| The ongoing climate change is projected to exert significant influences on the borealDahurian larch (Larix gmelinii Rupr.) forest, the predominant boreal forest in China. However,the effect of changing environments on carbon allocation of the forest is poorly understood. Inthis study, we developed a latitudinal transect study across the distribution range of Dahurianlarch in northeastern China to analyze the influence of the carbon distribution patterns underclimate wanning.Latitudinal sites exerted significant (α=0.05) effects on the allometric equations(intercepts and slopes) for biomass components, biomass allocation patterns (i.e., leaf massratio [LMR], stem mass ratio [SMR], root mass ratio [RMR], and root: shoot ratio [R/S]). Themean LMR, SMR, RMR and R/S for the latitudinal sites varied from 0.133 to 0.265, 0.232 to0.423, 0.142 to 0.242, and 0.186 to 0.386, respectively. The LMR, RMR and R/S tended toincrease with increasing latitudes, while the SMR decrease along the latitudinal gradient.The total carbon storage of the Larch forest varied from 122.3±29.9 to 300.3±41.5 g·m-2.Latitudinal sites exerted significant (α=0.05) effects on stand total carbon storage,aboveground carbon storage, coarse root (＞5 mm in diameter) carbon storage, and ratio ofbelow-to above-ground carbon storage. The ratios of below-to above-ground carbon rangedfrom 0.099±0.039 to 0.208±0.025, and decreased with increasing latitudes. The total rootcarbon storage varied from 10.2±1.2～51.2±5.4 g·m-2 across the latitudinal sites. But thecarbon of the understory and roots＜5 mm in diameter were not significantly affected by thedifference of latitudes. The proportion of the understory to the above-ground carbon storageand the roots＜5 mm in diameter to the total root carbon storage tended to increase withincreasing latitudes. The carbon of roots＜5 mm in diameter was distributed deeper as thelatitude decreased, and predominantly distributed at 0-10 cm depth. The net primaryproductivity (NPP) of the larch forests varied from 89.03 to 399.86 gC·m-2·a-1, also exertedsignificant effects by latitudinal sites.Latitudinal sites also exerted significant effects on stand mean depth of the soil profile, thetotal mean content and density of soil organic carbon (SOC). The depth of the soil profiletended to decrease with the latitude increasing, arranged from 24.50 to more than 100 cm. Themean SOC content varied from 50.84 to 121.27 mg·g-1, decreased with the soil depth, while theSOC density increased with the soil depth, varied from 14.10 to 36.58 kg·m-2. Our study may have a great academic significance in global change science and terrestrialecology. Our study suggested that the Dahurian larch may be not only temperature-sensitivebut also flexible in carbon metabolisms. It had an evident plasticity of carbon allocationpatterns under various environmental conditions, which should be considered in assessing andmodeling responses of structure and function of boreal forests in climate change scenarios.
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