Researching on hydraulic conductance of different stem parts of fir (abies bornmulleriana mattf.)

For a conductor which liquid flows through, hydraulic conductance (K, mls-1MPa-1) is defined as the ratio of pressure difference at the inlet and outlet to the fluid amount passing through the conductor in unit time period. This property is one of the key functions of the wood, and is obtained by the flow rate (F-Flow, mls-1) along the wood sample divided by the pressure difference driving the flow (∆P, MPa). In this study the relationship between the anatomical features and the measured hydraulic conductance values for Uludağ Fir (Abies bornmulleriana Mattf.) were examined. The study material Uludağ Fir (Abies bornmulleriana Mattf.) was obtained within the operational limits of Kale Forestry District Office, Bolu Regional Directorate of Forestry. The 75 years old tree is 25 m tall with a diameter of 30 cm. Samples for measurements were taken 0.3 m and 1.3 m from the base and at every 2 meters past that to the top at 19.3 m. Hydraulic conductance of the samples was determined using the test set up. Furthermore, for all samples diameter, length, width, number of axial tracheid in 1 mm2, lumen width, cell wall thickness, dimension of bordered pit and pores were analyzed. The measurements indicate that the hydraulic conductance increases starting from the 0.3 m mark up to the mid-height followed by a gradual decrease up to 19.3 m. Highest conductance value was 7.613 mls-1MPa-1x10-2, measured at 7.3 m. Hydraulic conductance measured at 0.3 m and 19.3 m were 5,596 mls-1MPa-1x10-2 and 6.193 mls-1MPa-1x10-2, respectively, showing no drastic changes along the entire length of the stem. Anatomical analysis showed that the length of tracheid has reached the peak value at 9.3 m, decreasing after this point along the stem and found to be the lowest at 19.3 m. Tracheid and lumen widths increased up to 5.3 m and showed no significant changes up to 15.3 m. A decrease was found again after 15.3 m. Cell wall thickness and radial and tangential diameter of early wood and late wood don't show significant changes till the top point of stem. Diameters of bordered pits and pores were in a decreasing trend up to 19.3 m, whereas the number of tracheid in 1 mm2 was found to be increasing up to 19.3 m. A relative examination of hydraulic conductance and anatomical features shows that the changes along the stem a similar, with both properties following an increasing trend up to the mid height of the stem, followed by a decrease.