Abstract Knowledge of the determinants of the viability of populations is essential in order to undertake effective conservation and management of endangered species. In this study, long-term demographic data was combined with genetic data to study the viability of an endangered orchid species, Epipactis atrorubens. The genetic analyses revealed low levels of genetic variation and the presence of population genetic differentiation independent of the spatial scale. Low levels of seed-mediated gene flow, possibly linked to low seedling recruitment, is the likely cause of the low levels of gene flow. Indications of slow post-glacial colonisation rates were found, which together with the low gene flow predict a limited capacity of the species to shift its range to more suitable habitats after environmental change. Low genetic variation as a proxy for low evolutionary potential also suggests that the species has limited capacity to adapt to new environmental conditions. Furthermore, poor seedling recruitment lowers population viability in small populations, as highlighted by the low population growth rates. In addition, we found a strong effect of stochasticity that limits the viability of populations. Both the genetic and demographic analyses indicated low viability of the studied species and that seedling recruitment could be the main determinant for the viability. / Tiivistelmä Luonnonsuojelun perusta on populaatioiden elinkykyyn vaikuttavien tekijöiden tuntemus. Tässä väitöskirjatyössä tutkittiin uhanalaisen orkidean, tummaneidonvaipan (Epipactis atrorubens), elinkykyyn vaikuttavia tekijöitä yhdistämällä pitkäaikaisseurannoilla kerätyt demografiset aineistot geneettisin menetelmin kerättyihin aineistoihin. Lajin populaatioiden geneettisen muuntelun määrän havaittiin olevan pieni ja populaatioiden todettiin olevan geneettisesti erilaistuneita maantieteellisestä skaalasta riippumatta. Geneettisen erilaistumisen syy voi olla alhainen geenivirta, joka on seurausta vähäisestä siemendispersaalista ja huonosta taimettumisesta. Populaatioiden evolutiivista historiaa tutkittaessa havaittiin merkkejä hitaasta jääkauden jälkeisestä kolonisaatiosta, mikä yhdessä alhaisen geenivirran kanssa ennustaa, että lajilla on huono kyky siirtyä sille sopivammille alueille, jos ympäristö muuttuu. Huonoa evolutiivista potentiaalia kuvastava vähäinen geneettinen muuntelu ennustaa, että lajilla on huono kyky sopeutua uusiin ympäristöoloihin. Tämän lisäksi huono taimettuminen laskee elinkykyä etenkin pienissä populaatioissa, mikä näkyy muun muassa pienten populaatioiden matalina kasvukertoimina. Stokastinen vaihtelu vaikutti elinkykyä alentavasti, mikä pitäisikin huomioida nykyistä paremmin elinkykyanalyyseissä. Sekä geneettiset että demografiset analyysit osoittivat taimettumisen mahdollisesti olevan määräävä tekijä tummaneidonvaipan populaatioiden elinkyvylle.

Abstract Many plant species inhabiting the seashore meadows of the Bothnian Bay, especially early successional ones, have become threatened. Isostatic land uplift creates virgin land for early successional species to colonise. However, at the same time it gradually elevates the habitat and eventually makes the habitat unsuitable for them. Disturbances of the waterfront may slow down succession and create new empty sites. In order to persist on the shores, pioneer species have to be able to colonise new sites by seeds, vegetative propagules or growth. In this thesis I studied the status of an endangered early successional grass species, A. fulva var. pendulina, at the Liminka Bay. According to a matrix population model based on eight years of observations (1992–1999), the population seemed not to be in immediate danger of extinction. However, simulations based on four-year field observations (2000–2003) indicated that if the current trend continues, the species will decrease considerably in area in the next 30 years. In the field studies no seedlings or viable seeds of A. fulva were found. In spite of this, high genotypic diversity was found in the A. fulva population, suggesting that sexual reproduction has taken place at some time during the history of the population. Analysis of the population structure revealed a low level of genotypic differentiation between subpopulations and significant sub-structuring within subpopulations. The overall pattern of genetic variation suggests that the population has characters of both stepping-stone and metapopulation models. The results of the study on the ability of a seashore plant Potentilla anserina ssp. egedii to change its allocation of resources to sexual and vegetative reproduction according to competitive stress implied that the species can modify the allocation of resources to different life-history traits. For a plant living in disturbance-prone environment, it may be beneficial to be able to rapidly track the competition-free space formed by disturbances by changing its reproductive pattern. Management studies on three endangered seashore plant species showed that deterioration of suitable habitats of A. fulva and Primula nutans var. jokelae could be slowed down by management, and the vegetative and/or sexual reproduction of these species was enhanced. However, in the case of Puccinellia phryganodes, no positive response to management was observed.

Amphibians are in decline globally and a significantly greater percentage of ambystomatid salamander species are in decline relative to other species; habitat loss contributes significantly to this decline. The goals of this thesis is to better understand extinction risk in a marbled salamander (ambystoma opacum) population and how forestry effects extinction risk. To achieve this goal we first estimated an important life history parameter (Chapter 1) then used a metapopulation model to estimate population viability and determine what aspects of their life history put them most at risk (Chapter 2) and finally predicted extinction risk in response to hypothetical forestry scenarios (Chapter 3). In Chapter 1 we estimated one of the requisite parameters for the model, juvenile survival, based on 8 years of field data. We estimated juvenile survival probabilities (to first breeding) at 17% for males and 11% for females. To our knowledge, these are the first estimates for marbled salamanders that include both returning and dispersing individuals. In Chapter 2 we used a metapopulation model to estimate extinction risk and sensitivity of extinction risk to changes in vital rates and other model parameters. We found that although there is considerable uncertainty in our estimate it is likely that extinction risk is low at our study site. Sensitivity analysis revealed that small changes in adult survival lead to relatively large changes in persistence and the presence of an apparent threshold in reproductive failure probabilities beyond which extinction risk rapidly increased. In Chapter 3 we used the extinction risk and sensitivity estimates to model the effects of forestry on the metapopulation. We parameterized several different levels of impact of forestry on salamander survival; for each parameterization we calculated the extinction risk for 20 different forestry scenarios involving buffer size (30 to 300 meters) and complete or partial restrictions on cutting (5 different levels). We found for all but the most optimistic parameterizations large buffers (around 200 meters) with high restrictions on cutting within the buffer were necessary to maintain a low extinction risk. Overall we show that although the population at our intensively studied field site is unlikely to go extinct under present conditions small decreases in adult survival, small increases in catastrophe rate, and intensive forestry can all make extinction likely.

No description available.

Weltweit sind viele Populationen großer Raubtiere bedroht. Die Suche nach Wegen zur Erhaltung und Wiederherstellung von Populationen großer Raubtiere ist daher ein zentrales Naturschutzziel. In einigen Regionen erholen sich die Populationen jedoch auch, was der Wissenschaft eine hervorragende Möglichkeit bietet potentielle Wege zum Schutz von Raubtieren zu identifizieren. Das Ziel dieser Arbeit war es, die Voraussetzungen, die eine Erholung von Raubtierpopulationen begünstigen, besser zu verstehen. Am Beispiel der sich erholenden Population des Persischen Leoparden im Kaukasus beantwortet diese Arbeit die folgenden Forschungsfragen: (1) Bietet die Ökoregion des Kaukasus einen geeigneten, sicheren und zusammenhängenden Lebensraum für Persische Leoparden und ihre Beutetiere? (2) Was sind wirksame Schutzstrategien, die eine Erholung der Population des Persischen Leoparden im Kaukasus begünstigen? Die Ergebnisse dieser Arbeit lassen den Schluss zu, dass für Leoparden und ihre Beutetiere im Kaukasus großflächig geeigneter Lebensraum vorhanden ist. Trotz dieser günstigen Ausgangsposition für den Artenschutz zeigt diese Arbeit jedoch auch klar auf, dass Schutzmaßnahmen erforderlich sind, um direkte Bedrohungen abzumildern. Als wichtigsten Faktor für eine Erholung der Leopardenpopulation identifiziert diese Arbeit das Verhindern von Tötungen. Diese Arbeit verdeutlicht somit die wichtige Rolle von Konfliktminderung zwischen Menschen und Raubtieren, um die daraus resultierende Tötung von Raubtieren zu verhindern. Darüber hinaus unterstreicht diese Dissertation die Notwendigkeit der Vernetzung sicherer Lebensräume und den Wert von internationaler Zusammenarbeit zur Förderung der Genesung von Populationen großer Raubtiere. Zusammengefasst liefert diese Arbeit Einblicke in Bedingungen, die die Genesung von Großraubtieren fördern, und umreißt mögliche zukünftige Wege eines vom Aussterben bedrohten Raubtiers in einem globalen Biodiversitäts-Hotspot. / Large carnivore populations are threatened globally. This is worrisome because of their intrinsic value and their importance for ecosystems and humans. Finding ways to maintain and restore large carnivore populations is therefore a central goal for conservation. Interestingly, large carnivores are also returning to areas where they were extirpated before, which provides a great opportunity for conservation science to identify pathways to safeguard large carnivore populations. The overall goal of this thesis was to better understand the conditions that foster large carnivore recoveries. Gaining a better understanding of large carnivore recoveries is challenging though, because it requires working across broad areas, where data on environmental characteristics and prey species is often limited and inconsistent. Using the Persian leopard recovery in the Caucasus ecoregion as an example, the specific research questions of this thesis were: (1) Does the Caucasus ecoregion have suitable, safe, and connected habitat for Persian leopards and their prey? (2) What are effective management strategies to foster the recovery of Persian leopards in the Caucasus? Results revealed that suitable habitat for Persian leopards and their prey is widespread in the Caucasus. However, habitat patches are often not safe and conservation efforts are needed to mitigate threats and restore, protect, and connect populations of leopards and their prey. Reducing the persecution of leopards seems the most important strategy to foster leopard recovery in the Caucasus. For large carnivore recoveries in general, this thesis underpins the importance of human-carnivore conflict mitigation to prevent killings of carnivores, particularly in areas where populations are small. Further, this thesis underlines the need of improving connectivity among safe habitat patches and the value of international cooperation. Overall, this thesis provides insights into conditions that foster large carnivore recovery and outlines potential future pathways for a critically endangered apex predator in a global biodiversity hotspot.

No description available.

Atlantic salmon (Salmo salar) are found in a range of locations along Sweden's coastline, but Sweden's largest lake, Vänern, also harbors a population of salmon; the rare freshwater migratory form. The majority of the salmon in Lake Vänern migrate upstream in River Klarälven in order to spawn, where they are assisted by humans through the "trap and transport" method to get past Klarälven's eight hydropower dams, which otherwise constitute definite obstacles to upstream migration. When the salmon later migrate downstream to Lake Vänern they receive no assistance and experience a high mortality rate as they are partially forced to swim through the turbines. The wild salmon population today includes over 1000 spawners annually, an increase from <200 in the 196os, but far below historic records of over 10,000 spawners.  This report therefore aimed to investigate the population growth rate and extinction risk for the salmon in Klarälven, both in the current situation and with passages installed past the hydropower plants, and in doing so answer the questions 1) How large is the population growth rate and risk of extinction for today’s population of salmon in Klarälven over the course of 100 years? and 2) How would passage solutions past the hydropower plants in Klarälven affect the population growth rate and risk of extinction for today’s population of salmon in Klarälven over the course of 100 years? These questions were answered by running a population viability analysis in the program Extinction Vortex, which allows the programming of model populations and the manipulation of parameters to test different scenarios. The scenarios that were tested were 1) Scenario 1: Today's method with trap and transport and total lack of passages, 2) Scenario 2: Trap and transport continues, and downstream passages are installed past all eight power plants, and 3) Scenario 3: Upstream and downstream passages are installed past all eight power plants and trap and transport ceases. The results of the vulnerability analysis did not show any risk of extinction for the next 100 years, but a long-term negative trend for the salmon in Klarälven using today's method was seen. However, the development became significantly more positive for the salmon in Klarälven when the installation of downstream passages was simulated, but after that not significantly more positive when the installation of upstream passages was simulated as well. This result provided answers to the research questions and based on them it could be concluded that even though the salmon in Klarälven are not under any acute threat at the moment, and that there may be other fish populations in other regulated streams and rivers that would benefit more from environmental adaptation, measures need to be taken also in Klarälven, to ensure the long-term conservation of the unique freshwater migrating salmon that inhabit the area. / Laxen (Salmo salar) förekommer på flera håll längst Sveriges havskuster, men även Sveriges största insjö Vänern hyser en population av lax; den sällsynta sötvattensvandrande formen. Majoriteten av Vänerlaxarna migrerar upp för att leka i Klarälven, där de assisteras av människan genom metoden ”trap and transport” som tar dem förbi Klarälvens åtta vattenkraftverk vilka annars utgör definitiva vandringshinder. När laxen sedan ska ta sig tillbaka ner till Vänern får de ingen assistans, i stället tvingas de delvis simma genom turbinerna med stor dödlighet som följd. Laxpopulationen idag består av över 1000 lekande fiskar varje år, en ökning från <200 individer på 1960-talet, men långt under historiska siffror på över 10 000 lekande laxar. Detta arbete syftade därför till att undersöka populationsutvecklingen och utdöenderisken för Klarälvslaxen, såväl i nuläget som vid en installation av passager förbi kraftverken, och genom detta besvara frågeställningarna 1) Hur stor är populationsutvecklingen och utdöenderisken för dagens population av Klarälvslax över kommande 100 år? och 2) Hur skulle passagelösningar förbi vattenkraftverken i Klarälven påverka populationsutvecklingen och utdöenderisken för dagens population av Klarälvslax över kommande 100 år? Dessa frågeställningar besvarades med hjälp av en sårbarhetsanalys i programmet Extinction Vortex, som tillåter uppbyggandet av modellpopulationer och manipulation av parametrar för att testa olika scenarier. Scenarierna som testades var 1) Scenario 1: Dagens metod med trap and transport och total avsaknad av passager, 2) Scenario 2: Trap and transport fortsätter samt nedströmspassager installeras förbi alla åtta kraftverk, och 3) Scenario 3: Upp- och nedströmspassager installeras förbi alla åtta kraftverk och trap and transport upphör. Resultatet av sårbarhetsanalysen visade inte på någon utdöenderisk kommande 100 år, men en negativ trend för Klarälvslaxens långsiktiga populationsutveckling med dagens metod. Utvecklingen blev dock signifikant mer positiv för Klarälvslaxen vid den simulerade installationen av nedströmspassager, och ännu något stabilare när även uppströmspassager installerades. Detta resultat gav svar på frågeställningarna, och utifrån detta kunde slutsatsen dras att trots att Klarälvslaxen inte befinner sig under något akut hot för närvarande, och att det kan finnas andra fiskpopulationer i andra vattendrag som är i mer akut behov av miljöanpassning, så behöver åtgärder komma på plats även i Klarälven, för att säkerställa det långsiktiga bevarandet av den unika sötvattensvandrande Klarälvslaxen.

The eurasian lynx (Lynx lynx) has a wide distribution and occurs in the palearctic region. In Europe, the lynx has been persecuted and exterminated from several of its natural distribution areas and has also been subject to persecution in Sweden, where a high hunting pressure led to a reduced population that almost went extinct. Today, the Swedish lynx population has recovered but is kept down by licensed hunting, which is strictly controlled due to the lynx's protection status. However, Sweden's government has backed a proposal for reduced protection that could potentially lead to higher hunting quotas and thus threaten the lynx's future, because of predators’ vulnerability to high hunting pressures and smaller populations’ vulnerability to stochastic events such as catastrophes. The purpose of this study was to investigate the development of the Swedish lynx population and how high the risk of extinction is now, with increased hunting quotas and if catastrophes would occur both with current hunting quotas and increased hunting quotas. Based on the purpose, the questions that were answered were the following: 1) What does the population development and extinction risk look like for the Swedish lynx population in the next 100 years with current hunting quotas? 2) How do higher hunting quotas affect the Swedish lynx population development and extinction risk in the next 100 years? 3) How would catastrophes with current hunting quotas and increased hunting quotas affect the Swedish lynx population development and extinction risk in the next 100 years? The questions were answered through a population viability analysis performed in Vortex 10 where four scenarios were created. In scenario 1, the null scenario, the Swedish lynx population development and extinction risk over 100 years were investigated in relation to current hunting quotas. In scenario 2, the Swedish lynx population development and extinction risk over 100 years were investigated in relation to current hunting quotas and catastrophes. In scenario 3, the Swedish lynx population development and extinction risk over 100 years were investigated in relation to increased hunting quotas. In scenario 4, the Swedish lynx population development and extinction risk over 100 years were investigated in relation to increased hunting quotas and catastrophes. The scenarios with the largest and smallest average population size after 100 years were scenario 1 and scenario 4, respectively. The growth rate was highest and lowest for scenario 1 and scenario 4, respectively. Scenarios 2, 3 and 4 had a negative growth rate. The extinction risk for scenarios 1 and 2 was 0% and scenarios 3 and 4 had an extinction risk of 1%. To conclude, the results indicate that the current hunting quotas do not threaten the Swedish lynx population, but that catastrophes have a negative impact on population growth at current hunting quotas, and that the increased hunting quotas have a negative impact as they result in a reduced population and a negative growth rate both with and without catastrophes. / Det eurasiska lodjuret (Lynx lynx) har en vid utbredning och förekommer i den palearktiska regionen. Lodjuret har i Europa förföljts och utrotats från flera av dess naturliga utbredningsområden och även i Sverige har lodjuret varit utsatt för förföljelse där ett högt jakttryck ledde till en minskad population som nästan utrotades. Idag har den svenska lodjursstammen återhämtat sig men hålls nere genom licensjakt, som är strikt kontrollerad på grund av lodjurets skyddsstatus. Däremot har Sveriges regering ställt sig bakom ett förslag till minskat skydd som potentiellt kan leda till högre jaktkvoter och därmed hota lodjurets framtid eftersom rovdjur är sårbara för höga jakttryck, samt att mindre populationer är mer sårbara för slumpmässiga händelser såsom katastrofer. Syftet med arbetet var att undersöka den svenska lodjursstammens utveckling och utdöenderisk i nuläget, vid förhöjda jaktkvoter, samt om katastrofer skulle inträffa vid nuvarande jaktkvoter respektive förhöjda jaktkvoter. Utifrån syftet besvarades följande frågeställningar: 1) Hur ser populationsutvecklingen och utdöenderisken ut för den svenska lodjursstammen under kommande 100 år med nuvarande jaktkvoter? 2) Hur påverkar högre jaktkvoter den svenska lodjursstammens populationsutveckling och utdöenderisk under kommande 100 år? 3) Hur skulle katastrofer vid nuvarande jaktkvoter respektive förhöjda jaktkvoter påverka den svenska lodjursstammens populationsutveckling och utdöenderisk under kommande 100 år? Frågeställningarna besvarades genom en sårbarhetsanalys som utfördes i Vortex 10 där fyra scenarier skapades. I scenario 1, grundscenariot, undersöktes den svenska lodjursstammens populationsutveckling och utdöenderisk över 100 år i förhållande till nuvarande jaktkvoter. I scenario 2 undersöktes den svenska lodjursstammens populationsutveckling och utdöenderisk över 100 år i förhållande till nuvarande jaktkvoter och katastrofer. I scenario 3 undersöktes den svenska lodjursstammens populationsutveckling och utdöenderisk över 100 år i förhållande till förhöjda jaktkvoter. I scenario 4 undersöktes den svenska lodjursstammens populationsutveckling och utdöenderisk över 100 år i förhållande till förhöjda jaktkvoter och katastrofer. Största respektive minsta genomsnittlig populationsstorlek efter 100 år fick scenario 1 respektive scenario 4. Tillväxthastigheten var högst respektive lägst för scenario 1 respektive scenario 4. Scenario 2, 3 och 4 hade alla en negativ tillväxthastighet. Utdöenderisken för scenario 1 och 2 blev 0% och scenario 3 och 4 hade en utdöenderisk på 1%. Resultaten tyder på att de nuvarande jaktkvoterna inte hotar den svenska lodjursstammen men att katastrofer ger en negativ påverkan på populationstillväxten vid nuvarande jaktkvoter, samt att de förhöjda jaktkvoterna har en negativ påverkan då de ger en minskad population och en negativ tillväxthastighet både med och utan katastrofer.

The northern Norwegian killer whale (Orcinus orca) is an important predator but little is known about its population dynamics, particular in response to changes in its main prey, the highly dynamic Norwegian spring spawning (NSS) herring (Clupea harengus). The main aims of this thesis were to estimate killer whale population parameters, to explore the future viability of the population, and to explore the response of this predator to changes in distribution and abundance of its main prey over the last 25 years. Population size was estimated as ~ 700 individuals, taking heterogeneity of capture probabilities into account and correcting for unmarked animals. Apparent survival rates of 0.974 (SE = 0.006) for adult males and 0.984 (SE = 0.006) for adult females were estimated accounting for temporary emigration, transience and trap-dependency. Temporary emigration was greater for males than females. Calving intervals ranged from 3 to 14 years (mean = 5.06); equivalent to 0.197 calves per mature female per year. Future viability of the killer whale population was evaluated under various plausible scenarios. The baseline scenario using the best available information predicted a viable population and indicated that the population may be increasing size. Analysis of data on naval sonar activity, killer whale sightings and herring abundance showed that naval sonar activity appeared to have a negative effect on killer whale presence during a period of low prey availability. A time lag of four years was found between the first sign of NSS herring changing its distribution and reduced killer whale presence inside the fjord system. Analysis of energy budgets showed that killer whales spent more time travelling/foraging in 2005/06 than the 1990s. The fjord system was inferred to be a preferred habitat for killer whales when there was a higher density of NSS herring in this area compared to offshore area.

Thesis (M.S.)--University of Tennessee, Knoxville, 2009. / Title from title page screen (viewed on Mar. 8, 2010). Thesis advisor: Frank T. van Manen. Vita. Includes bibliographical references.