IMPACT4SOIL OpenAire Bielefeld Academic Search Engine (BASE) Crossref Microsoft Academic Graph Soil Biology and Biochemistry Closed Access 2007-04-24 Approximately 30% of global soil organic carbon (SOC) is stored in subtropical and tropical ecosystems but it is being rapidly lost due to continuous deforestation. Tree plantations are advocated as a C sink, however, little is known about rates of C turnover and sequestration into soil organic matter under subtropical and tropical tree plantations. We studied changes in SOC in a chronosequence of hoop pine (Araucaria cwunninghamii) plantations established on former rainforest sites in seasonally dry subtropical Australia. SOC, delta C-13, and light fraction organic C (LF C < 1.6 g cm(-3)) Were determined in plantations, secondary rainforest and pasture. We calculated loss of rainforest SOC after clearing for pasture using an isotope mixing model, and used the decay rate of rainforest-derived C to predict input of hoop pine-derived C into the soil. Total SOC stocks to 100 cm depth were significantly (P < 0.01) higher under rainforest (241 t ha(-1)) and pasture (254 t ha(-1)) compared to hoop pine (176-211 t ha(-1)). We calculated that SOC derived from hoop pine inputs ranged from 32% (25 year plantation) to 61% (63 year plantation) of total SOC in the 0-30 cm soil layer, but below 30 cm all C originated from rainforest. These results were compared to simulations made by the Century soil organic matter model. The Century model Simulations showed that lower C stocks under hoop pine plantations were due to reduced C inputs to the slow turnover C pool, such that this pool only recovers to within 45% of the original rainforest C pool after 63 years. This may indicate differences in soil C stabilization mechanisms under hoop pine plantations compared with rainforest and pasture. These results demonstrate that subtropical hoop pine plantations do not rapidly sequester SOC into long-term storage pools, and that alternative plantation systems may need to be investigated to achieve greater soil C sequestration. (c) 2007 Elsevier Ltd. All rights reserved. Araucaria C-13 Soil Science Land-use Change Storage Puerto-rico Century model 01 natural sciences C1 light fraction carbon Pasture 300103 Soil Chemistry Southern Queensland Rain-forest 0105 earth and related environmental sciences tree plantations Organic-matter Dynamics 770702 Land and water management 04 agricultural and veterinary sciences 15. Life on land Long-term Trends carbon sequestration soil organic carbon Forest Conversion Continuous Cultivation 0401 agriculture, forestry, and fisheries Anna E. Richards, Anna E. Richards, Ram C. Dalal, Ram C. Dalal, Susanne Schmidt, 2007-08-01 journalpaper Approximately 30% of global soil organic carbon (SOC) is stored in subtropical and tropical ecosystems but it is being rapidly lost due to continuous deforestation. Tree plantations are advocated as a C sink, however, little is known about rates of C turnover and sequestration into soil organic matter under subtropical and tropical tree plantations. We studied changes in SOC in a chronosequence of hoop pine (Araucaria cwunninghamii) plantations established on former rainforest sites in seasonally dry subtropical Australia. SOC, delta C-13, and light fraction organic C (LF C < 1.6 g cm(-3)) Were determined in plantations, secondary rainforest and pasture. We calculated loss of rainforest SOC after clearing for pasture using an isotope mixing model, and used the decay rate of rainforest-derived C to predict input of hoop pine-derived C into the soil. Total SOC stocks to 100 cm depth were significantly (P < 0.01) higher under rainforest (241 t ha(-1)) and pasture (254 t ha(-1)) compared to hoop pine (176-211 t ha(-1)). We calculated that SOC derived from hoop pine inputs ranged from 32% (25 year plantation) to 61% (63 year plantation) of total SOC in the 0-30 cm soil layer, but below 30 cm all C originated from rainforest. These results were compared to simulations made by the Century soil organic matter model. The Century model Simulations showed that lower C stocks under hoop pine plantations were due to reduced C inputs to the slow turnover C pool, such that this pool only recovers to within 45% of the original rainforest C pool after 63 years. This may indicate differences in soil C stabilization mechanisms under hoop pine plantations compared with rainforest and pasture. These results demonstrate that subtropical hoop pine plantations do not rapidly sequester SOC into long-term storage pools, and that alternative plantation systems may need to be investigated to achieve greater soil C sequestration. (c) 2007 Elsevier Ltd. All rights reserved. Soil Carbon Turnover And Sequestration In Native Subtropical Tree Plantations 10.1016/j.soilbio.2007.03.012 https://doi.org/10.1016/j.soilbio.2007.03.012