Estimativa da variabilidade da quantidade de carbono absorvido pela caatinga.

Abstract

The present work quantifiy the carbon sequestration by Caatinga during events of El Niño South Oscillation (ENSO) and absence of ENSO, as well as the relationships among the Net Primary Production (NPP) and the climatic variables precipitation, radiation and temperature for the periods of six (1981-88), twelve (1981-93) and eighteen years (198199), where, for this, the data of Normalized Difference Vegetation Index (NDVI) were used of the AVHRR/NOAA and of reanalysis of the NCEP/NCAR. To observe the possible internal changes of each regime of precipitation were divided the Caatinga in two areas denominated of North Caatinga, under the domain of the regime of precipitation of the north of the Northeast, with maximum of rain from March to April, and South Caatinga, with regime of precipitation of the south of the Northeast, with maximum of rain from December to January. The results showed that occur a great spatial variability in the carbon sequestration in areas of Caatinga, and this spatial variability was more accentuated in El Niño events, where the smallest values of NPP were registered, and the largest values sequestrated happen in years of La Niña occurence. The simple correlation betwenn NPP and the variables precipitation, radiation and temperature follows the same pattern for the all Caatinga, North Caatinga and South Caatinga, so that the correlation between NPP and the precipitation had statistical significancy for all the analyzed periods, the radiation did not show correlation with NPP and the correlation between NPP and the temperature is significant just for the first period analyzed. Even so, the multiple correlation involving all the climatic variables as answer of NPP showed statistical significancy for all the periods analyzed.