A Strategic Forest Management Model for Optimizing Timber Yield and Carbon Sequestration

Strategic forest management planning models designed to maintain existing carbon stocks and maximize capacity for future sequestration can help identify underused opportunities to increase carbon stocks without diminishing other forest products. This study proposed a carbon stock unit that allows summing up the stocks in the different forest pools even if the decomposition far exceeds the planning horizon. This unit is used to integrate the methods and algorithms from the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3) model into a wood supply model. The resulting model could be used to predict changes in carbon stocks, transfers between carbon pools, and greenhouse gas emissions that would result from every forest management activity. We tailored this model to meet different strategies: maximizing carbon storage in the forest, maximizing high-sustained timber yield, and achieving the dual objectives of yield and carbon storage. A range of management scenarios were simulated using the data of a 485,000 hectares mixed-wood forest in Quebec, Canada. Our results demonstrate that, with the reduction in the harvest rates, the increase in the ecosystem carbon storage is insufficient to offset the carbon losses associated with the increase in the harvest rates. Study Implications In this article, we adopt the perspective of forest managers who contend that removing lumber from the forest can be achieved in a responsible way or in a way that does not affect the carbon stocks in the forest in the long term. We propose a model that integrates methods and algorithms from the CBM-CFS3 model to simulate carbon dynamics of aboveground and belowground biomass and dead organic matter, including soils. The model can be used to predict carbon storage potential within a forest region assuming a given management strategy. We used data of a large forest area to develop a number of sophisticated scenarios of strategic forest planning. Our results are consistent with the forest managers’ contentions. When carbon was maximized regardless of volume, the increase in the ecosystem carbon storage was insufficient to offset the carbon losses associated with the reduction in the harvest rates.

Thinning scenarios to reconcile biodiversity conservation and socio-economic co-benefits in protected forest of Vietnam: Effects on habitat value and timber yield

Segalina F, Dang CN, Grado RSD. 2020. Thinning scenarios to reconcile biodiversity conservation and socio-economic co-benefits in protected forest of Vietnam: effects on habitat value and timber yield. Asian J For 4: 22-35. Forest protection policy since the 1990s in Vietnam has led to an overall increase in forest cover, but has also adversely impacted the livelihoods of local populations and has displaced deforestation to neighboring countries. As such, it is necessary to explore strategies to achieve sustainable utilization of tropical forests in a way that is compatible with the preservation of biodiversity. One of which is by selective thinning. This study aimed to analyze the habitat and economic value of the trees in a forest block, then comparing the effects of four thinning scenarios on profit and habitat value. We simulated four thinning scenarios and assessed their effects on biodiversity and economic value. The scenarios were defined according to two criteria: tree dominance and tree habitat value. The study took place in a one-hectare plot of marteloscope located in a naturally regenerated mixed forest enriched with native tree species. The habitat value, evaluated by tree-related microhabitats, was used as a proxy for biodiversity. In our study, as many 58 different tree species were found within the marteloscope. Co-dominant trees with a higher diameter at breast height yielded the highest average habitat value, which coincides weakly with findings in temperate forests. In our study, the biodiversity conservation criterion had only a marginal effect on economic benefit. Both results together show that a meeting point between profitability and biodiversity conservation is possible.

Effects of even-aged and uneven-aged management on carbon dynamics and timber yield in boreal Norway spruce stands: a forest ecosystem model approach

We used a gap-type forest ecosystem model to study how even- and uneven-aged management affected the carbon dynamics and timber production in boreal Norway spruce stands. In business-as-usual management, the intensity of thinnings (from below) and single-tree selective cuttings followed those recommended for even-aged (BT) and uneven-aged management (BSC) in practical forestry in Finland. Moreover, higher or lower basal area thresholds, and shorter or longer production cycles, were used in simulations. We found that, the mean annual carbon uptake, volume growth, and carbon stock in trees and harvested timber, were nearly the same under even-aged (BT) and uneven-aged (BSC) management, when assuming full seed crop in latter one. However, the carbon stock in the soil and ecosystem and the mean annual net ecosystem exchange were slightly smaller under BT. The carbon retention time was longer under BSC. The net present value (NPV with interest rate of 3 per cent) of timber production was clearly lower under BT, when the calculation was initiated at planting on clear-cutting area, in opposite to when initiating calculation a few years before the second thinning. Higher basal area thresholds and longer production cycles increased carbon stocks, carbon retention and timber yield, regardless of management system. On the other hand, the results of uneven-aged management (BSC) were very sensitive to the success of natural regeneration and ingrowth of seedlings, as a reduction of the seed crop by 25–75 per cent from the full seed crop decreases the volume growth by 44–74 per cent and timber yield up to 46 per cent.

YIELD IN SAWN WOOD AND RESIDUE UTILIZATION OF Qualea paraensis DUCKE AND Erisma uncinatum WARM

The study was developed in Nova Maringá - MT. The objectives of this work were to evaluate the sawn timber yield, the use of wood residues and the quantification of products for the species Qualea paraensis (cambará) and Erisma uncinatum (cedrinho) in three diametric classes: Class A - 40.0 to 49.9 cm; Class B - 50.0 to 59.9 cm; Class C - 60.0 to 69.9 cm. Four replicates per class were evaluated, totaling 12 logs per species of varied lengths. The sawn timber yield did not show a statistical difference between diametric classes for both species. Average yield for Qualea paraensis was equal to 43.97% and for Erisma uncinatum, 42.05%. The residues use increased the total yield in 4.40% and 6.52% for Qualea paraensis and Erisma uncinatum, respectively. For Erisma uncinatum, the sawed products with the highest production were the board in the primary unfolding and the short board in the residues use. As for Qualea paraensis, there was more production of rafters and short battens in the same processes.

Black locust (Robinia pseudoacacia L.) selection programmes in Hungary: a short review

Black locust (Robinia pseudoacacia L.) was the first forest tree species introduced from North America to Europe, at the beginning of the 17th century. Its unprecedented fast spread is due to its high-grade adaptability, drought-tolerance, abundant and frequent seed crop, excellent sprouting ability, fast growth and relatively high timber yield. Other advantages are, that it has scarcely any fungi or insect pests. This review is a short summary on black locust improvement in Hungary, giving guidance for specialists who are interested in black locust management.