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Conflicts often arise when large predators and free-ranging livestock share a common area. Various compensation schemes arc used to attempt solving these conflicts, but the costs of predation to suffering stakeholders arc often unknown. Semi-domesticated reindeer husbandry and large carnivores form one such system, where conflicts between predator conservation and the traditional livelihood are common. We apply an age- and sex-structured reindeer-lichen model to examine the effects of predation on reindeer management. Based on the previous studies we specify age- and sex-class-specific mortalities due to various predators, and study optimal reindeer husbandry under predation pressure and the costs of predation. We show that the costs of predation highly depend on the age-class-specific killing rates of reindeer by various predator species, but not on interest rate or pasture conditions. Regarding species that are more likely to kill adult reindeer in addition to calves, the total predation costs are clearly higher than the net slaughtering value of the predated animals. The decrease in steady-state yearly net income is highest for the gray wolf and lower for other predator species. Adapting to predation pressure includes increasing the size of the reindeer population in winter and changing the slaughtering age of males towards young adults, thus reducing the importance of calf harvesting. This result contrasts with the previous results from stage-structured models that do not fully include time lags related to long-living ungulate species. The costs of predation appear to be much higher in an ex post system than in a territorial compensation system, as in an cx post system herders have not adapted to the predation pressure and must search for the predated reindeer to gain compensations. Our results suggest that co-existence of a viable gray wolf population and profitable reindeer husbandry in the same area is not possible in most cases.

Publisher Copyright: © 2022 selection and editorial matter, Tim Horstkotte, Øystein Holand, Jouko Kumpula and Jon Moen. Reindeer husbandry is an important economic activity in the Arctic. Growth rate and productivity of reindeer populations depend on pasture conditions, but herders’ decisions are also influenced by economic factors. Thus, to understand the reindeer husbandry system, an economic–ecological analysis is needed. Bioeconomic models provide a suitable approach for studying economic–ecological systems. Reindeer populations, as well as their pastures, can be viewed as biological resources utilized in reindeer husbandry. To analyse optimal herd structure and slaughter strategy, structured models are needed. This chapter employs a bioeconomic, age- and sex-structured reindeer-pasture model to study economically sustainable adaptation and management under different conditions. The model is run for three hypothetical herding districts, which represent the typical variation in conditions between and within Fennoscandian countries. The chapter analyses how these differences in ecological and economic conditions affect the model solutions and explores optimal herd sizes, slaughter and feeding strategies, lichen biomass dynamics and net revenues under different conditions. Finally, the chapter discusses and compares economic incentives, pasture conditions and government regulation in Nordic countries in the light of the model analysis.

Wild and semidomesticated reindeer are one of the key species in Arctic and subarctic areas, and their population dynamics are closely tied to winter conditions. Difficult snow conditions have been found to decrease the calving success and survivability of reindeer, but the economic effects of variation in winter conditions on reindeer husbandry have not been studied. In this study, we combine state-of-the-art economic-ecological modeling with the analysis of annual reindeer management reports from Finland. These contain local knowledge of herding communities. We quantify the occurrence probabilities of different types of winters from annual management reports and analyze the effects of this variation in winter conditions on reindeer husbandry using an age- and sex-structured bioeconomic reindeer-lichen model. Our results show that difficult winters decrease the net revenues of reindeer husbandry. However, they also protect lichen pastures from grazing, thereby increasing future net revenues. Nonetheless, our solutions show that the variability of winter conditions overall decrease the net income of herders compared to constant winter conditions. Low lichen biomass appears to make reindeer management more sensitive to the effects of difficult winter conditions. We also found that it is economically sensible to use supplementary feeding during difficult winters, but the net revenues still decrease compared to average winters because of the high feeding costs. Overall, our analysis suggests that the increasing variability of winter conditions due to climate change will decrease net revenues in reindeer husbandry. This decrease will still occur even if the most extreme effects of climate change do not occur. This study shows that combining a state-of-the-art bioeconomic model and practitioner knowledge can bring compatible insights, ideas, results, and a bottom-up perspective to the discussion.

Publisher Copyright: © 2022 selection and editorial matter, Tim Horstkotte, Øystein Holand, Jouko Kumpula and Jon Moen. This chapter examines the complexities and challenges in state governance of the maximum permitted number of reindeer in Finland, Norway and Sweden. The common findings regarding the three countries are that (1) maximum permitted numbers of reindeer set by the nation states primarily seem to promote objectives other than those of herders; (2) various contextual aspects (e.g., laws, other land users, trends in science, herding practices and historical developments) partly explain the sustainable maximum permitted numbers; (3) reductionist assessments of pasture – reindeer relations easily neglect the impacts of other land users on condition and availability of pastures, thereby making the assessments biased and stigmatizing herders for alleged overgrazing. The chapter also explores issues related to reindeer numbers that vary across the three countries including (4) herders’ opportunities to participate in knowledge production and resulting decisions over maximum reindeer numbers, (5) clashes between herders’ experience and practice-based knowledge and scientific knowledge on which the definitions of maximum numbers are often based and (6) the ways in which the borders between reindeer herding districts and nation states have implications for the governance of reindeer numbers.

Alien predators are known to potentially strongly affect their prey populations. We studied the impact of raccoon dogs (Nyctereutes procyonoides) on waterbird breeding success in eight semi-urban wetlands in Finland. We manipulated raccoon dog density in two wetlands by removing individuals (2002 protection year, 2003 and 2004 removal years). We additionally performed nest predation experiments. We monitored raccoon dog density, estimated hunting bag size and observed waterbird breeding success. Our hypothesis predicts that the omnivorous raccoon dog plays a role in waterbird breeding success by depredating nests. Our experiments shown that the raccoon dog hunting bag in eutrophic wetlands may be large, as we removed 8.6–20.0 animals per km2. Both our nest predation experiment and field data indicated that raccoon dogs affect the breeding success of waterbirds. We found a significant relationship between raccoon dog density index and predation rate of the artificial nests, but not between red fox (Vulpes vulpes) density and predation on artificial nests. We did not find an association between raccoon dog abundance and the breeding success of mallards (Anas platyrhynchos) and great crested grebes (Podiceps cristatus). However, our study shows that birds species with different breeding strategies – e.g. great crested grebe, mute swan (Cygnus olor), mallard, Eurasian wigeon (Mareca penelope), coot (Fulica atra), lapwing (Vanellus vanellus) and marsh harrier (Circus aeruginosus) – when considered together showed higher breeding success both in 2003 and 2004 when compared to breeding success before removal. There was, however, variation in how strongly the species responded to raccoon dog removal. Our results indicate that the removal of alien raccoon dogs can be an important tool in wetland management. Keywords: ducks, invasive species, lapwing, nest predation experiment, Nyctereutes procyonoides, predator removal

All Nordic countries regulate the maximum number of reindeer. However, long-term grazing pressure by reindeer together with the effects of forestry and other land uses raise concern regarding the possible overgrazing of the important winter lichen pastures. Understanding the dynamics between pastures and the reindeer population is imperative for determining the size of sustainable reindeer populations. Governmental regulation and subsidy systems additionally create economic incentives and set restrictions on reindeer management. Current herd sizes are, thus, based on both biological and economic factors. In this chapter, we provide an economic-ecological model of a reindeer herding system that can be used to analyze how the various forces drive reindeer numbers. We first show how ecological and economic factors affect model results. We then use Finland as an example to demonstrate how bioeconomic analysis can be used as a tool for understanding the reindeer herding system. Finally, we discuss how current restrictions on the maximum number of reindeer relate to economically and ecologically sustainable model solutions.

The reindeer (Rangifer tarandus L.) is a key species in Fennoscandia, where nearly 40% of the land area is used as reindeer pasture. Reindeer herding is an important source of income for local people and an intrinsic part of the Sami culture In this thesis, the reindeer herding system is studied using a detailed interdisciplinary dynamic model. An age- and sex-structured reindeer-lichen model is developed using findings from previous research and novel data. The model also takes other winter resources, including supplementary food, into account in addition to ground lichens. This ecological model is combined with economic optimization and a description of the herding system with empirically estimated prices, costs, and governmental subsidies. The model is validated and calibrated to describe the reindeer herding system in the northern part of Finnish Lapland. The results for population dynamics without harvesting show that the reindeer-lichen system described by the model is unstable in the absence of predators. However, high availability of arboreal lichens stabilizes the system. In economically optimal solutions increasing the interest rate increases the steady-state reindeer population level, opposite to classical understanding in resource economics. Natural mortality is close to zero in optimal steady-state solutions and harvesting is concentrated on calves. The number of adult males is kept as low as possible without decreasing the reproduction rate of the population. This leads to much higher shadow values for males compared to females. The results show that in order to study sustainable and economically viable reindeer management, both ecological and economic factors must be taken into account, as they strongly affect the solutions and management recommendations. One of the main findings is that the economically optimal steady-state lichen biomass can be surprisingly low. High interest rate, lack of pasture rotation, low growth rate of ground lichen, high availability of arboreal lichens, and government subsidies all decrease the steady-state lichen biomass. Using intensive supplementary feeding to support larger reindeer herds, which leads to the depletation of lichens, can additionally become optimal in certain cases. When recovering from overgrazed lichen pastures, use of supplementary feeding and the amount of arboreal lichens have an important role in the optimal adaptation process. The wintertime wastages estimated in this study are close to earlier suggestions, but summertime wastage is higher than expected. Seasonal pasture rotation could thus considerably help reduce the summertime trampling of winter pastures. The model validation solutions show that the model is able to describe changes in lichen biomass with good accuracy. Using the validated model and calibrated wastage values we found that reindeer numbers in northernmost Finland in the present situation are in most cases higher than in the management solutions given by the model. Tässä väitöskirjassa kehitetään, parametrisoidaan ja validoidaan yksityiskohtainen taloudellis-ekologinen malli poropopulaatiosta, sen energiaresursseista ja käytöstä. Mallin avulla tutkitaan paliskunnan mahdollisimman suurta kestävää tulotasoa tavoittelevaa teurastusta, populaation ruokintaa ja laidunten käytön säätelyä. Erilaisiin lähtökohtiin perustuvia arvioita taloudellis-ekologisista optimiratkaisuista verrataan poronhoidon nykytilaan. Poronhoito on merkittävä elinkeino erityisesti Ylä-Lapin alueella ja samalla kiinteä osa saamelaista kulttuuria. Poro (Rangifer tarandus L.) vaikuttaa arktiseen ympäristöön ja populaation omiin ravintoresursseihin erityisesti jäkälikköjä kuluttamalla. Poron riippuvuus jäkälän määrästä vastaakin ekologiassa paljon tutkittua dynaamista kuluttaja-resurssi – systeemiä. Taloudellinen tarkastelu lisää tähän klassiseen ekologiseen malliin ihmisen vaikutuksen luonnonvarojen hyödyntäjänä ja muokkaajana. Tämä lisäys on välttämätön, jotta poronhoidosta saataisiin kuva pohjoiseen arktiseen luontoon sopeutuneena tärkeänä ja kulttuurisesti omaleimaisena taloudellista ylijäämää tavoittelevana elinkeinona. Väitöskirjan malli perustuu poro-jäkälä dynamiikkaan, mutta sisältää myös muut luontaiset ravintolähteet sekä lisärehun. Ekologinen malli nojaa laajasti käytettyihin teorioihin ja metodeihin, kuten eläinyksilöiden optimaalisen ravinnon valinnan teoriaan ja dynaamiseen ikä- ja sukupuoliluokkaiseen mallirakenteeseen. Optimointi ratkaistaan kehittyneillä matemaattisilla algoritmeilla. Malli sisältää yksityiskohtaisen kuvauksen tuloista, kustannuksista, poronhoidolle maksetuista tuista ja huomioi korkokannan vaikutukset. Tuloksena on aikaisempaa tutkimusta oleellisesti realistisempi monitieteinen kuvaus poro-laidun dynamiikasta ja porotaloudesta. Vastoin luonnonvarataloustieteen klassista tulosta poropopulaation optimaalinen koko on realistisilla positiivisilla korkokannoilla suurempi kuin koron ollessa nolla. Vastaavasti jäkälämäärä on alhaisempi. Yksi tutkimuksen päätuloksista on, että, taloudellisesti optimaaliset teurastukset kohdistetaan vasoihin. Aikuiset naaraat on kannattavinta teurastaa yhdeksän ja koiraat viiden vuoden ikäisinä. Verrattuna aikaisempaan tutkimukseen yksi väitöskirjan mallien edistysaskel on joustavan poron polygamisen luonteen huomioivan pariutumismallin käyttäminen. Tämän seurauksena saadaan arvio optimaalisesta populaation sukupuolijakaumasta samoin kuin eri sukupuolta olevien eläinyksilöiden taloudellisesta arvosta. Sovelletussa pariutumismallissa sekä koiras-naaras suhde että koiraiden ja naaraiden ikäluokkarakenne vaikuttavat syntyvien vasojen määrään. Koiraiden määrä voidaan pitää pienenä niiden korkean lisääntymiskyvykkyyden seurauksena. Tästä seuraa, että marginaalisen koiraan taloudellinen arvo on naarasta korkeampi. Väitöskirjan tulokset osoittavat, että tutkittaessa taloudellisesti kestävää poronhoitoa tulee sekä ekologiset että taloustieteelliset tekijät huomioida monipuolisesti. Yksi väitöskirjan päätuloksista on, että taloudellisesti optimaalinen jäkäläbiomassa on selvästi pienempi kuin aikaisemmissa tutkimuksissa. Tähän on sekä ekologisia ja taloudellisia että poronhoidollisia syitä: korkea korko, vähäinen vanhan metsän määrä, laidunkierron puuttuminen, runsas lupon määrä ja valtion suorat tulotuet alentavat kaikki jäkäläbiomassan määrää tasapainotilassa. Lisäksi joissain tapauksissa intensiiviseen lisäruokintaan pohjautuva poronhoito saattaa olla taloudellisesti kannattavinta. Tämä johtaa alhaisiin jäkälämääriin ja jäkälälaidunten kulumiseen. Väitöskirjassa arvioitu talviaikainen jäkälän hukkaantuminen laidunnuksen seurauksena vastaa jo aikaisemmissa optimointimalleissa käytettyä, mutta kesäaikainen jäkälän hukkaantuminen on tallaantumisen vuoksi huomattavasti suurempaa. Tulos korostaa vuodenaikaisen laidunkierron merkitystä jäkälän kulumisen estämisessä. Validointitulokset osoittavat, että malli pystyy myös hyvin kuvamaan jäkälän määrän kehitystä. Validoidulla mallilla tehdyt arviot taloudellisesti optimaalisesta jäkälämäärästä ovat korkeampia verrattuna laidunten nykytilaan poronhoitoalueella. Jäkälän lisääminen tasolle, jossa taloudellisesti kannattava poronhoito voi perustua luonnonlaitumiin kestää mallilla saatavien arvioiden mukaan vuosikymmeniä ja vaatisi osin myös voimakkaita poromäärien leikkauksia. Myös lisäruokinnan käyttäminen on kannattavaa sopeutumisen alkuvuosina. Kuitenkaan välittömillä teurastuksilla toteutettu mahdollisimman nopea sopeutumisratkaisu jäkäliköiden elvyttämiseksi ei näytä taloudellisesti perustellulta. Hitaampi sopeuttaminen hyödyntää paremmin poropopulaation ikäluokkarakennetta ja huomioi poronomistajien tarpeen säilyttää riittävä tulotaso myös sopeuttamisjakson aikana. Bioekonomisia malleja on metsä- ja kalataloudesta käytetty runsaasti käytännön kysymysten ja suositusten laatimiseen. Myös tässä väitöskirjassa kehitettyä porotalouden mallia voidaan käyttää monien empiiristen, soveltavien ja käytännön kysymysten tarkasteluun. Mallilla voidaan tutkia kilpailevien maankäyttömuotojen aiheuttamia kustannuksia ja esimerkiksi erilaisten geneettisten muutosten taloudellista potentiaalia. Lisäksi voidaan arvioida petoeläinten porotaloudelle aiheuttamia kustannuksia. Maa- ja metsätalousministeriö määrittää kymmenvuosittain suurimmat sallitut poroluvut eri paliskunnille. Kehitetyllä mallilla voidaan tuottaa erilaisiin lähtökohtiin perustuvia arvioita taloudellis-ekologisesti perustelluista poromääristä. Mallin dynaaminen rakenne huomioi ikäluokkarakenteesta syntyvät viiveet sopeutumisprosesseissa ja näin voidaan arvioida kannattavimpia sopeutumispolkuja nykytilanteesta kohti tavoiteltavia poromääriä.

We apply an age- and sex-structured reindeer-lichen model to examine the role of winter pastures, pasture rotation, and supplementary feeding on economically optimal reindeer management. The model includes 17 age classes of females, 13 classes of males and a detailed description of winter energy resource utilization by the reindeer population. Reproduction is specified by a modified harmonic mean mating system and the diet choice between different winter energy resources follows the principles of the optimal foraging theory. Wintertime energy intake defines an individual's weight decrease and its consequences on mortality and reproduction. Lichen growth depends on habitat type and lichen biomass. The decision variables are the animals chosen for slaughter from each age and sex class and the amount of supplementary food given. Results show that the availability of arboreal lichens, the growth rate of ground lichens, and pasture rotation all determine the optimal solutions. Reindeer management aiming to maximize long-term net economic revenues leads to very low lichen densities if intensive feeding becomes optimal in the long-term steady state. Government subsidies promote reindeer herders to base management on supplementary feeding leading to lower pasture conditions and to the depletion of lichens.

This study presents an optimal harvesting model for the semi-domesticated reindeer (Rangifer t. tarandus) and its main winter energy source, ground lichens (Cladonia spp.). Females are divided into 17 age classes and males into 13. Reproduction is specified by a modified harmonic mean mating function and an age-specific reproduction success. Lichen availability determines individuals’ overwinter weight decrease, natural mortality, the number of calves per females and calves’ birth weight. The reindeer herding cooperative can choose the number of animals harvested from the 30 age/sex classes and is assumed to maximize the preset value of net income. The structured optimization model is solved as a fully dynamic system and for initial states that may not be close to the optimal steady state. This enables to study optimal recovery from overgrazed pastures and the optimality of the constant escapement policy. We show that given zero interest rate the optimal steady-state lichen density is less than 50% of the maximum sustainable yield level but nearly twice as high as empirically observed. Density dependence at optimal equilibrium is realized in calf weight and in the average number of calves per female. Optimal slaughtering is concentrated on six-month-old calves. Adult females are slaughtered at the age of 9.5 years and males at the age of 5.5 years. A moderate or high interest rate increases the steady state reindeer population but decreases pasture conditions. Dynamic solutions deviate from constant escapement, implying that the optimal recovery from initially overgrazed pastures is slower than suggested in existing studies and actual policy. The shadow value for males is three times higher than for females.