Productivity of Populus in monoclonal and polyclonal blocks at three spacings.

Abstract

Four Populus clones were grown at three spacings (0.5, 1.0, and 1.5 m) in monoclonal plots and in polyclonal plots with all clones in intimate mixture. After the third year, many individual tree and stand traits differed significantly by clone, spacing, deployment method, and their interactions. Differences among clones in growth and stem form were greater in polyclonal than in monoclonal plots, and differences in performance between deployment methods were greater in the denser spacings. Monoclonal stands had greater uniformity in tree size than polyclonal stands. Total aboveground oven-dry woody yield averaged 48.0 Mg.ha -1 in the 0.5-m spacing and decreased as spacing increased. Some clones differed in yield from other clones in both monoclonai and polyclonal plots. Assuming that equal numbers of plants from the same clones were planted, the manner of deployment did not affect productivity; that is, although there were clonal differences in yield, mean yield of the four clones in monoclonal plots (44.3 Mg.ha -I) did not differ from the yield of polyclonal plots (43.1 Mg.ha-1). Comparative yields (yield in polyclonal plots/yield in monoclonal plots) differed substantially, however, and the increases or decreases in comparative yield differed with spacing and clone. Production and inventory were less evenly balanced among clones with polyclonal than with monoclonal deployment.

Citation

DeBell, Dean S.; Harrington, Constance A. 1997. Productivity of Populus in monoclonal and polyclonal blocks at three spacings. Canadian Journal of Forest Research. 27: 978-985