The growth of Larix gmelinii seedlings as affected by charcoal produced at two different temperatures

Fires burn forest with spatially heterogeneous intensity and charcoals generated at various temperatures during fires exhibit variable physical and chemical characteristics. These variable properties of charcoal may, in turn, influence germination and growth of tree seedlings. To examine the effects of different charcoal properties on the growth of Gmelin larch (Larix gmelinii) seedlings, we conducted an experiment with larch-branch-derived charcoals produced at 400°C (low charcoal) and 800°C (high charcoal); charcoal was combined with sand at three different rates (5%, 20% and 50%, v/v charcoal in sand). The high charcoal had no significant effects on any measured property while the low charcoal application stimulated growth and the effect increased with the addition rate. The low charcoal application resulted in the greater available P content, a lower N/P in needles and the greater growth of seedlings than high charcoal application. The growth of seedlings was not affected by the application of the high charcoal at any rate probably because the high charcoal inhibited the seedling growth due to its high pH. These results indicate that charcoal produced at different temperatures during forest fires can affect the growth of Gmelin larch seedlings differently.