Multi-proxy analysis on dendrocronology, anatomy and stable carbon isotopes of two species of jatobá (Hymenaea, Leguminosae) to identify possible atmospheric CO2 concentration and climate change effects

Author(s)

Giuliano Maselli Locosselli

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB)
• Defense date: 2010-09-16

Examining board members

Gregório Cardoso Tápias Ceccantini; Marcos Silveira Buckeridge; Jochen Schongart

• Advisor: Gregório Cardoso Tápias Ceccantini

Abstract

The development of human activities is taking place at a high environmental cost. The increasing atmospheric CO2 concentrations and changes in land-use are unleashing relevant changes in global climatic. The objective of this study is to determinate how H. courbaril L. (from forest) and H. stigonocarpa Mart ex. Hayne (from cerrado) are responding to the climatic change through tree-ring width, vessel area and stable carbon isotope analysis. Twelve specimens of H. stigonocarpa and eleven of H. courbaril were sampled. Then, samples were polished and tree-rings were identified, dated, measured and chronologies were built using COFECHA and ARSTAN softwares. With tree-rings dated, early wood vessel areas were measured and α-celluloses were sampled from wood of each tree-ring to ∂13C analysis and intrinsic water-use efficiency estimation (Wi). The results shows that tree-ring width in H. courbaril are positively related with the precipitation, and negatively related to temperature, during the end of growth period. Also, vessel areas are positively related to precipitation during the middle growth period and negatively related with temperature during the dry season previous to growth period. Tree-rings width in H. stigonocarpa were positively related to precipitation during dry season previous to growth period and were negatively related to temperature during the same period. Also, vessel areas were positively related to precipitation during the beginning of dry season, previous to the current growth period, and negatively related to temperature during the beginning of growth period. In relation to ∂13C, climate signals were found during the current growth period and the previous one. Beyond that, H. stigonocarpa showed a clear increasing trend on i during the last five decades, that was not found in H. courbaril. The results indicate that these species respond to different environmental demands, and that shall lead to different responses regarding the climatic change scenarios. In these scenarios, both species shall be negatively influenced, which will be probably worse in H. courbaril. But, there is another immediate pressure on both species that is related with deforestation. The growth ratio analysis can help policy-makers in projects that have forest and cerrado suppression. In this context, H. stigonocarpa has a mean growth ratio 2.4x smaller than H. courbaril, what implicates longer time for those species reach a mature size. (AU)

• FAPESP's process: 06/58698-0 - Integrated analysis of dendrochronology, anatomy and stable isotopes of carbon in Hymenaea courbaril L. for identification of possible effects of the elevation of atmospheric CO2 and climatic changes
• Grantee: Giuliano Maselli Locosselli
• Support Opportunities: Scholarships in Brazil - Master