**2. Materials and methods**

## **2.1 Site and wood sampling**

Five elite *Eucalyptus* spp. clones at 4 years old were selected from a clonal trial located in Goiás State, central-western Brazil (16° 16′ 37″ S; 47° 44′ 02″ W; 930 m *Wood Quality and Pulping Process Efficiency of Elite* Eucalyptus *spp. Clones Field-Grown… DOI: http://dx.doi.org/10.5772/intechopen.106341*

**Figure 1.**

*Climatological normal (1990–2020) of temperature (°C) and accumulated precipitation (mm) of Luziânia, Goiás, Brazil - NASA power climate data.*

above sea level). The experiment was established in December 2012, with 93 *Eucalyptus* species/hybrids, using single tree plots and 29 replications. Trees were planted at 3.0 × 3.0 m spacing and were managed according to the operational practices for *Eucalyptus* plantations in Brazil (i.e., with limestone and NPK fertilization, and control of weeds and ants). According to the Köppen-Geiger climate classification, the region's climate is subtropical humid with dry winters and wet summers [20]. The mean annual rainfall is near 1300 mm with five dry months per year, and the annual average temperature is 22.0°C (**Figure 1**). The soil is Plinthosol, being characterized as gravelly with an acidic pH, low base saturation and high aluminum saturation.

A total of 25 trees were systematically felled (five genotypes, five trees each). The selected clones were among the most productive of the experiment and are hybrids from a diversity of species. **Table 1** shows the species, growth and wood properties obtained from disks at breast height of five elite *Eucalyptus* clones. The wood disks for this work were obtained at five different Heights (base, 25%, 50%, 75% and at 100% of the commercial height) for determining basic density and fiber characteristics. In addition, wood logs of approximately 50 cm were obtained at intermediate heights regarding those previously mentioned. These logs were chipped into small sized pieces (around 5 mm) and kept stored before kraft pulping. **Figure 2** illustrates the sampling process and respective analysis.
