Abstract:

On the background of implementing the strategy of carbon peak and carbon neutralization,the carbon sequestration capacity of forest ecosystem has become the focus of attention. Based on the carbon storage data of 1 091 sample plots from the 9^th national forest inventory in three provinces of northeast China,the carbon growth models of both natural and planted larch forest stands were developed,the impacts of topographic and soil factors to model parameters were analyzed,and the differences of carbon sequestration capacity between natural and planted larch forest stands were compared. The results showed that 1) the annual carbon growth (AG) of planted larch forest stands reached to the highest 2.70 t/hm² at 12 years old,and the mean carbon growth (MG) reached to the highest 1.85 t/hm² at 20 years old;while the AG of natural stands reached to the highest 0.94 t/hm² at 18 years old,and the MG reached to the highest 0.78 t/hm² at 32 years old;2) when forest stand age was 30,the mean carbon storage per hectare of planted larch forest stands was up to 49.36t/hm²,which was 111%higher than 23.37t/hm² of natural stands;and when forest stand age was 50,that of planted stands was up to 55.47t/hm²,which was 53%higher than 36.30t/hm² of natural stands;3)the developed carbon growth models for both natural and planted larch forest stands reflected objectively the overall average growth process of carbon storage in three northeast provinces,of which mean prediction errors were about 5%,total relative errors were nearly to zero for modeling and less than 2% for cross-validation;4) the impacts of topographic and soil factors to the growth of planted larch forest stands were not significant,only slope position had significant impact to the growth of natural stands;the carbon sequestration capacity of planted larch forest stands was obviously higher than the natural stands.

Key words: forest carbon storage, carbon sequestration capacity, growth model, mixed model, larch forest stand