Afforestation/reforestation of New Zealand marginal pasture lands by indigenous shrublands: the potential for Kyoto forest sinks

Abstract

-New Zealand will use the afforestation/reforestation (A/R) provisions of article 3.3 of the Kyoto protocol to help offset greenhouse gas emissions during the first commitment period, 2008 to 2012. We assess here the potential initial C sink available from A/R of marginal pasture lands by New Zealand's most common shrubland species: mānuka (Leptospermum scoparium) and kānuka (Kunzea ericoides). Plotbased mensuration shows that mean net C accumulation rates for mānuka/kānuka shrubland are in the range 1.9 to 2.5 t C ha -1 yr -1 , when averaged over the active growth phase of about 40 years. Estimates of the change in mineral soil C with shrubland A/R of grassland suggest small losses occur, although these appear to be largely offset by accumulation of C in the litter layers. Analysis shows that nationally there are about 1.45 Mha of marginal pastoral land suitable for A/R by indigenous shrubland or forest. This area could accumulate about 2.9 ± 0.5 Mt C yr -1 , a significant offset to New Zealand's annual energy-related CO 2 emissions of 8.81 Mt CO 2 -C yr -1 . An initial economic analysis of livestock farming for a region with large areas of land marginal for sustained pastoral agriculture suggests "carbon farming" may prove an attractive alternative land use if international prices for biomass-C reach about €10 per tonne CO 2 . afforestation / reforestation / Kyoto protocol / carbon sink / shrublandRésumé -Boisement/reboisement des pâturages marginaux de Nouvelle-Zélande par des formations arbustives indigènes : potentiel pour les puits de carbone du protocole de Kyoto. La Nouvelle-Zélande va utiliser les provisions de boisement/reboisement (A/R) de l'article 3.3 du protocole de Kyoto pour compenser les émissions de gaz à effets de serre, pendant la première période d'engagement 2008-2012. Nous évaluons ici le potentiel initial de puits de C rendus disponible par l'A/R des pâturages marginaux par les espèces arbustives les plus communes de Nouvelle-Zélande : le mānuka (Leptospermum scoparium) et le kānuka (Kunzea ericiodes). Les mesures réalisées sur des parcelles d'étude de comparaison par paire montrent que la moyenne du taux net d'accumulation de carbone pour le mānuka/kānuka, sur une période d'environ 40 ans de la phase de croissance active, est de l'ordre de 1,9 à 2,5 t C ha -1 par an. Des études sur les changements en C minéral du sol sur une A/R arbustive de prairies suggèrent des pertes mineures, qui seraient apparemment largement compensées par une accumulation dans la litière et dans la couche d'humus. Des études sur les changements en C minéral du sol sur une A/R arbustive de prairies suggèrent des pertes mineures, qui seraient apparemment largement compensées par une accumulation dans la litière. Des analyses montrent qu'au niveau national environ 1,45 Mha de pâturages marginaux seraient appropriés pour une A/R par arbuste ou forêt indigène. Ces zones pourraient accumuler environ 2.9 ± 0.5 Mt de C par an, une compensation significative aux émissions annuelles de combustible fossile en CO 2 ...

Biomass and composition of understory vegetation and the forest floor carbon stock across Siberian larch and mountain birch chronosequences in Iceland

“…A chronosequence is a common way to evaluate the effects of landuse change on ecosystems (e.g., [34,36]). Often this method offers the only practical way to study changes that may take decades or even centuries to occur.…”

“…Afforestation of treeless landscapes causes a net carbon (C) sequestration in biomass [12,30,34,36]. This phenomenon was recently highlighted by the appearance of the Kyoto-protocol [35].…”

Individual-Based Allometric Equations Accurately Measure Carbon Storage and Sequestration in Shrublands

“…Accurate documentation of C gain during succession from shrubland to forest is vital for including abandoned agricultural land in afforestation-based emissions trading schemes. Further, accurate models of C gain during succession are needed for assessing potential C sequestration under different scenarios of land-use change [8,9], and these can, then, be used by landowners to assess economic viability of carbon farming as an alternative to traditional grazing [8].…”

Comparison of carbon sequestration potential in agricultural and afforestation farming systems

“…Additional research such as that investigating a hybrid poplar forest (Updegraff et al, 2004) and a coniferous-deciduous mix afforestation forest (Niu and Duiker, 2006) have carbon sequestration rates around 8.98 and 9.53 t CO 2 ha -1 year -1 after 20 years. Carbon sequestration rates of forest in New Zealand can be found in work by Hollinger et al (1993), Tate et al (1997), Scott et al (2000), and Trotter et al (2005).…”