NSW Department of Primary Industries, Wagga Wagga Agricultural Institute, Pine Gully Road Wagga Wagga, NSW, 2650, Australia.
NSW Department of Primary Industries, Dubbo, NSW, 2830, Australia.
J Environ Manage. 2022 Jan 15;302(Pt A):113964. doi: 10.1016/j.jenvman.2021.113964. Epub 2021 Oct 19.
Reforestation is identified as one of the key nature-based solutions to deliver carbon dioxide removal, which will be required to achieve the net zero ambition of the Paris Agreement. However, the potential for sequestration through reforestation is uncertain because climate change is expected to affect the drivers of forest growth. This study used the process-based 3-PG model to investigate the effects of climate change on development of above-ground biomass (AGB), as an indicator of forest growth, in regenerating native forests in southeast Australia. We investigated how changing climate affects AGB, by combining historical data and future climate projections based on 25 global climate models (GCMs) for the Coupled Model Intercomparison Project Phase 6 (CMIP6) under two Shared Socioeconomic Pathways. We found that the ensemble means of 25 GCMs indicated an increase in temperature with large variations in projected rainfall. When these changes were applied in 3-PG, we found an increase in the simulated AGB by as much as 25% under a moderate emission scenario. This estimate rose to 51% under a high emission scenario by the end of the 21st century across nine selected sites in southeast Australia. However, when CO response was excluded, we found a large decrease in AGB at the nine sites. Our modelling results showed that the modelled response to elevated atmospheric CO (the CO fertilization effect) was largely responsible for the simulated increase of AGB (%). We found that the estimates of future changes in the AGB were subject to uncertainties originating from climate projections, future emission scenarios, and the assumed response to CO fertilization. Such modelling simulation improves understanding of possible climate change impacts on forest growth and the inherent uncertainties in estimating mitigation potential through reforestation, with implications for climate policy in Australia.
重新造林被确定为实现《巴黎协定》净零目标所需的去除二氧化碳的关键自然解决方案之一。然而，通过重新造林进行固碳的潜力是不确定的，因为气候变化预计会影响森林生长的驱动因素。本研究使用基于过程的 3-PG 模型来研究气候变化对澳大利亚东南部原生林地上生物量（AGB）发育的影响，AGB 是森林生长的一个指标。我们通过结合历史数据和基于 25 个全球气候模型（GCMs）的未来气候预测来研究气候变化如何影响 AGB，这些预测是耦合模式比较计划第六阶段（CMIP6）下两种共享社会经济途径的结果。我们发现，25 个 GCMs 的集合平均值表明温度升高，预计降雨量变化很大。当这些变化应用于 3-PG 时，我们发现，在中度排放情景下，模拟的 AGB 增加了 25%。到 21 世纪末，在澳大利亚东南部的九个选定地点，这一估计值在高排放情景下上升到 51%。然而，当排除 CO 响应时，我们发现九个地点的 AGB 大量减少。我们的模型结果表明，大气 CO 升高的模拟响应（CO 施肥效应）在很大程度上导致了 AGB 的模拟增加（%）。我们发现，未来 AGB 变化的估计受到气候预测、未来排放情景以及对 CO 施肥的假设响应的不确定性的影响。这种建模模拟提高了对森林生长可能受到气候变化影响的理解，以及通过重新造林估算缓解潜力的固有不确定性，对澳大利亚的气候政策具有重要意义。
