetation dynamics are influenced by rainfall, yet quantitative studies are scarce.
- Northeast Brazil faces projected rainfall reductions of up to 60% by the 21st century (IPCC scenario AII).
Purpose of the Study:
- To quantitatively analyze the relationship between rainfall and vegetation dynamics in Paraíba State, Brazil.
- To assess the impact of rainfall anomalies on plant productivity.
Main Methods:
- Analysis of satellite-derived monthly rainfall and vegetation index data for 40 natural vegetation sites (2001-2012).
- Calculation of rainfall and vegetation index anomalies.
- Correlation analysis between rainfall variation/anomaly and vegetation productivity.
Main Results:
- Rainfall variation explained up to 50% of plant productivity (vegetation index).
- Rainfall anomaly explained up to 80% of vegetation productivity anomaly.
- An extreme dry year (2012) saw 65% less rainfall and a 25% decrease in the vegetation index.
Conclusions:
- Decreased vegetation productivity due to reduced rainfall poses a risk to ecosystem functioning.
- Long-term rainfall reduction could lead to desertification, with significant environmental, social, and economic consequences.
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