Spatial distribution in Norwegian lemming Lemmus lemmus in relation to the phase of the cycle

Competition between individuals of the same or different species affects spatial distribution of organisms at any given time. Consequently, a species geographical distribution is related to population dynamics through density-dependent processes. Small Arctic rodents are important prey species in many Arctic ecosystems. They commonly show large cyclic fluctuations in abundance offering a potential to investigate how landscape characteristics relates to density-dependent habitat selection. Based on long-term summer trapping data of the Norwegian lemming (Lemmus lemmus) in the Scandinavian Mountain tundra, we applied species distribution modeling to test if the effect of environmental variables on lemming distribution changed in relation to the lemming cycle. Lemmings were less habitat specific during the peak phase, as their distribution was only related to primary productivity. During the increase phase, however, lemming distribution was, in addition, associated with landscape characteristics such as hilly terrain and slopes that are less likely to get flooded. Lemming habitat use varied during the cycle, suggesting density-dependent changes in habitat selection that could be explained by intraspecific competition. We believe that the distribution patterns observed during the increase phase show a stronger ecological signal for habitat preference and that the less specific habitat use during the peak phase is a result of lemmings grazing themselves out of the best habitat as the population grows. Future research on lemming winter distribution would make it possible to investigate the year around strategies of habitat selection in lemmings and a better understanding of a fundamental actor in many Arctic ecosystems.publishedVersio

Status and conservation goals for the critically endangered Arctic fox in Scandinavia. Is the mission completed?

201

Status and Ecological Effects of the World’s Largest Carnivores

Large carnivores face serious threats and are experiencing massive declines in their populations and geographic ranges around the world. We highlight how these threats have affected the conservation status and ecological functioning of the 31 largest mammalian carnivores on Earth. Consistent with theory, empirical studies increasingly show that large carnivores have substantial effects on the structure and function of diverse ecosystems. Significant cascading trophic interactions, mediated by their prey or sympatric mesopredators, arise when some of these carnivores are extirpated from or repatriated to ecosystems. Unexpected effects of trophic cascades on various taxa and processes include changes to bird, mammal, invertebrate, and herpetofauna abundance or richness; subsidies to scavengers; altered disease dynamics; carbon sequestration; modified stream morphology; and crop damage. Promoting tolerance and coexistence with large carnivores is a crucial societal challenge that will ultimately determine the fate of Earth’s largest carnivores and all that depends upon them, including humans.This is the author's version of the work. It is posted here by permission of the American Association for the Advancement of Science for personal use, not for redistribution. The definitive version was published in Science, Vol. 343 (2014), doi:10.1126/science.1241484. The published article can be found at: http://www.sciencemag.org/

Viltets ekosystemtjänster : En kunskapssammanställning till stöd för värdering och förvaltning

Det finns en mängd mer eller mindre strikta definitioner och indelningar av ekosystemtjänster. Vi föredrar att inte göra någon åtskillnad mellan processer som levererar nyttigheter och de nyttigheter som produceras. I rapporten ser vi därmed exempelvis viltkött, eller glädjen över att se en björn, som ekosystemtjänster, inte som nyttigheter som är ett resultat av ekosystemtjänster.  Det stora värdet med konceptet ekosystemtjänster ligger i att olika värden identifieras, samt insikten att olika tjänster ofta begränsar varandra. Det går följaktligen inte att maximera alla tjänster, utan förvaltning av naturresurser ur ett ekosystemtjänstperspektiv bygger på accepterade avvägningar mellan identifierade tjänster.  Människan är en del av ekosystemen. Leveransen av viltets ekosystemtjänster påverkas i stor utsträckning av landskapet och därmed av mänsklig markanvändning. För att värdera och förvalta viltets ekosystemtjänster är det nödvändigt att känna till hur viltet påverkar landskapet, hur landskapet och markanvändningen påverkar viltet samt hur olika avvägningar ger återkopplingar till ekosystemen. Ekosystemtjänster samskapas genom komplicerade samspel mellan biologisk mångfald och ekologiska processer å ena sidan och människans sociala system, aktiviteter och investeringar å andra sidan.  Ofta beror problem med att omsätta ekosystemtjänstkonceptet i praktisk förvaltning på svårigheter att samtidigt hantera försörjande (materiella) och kulturella (immateriella) tjänster, där de senare ofta inte kan värdesättas kvantitativt. Det gör det svårt att finna goda avvägningar mellan försörjande och kulturella tjänster. Det totala värdet av de kulturella tjänsterna i landskapet överstiger ofta det totala värdet av alla de försörjande tjänsterna. Det gäller även värdet av viltets ekosystemtjänster.  Olika intressegrupper, och individer inom intressegrupper, värderar ofta samma ekosystemtjänst olika. Förvaltning av naturresurser ur ett ekosystemtjänstperspektiv kräver dialog mellan aktörer om identifiering, värdering och förvaltning av ekosystemtjänster. Strikta, exkluderande definitioner och fokus på kvantitativ, monetär värdering försvårar ofta processen och tillämpningen; vi förordar inkluderande förhållningssätt, även om det försvårar eller omöjliggör monetär värdering och ekonomiska kostnads-nyttoanalyser. Stammarna av klövvilt, storfåglar (gäss, trana och sångsvan) och stora rovdjur har vuxit starkt under de senaste hundra åren till följd av framgångsrik förvaltning. Dagens starka stammar levererar stora ekosystemtjänster direkt och indirekt (Figur 1), men kan även leverera ‑otjänster. Detta skapar konflikter och behov av avvägningar mellan olika intressen inom samförvaltningen av vilt, andra naturresurser och upplevelsevärden.  Betande klövvilt och betande storfåglar har viktiga strukturerande effekter på vegetationen. Låga och medelhöga betestryck har generellt positiva effekter på den biologiska mångfalden, särskilt om betestrycket varierar i tid och rum på landskapsnivå. Avsaknad av bete kan precis som höga betestryck ha negativa effekter på den biologiska mångfalden, genom att det ger minskad variation av livsmiljöer.  De stora rovdjuren levererar stora kulturella ekosystemtjänster, men har ofta begränsad populationsreglerande effekt på klövvilt i Sverige eftersom klövviltsstammarna begränsas genom jakt. Jägarna kompenserar dessutom för de stora rovdjurens predation genom minskat jaktuttag. Det gör att rovdjuren kan begränsa ekosystemtjänsterna från jakt på klövvilt mer eller mindre kraftigt, men samtidigt har begränsad inverkan på klövviltstammarnas storlek. Det går inte att jämföra de stora rovdjurens ekologiska roll utan jakt, exempelvis i nationalparker, med effekter i normala svenska produktionslandskap. Kvantitativa värderingar av psykosociala effekter av rovdjur saknas i stor utsträckning; innan både positiva och negativa effekter studerats är det svårt eller omöjligt att finna goda avvägningar. Generellt saknas kvantitativa data för många kulturella ekosystemtjänster från vilt, som exempelvis upplevelsevärden av att se vilt för allmänhet och turister.  Skador från vilt är ofta ojämnt fördelade i tid och rum. Genomsnittliga nationella och regionala skadenivåer kan därmed vara vilseledande när det gäller vilka utmaningar enskilda brukare och förvaltningen ställs inför. Viltförvaltningen måste därmed utgå från lokala förhållanden för att åtgärder ska kunna skräddarsys efter upplevda behov och bidra till god måluppfyllnad, exempelvis när det gäller att hantera omfattande, men lokala, skador. Lokal delaktighet ökar samtidigt sannolikheten att nå acceptans för avvägningar mellan konkurrerande ekosystemtjänster.  Nödvändiga data för att göra en komplett samhällsekonomisk analys av ekosystemtjänster och -otjänster från vilt saknas idag. Vi har medvetet avstått från att jämföra de ekonomiska värden som trots allt finns i en kostnadsnyttoanalys, eftersom en sådan inte skulle inkludera alla relevanta ekosystemtjänster. Eventuella avvägningar baserade på en sådan analys skulle därmed inte inkludera alla tjänster eller intressen, och skulle därmed riskera att öka snarare än minska mängden konflikter om förvaltningsbeslut och -åtgärder baseras på ofullständiga beslutsunderlag.  Jaktlagen uttrycker sedan revideringen 1987 ett gemensamt ansvar mellan jakträttshavare och markägare att förvalta viltet utifrån enskilda och allmänna intressen. Lagstiftningen bygger på grundprinciperna inom ekosystemtjänstkonceptet, och har bidragit till att det idag finns formaliserade arenor för att finna avvägningar mellan ekosystemtjänster på olika nivåer. Viltförvaltningen ligger därmed långt framme i omställningen mot att förvalta naturresurser utifrån ett ekosystemtjänstperspektiv, i enlighet med fattade riksdagsbeslut. Här finns generella lärdomar att dra för den övriga förvaltningen.  För att nå längre mot en adaptiv förvaltning av vilt med accepterade avvägningar mellan olika ekosystemtjänster och -otjänster krävs ytterligare fokus på underifrånperspektiv, delaktighet och breda analyser. Det är nödvändigt att viltets reglerande ekosystemtjänster, kulturella ekosystemtjänster respektive strukturerande effekter på ekosystemen inkluderas i beslutsunderlagen i större utsträckning än idag. För vilt som rör sig över stora områden måste lokal förvaltning kombineras med regional, nationell och internationell samverkan.There are many more or less strict ways to define ecosystem services. We have chosen not to make a distinction between the processes delivering the benefits and the actual benefits. For example, we regard both game meat and the positive experience of seeing a bear as ecosystem services in the report, not as benefits from ecosystem services. We feel that the main benefit of the concept of ecosystem services is the focus on identifying all relevant contributions to people from the ecosystems and the realisation that ecosystem services often limit one another. Thus, it is not possible to maximise all ecosystem services simultaneously. Adopting an ecosystem services approach to managing natural resources requires finding accepted trade-offs between relevant services. We humans are part of the ecosystem. The delivery of ecosystem services is influenced greatly by landscape characteristics and thus by land use and other human activities. In order to evaluate and manage ecosystem services from game, it is necessary to know how the landscape is influencing the game, how the game is affecting the landscape and how land use (including for example hunting) influences these processes. This includes taking complex feedback loops into account. In fact, virtually all ecosystem services are co- produced by an interplay between biodiversity and ecological processes on the one hand and human activities, investments and social context on the other hand. Assigning monetary values to ecosystem services can be convenient for comparing different values in a common currency. This may facilitate finding trade-offs between competing services and interests. Unfortunately, it may often be difficult, impossible or even deemed inappropriate to assign quantitative values to some cultural services. This is especially true for assigning monetary values to for example feelings and beliefs. Thus, operationalization of the ecosystem services concept is often hampered by the difficulties of handling provisioning (material) and cultural (immaterial) services simultaneously. To make things more complicated, the total value of cultural ecosystem services in a landscape often exceeds the total value of provisioning services from agriculture or forestry, in cases where monetary values have been assigned. This holds true for ecosystem services from game as well. Thus, the services deemed most important by stakeholders are especially difficult to include in quantitative cost-benefit analyses. Often, different stakeholders, and individuals within stakeholder groups, will value ecosystem services differently. Management of natural resources from an ecosystem services perspective requires dialogue between relevant parties about identifying, evaluating and managing ecosystem services. Strict, excluding definitions on what constitutes a service, and focus on determining monetary values, may exclude relevant services and stakeholders from the analyses and negotiations. We advocate broad, inclusive approaches, even if this makes it difficult or impossible to assign monetary values to all services, in order to generate acceptance for the trade-offs and reduce conflict. The populations of ungulates, large grazing birds and large carnivores have increased dramatically over the last century in Scandinavia, as a result of successful conservation and sustainable management. Today’s strong populations of game deliver substantial ecosystem services, but may also yield disservices e.g. in the form of damage to crops and to regenerating forests. This creates conflict and necessitates trade-offs between interests through co-management of game and other natural resources, while for example taking recreational values into account. Damage from game to crops and to regenerating forests are often unevenly distributed in time and, particularly, space. Thus, average levels of damage at regional and national levels can be misleading for discussing the challenges facing individual farmers and forest owners. Game management must have a bottom-up approach, where decisions depend on local conditions, in order to manage local problems and simultaneously enable us to utilise the ecosystem services from game to even a fraction of its potential. Furthermore, a bottom up approach increases the probability to find acceptance for trade-offs between competing ecosystem services by those directly affected. Grazing ungulates and birds have important structuring impacts on the vegetation and the ecosystems. In general, intermediate grazing pressures have positive effects on biodiversity, especially if the grazing pressures vary in space and in time. By contrast, both low and high grazing pressures may have negative consequences for biodiversity, by limiting the variation in habitats. Taxa may be affected in different ways, but the overall effect on biodiversity from grazing at today’s ungulate densities is positive in Scandinavia. In forests, ungulates are partly filling the ecological niche previously occupied by livestock, thus maintaining biodiversity that was favoured by traditional land use previously. The large carnivores deliver substantial cultural ecosystem services, but have limited regulating effect on the populations of ungulates in Scandinavia. Population size of ungulates is mainly limited through hunting and the harvest rate is similar to the predation rate of large carnivores in areas elsewhere without hunting. Thus, large carnivores may have substantial effects on the opportunity to hunt and ecosystem services from hunting, but will have small effects on ungulates as hunters compensate for the predation by decreased hunting. The ecological role of large carnivores in Scandinavian ‘production landscapes’ cannot be compared to the situation in national parks without hunting. Largely, quantitative evaluations of the psychosocial effects of large carnivores are lacking. It will not be possible to make a complete assessment of the ecosystem services from large carnivores until both the negative and the positive effects have been studied. In general, quantitative data is scant for many of the cultural ecosystem services from game, such as e.g. recreational values of observing game for the public or for tourists. Thus, the data required for a complete cost-benefit analysis of the ecosystem services, and disservices, from game are not available yet. We have refrained from comparing those monetary values that are available, as this analysis would be incomplete. Thus, trade-offs from such an analysis would not include all relevant services, or stakeholders’ interests, and may result in more rather than less conflict over management decisions and actions. The Swedish Hunting Act was revised in 1987, right after the exponential increase in the moose population had been halted through increased hunting pressure. The legislation rests on several of the principles that later have been included in the ecosystem services concept: landowners and hunters have a shared responsibility both to limit game populations through hunting and to support game populations through direct actions. Furthermore, both private and public interests have to be taken into account in management, when striking a balance between ecosystem services from game and other ecosystem services. The principles of shared responsibility and trade-offs between different interests have resulted in the establishment of formalised platforms for finding accepted trade-offs between stakeholder interests from a local to a national level of game management. While conflicts still occur over trade-offs, the game management is ahead of much of the Swedish management of natural resources when it comes to implementing the ecosystem services concept. In the future, more focus should be devoted to maintaining a bottom-up perspective, while performing broad analyses and seeking inclusive trade-offs based on all relevant ecosystem services. Regulating and cultural ecosystem services, as well as structuring effects of game on ecosystems, must be included in the basis of analyses and management decisions when appropriate. Furthermore, local management must be combined with cooperation at regional, national and international levels for game that moves over large areas

Viltets ekosystemtjänster : En kunskapssammanställning till stöd för värdering och förvaltning

Det finns en mängd mer eller mindre strikta definitioner och indelningar av ekosystemtjänster. Vi föredrar att inte göra någon åtskillnad mellan processer som levererar nyttigheter och de nyttigheter som produceras. I rapporten ser vi därmed exempelvis viltkött, eller glädjen över att se en björn, som ekosystemtjänster, inte som nyttigheter som är ett resultat av ekosystemtjänster.  Det stora värdet med konceptet ekosystemtjänster ligger i att olika värden identifieras, samt insikten att olika tjänster ofta begränsar varandra. Det går följaktligen inte att maximera alla tjänster, utan förvaltning av naturresurser ur ett ekosystemtjänstperspektiv bygger på accepterade avvägningar mellan identifierade tjänster.  Människan är en del av ekosystemen. Leveransen av viltets ekosystemtjänster påverkas i stor utsträckning av landskapet och därmed av mänsklig markanvändning. För att värdera och förvalta viltets ekosystemtjänster är det nödvändigt att känna till hur viltet påverkar landskapet, hur landskapet och markanvändningen påverkar viltet samt hur olika avvägningar ger återkopplingar till ekosystemen. Ekosystemtjänster samskapas genom komplicerade samspel mellan biologisk mångfald och ekologiska processer å ena sidan och människans sociala system, aktiviteter och investeringar å andra sidan.  Ofta beror problem med att omsätta ekosystemtjänstkonceptet i praktisk förvaltning på svårigheter att samtidigt hantera försörjande (materiella) och kulturella (immateriella) tjänster, där de senare ofta inte kan värdesättas kvantitativt. Det gör det svårt att finna goda avvägningar mellan försörjande och kulturella tjänster. Det totala värdet av de kulturella tjänsterna i landskapet överstiger ofta det totala värdet av alla de försörjande tjänsterna. Det gäller även värdet av viltets ekosystemtjänster.  Olika intressegrupper, och individer inom intressegrupper, värderar ofta samma ekosystemtjänst olika. Förvaltning av naturresurser ur ett ekosystemtjänstperspektiv kräver dialog mellan aktörer om identifiering, värdering och förvaltning av ekosystemtjänster. Strikta, exkluderande definitioner och fokus på kvantitativ, monetär värdering försvårar ofta processen och tillämpningen; vi förordar inkluderande förhållningssätt, även om det försvårar eller omöjliggör monetär värdering och ekonomiska kostnads-nyttoanalyser. Stammarna av klövvilt, storfåglar (gäss, trana och sångsvan) och stora rovdjur har vuxit starkt under de senaste hundra åren till följd av framgångsrik förvaltning. Dagens starka stammar levererar stora ekosystemtjänster direkt och indirekt (Figur 1), men kan även leverera ‑otjänster. Detta skapar konflikter och behov av avvägningar mellan olika intressen inom samförvaltningen av vilt, andra naturresurser och upplevelsevärden.  Betande klövvilt och betande storfåglar har viktiga strukturerande effekter på vegetationen. Låga och medelhöga betestryck har generellt positiva effekter på den biologiska mångfalden, särskilt om betestrycket varierar i tid och rum på landskapsnivå. Avsaknad av bete kan precis som höga betestryck ha negativa effekter på den biologiska mångfalden, genom att det ger minskad variation av livsmiljöer.  De stora rovdjuren levererar stora kulturella ekosystemtjänster, men har ofta begränsad populationsreglerande effekt på klövvilt i Sverige eftersom klövviltsstammarna begränsas genom jakt. Jägarna kompenserar dessutom för de stora rovdjurens predation genom minskat jaktuttag. Det gör att rovdjuren kan begränsa ekosystemtjänsterna från jakt på klövvilt mer eller mindre kraftigt, men samtidigt har begränsad inverkan på klövviltstammarnas storlek. Det går inte att jämföra de stora rovdjurens ekologiska roll utan jakt, exempelvis i nationalparker, med effekter i normala svenska produktionslandskap. Kvantitativa värderingar av psykosociala effekter av rovdjur saknas i stor utsträckning; innan både positiva och negativa effekter studerats är det svårt eller omöjligt att finna goda avvägningar. Generellt saknas kvantitativa data för många kulturella ekosystemtjänster från vilt, som exempelvis upplevelsevärden av att se vilt för allmänhet och turister.  Skador från vilt är ofta ojämnt fördelade i tid och rum. Genomsnittliga nationella och regionala skadenivåer kan därmed vara vilseledande när det gäller vilka utmaningar enskilda brukare och förvaltningen ställs inför. Viltförvaltningen måste därmed utgå från lokala förhållanden för att åtgärder ska kunna skräddarsys efter upplevda behov och bidra till god måluppfyllnad, exempelvis när det gäller att hantera omfattande, men lokala, skador. Lokal delaktighet ökar samtidigt sannolikheten att nå acceptans för avvägningar mellan konkurrerande ekosystemtjänster.  Nödvändiga data för att göra en komplett samhällsekonomisk analys av ekosystemtjänster och -otjänster från vilt saknas idag. Vi har medvetet avstått från att jämföra de ekonomiska värden som trots allt finns i en kostnadsnyttoanalys, eftersom en sådan inte skulle inkludera alla relevanta ekosystemtjänster. Eventuella avvägningar baserade på en sådan analys skulle därmed inte inkludera alla tjänster eller intressen, och skulle därmed riskera att öka snarare än minska mängden konflikter om förvaltningsbeslut och -åtgärder baseras på ofullständiga beslutsunderlag.  Jaktlagen uttrycker sedan revideringen 1987 ett gemensamt ansvar mellan jakträttshavare och markägare att förvalta viltet utifrån enskilda och allmänna intressen. Lagstiftningen bygger på grundprinciperna inom ekosystemtjänstkonceptet, och har bidragit till att det idag finns formaliserade arenor för att finna avvägningar mellan ekosystemtjänster på olika nivåer. Viltförvaltningen ligger därmed långt framme i omställningen mot att förvalta naturresurser utifrån ett ekosystemtjänstperspektiv, i enlighet med fattade riksdagsbeslut. Här finns generella lärdomar att dra för den övriga förvaltningen.  För att nå längre mot en adaptiv förvaltning av vilt med accepterade avvägningar mellan olika ekosystemtjänster och -otjänster krävs ytterligare fokus på underifrånperspektiv, delaktighet och breda analyser. Det är nödvändigt att viltets reglerande ekosystemtjänster, kulturella ekosystemtjänster respektive strukturerande effekter på ekosystemen inkluderas i beslutsunderlagen i större utsträckning än idag. För vilt som rör sig över stora områden måste lokal förvaltning kombineras med regional, nationell och internationell samverkan.There are many more or less strict ways to define ecosystem services. We have chosen not to make a distinction between the processes delivering the benefits and the actual benefits. For example, we regard both game meat and the positive experience of seeing a bear as ecosystem services in the report, not as benefits from ecosystem services. We feel that the main benefit of the concept of ecosystem services is the focus on identifying all relevant contributions to people from the ecosystems and the realisation that ecosystem services often limit one another. Thus, it is not possible to maximise all ecosystem services simultaneously. Adopting an ecosystem services approach to managing natural resources requires finding accepted trade-offs between relevant services. We humans are part of the ecosystem. The delivery of ecosystem services is influenced greatly by landscape characteristics and thus by land use and other human activities. In order to evaluate and manage ecosystem services from game, it is necessary to know how the landscape is influencing the game, how the game is affecting the landscape and how land use (including for example hunting) influences these processes. This includes taking complex feedback loops into account. In fact, virtually all ecosystem services are co- produced by an interplay between biodiversity and ecological processes on the one hand and human activities, investments and social context on the other hand. Assigning monetary values to ecosystem services can be convenient for comparing different values in a common currency. This may facilitate finding trade-offs between competing services and interests. Unfortunately, it may often be difficult, impossible or even deemed inappropriate to assign quantitative values to some cultural services. This is especially true for assigning monetary values to for example feelings and beliefs. Thus, operationalization of the ecosystem services concept is often hampered by the difficulties of handling provisioning (material) and cultural (immaterial) services simultaneously. To make things more complicated, the total value of cultural ecosystem services in a landscape often exceeds the total value of provisioning services from agriculture or forestry, in cases where monetary values have been assigned. This holds true for ecosystem services from game as well. Thus, the services deemed most important by stakeholders are especially difficult to include in quantitative cost-benefit analyses. Often, different stakeholders, and individuals within stakeholder groups, will value ecosystem services differently. Management of natural resources from an ecosystem services perspective requires dialogue between relevant parties about identifying, evaluating and managing ecosystem services. Strict, excluding definitions on what constitutes a service, and focus on determining monetary values, may exclude relevant services and stakeholders from the analyses and negotiations. We advocate broad, inclusive approaches, even if this makes it difficult or impossible to assign monetary values to all services, in order to generate acceptance for the trade-offs and reduce conflict. The populations of ungulates, large grazing birds and large carnivores have increased dramatically over the last century in Scandinavia, as a result of successful conservation and sustainable management. Today’s strong populations of game deliver substantial ecosystem services, but may also yield disservices e.g. in the form of damage to crops and to regenerating forests. This creates conflict and necessitates trade-offs between interests through co-management of game and other natural resources, while for example taking recreational values into account. Damage from game to crops and to regenerating forests are often unevenly distributed in time and, particularly, space. Thus, average levels of damage at regional and national levels can be misleading for discussing the challenges facing individual farmers and forest owners. Game management must have a bottom-up approach, where decisions depend on local conditions, in order to manage local problems and simultaneously enable us to utilise the ecosystem services from game to even a fraction of its potential. Furthermore, a bottom up approach increases the probability to find acceptance for trade-offs between competing ecosystem services by those directly affected. Grazing ungulates and birds have important structuring impacts on the vegetation and the ecosystems. In general, intermediate grazing pressures have positive effects on biodiversity, especially if the grazing pressures vary in space and in time. By contrast, both low and high grazing pressures may have negative consequences for biodiversity, by limiting the variation in habitats. Taxa may be affected in different ways, but the overall effect on biodiversity from grazing at today’s ungulate densities is positive in Scandinavia. In forests, ungulates are partly filling the ecological niche previously occupied by livestock, thus maintaining biodiversity that was favoured by traditional land use previously. The large carnivores deliver substantial cultural ecosystem services, but have limited regulating effect on the populations of ungulates in Scandinavia. Population size of ungulates is mainly limited through hunting and the harvest rate is similar to the predation rate of large carnivores in areas elsewhere without hunting. Thus, large carnivores may have substantial effects on the opportunity to hunt and ecosystem services from hunting, but will have small effects on ungulates as hunters compensate for the predation by decreased hunting. The ecological role of large carnivores in Scandinavian ‘production landscapes’ cannot be compared to the situation in national parks without hunting. Largely, quantitative evaluations of the psychosocial effects of large carnivores are lacking. It will not be possible to make a complete assessment of the ecosystem services from large carnivores until both the negative and the positive effects have been studied. In general, quantitative data is scant for many of the cultural ecosystem services from game, such as e.g. recreational values of observing game for the public or for tourists. Thus, the data required for a complete cost-benefit analysis of the ecosystem services, and disservices, from game are not available yet. We have refrained from comparing those monetary values that are available, as this analysis would be incomplete. Thus, trade-offs from such an analysis would not include all relevant services, or stakeholders’ interests, and may result in more rather than less conflict over management decisions and actions. The Swedish Hunting Act was revised in 1987, right after the exponential increase in the moose population had been halted through increased hunting pressure. The legislation rests on several of the principles that later have been included in the ecosystem services concept: landowners and hunters have a shared responsibility both to limit game populations through hunting and to support game populations through direct actions. Furthermore, both private and public interests have to be taken into account in management, when striking a balance between ecosystem services from game and other ecosystem services. The principles of shared responsibility and trade-offs between different interests have resulted in the establishment of formalised platforms for finding accepted trade-offs between stakeholder interests from a local to a national level of game management. While conflicts still occur over trade-offs, the game management is ahead of much of the Swedish management of natural resources when it comes to implementing the ecosystem services concept. In the future, more focus should be devoted to maintaining a bottom-up perspective, while performing broad analyses and seeking inclusive trade-offs based on all relevant ecosystem services. Regulating and cultural ecosystem services, as well as structuring effects of game on ecosystems, must be included in the basis of analyses and management decisions when appropriate. Furthermore, local management must be combined with cooperation at regional, national and international levels for game that moves over large areas

Data from: The fluctuating world of a tundra predator guild: bottom-up constraints overrule top-down species interactions in winter

Global warming is predicted to change ecosystem functioning and structure in Arctic ecosystems by strengthening top-down species interactions, i.e. predation pressure on small herbivores and interference between predators. Yet, previous research is biased towards the summer season. Due to greater abiotic constraints, Arctic ecosystem characteristics might be more pronounced in winter. Here we test the hypothesis that top-down species interactions prevail over bottom-up effects in Scandinavian mountain tundra (Northern Sweden) where effects of climate warming have been observed and top-down interactions are expected to strengthen. But we test this a-priori hypothesis in winter and throughout the 3-4 year rodent cycle, which imposes additional pulsed resource constraints. We used snowtracking data recorded in 12 winters (2004-2015) to analyse the spatial patterns of a tundra predator guild (arctic fox Vulpes lagopus, red fox Vulpes vulpes, wolverine Gulo gulo) and small prey (ptarmigan, Lagopus spp). The a-priori top-down hypothesis was then tested through structural equation modelling, for each phase of the rodent cycle. There was weak support for this hypothesis, with top-down effects only discerned on arctic fox (weakly, by wolverine) and ptarmigan (by arctic fox) at intermediate and high rodent availability respectively. Overall, bottom-up constraints appeared more influential on the winter community structure. Cold specialist predators (arctic fox and wolverine) showed variable landscape associations, while the boreal predator (red fox) appeared strongly dependent on productive habitats and ptarmigan abundance. Thus, we suggest that the unpredictability of food resources determines the winter ecology of the cold specialist predators, while the boreal predator relies on resource rich habitats. The constraints imposed by winters and temporary resource lows should therefore counteract productivity-driven ecosystem change and have a stabilizing effect on community structure. Hence, the interplay between summer and winter conditions should determine the rate of Arctic ecosystem change in the context of global warming

The fluctuating world of a tundra predator guild : bottom‐up constraints overrule top‐down species interactions in winter

Global warming is predicted to change ecosystem functioning and structure in Arctic ecosystems by strengthening top‐down species interactions, i.e. predation pressure on small herbivores and interference between predators. Yet, previous research is biased towards the summer season. Due to greater abiotic constraints, Arctic ecosystem characteristics might be more pronounced in winter. Here we test the hypothesis that top‐down species interactions prevail over bottom‐up effects in Scandinavian mountain tundra (Northern Sweden) where effects of climate warming have been observed and top‐down interactions are expected to strengthen. But we test this ‘a priori’ hypothesis in winter and throughout the 3–4 yr rodent cycle, which imposes additional pulsed resource constraints. We used snowtracking data recorded in 12 winters (2004–2015) to analyse the spatial patterns of a tundra predator guild (arctic fox Vulpes lagopus, red fox Vulpes vulpes, wolverine Gulo gulo) and small prey (ptarmigan, Lagopus spp). The a priori top‐down hypothesis was then tested through structural equation modelling, for each phase of the rodent cycle. There was weak support for this hypothesis, with top‐down effects only discerned on arctic fox (weakly, by wolverine) and ptarmigan (by arctic fox) at intermediate and high rodent availability respectively. Overall, bottom‐up constraints appeared more influential on the winter community structure. Cold specialist predators (arctic fox and wolverine) showed variable landscape associations, while the boreal predator (red fox) appeared strongly dependent on productive habitats and ptarmigan abundance. Thus, we suggest that the unpredictability of food resources determines the winter ecology of the cold specialist predators, while the boreal predator relies on resource‐rich habitats. The constraints imposed by winters and temporary resource lows should therefore counteract productivity‐driven ecosystem change and have a stabilising effect on community structure. Hence, the interplay between summer and winter conditions should determine the rate of Arctic ecosystem change in the context of global warming