A study concerning the productivity of eucalyptus and the soil water availability was carried out in Guanhães region, Minas Gerais State, Brazil. Evaluations were accomplished for precipitation events occurring over the rainy seasons (PEC), water balance components, annual indices for aridity (Ia), hydric (Ih) and moisture (Im), as well as the monthly periodic increment (IPM), annual average, over the period from 1985 to 1998. The wood productivity was affected by PEC, and the lowest IPM values were observed in the years preceded by either dry rainy season or very dry rainy season, whereas the highest IPM values were observed in those years preceded by rainy season classified as rainy or very rainy one. For periods with increased or decreased PEC, a correlation of this variable with IPM was verified, and a R² value above 0.80 was obtained. For an increase and reduction of 100 mm in PEC, the IPM showed an increase of 0.51 m³ ha-1 month-1 and a reduction of 0.80 m³ ha-1 month-1, respectively. With some exceptions, higher IPM values were observed in the years subsequent to the years with higher Im and Ih; and in those years preceded by a negative Im, a reduction was verified in IPM. The IPM was higher for the age range from 3 to 5 than for that from 5 to 7 years, whereas the value for the average local index was 28.90.
forest productivity; sequential water balance; rainy season; moisture indexes; eucalyptus growth rate
