Assessing carbon sequestration in plantation forests of important conifers based on the system of permanent sample plots across Taiwan.

Plantation forests play a critical role in forest management due to their high productivity and large contribution to carbon sequestration (CSE). The purpose of this study was to assess the CSE of plantations containing four important conifer species distributed across Taiwan, namely, the China fir (Cunninghamia lanceolata), Japanese cedar (Cryptomeria japonica), Taiwania (Taiwania cryptomerioides) and Taiwan red cypress (Chamaecyparis formosensis). Data regarding the plantations were obtained from a survey of permanent sample plots (PSPs). We used these data to calculate the CSE in each PSP and adopted CSEmean and CSEperiod as indicators to assess the CSE of the four conifers. According to the CSEmean obtained from analysis of variance and the least significant difference method, two groups were identified among these four conifers: the Japanese cedar (4.03 Mg ha−1 yr−1) and Taiwania (3.52 Mg ha−1 yr−1) yielded higher CSEmean values and the China fir (1.79 Mg ha−1 yr−1) and Taiwan red cypress (2.36 Mg ha−1 yr−1) yielded lower CSEmean values. The same patterns were observed in the CSEperiod values; however, no significant difference in CSEperiod was observed between Taiwan red cypress and either of the two groups. Therefore, Japanese cedar and Taiwania have high CSE potential among conifers. [ABSTRACT FROM AUTHOR]