Current Forest Management Research Articles

Idiosyncratic responses of Pacific salmon species to land cover, fragmentation, and scale

Salmon are critical to the ecology and livelihood of the Pacific Northwest, and are declining throughout much of their range. While much of their life cycle occurs in open ocean, freshwater conditions also contribute to population trends. Because stream habitats are connected to uplands by water flow, salmon can be influenced by the characteristics of terrestrial systems. We analyzed the relationships between the population trends of Pacific salmon (1953-2006) and land cover, fragmentation, and forest age derived from remotely-sensed, landscape level datasets. Analyses included 425 populations of all native salmon species in 156 watersheds on Vancouver Island, British Columbia, Canada. Vancouver Island salmon escapements exhibited general patterns of decline, which may be largely controlled by broad-scale marine conditions. The spatial variation in these population trends was related to landscape variables at watershed and riparian scales with regression trees. Results were found to be species specific, but characteristics indicating a legacy of historic and current forest management (such as fragmented forests and non-forested or early-successional forest cover) generally had negative effects, driven by a small subset of highly fragmented watersheds. Chum and coho had strong negative relationships with fragmentation, pink had a strong positive relationship with wetland abundance, and Chinook and sockeye were most closely related to geomorphology. There was no 'single best' scale of analysis. Salmon trends were generally more closely related to variables estimated over the entire watershed, however, the relative importances of watershed and riparian level predictors varied by both variable and species. Efforts to restore salmon habitat will be complicated by marine and freshwater processes, terrestrial conditions throughout watersheds, and the idiosyncratic requirements of each species.

Long-term ecological impacts of clear-fell logging on tree species diversity in a subtropical forest, southern Japan

Defining the spatial arrangement and length of the cutting cycle in a logged area is crucial for reconciling potential conflicts between timber yields and maintenance of ecosystem services in natural forests. In this study, we investigated long-term impacts of clear-fell logging on timber production and tree species diversity in a subtropical forest on the Ryukyu Islands, using an individual-based simulation model. We assumed six logging scenarios defined by combinations of forest type and regeneration processes, which acted as surrogates for spatial scales of clear-fell logging. These scenarios were simulated under cutting cycles ranging from 20 to 150 years. Short-cutting cycles resulted in dominance by the sprouting species Castanopsis sieboldii. The compositional shift was accelerated by the lack of seed dispersal from surrounding forest areas. The simulations demonstrated that a sustainable logging regime maintaining both yield and tree species diversity requires a cutting cycle longer than 50 years. The simulation results also suggest that the trade-off between the recovery of tree species diversity and timber production is favored more in stands surrounded by mature forest than in isolated stands or stands surrounded by immature forest. Ecological risk assessments based on model simulations provide an alternative to current forest management practices that rely on empirical knowledge.

Future Spruce Budworm Outbreak May Create a Carbon Source in Eastern Canadian Forests

Spruce budworm (Choristoneura fumiferana Clem.) is an important and recurrent disturbance throughout spruce (Picea sp.) and balsam fir (Abies balsamea L.) dominated forests of North America. Forest carbon (C) dynamics in these ecosystems are affected during insect outbreaks because millions of square kilometers of forest suffer growth loss and mortality. We tested the hypothesis that a spruce budworm outbreak similar to those in the past could switch a forest from a C sink to a source in the near future. We used a model of ecosystem C to integrate past spruce budworm impact sequences with current forest management data on 106,000 km2 of forest in eastern Quebec. Spruce budworm-caused mortality decreased stand-level merchantable C stocks by 11–90% and decreased ecosystem C stocks by 2–10% by the end of the simulation. For the first 13 years (2011–2024), adding spruce budworm significantly reduced ecosystem C stock change for the landscape from a sink (4.6 ± 2.7 g C m−2 y−1 in 2018) to a source (−16.8 ± 3.0 g C m−2 y−1 in 2018). This result was mostly due to reduced net primary production. The ecosystem stock change was reduced on average by 2 Tg C y−1 for the entire simulated area. This study provides the first estimate that spruce budworm can significantly affect the C sink or source status of a large landscape. These results indicate that reducing spruce budworm impacts on timber may also provide an opportunity to mitigate a C source.

The legal aspects of public participation in forest management in Turkey.

Dealing with forest resources management, “participation” emerged as a central theme. There has, for some time, been a growing recognition within the government and society at large that the future of sustainable forest management in Turkey depends on more effective participation of multiple stakeholders. Along with growing appreciation of the potential benefits, these has become more systematic in understanding the factors that currently inhibit wider and more effective use of participatory techniques in Turkey. Over the last decade, there has been a succession of studies pointing to the conclusion that current forest management practices, entrenched institutional arrangements and attitudes, and poorly adapted laws are major constraints on participatory forest management. With specific reference to the legal framework, there is a growing consensus that Turkish legislation falls short of these in most developed countries. This acts as a constraint on participation because of its command and control approach, in which most decisions are made by the state. The principle of rule of law is to ensure compliance and penalise non-compliance with those decisions and the law does not fully reflect current social, economic and environmental realities. The purpose of this study is to focus on the strengths and weaknesses of Turkey’s forest law per se, by highlighting some international lessons and practices that might be useful to Turkey as it considers what future steps should be taken in improving the legal framework for participation in forest management. As a result, this study concluded that public participation requires a well established legal system, public sensitivity and local knowledge for a better participatory forest management. Key words: Public participation, forests, management, planning, legislation.

Tools for assessment of human health dimensions in forests | Tools for assessment of human health dimensions in forests

Human health related to forests can be evaluated by Health Impact Assessment (HIA) methodologies and by using indicators of Sustainable Forest Management (SFM). The HIA systematically reviews the health aspects associated with a development policy, plan or project for a forested area, whereas the indicators of SFM can be used to monitor and give information on the existing forests, and their management, including planning. A prerequisite for the assessment of human health aspects in forestry context is defining the relevant indicators. The physical and mental aspects of human health as well as human diseases related to forest conditions are not covered comprehensively and in an operational way for use in current forest management. The health aspects need more multidisciplinary research on the cause-effect relationships between health, forest management and biodiversity. It is also necessary to develop methodologies for the estimation of the economic value of the non-market forest ecosystem services. This article outlines several possibilities to collaborate and develop joint approaches between forest and health sector to assess the health aspect in forests and to ensure that the health aspects in forest management are taken into consideration.

Over‐harvesting driven by consumer demand leads to population decline: big‐leaf mahogany in South America

AbstractConsumer demand for the premier neotropical luxury timber, big‐leaf mahogany (Swietenia macrophylla), has driven boom‐and‐bust logging cycles for centuries, depleting local and regional supplies from Mexico to Bolivia. We revise the standard historic range map for mahogany in South America and estimate the extent to which commercial stocks have been depleted using satellite data, expert surveys, and sawmill processing center data from Brazil. We estimate an historic range of 278 million hectares spanning Venezuela to Bolivia, 57% of this in Brazil. Approximately 58 million hectares (21%) of mahogany's historic range had been lost to forest conversion by 2001. Commercial populations had been logged from at least 125 million more hectares, reducing the commercial range to 94 million hectares (34% of historic). Surviving stocks are extremely low‐density populations in remote regions representing a smaller fraction of historic stocks than expected based on estimated current commercial range. Our method could advance international policy debates such as listing proposals for CITES Appendices by clarifying the commercial and conservation status of high‐value timber species similar to mahogany about which little information is available. The fate of remaining mahogany stocks in South America will depend on transforming current forest management practices into sustainable production systems.

Potential future dead wood dynamics in a multi-ownership region: The Coastal Province of Oregon, USA

Dead wood is important to the processes, structural complexity, and biodiversity of forested ecosystems. Forest management may have unforeseen consequences to dead wood via the interaction of proposed activities with the legacy of past management, natural disturbance, and site productivity. We assessed the potential effects of future forest management for a 300-year period across a large (ca. 23,000km2) forested region that contains numerous ownerships and land management strategies. To do this, we used an ecological gap model (ZELIG), a dead wood decomposition dynamics model (CWDM), live and dead wood data from a physiographic province-wide plot database, and ownership- and land-allocation-specific management prescriptions. Dead wood amounts were projected to increase over the simulation period across the region, primarily because conservation-oriented management approaches utilized on federal lands increased the volume of large logs and snags and number of large snags on federal lands. Large snags and logs decreased on forest industry lands as legacy dead wood derived from historical natural disturbance events was not replaced through management. The results of this study provide an estimate of the maximum potential amounts of dead wood in the forests of the Coastal Province of Oregon, USA, under current policies and forest management, given model assumptions. In cases where current amounts of dead wood may be lower than those present historically, conservation-oriented policies designed to maintain or increase dead wood amounts, such as the Northwest Forest Plan, may have a strong positive influence on large dead wood abundance and related biodiversity in parts of a region that are also under intensive management.

Determinants of floodplain forest development illustrated by the example of the floodplain forest in the District of Leipzig

This paper discusses determinants of the historical and current spatial extent of the floodplain forest in Leipzig as well as its tree species composition using a GIS-data based delineation model and historical forest inventories for the floodplain forest in the district of Leipzig in Germany from the 19th to the 20th century. We found that the spatial extent of the floodplain forest remained considerably stable in spite of an overall decline in the entire floodplain area from the period where the city first experienced industrialisation in the 19th century to now. However, with river regulations and the alteration of forest management from coppice-with-standards forest to high forest in the 19th century, major changes can be found in the tree species composition of the floodplain forest. Comparing these findings with references from other European floodplain forests we discuss the impact of historical and current forest management as well as the city location's influence on the extent and tree species composition of urban floodplain forests. For urban forest management in particular there is a great need to integrate biophysical, historical and forestry knowledge when predicting future developmental trends.

Snag dynamics in post-harvest landscapes of western Newfoundland balsam fir-dominated boreal forests

We examined changes in standing dead tree (snag) density and biomass with time following harvest across a chronosequence of balsam fir (Abies balsamea) dominated boreal forests in western Newfoundland, Canada. Current snag management practices in Newfoundland recommend a minimum of 10snags/ha on the post-harvest landscape. Snags declined significantly in the first two decades of the chronosequence. The rapid rate of decline in snag density which occurred immediately post harvest was likely attributable to windfall and domestic harvest for firewood. A second rapid rate of snag density decline occurred 10–15 years post harvest which potentially reflected the average lifespan of snags in western Newfoundland. Average snag densities approximated the minimum management goal during the period from 15 to 60 years since harvest (YSH). However, 53–60% of sites sampled in the 15–60 YSH period contained <10snags/ha. Snag densities then increased with forest age, again reaching high levels 81–100 YSH which were comparable to the density at the beginning of the chronosequence. Achieving the goal of 10snags/ha on all post-harvest sites in western Newfoundland, especially between 15 and 60 YSH, will require changes to current forest management practices.

Relationships between canopy transmittance and stand parameters in Sitka spruce and Scots pine stands in Britain

Summary The changing emphasis within British forestry from a clearfell/replant system focussed on timber production, to multipurpose forestry encompassing biodiversity and recreation, has resulted in a need for changes to forest management. Manipulation of the forest canopy through thinnings is a powerful tool for forest managers to modify the canopy transmittance, and therefore the belowcanopy light levels. This helps to achieve specifi c objectives such as habitat management or seedling growth as part of transformation of an even-aged stand to a continuous cover forestry regime. In this study, hemispherical photography was used to assess canopy transmittance in a range of Sitka spruce ( Picea sitchensis (Bong.) Carr) and Scots pine ( Pinus sylvestris L.) stands in Britain. Speciesspecifi c relationships were developed between canopy transmittance and easily-measured stand parameters. The models that provided the best fi t to the data were based on basal area and stocking for Sitka spruce and basal area alone for Scots pine. The models indicate that a Sitka spruce stand with a basal area of 30 m 2 ha 1 should have a stocking density <450 stems ha 1 to favour growth of Sitka spruce seedlings. Similarly, a Scots pine stand should have a basal area <27 m 2 ha 1 to achieve transmittance suitable for growth of Scots pine seedlings. In conjunction with a knowledge of the light requirements of different vegetation types, these models can provide a valuable contribution to guidance on current and changing forest management practice.

Effects of presenting forest simulation results on the forest values and attitudes of forestry professionals and other forest users in Central Labrador

This research tested whether demonstration of the long term effect of different forest management scenarios in a large forested area changes people's forest values and attitudes. Forestry professionals and other forest users in Central Labrador were shown simulation results of three alternative forest management scenarios illustrating possible long term effects on various indicators. Forest values and attitudes towards forestry were measured before and after the presentation. Our conception of values and attitudes is based on the cognitive hierarchy model of human behaviour which states that values are more enduring and more difficult to change than attitudes. It was thus hypothesized that attitudes would change but not values and that change in forestry professionals would be less than in other forest users since foresters are trained to think about long-term effects and large-scale processes of forest management scenarios. We also hypothesized that a greater number of people would have an opinion on forest management after the presentation. All three hypotheses were partially supported by the results. The results indicated that some attitude change occurred, but that values also changed somewhat. Most of the significant changes occurred when persons with no clear opinion on several forest-related questions formed an opinion. Long-term, landscape simulation results provide valuable information and enhance understanding of both forestry professionals and other forest users. However, being provided the same information, the two groups learned different things. While forest users gained more confidence in the current forest management plan and were motivated to further participate, professionals learned more specific things. This reflects differences between technical and local knowledge.

Patterns of field layer invertebrates in successional stages of managed boreal forest: Implications for the declining Capercaillie Tetrao urogallus L. population

Capercaillie ( Tetrao urogallus L.) populations in Finland have decreased markedly during past decades. One of the assumed reasons is the decreased quality of brood feeding grounds since current forest management transfers mature forests to younger successional stages. We studied how different types of managed Finnish forests offer resources for capercaillie broods by comparing the vegetation and invertebrate fauna of four successional stages in the two most common forest types in Finland, spruce dominated Vaccinium myrtillus (MT) and pine dominated Vaccinium vitis-idaea (VT) type. Forest age class had a significant effect on the cover of bilberry. There was a positive correlation between bilberry cover and the biomass of larvae and of all invertebrates (including all developmental stages) both at the stand and the sample level. Both forest type and age class significantly affected the biomass of larvae. Mature stands and young stands had the highest biomass of larvae in both MT and VT. In both forest site types the sapling stands hosted the smallest biomass of larvae. The results suggest that successional stages that follow clear cutting seriously lowers the food availability for capercaillie chicks and also reduces the shelter that field layer might provide. However, already the young stages that follow sapling phases seem to provide both bilberries and invertebrates so it is quite unlikely that the bilberry abundance alone could explain the dramatic decline of the capercaillie.

Thresholds for channel initiation at road drain outlets

Abstract Slope–Area relationships have been widely used to identify channel initiation points in the landscape. More recently, the importance of road-related rill and gully erosion has been highlighted. Previous studies indicate that channel initiation at road drain outlets can be predicted from the contributing road area and hillslope gradient at the drain outlet. In this study the validity and usefulness of channel initiation thresholds for road runoff management has been evaluated using field data from three catchments in south-east Australia. None of these catchments show a clear separation between channelised and non-channelised sites based on contributing road area and hillslope gradient. Many drains without channel have similar contributing road area and slope gradients as drain with a channel at the outlet. This demonstrates a relatively large variability within our dataset and limits the identification of a slope–area threshold for these catchments. Logistic regression using road area and slope gradient shows that both variables contribute significantly to channel initiation in the Albert and Tyers River catchments, while for the Sandy Creek catchment only slope gradient is significant at the 0.05 level. Stepwise logistic regression on a wider range of variables shows the significance of cut-batter height in two of the catchments, indicating that flow interception at cut-and-fill roads may be important. Comparison of road-related channel initiation thresholds to previously published topographic thresholds, indicates that channels at road outlets tend to form at relatively small contributing areas and steep slopes. Current forest management guidelines do not consider the risk of channel initiation at road drain outlets in road design and drain spacing. The slope–area thresholds are still considered useful in minimising the risk of gully erosion, especially in forestry areas where it appears most likely that channel initiation occurs during a significant rainfall event immediately following hillslope disturbance or road construction.

The usefulness of a long-term perspective in assessing current forest conservation management in the Apuseni Natural Park, Romania

The forest ecosystem of the Apuseni National Park (ANP) in NW Romania is recognized for its high species and genetic diversity and is protected through various conservation measures. As ANP is the most populated natural park in Romania, the focus is on the need for communities to manage, sustain and prosper by using, exploring and sustaining the natural resources. But what activities are the most appropriate for the conservation of a highly diverse natural forest? This paper presents results from a long-term ecological study using fossil pollen, microscopic and macroscopic charcoal and AMS 14C dating on a site in the ANP in order to examine how the interaction between climate change, human activities and other disturbances have shaped the present protected landscapes over the last 5700 years in this part of the reserve. Results from this study show that the landscape in this region has been continuously forested over the last 5700 years BP, but the forest composition and structure have been dynamic throughout much of the time. In particular, distinct changes in forest composition have occurred over the last 700 years of the record. Fagus sylvatica was the major taxon between 5200 and 200 years BP and its dominance is associated with the highest forest stability. The formation of the current Picea abies forests started 400 years ago and spruce became the dominant forest species during the last two centuries as a result of selective forest clearance, intensive grazing, and more recently, plantations. This led to a large reduction in forest diversity, decline of F. sylvatica and local extinction of several species including Abies alba, Ulmus, Tilia, and Acer. Our results show the high conservation values of A. alba and F. sylvatica in the ANP. Current management practices that allow the anthropogenic activities of timber production and fast tree regeneration, usually involving the plantation of P. abies in this part of the ANP are not in keeping with the NATURA 2000 objectives of ensuring the persistence of the most vulnerable species and habitats.

American Woodcock on Fort Drum Military Installation, New York

American Woodcock singing-ground surveys (SGS) have been conducted annually on Fort Drum Military Installation since 1992 (excluding 1993 and 2000). These SGS indicate Fort Drum has a stable to slightly increasing breeding woodcock population, with average numbers of males heard per route ranging between 13.00 and 22.58 birds. These numbers are significantly higher, and in stark contrast, to many parts of the American Woodcock's range, where numbers have been in decline for over 30 years. We suggest that current forest management practices and military training create favorable successional regimes that satisfy all necessary life-history requirements and help sustain these densities of breeding woodcock at Fort Drum.

Current status and future directions of traditional ecological knowledge in forest management: a review

In the last 25 years, the number of published studies that refer to traditional ecological knowledge (TEK) has constantly increased, with now more than 200 papers published each year. The objective of this review was to determine how this knowledge is used in current forest management around the world, and how local communities are involved in forest management planning. Published papers from 1983 to 2005 relating to TEK were found using the ISI Web of Science database. Despite the growing amount of literature published on TEK, we found only 21 studies that specifically address forest management per se. In these studies, TEK integration took different paths: using traditional management rules as a framework (five studies), using value maps to adapt practices in time and space (three studies), or by a zoning process that divides the land into areas in which different land uses are emphasized (six studies). Some community involvements are “active” with co-management committees composed of stakeholders (including community members), each having a voice; some are “passive” with external managers using criteria and indicators previously developed from community values and objectives. Although important changes in mentality and firm political decisions are still required before more efficient partnership between TEK and western science is reached in forest management planning, our review showed that Canadian initiatives proposed promising processes that could ensure better TEK incorporation and improved community participation. Key words: traditional ecological knowledge, TEK, sustainable forest management, community participation, first nations, forest management planning

Simulação de estratégias de manejo florestal na Amazônia com o uso do modelo SYMFOR

O modelo SYMFOR foi utilizado para simular os processos ecológicos de crescimento, mortalidade e recrutamento e o manejo de uma floresta de terra firme na Amazônia Oriental. Na simulação foram utilizadas todas as árvores com DAP ≥ 5 cm, medidas em 40 parcelas permanentes de 1,0 ha, sendo 36 exploradas e quatro não exploradas. As parcelas foram medidas em 1984, exploradas em 1985 e remedidas em 1986, 1988, 1990, 1994, 1996 e 2004. Usaram-se dez grupos de espécies para descrever os processos naturais e o comportamento de cada árvore. Na avaliação do desempenho do modelo, os resultados da simulação foram comparados com os dados reais que descrevem a recuperação da floresta dezenove anos após a exploração. Os tratamentos, combinações de intensidades de exploração (15%, 25% e 35% do volume total das árvores com DAP &gt; 60 cm) com intensidades de desbastes (0%, 30%, 50% e 70% da área basal original), foram analisados como estratégias de manejo. O modelo foi aplicado também para simular o manejo florestal atualmente praticado na Amazônia, com extração de 30 m³ ha-1 e com um ciclo de corte de 30 anos. Resultados mostram que a semelhança entre os dados observados e simulados pelo SYMFOR validou o modelo para representar a dinâmica da floresta não explorada. Na simulação das práticas atuais de manejos aplicados na floresta amazônica, sugere-se que os benefícios financeiros diminuem com as sucessivas colheitas e, conseqüentemente, o rendimento de volume de madeira não é sustentável.

Biodiversity and multiple disturbances: boreal forest ground beetle (Coleoptera: Carabidae) responses to wildfire, harvesting, and herbicide

Rising societal demands for forest resources along with existing natural disturbance regimes suggest that sustainable forest management will increasingly depend on better understanding the cumulative effects of natural and anthropogenic disturbances. In North America, for example, there is increasing economic pressure to salvage log burned forests, although the ecological consequences of combining fire and harvesting on the same sites are unclear. We examined the short-term (2 year) responses of boreal forest ground beetles (Coleoptera: Carabidae) to the individual and combined effects of wildfire, harvesting, and herbicide. Ground beetle responses to wildfire and forestry-related disturbances differed strongly and suggested that, although some species may appear to benefit from disturbance combinations (e.g., Sericoda quadripunctata (DeGeer)), these effects are detrimental to others (e.g., Sericoda bembidioides Kirby). Species compositional variability was significantly reduced by disturbance combinations suggesting that multiple disturbances may lead to a simplification of this entire assemblage. In addition, ground beetle responses were correlated with changes in several key habitat parameters such as amount of woody debris, exposed ground, and plant species richness suggesting avenues for future study. Overall, however, our results suggest that efforts to avoid compounding disturbances on any site should be considered when developing current and future forest management guidelines.

Biodiversity Conservation in Commercial Boreal Forestry: The Optimal Rotation Age and Retention Tree Volume

Abstract This article examines biodiversity conservation in commercial boreal forests. The means of promoting biodiversity are green tree retention and prolonged rotation age, which create dead and decaying wood artificially and via natural mortality, respectively. We extend the Hartman model to cover biodiversity benefits and to allow for leaving retention trees standing at the final felling. We first characterize qualitatively the socially optimal choice of the harvest volume and rotation age. We then assess empirically the optimal solution in a simulation model calibrated to the Finnish forestry for a pine stand. We find that biodiversity conservation increases the socially optimal rotation age beyond the Faustmann rotation age. The optimal volume of retention trees increases (decreases) with biodiversity valuation (timber price). The optimal retention volume is higher than suggested by the current forest management recommendations or certification systems.

Using knowledge of natural disturbances to support sustainable forest management in the northern Clay Belt

Several concepts are at the basis of forest ecosystem management, but a relative consensus exists around the idea of a forest management approach that is based on natural disturbances and forest dynamics. This type of approach aims to reproduce the main attributes of natural landscapes in order to maintain ecosystems within their natural range of variability and avoid creating an environment to which species are not adapted. By comparing attributes associated with natural fire regimes and current forest management, we were able to identify four major differences for the black spruce forest of the Clay Belt. The maintenance of older forests, the spatial extent of cutover areas, the maintenance of residuals within cutovers and disturbance severity on soils are major issues that should be addressed. Silvicultural strategies that mitigate differences between natural and managed forests are briefly discussed. Key words: natural disturbance, landscape patterns, coarse filter, harvest pattern, volume retention, historic variability, even-aged management