Reconciling Biodiversity Conservation and Timber Production in Mixed Uneven-Aged Mountain Forests: Identification of Ecological Intensification Pathways

Abstract

Mixed uneven-aged forests are considered favorable to the provision of multiple ecosystem services and to the conciliation of timber production and biodiversity conservation. However, some forest managers now plan to increase the intensity of thinning and harvesting operations in these forests. Retention measures or gap creation are considered to compensate potential negative impacts on biodiversity. Our objectives were to assess the effect of these management practices on timber production and biodiversity conservation and identify potential compensating effects between these practices, using the concept of ecological intensification as a framework. We performed a simulation study coupling Samsara2, a simulation model designed for spruce-fir uneven-aged mountain forests, an uneven-aged silviculture algorithm, and biodiversity models. We analyzed the effect of parameters related to uneven-aged management practices on timber production, biodiversity, and sustainability indicators. Our study confirmed that the indicators responded differently to management practices, leading to trade-offs situations. Increasing management intensity had negative impacts on several biodiversity indicators, which could be partly compensated by the positive effect of retention measures targeting large trees, non-dominant species, and deadwood. The impact of gap creation was more mitigated, with a positive effect on the diversity of tree sizes and deadwood but a negative impact on the spruce-fir mixing balance and on the diversity of the understory layer. Through the analysis of compensating effects, we finally revealed the existence of possible ecological intensification pathways, i.e., the possibility to increase management intensity while maintaining biodiversity through the promotion of nature-based management principles (gap creation and retention measures).

Modelling the probability of microhabitat formation on trees using cross‐sectional data

“…Simulation experiments can then be conducted by varying the levels of these controls among modalities (Lafond et al . , ; Lafond, Cordonnier & Courbaud ). Implementing a TreM formation model in Samsara2 will make it possible to test more precise conservation strategies such as retention of TreM‐bearing trees and to analyse their effect on the dynamics of TreMs in forest stands over long time periods.…”

Sensitivity and uncertainty analysis of the carbon and water fluxes at the tree scale inEucalyptusplantations using a metamodeling approach

“…In the current study, second-level metamodels for APAR, GPP, LUE, and WUE were also created but were not presented in this article due to the unavailability of a proper validation dataset. Similarly to our second-level metamodel, simple metamodels are generally built after removing parameters with low sensitivity and by using aggregated parameters (e.g., Lafond et al 2015). The difference between our approach and the one of Lafond et al (2015) is that they performed the sensitivity analysis on the original model and built a metamodel using the selected inputs, while we have built our first metamodel using almost all inputs of the original model and simplified it afterwards.…”

Integrating ecological engineering and ecological intensification from management practices to ecosystem services into a generic framework: a review

“…They usually focus on three main topics: the effect of specific practices on the provision of one or several ecosystem services (Snapp et al 2010;Schwenk et al 2012); the interaction, trade-offs and synergies between ecosystem services, possibly under different management scenarios (Bennett et al 2009;Duncker et al 2012;Briner et al 2013;Cavender-Bares et al 2015); and how biological regulation may help drive ecosystem services (Bommarco et al 2013). For instance, Lafond et al (2015) showed that forest management practices inspired from natural ecosystem dynamics (i.e. retention of dead wood and creation of gaps) could sustain wood production while better preserving biodiversity.…”