Jean-Michel Roberge

Replacing monocultures with mixed-species stands: Ecosystem service implications of two production forest alternatives in Sweden

Whereas there is evidence that mixed-species approaches to production forestry in general can provide positive outcomes relative to monocultures, it is less clear to what extent multiple benefits can be derived from specific mixed-species alternatives. To provide such insights requires evaluations of an encompassing suite of ecosystem services, biodiversity, and forest management considerations provided by specific mixtures and monocultures within a region. Here, we conduct such an assessment in Sweden by contrasting even-aged Norway spruce (Piceaabies)-dominated stands, with mixed-species stands of spruce and birch (Betula pendula or B. pubescens), or spruce and Scots pine (Pinussylvestris). By synthesizing the available evidence, we identify positive outcomes from mixtures including increased biodiversity, water quality, esthetic and recreational values, as well as reduced stand vulnerability to pest and pathogen damage. However, some uncertainties and risks were projected to increase, highlighting the importance of conducting comprehensive interdisciplinary evaluations when assessing the pros and cons of mixtures.

Evidence-Based Knowledge Versus Negotiated Indicators for Assessment of Ecological Sustainability: The Swedish Forest Stewardship Council Standard as a Case Study

Assessing ecological sustainability involves monitoring of indicators and comparison of their states with performance targets that are deemed sustainable. First, a normative model was developed centered on evidence-based knowledge about (a) forest composition, structure, and function at multiple scales, and (b) performance targets derived by quantifying the habitat amount in naturally dynamic forests, and as required for presence of populations of specialized focal species. Second, we compared the Forest Stewardship Council (FSC) certification standards’ ecological indicators from 1998 and 2010 in Sweden to the normative model using a Specific, Measurable, Accurate, Realistic, and Timebound (SMART) indicator approach. Indicator variables and targets for riparian and aquatic ecosystems were clearly under-represented compared to terrestrial ones. FSC’s ecological indicators expanded over time from composition and structure towards function, and from finer to coarser spatial scales. However, SMART indicators were few. Moreover, they poorly reflected quantitative evidence-based knowledge, a consequence of the fact that forest certification mirrors the outcome of a complex social negotiation process.

Socio-ecological implications of modifying rotation lengths in forestry

The rotation length is a key component of even-aged forest management systems. Using Fennoscandian forestry as a case, we review the socio-ecological implications of modifying rotation lengths relative to current practice by evaluating effects on a range of ecosystem services and on biodiversity conservation. The effects of shortening rotations on provisioning services are expected to be mostly negative to neutral (e.g. production of wood, bilberries, reindeer forage), while those of extending rotations would be more varied. Shortening rotations may help limit damage by some of today’s major damaging agents (e.g. root rot, cambium-feeding insects), but may also increase other damage types (e.g. regeneration pests) and impede climate mitigation. Supporting (water, soil nutrients) and cultural (aesthetics, cultural heritage) ecosystem services would generally be affected negatively by shortened rotations and positively by extended rotations, as would most biodiversity indicators. Several effect modifiers, such as changes to thinning regimes, could alter these patterns.

Usefulness of biophysical proxy data for modelling habitat of an endangered forest species: The white-backed woodpecker Dendrocopos leucotos

Abstract Efficient conservation planning in managed forest landscapes requires knowledge about the location of functional habitat for specialised species. We explored the importance of different variables to predict habitat suitability for the white-backed woodpecker (Dendrocopos leucotos Bechstein), a proposed umbrella species in deciduous forest. Specifically, we tested whether biophysical proxy variables indicating management intensity and the occurrence of natural processes constituted a useful complement to traditional remotely sensed data on tree species composition and forest stand age for modelling the woodpeckers habitat. Presence–absence of the woodpecker during the study period (1986–2006) in southwestern Sweden was explained by the area of edge habitats (forest bordering water or farmland) and wetland forest, and location relative to the historical marine limit. The number of years with occurrence of the woodpecker in a territory was explained by the area of forest bordering water and wetland forest. Among traditional forest variables, the area of deciduous forest had a strong positive effect on both woodpecker presence–absence and the number of years with occurrence. The results support the hypothesis that edge habitats and forest types subject to natural processes favouring deciduous trees and dead wood creation are valuable to the woodpecker and should be prioritised in conservation planning.

Afforestation Planning and Biodiversity Conservation: Predicting Effects on Habitat Functionality in Lithuania

Habitat re-creation is one of the multiple faces of biodiversity restoration and encompasses the attempts to reconstruct an ecosystem on severely disturbed sites with little left to restore. Afforestation of abandoned or marginal agricultural land is an important tool for the re-creation of forest ecosystems and re-establishment of functional habitat networks for the maintenance of biodiversity. This study was performed in the context of the Danish-Lithuanian project ‘Afforestation of abandoned agricultural land based on sustainable land use planning and environmentally sound forest management’. The study assessed how habitat re-creation as designed in alternative afforestation plans for two administrative regions in Lithuania will affect the functionality of the landscapes for bird species of conservation concern. Spatial analysis of the forest cover was performed under existing and proposed conditions using general landscape ecological principles concerning core and edge habitats as well as nearest-neighbour metrics. The results show that the use of general criteria may result in proportionally negative changes in the availability of some forest habitats relative to changes in total forest cover, thus leading to less significant improvements in the habitats of many naturally occurring (and even protected) species compared to what would be expected from changes in forest cover alone. To solve this dilemma it is suggested that the requirements of focal species and quantitative conservation objectives should be considered in a spatially explicit – each main forest type. It is concluded that to ensure functionality of habitat networks, knowledge and experience from the fields of landscape ecology and conservation biology should be more commonly incorporated into afforestation planning.

The next common and widespread bunting to go? Global population decline in the Rustic Bunting Emberiza rustica

Populations of several long-distance migratory songbirds in Eurasia are in peril, drastically illustrated by the recent range-wide population collapse in the Yellow-breasted Bunting Emberiza aureola . There are signals of a strong decline also in the Rustic Bunting E. rustica , but no range-wide assessment of population trends in this superabundant and widespread bunting species has yet been undertaken. The conservation status of Rustic Bunting is ‘Least Concern’ on the global IUCN Red List, but it has recently been upgraded to ‘Vulnerable’ on the European Red List. To assess the Rustic Bunting’s global conservation status we compiled, for the first time, population data across its breeding and wintering ranges. The analysis reveals a 75–87% decline in overall population size over the last 30 years and a 32–91% decline over the last 10 years. The trend estimates indicate that the long-term (30-year) range-wide population decline in the Rustic Bunting is of similar magnitude to two well-known examples of declining species within the same genus, the Yellow-breasted Bunting and the Ortolan Bunting E. hortulana . The magnitude of the range-wide population decline over the last 10 years suggests that the Rustic Bunting could be upgraded from ‘Least Concern’ to ‘Vulnerable’ or ‘Endangered’ on the IUCN global Red List. Agricultural intensification in the wintering range and intensified levels of disturbance, including logging and fire, in the breeding range could be important drivers of the range-wide population decline, and persecution could also contribute. Untangling threat factors and their interactions on Rustic Bunting is necessary for conservation, but hampered by our currently limited understanding of the relationships between population dynamics and different threats.

Age-related effects of clear-cut–old forest edges on bird communities in Lithuania

Abstract The influence of forestry-induced edges on plant and animal communities is dynamic in time, a fact that has been overlooked in many studies on the edge effect. This study assessed age-related changes in edge effects on breeding forest birds after clear-cutting in mixed deciduous old forest in south-west Lithuania. In total, 182 transects starting at the edge and extending 200 m into the forest were visited twice during the breeding season. The mean abundance of birds was higher in the 10 m wide zone closest to the edge than farther inside the forest (10–200 m from the edge) and increased in this 10 m wide zone from young edges (1–3 years) to middle-aged (4–9 years) and old (10–20 years) edges. The edge influence on the structure of forest bird communities penetrated deeper and deeper into the forest during the first 20 years after clear-cutting: young edges were characterized by a 50 m wide zone of influence into the forest, middle-aged edges by a 90 m wide zone and old edges by a 120 m wide zone. Based on changes in bird community patterns along transects penetrating into the forest, four zones were distinguished: the edge contact zone, the main edge zone, the intermediate zone and the forest interior zone.

Food plots as a habitat management tool: forage production and ungulate browsing in adjacent forest

A key challenge for wildlife management is to handle competing goals. High ungulate densities may be desirable from hunting and recreational perspectives, but may come in conflict with needs to limit or reduce browsing damage. Since browsing intensity is negatively related to forage availability it may be possible to mitigate damage on forest by increasing forage availability within the landscape. A commonly used method to increase the attractiveness of a localized part of the landscape is to establish food plots. In a multiyear setup using enclosures, wildlife observations, field surveys, and controlled biomass removal, we studied food plots to document forage production, utilization by ungulates, and browsing on adjacent forests in southern Sweden. The fenced parts of the food plots produced on average 2230 to 5810 kg ha-1 marrow-stem kale, second-year clover mix or early-sown rapeseed. The biomass of target crops was generally higher within ungrazed (exclosures) compared to grazed (controls) quadrats on the food plots, which demonstrates that the crops were used as forage by ungulates. Browsing on deciduous trees in the adjacent forest was higher within 70–135 m from the food plots compared to areas further away. For wildlife management, our study shows that establishment of food plots provides substantial amounts of forage both during growing season and at the onset of the dormant season, and that a large share of this food is consumed. Finally, our study documents that forage availability for ungulates at the onset of the often-limiting dormant season can be increased by fencing food plots throughout the growing season.

Has the term “conservation biology” had its day?

© The Ecological Society of America www.frontiersinecology.org Has the term “conservation biology” had its day? The “conservation biology” literature has increased tremendously in volume during the past two decades. Furthermore, the field has expanded in breadth to include various disciplines, reaching far beyond biological or ecological science. Consequently, is it time for a name change? Although the importance of social science disciplines within conservation biology has already been acknowledged in Soulé’s landmark paper (Soulé 1985), non-biological disciplines therein were largely neglected during the 1980s and 1990s. For example, the topics covered at the Society for Conservation Biology’s (SCB’s) first annual meeting, held in 1987, were almost entirely restricted to biology and land management (Ginsberg 1987). Since then, there is no doubt that conservation biology has – in practice – developed into a truly interdisciplinary subject (see eg Meine et al. [2006] for a historical account). Thus, the list of topic areas for SCB’s 2009 annual meeting included – in addition to more “traditional” conservation topics – environmental economics, politics and policy, anthropology, sociology, and psychology. A question that is increasingly being asked is whether the term “conservation biology” is appropriate in light of that conceptual expansion. We do not think so. In “conservation biology”, the word “conservation” is used as a noun adjunct modifying “biology”. Linguistically, this makes conservation biology a subdiscipline of biology, just like cell biology, freshwater biology, or invasion biology. Are there any alternative naming conventions that would capture the full contemporary span of this discipline? The term “conservation research”, which is already being used to some extent (eg Bhagabati 2007), would better acknowledge the field’s breadth. In cases where the ecological context may not be obvious, it may also be necessary to add qualifiers to distinguish the field from other disciplines that involve conserving things (eg architecture, art, or digital information). Here, terms such as “biodiversity conservation research” could be used. The term “conservation biology” is certainly appropriate as a name for the discipline addressing biological aspects of conservation. However, when referring to the wider interdisciplinary field that has developed over time, we argue that adopting a new terminology is warranted. This is an important step toward embracing the broad range of actors – from many disciplines – who are needed to save the world’s biodiversity. Jean-Michel Roberge, Grzegorz Mikusiński, and Hugh P Possingham Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences, Umeå, Sweden (Jean-Michel.Roberge @vfm.slu.se); Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, Riddarhyttan, Sweden; The Ecology Centre, School of Integrative Biology, University of Queensland, St Lucia, Queensland, Australia

Browsing and damage inflicted by moose in young Scots pine stands subjected to high-stump precommercial thinning

In Fennoscandia, young stands of Scots pine (Pinus sylvestris L.) are intensively used by moose (Alces alces L.) during winter. We studied whether forage amounts on high-cut pines in high-stump commercial thinning influenced browsing intensity and damage incidence on retained (i.e. uncut) pine stems. High-cut pines were browsed, but to a lesser extent than retained pines. At a scale corresponding to individual feeding sites (≈40 m2), browsing intensity on retained pines was not influenced by the amount of forage on high-cut pines but was positively related to moose pellet group counts. The incidence of lower-height damage (stem breakage and bark stripping) was positively related to the amount of forage on high-cut pines, whereas higher damage (leader shoot browsing) was not. Overall browsing damage incidence on retained pines was positively related to the density of deciduous trees and negatively related to the amount of forage on retained pines. Our results suggest that although high-stump thinning supplies additional food resources for moose, larger amounts of forage on high-cut pines may increase the risk for bark stripping and stem breakage on retained trees. Further research is needed at larger spatial scales to assess the feasibility of high-stump thinning as a damage mitigation measure.