Dobor Laura, Hlásny Tomáš, Rammer Werner, Barka Ivan, Trombik Jiří, Pavlenda Pavol, Šebeň Vladimír, Štepánek Petr, Seidl Rupert
Czech University of Life Sciences Prague, Faculty of Forestry and Wood Sciences, Kamýcká 129, 165 21 Prague 6, Czech Republic.
University of Natural Resources and Life Sciences (BOKU) Vienna, Peter Jordan Straße 82, 1190 Wien, Austria.
Agric For Meteorol. 2018 Dec 15;263:308-322. doi: 10.1016/j.agrformet.2018.08.028. Epub 2018 Sep 13.
Disturbances alter composition, structure, and functioning of forest ecosystems, and their legacies persist for decades to centuries. We investigated how temperate forest landscapes may recover their carbon (C) after severe wind and bark beetle disturbance, while being exposed to climate change. We used the forest landscape and disturbance model iLand to quantify (i) the recovery times of the total ecosystem C, (ii) the effect of climate change on C recovery, and (iii) the differential factors contributing to C recovery. We reconstructed a recent disturbance episode (2008-2016) based on Landsat satellite imagery, which affected 39% of the forest area in the 16,000 ha study landscape. We subsequently simulated forest recovery under a continuation of business-asusual management until 2100. Our results indicated that the recovery of the pre-disturbance C stocks (C payback time) was reached 17 years after the end of the disturbance episode. The C stocks of a theoretical undisturbed development trajectory were reached 30 years after the disturbance episode (C sequestration parity). Drier and warmer climates delayed simulated C recovery. Without the fertilizing effect of CO, C payback times were delayed by 5-9 years, while C parity was not reached within the 21st century. Recovery was accelerated by an enhanced C uptake compared to undisturbed conditions (disturbance legacy sink effect) that persisted for 35 years after the disturbance episode. Future climate could have negative impacts on forest recovery and thus further amplify climate change through C loss from ecosystems, but the effect is strongly contingent on the magnitude and persistence of alleviating CO effects. Our modelling study highlights the need to consider both negative and positive effects of disturbance (i.e., C loss immediately after an event vs. enhanced C uptake of the recovering forest) in order to obtain a comprehensive understanding of disturbance effects on the forest C cycle.
干扰会改变森林生态系统的组成、结构和功能，其影响会持续数十年至数百年。我们研究了温带森林景观在遭受严重风灾和树皮甲虫侵扰并面临气候变化的情况下，如何恢复其碳（C）储量。我们使用森林景观和干扰模型iLand来量化：（i）生态系统总碳的恢复时间；（ii）气候变化对碳恢复的影响；（iii）促进碳恢复的差异因素。我们根据陆地卫星图像重建了近期一次干扰事件（2008 - 2016年），该事件影响了16000公顷研究区域内39%的森林面积。随后，我们模拟了在照常经营管理持续到2100年的情况下森林的恢复情况。我们的结果表明，在干扰事件结束后17年达到了干扰前碳储量的恢复（碳回报时间）。在干扰事件发生30年后达到了理论上未受干扰发展轨迹的碳储量（碳固存平衡）。更干燥、更温暖的气候会延迟模拟的碳恢复。如果没有二氧化碳的施肥效应，碳回报时间会延迟5 - 9年，而在21世纪内无法达到碳平衡。与未受干扰的情况相比，由于干扰后持续35年的碳吸收增强（干扰遗留汇效应），恢复进程加快。未来气候可能对森林恢复产生负面影响，从而通过生态系统的碳损失进一步加剧气候变化，但这种影响很大程度上取决于缓解二氧化碳效应的程度和持续性。我们的建模研究强调，需要考虑干扰的正负两方面影响（即事件发生后立即的碳损失与恢复森林增强的碳吸收），以便全面理解干扰对森林碳循环的影响。
