The Inventory of Carbon Stocks in New Zealand's Post-1989 Natural Forest for Reporting under the Kyoto Protocol.

To meet international greenhouse gas reporting obligations, New Zealand must report on carbon stocks in forests established after 1989 (post-1989 forest). Although predominately comprised of planted forest, post-1989 forest also contains a component of natural vegetation amounting to less than 10% by area. New Zealand undertook a national inventory of this natural stratum of post-1989 forest to provide estimates of carbon stocks and stock change in woody species over the first commitment period (2008-2012) of the Kyoto Protocol. Plots were installed on a 4-km grid, and the basal diameters and heights of trees and shrubs were measured for the first time from November 2012, to March 2013. Carbon stocks in 2012 were calculated using allometric functions developed from biomass samples from each site. Basal disc samples provided data on diameter increment and shrub and tree age annually from 1990 to 2012. These were used to predict carbon stocks per ha for individual plots in 2008 and to provide annual predictions by pool back to 1990. Carbon stocks summed across live and dead biomass pools (excluding soil) averaged 3.04, 16.70 and 28.73 t C/ha in 1990, 2008 and 2012, respectively. The disposition by pool was 2.25, 12.54 and 21.84 t C/ha in aboveground biomass, 0.56, 3.13 and 5.46 t C/ha in belowground biomass (using a root/shoot ratio of 0.25), 0.03, 0.17 and 0.23 t C/ha in deadwood, and 0.18, 0.86 and 1.21 t C/ha in litter in 1990, 2008 and 2012, respectively. [ABSTRACT FROM AUTHOR]