Hardy Clément, Messier Christian, Boulanger Yan, Cyr Dominic, Filotas Élise
Department of Biological Sciences, Centre d'Étude de la Forêt (CEF), Université du Québec à Montréal, Canada (UQAM), Montréal, Québec, Canada.
Department of Natural Sciences, Institut des Sciences de la forêt tempérée (ISFORT), Université du Québec en Outaouais (UQO), Québec, Canada.
PLoS One. 2025 Jun 27;20(6):e0326627. doi: 10.1371/journal.pone.0326627. eCollection 2025.
In the face of global changes, forest management must now consider adapting forests to novel and uncertain conditions alongside objectives of conservation and production. In this perspective, we modified the TRIAD zoning approach to add a resilience component through functionally diverse plantations following harvesting in the extensive areas. We then assessed the capacity of this new "TRIAD+" zoning approach for improving the resilience of the mature forest biomass to climate change and three potential extreme pulse disturbances: a large fire, a severe drought, and an insect outbreak. We used the forest landscape simulation model LANDIS-II on a management unit in Mauricie (Quebec, Canada) to simulate and compare the TRIAD+ scenario with a classic TRIAD zoning scenario, and two business-as-usual harvesting scenarios with and without functional enrichment planting. We also simulated three different climate change scenarios (Baseline, RCP 4.5 and RCP 8.5) in which these management and extreme disturbance scenarios took place. We monitored the changes in three variables: the mature wood biomass across the landscape, the mature biomass of each functional group, and the functional diversity of stands in the landscape. Resilience was measured according to three indicators: resistance, net change and recovery time of mature biomass. TRIAD+ management resulted in a good compromise, harvesting the same amount of wood as other scenarios while increasing the surface of protected forests by around 240% compared to BAU scenarios, and improving the mean functional diversity of stands by around 15% compared to the classic TRIAD and BAU without plantations. Following the pulse disturbance events, TRIAD+ also increased the resilience of the mature biomass across the landscape. However, this increase was limited, depended on the resilience indicator and the event considered, and was negligible in terms of tree biomass recovered in the long term. It's uncertain whether these results stemmed from the relative lack of small-scale interactions in LANDIS-II through which the effect of functional diversity on stand resilience should occur, or if this effect is small to begin with. Overall, our study reveals that an adaptation component can be included in current or future management strategies, but that increasing functional diversity via plantations will likely be insufficient to significantly boost forest resilience. Future research should therefore explore other (combined) means of increasing forest resilience, and improve the representation of small-scale interactions in landscape-scale models.
面对全球变化，森林管理如今必须在考虑森林保护和生产目标的同时，思考如何使森林适应新的不确定条件。从这一角度出发，我们对TRIAD分区方法进行了改进，通过在大面积采伐后营造功能多样的人工林来增加恢复力要素。随后，我们评估了这种新的“TRIAD+”分区方法提升成熟森林生物量对气候变化和三种潜在极端脉冲干扰（一场大型火灾、一次严重干旱和一次虫害爆发）恢复力的能力。我们在加拿大魁北克省毛里求斯的一个管理单元上使用森林景观模拟模型LANDIS-II，将TRIAD+情景与经典的TRIAD分区情景以及两种常规采伐情景（有无功能强化种植）进行模拟和比较。我们还模拟了三种不同的气候变化情景（基线情景、代表性浓度路径4.5和代表性浓度路径8.5），这些管理和极端干扰情景均在其中发生。我们监测了三个变量的变化：景观中成熟木材生物量、每个功能组的成熟生物量以及景观中林分的功能多样性。根据三个指标衡量恢复力：成熟生物量的抵抗力、净变化和恢复时间。TRIAD+管理实现了良好的平衡，采伐的木材量与其他情景相同，同时与常规情景相比，保护森林面积增加了约240%，与经典TRIAD和无种植的常规情景相比，林分的平均功能多样性提高了约15%。在脉冲干扰事件之后，TRIAD+还提高了景观中成熟生物量的恢复力。然而，这种提高是有限的，取决于恢复力指标和所考虑的事件，从长期恢复的树木生物量来看可以忽略不计。尚不确定这些结果是源于LANDIS-II中相对缺乏小规模相互作用（功能多样性对林分恢复力的影响应通过这种相互作用发生），还是这种影响本身就很小。总体而言，我们的研究表明，可以在当前或未来的管理策略中纳入适应要素，但通过人工林增加功能多样性可能不足以显著提高森林恢复力。因此，未来的研究应探索其他（组合）提高森林恢复力的方法，并改进景观尺度模型中对小规模相互作用的表征。
