Department of Forest Ecosystems and Society, Oregon State University, Corvallis, Oregon, United States of America.
Department of Forest Engineering, Resources and Management Oregon State University, Corvallis, Oregon, United States of America.
PLoS One. 2018 Sep 13;13(9):e0203475. doi: 10.1371/journal.pone.0203475. eCollection 2018.
The industrial production of long-lived charcoal products (commonly referred to as biochar) from otherwise shorter-lived logging resides (commonly referred to a slash) has been proposed as a means to increasing terrestrial carbon storage thus mitigating global warming caused by anthropogenic greenhouse gas emissions. We present a generalized model that describes the temporal dynamics of biochar carbon stocks, relative to carbon of unmodified logging residue, and evaluate the sensitivity of carbon storage to various biophysical and production parameters. Using this model, we then attribute net carbon storage to several potential biochar production scenarios, specifically engineered to use wood recovered from harvests prescribed to reduce fire hazard in mixed-conifer forests of South-central Oregon. Relative to a baseline scenario where logging residue is left to decay on site, the net carbon storage attributed to 20 years of biochar production is generally negative for the first several decades, then remains positive for several centuries at levels approximately one-fourth the total feedstock carbon processed. Positive net carbon storage and the time required for it to manifest is notably sensitive to biochar conversion efficiencies, logging residue decay rates, and alternate baseline fates of logging residue. The magnitude of net carbon storage, and the time required for it to become positive, is largely similar across range of production facility types. Moreover, the time required for net carbon storage to become positive, and its magnitude over the first 100 years is notably insensitive to biochar decomposition rates provided biochar decays at least ten-times slower than the logging residue it is made from.
从原本寿命更短的采伐残留物（通常称为采伐剩余物）中工业生产长寿命的木炭产品（通常称为生物炭），已被提议作为增加陆地碳储存的一种手段，从而减轻人为温室气体排放引起的全球变暖。我们提出了一个通用模型，描述了生物炭碳储量相对于未改性采伐残留物的碳的时间动态，并评估了碳储存对各种生物物理和生产参数的敏感性。使用该模型，我们将净碳储存归因于几种潜在的生物炭生产情景，这些情景专门设计用于使用从南俄勒冈州混交林采伐中回收的木材来减少火灾危险。与将采伐剩余物留在现场自然分解的基线情景相比，在 20 年的生物炭生产过程中，净碳储存通常在最初几十年为负，然后在几个世纪内保持正值，大约是处理的总原料碳的四分之一。净碳储存的正值及其显现所需的时间明显取决于生物炭转化效率、采伐剩余物分解率以及采伐剩余物的替代基线命运。在各种生产设施类型中，净碳储存的幅度及其在 100 年内成为正值所需的时间大致相似。此外，只要生物炭的分解速度比它所制成的采伐剩余物慢至少十倍，净碳储存成为正值所需的时间及其在头 100 年内的幅度就明显不受生物炭分解速度的影响。
