The role of forest trees and their mycorrhizal fungi in carbonate rock weathering and its significance for global carbon cycling.
The role of forest trees and their mycorrhizal fungi in carbonate rock weathering and its significance for global carbon cycling.
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DOI：
10.1111/pce.12444
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发表时间：
2015-09
期刊：
影响因子：
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通讯作者：
R. Thorley;Lyla L. Taylor;S. Banwart;J. Leake;D. Beerling
中科院分区：
文献类型：
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作者：
R. Thorley;Lyla L. Taylor;S. Banwart;J. Leake;D. Beerling
在百万年的时间尺度上，碳酸盐岩风化对大气CO2浓度没有净影响。然而，在几十年到几百年的时间尺度上，它可以有助于固存人为二氧化碳，增加陆地-海洋碱度通量，抵消海洋酸化。历史证据表明，这种通量对土地利用变化很敏感，最近的实验证据表明，树木及其相关的土壤微生物群落是大陆矿物风化的主要驱动力。在这里，我们回顾了关键的物理和化学机制，林木根系共生菌根真菌可能增强碳酸盐岩风化。我们在英国国家松林进行的实地研究的证据证实，形成丛枝（AM）或外生菌根（EM）真菌伙伴关系的各种裸子植物和被子植物树种对碳酸盐岩的风化作用增加。我们表明，含方解石的岩石颗粒下EM树种的天气显着快于AM树下的，与EM树更大的土壤酸化的影响。风化和相应的碱度输出可能会随着大气CO2的增加和相关的气候变化而增加。我们的分析表明，战略性种植快速增长的EM被子植物类群的方解石和方解石丰富的地形可能会加速大气CO2和海洋酸化的速度缓慢的瞬态汇。
On million-year timescales, carbonate rock weathering exerts no net effect on atmospheric CO2 concentration. However, on timescales of decades-to-centuries, it can contribute to sequestration of anthropogenic CO2 and increase land-ocean alkalinity flux, counteracting ocean acidification. Historical evidence indicates this flux is sensitive to land use change, and recent experimental evidence suggests that trees and their associated soil microbial communities are major drivers of continental mineral weathering. Here, we review key physical and chemical mechanisms by which the symbiotic mycorrhizal fungi of forest tree roots potentially enhance carbonate rock weathering. Evidence from our ongoing field study at the UK's national pinetum confirms increased weathering of carbonate rocks by a wide range of gymnosperm and angiosperm tree species that form arbuscular (AM) or ectomycorrhizal (EM) fungal partnerships. We demonstrate that calcite-containing rock grains under EM tree species weather significantly faster than those under AM trees, an effect linked to greater soil acidification by EM trees. Weathering and corresponding alkalinity export are likely to increase with rising atmospheric CO2 and associated climate change. Our analyses suggest that strategic planting of fast-growing EM angiosperm taxa on calcite- and dolomite-rich terrain might accelerate the transient sink for atmospheric CO2 and slow rates of ocean acidification.