Abstract:

Aims Studying the impact of climate warming on radial growth and biomass allocation of trees is crucial for accurately evaluating the carbon sequestration capacity of trees under climate change.
Methods In 2004, the seedlings of Larix gmelinii from four different locations (i.e., Tahe, Songling, Heihe and Dailing from north to south) were transplanted southward to a common garden at Mao’ershan Forestry Research Station in Heilongjiang Province to simulate climate warming. The radial growth and biomass allocation of trees in common garden and original sites were measured simultaneously.
Important findings Warming treatment significantly increased the radial growth of trees from Songling and Tahe sites. The stem diameter at breast height (DBH), diameter at 10 cm from the ground (D₁₀), relative increasing rate of DBH and D₁₀, and relative increasing rate per warming unit of DBH and D₁₀ increased with the increasing warming degree. The relative increasing rate of DBH for Songling and Tahe sites were 58.62% and 101.49%, and the relative increasing rate per warming unit were 16.11%·°C^-1 and 18.79%·°C^-1, respectively. Warming treatment significantly decreased the proportion of leaf, branch and root biomass and increased the proportion of stem, aboveground biomass of trees from Tahe site. The proportion of root biomass significantly decreased and the proportion of stem biomass increased for the trees from Songling site under warming treatment. The root-shoot ratio significantly decreased for the trees from Songling and Tahe sites under warming treatment. Climate warming can affect the radial growth and biomass allocation of L. gmelinii, and this effect varied with the degree of warming.

Key words: climate change, Larix gmelinii, transplanting experiment, diameter at breast height, biomass allocation