Since 2013, yellowing of the needles (chlorosis) and decline of adult trees have been seen inplantations of Pinus taeda (loblolly pine) plantations in different parts of the Santa CatarinaPlateau. In addition to chlorosis, mortality has also been observed in the plantations to a lesserdegree, due to attack by the fungus Armillaria sp. Few data are available on the incidence andseverity of this disease, as well as its distribution in adult pine plantations. For this reason,further research is needed to determine what environmental attributes (alone or combined)are contributing to this problem. The objective of this project is to identify the main biotic(diseases and pests) and abiotic (soil, climate, and other) factors associated with chlorosis andmortality in commercial pine plantations in the state of Santa Catarina. A database will beestablished in order to determine the spatial and temporal distribution of this problem and thespecies that exhibit this disease. By the end of this study, data will be obtained to establishmitigation and control measures through silvicultural interventions in plots where this problemis present in order to reverse chlorosis in the affected trees.