Background and aims

Forest management towards increased carbon (C) sequestration has repeatedly been suggested as a “natural climate solution”. We evaluated the potential of altered management to increase C sequestration in boreal Pinus sylvestris forest plantations.

Methods

At 29 forest sites, distributed along a 1300 km latitudinal gradient in Sweden, we studied interactive effects of fertilization and thinning on accumulation of C in standing biomass and the organic horizon over a 40 year period.

Results

Abstention from thinning increased the total C stock by 50% on average. The increase was significant (14% on average) even when C in the removed timber was included in the total ecosystem C pool. Fertilization of thinned stands increased stocks similarly regardless of including (11%) or excluding (12%) removed biomass, and fertilization combined with abstention from thinning had a synergistic effect on C stocks that generated an increase of 79% (35% when removed timber was included in the C stock). A positive effect of fertilization on C stocks was observed along the entire gradient but was greater in relative terms at high latitudes. Fertilization also reduced soil respiration rates.

Conclusion

Taken together, our results suggest that changed forest management practices have major potential to increase the C sink of boreal forests. Although promising, these benefits should be evaluated against the undesired effects that such management can have on economic revenue, timber quality, biodiversity and delivery of other ecosystem services.

中文翻译：

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森林管理以增加北方樟子松森林的碳固存

背景和目标

以增加碳（C）固存为目标的森林管理一再被建议作为“自然气候解决方案”。我们评估了改变管理以增加北方樟子松林人工林中碳封存的潜力。

方法

在瑞典沿 1300 公里纬度梯度分布的 29 个森林地点，我们研究了 40 年间施肥和间伐对立生生物量和有机层中碳积累的交互影响。

结果

避免间伐使总碳储量平均增加了 50%。即使将移出的木材中的 C 包括在总生态系统 C 库中，这种增加也是显着的（平均 14%）。无论包括 (11%) 还是不包括 (12%) 去除的生物量，对间伐林分施肥都类似地增加了蓄积量，施肥结合不进行间伐对碳储量具有协同效应，增加了 79%（去除木材时为 35%）已包含在 C 股票中）。在整个梯度上观察到施肥对碳储量的积极影响，但在高纬度相对而言更大。施肥还降低了土壤呼吸率。

结论

总之，我们的结果表明，改变森林管理做法具有增加北方森林碳汇的巨大潜力。尽管有希望，但应对照此类管理可能对经济收入、木材质量、生物多样性和其他生态系统服务提供的不良影响来评估这些收益。