| 1. |
- Loman, Jon
(author)
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Rana temporaria metamorph production and population dynamics in the field Effects of tadpole density, predation and pond drying
- 2002
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In: Journal for Nature Conservation. - : Elsevier BV. - 1617-1381. ; 10:2, s. 95-107
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Journal article (other academic/artistic)abstract
- This study investigates factors of importance for tadpoles survival and metamorph production in the common frog Rana temporaria. It also assess the importance of this for the population dynamics of the species. Eighteen ponds were studied for up to 8 years. Data collected each year included: number of spawn clumps deposited, tadpole number and metamorph number. The permanency of the ponds was also recorded each year. Measures were taken of predator density. There was no suggestion of density dependence in the survival of tadpoles. In contrast, the number of spawn clumps deposited per pond area was highest for ponds with high survival. Density of predators (sticklebacks, newts and invertebrates) was negatively correlated to tadpole and metamorph survival. This was true both within (among years) and among ponds. Several of the study ponds dried completely before metamorphosis in some years. However, those ponds also were those with the smallest number of predators and in years with successful metamorphosis, these ponds produced more metamorphs than more permanent ponds. An analysis of the year to year dynamics showed that population size (number of deposited spawn clumps) was correlated to that in the previous year, suggesting a fairly high adult survival, but also on the number of metamorphs emerging two or three years before (corresponding to the age of sexual maturity of the species). It is concluded that the aquatic stage is not strongly limiting in these ponds but conservation efforts should be focused on the terrestrial habitat. Also, the study stresses the value of temporary ponds, despite the fact that recruitment often fails totally in these.
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| 2. |
- Bach, Lars, et al.
(author)
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Assessing re-introductions of the African Wild dog (Lycaon pictus) in the Limpopo Valley Conservancy, South Africa, using the stochastic simulation program VORTEX
- 2010
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In: Journal for Nature Conservation. - : Elsevier BV. - 1617-1381. ; 18:4, s. 237-246
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Journal article (peer-reviewed)abstract
- The African wild dog (Lycaon pictus) is one of Africa's most endangered species and therefore classified as endangered by IUCN. Earlier distributions included most of Africa but currently the African wild dog only has populations larger than 300 individuals in three countries (Botswana, Tanzania and South Africa). In 1998, a plan was launched in South Africa to manage sub-populations of the African wild dog in several small, geographically isolated, conservation areas. This management program involved the reintroduction of wild dogs into suitable conservation areas and periodic translocations among them. We used the stochastic population simulation model VORTEX to evaluate the Limpopo Valley Conservancy in the north of South Africa, as a possible reintroduction site for African wild dogs. The simulations showed that the size of the initial population released only had a small effect on the population dynamics. However, when individuals were supplemented and harvested over a longer period the probability of persistence increased. Number of females breeding, male mortality, and carrying capacity were key factors in the population dynamics, but according to VORTEX the severity of natural catastrophes had the greatest influence on the extinction risk and inbreeding. We suggest that the reintroduction program may be successful, if areas are properly secured, the dogs are held in a boma before release, wild animals or at least a mix of wild and captive animals are used for the release and the animals are vaccinated against rabies. It is, however, essential to continue monitoring followed by modelling efforts to re-evaluate the success of the reintroduction program. (C) 2009 Elsevier GmbH. All rights reserved.
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| 3. |
- Burgos-Ayala, Aracely, et al.
(author)
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Lessons learned and challenges for environmental management in Colombia : The role of communication, education and participation strategies
- 2022
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In: Journal for Nature Conservation. - : Elsevier GmbH. - 1617-1381 .- 1618-1093. ; 70
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Journal article (peer-reviewed)abstract
- Environmental management has increasingly focused on promoting social engagement in biodiversity and ecosystem services conservation as a way to foster sustainability. However, a critical challenge that still remains is the adequate implementation of strategies of communication, education, and participation (CEPA) oriented to reconnect the social and ecological dimensions in the systems. This study analyzed the main features and types of CEPA implemented by the Colombian Regional Autonomous Corporations in environmental management projects that consider ecosystem services. We found a variety of CEPA focused on a wide range of stakeholders. Communication and education were the most frequently implemented in the projects. Within communication, spreading information about the projects was the most common, while education focused on instrumental training of local communities. Participation, the less frequently implemented, mainly aimed to ensure government and decision-makers involved in the initial phases of the projects. We conclude that there is a need to increase and improve education strategies in conservation projects to make decisions based on critical and reflective thinking, and foster the engagement of a broader set of stakeholders in the processes.
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| 4. |
- Champagnon, Jocelyn, et al.
(author)
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Conspecifics can be aliens too : a review of effects of restocking practices in vertebrates
- 2012
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In: Journal for Nature Conservation. - 1617-1381 .- 1618-1093. ; 20:4, s. 231-241
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Journal article (peer-reviewed)abstract
- We review the indexed scientific literature (233 papers) dealing with ‘restocking’ of vertebrates, i.e. reinforcement of wild populations by release of individuals of the same species. We found evidence that restocking may have desired beneficial effects such as: increased genetic diversity and mitigation of Allee effects in small populations; increased size or even salvation of threatened populations; increased harvest opportunities; and, redirection of harvest pressure from wild to captive-bred individuals. However, restocking may also have negative effects like changes in behaviour, morphology, and demography in recipient populations, as well as enhancement of pathogen spread. Negative genetic effects on recipient populations include homogenisation, introduction of non-native genes, and loss of local adaptation. Research thus far is strongly biased towards birds and mammals, and geographically to Europe and North America. Restocking for conservation purposes has been studied more than that for harvest management, while the latter may be of far greater importance in terms of number of released individuals. Demographic and genetic effects have been studied more than effects on behaviour, which in turn have received more attention than effects on morphology and pathogen spread. There is a general tendency for research on restocking to be fragmented taxonomically and by biological sub-disciplines. Our review demonstrates that restocking practices may and do cause significant disruptions of natural patterns in wild recipient populations. It also highlights the diversity, frequency and extent of these activities, leading us to argue that restocking is an emerging conservation and ecosystem resilience issue of global significance. Based on this review we outline monitoring and research needs for the future. We also provide guidelines to practitioners in conservation, game management, fisheries, epidemiology and other fields involved in restocking of vertebrates, who are likely to benefit from merging their perspectives and adopting a more cross-taxonomical and interdisciplinary attitude when laying out future agendas for evaluation and policy-making in this field.
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| 5. |
- Champagnon, Jocelyn, et al.
(author)
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Conspecifics can be aliens too : a review of effects of restocking practices in vertebrates
- 2012
-
In: Journal for Nature Conservation. - : Urban und Fischer Verlag GmbH und Co. KG. - 1617-1381. ; 20:4, s. 231-241
-
Journal article (peer-reviewed)abstract
- We review the indexed scientific literature (233 papers) dealing with ‘restocking’ of vertebrates, i.e. reinforcement of wild populations by release of individuals of the same species. We found evidence that restocking may have desired beneficial effects such as: increased genetic diversity and mitigation of Allee effects in small populations; increased size or even salvation of threatened populations; increased harvest opportunities; and, redirection of harvest pressure from wild to captive-bred individuals. However, restocking may also have negative effects like changes in behaviour, morphology, and demography in recipient populations, as well as enhancement of pathogen spread. Negative genetic effects on recipient populations include homogenisation, introduction of non-native genes, and loss of local adaptation. Research thus far is strongly biased towards birds and mammals, and geographically to Europe and North America. Restocking for conservation purposes has been studied more than that for harvest management, while the latter may be of far greater importance in terms of number of released individuals. Demographic and genetic effects have been studied more than effects on behaviour, which in turn have received more attention than effects on morphology and pathogen spread. There is a general tendency for research on restocking to be fragmented taxonomically and by biological sub-disciplines. Our review demonstrates that restocking practices may and do cause significant disruptions of natural patterns in wild recipient populations. It also highlights the diversity, frequency and extent of these activities, leading us to argue that restocking is an emerging conservation and ecosystem resilience issue of global significance. Based on this review we outline monitoring and research needs for the future. We also provide guidelines to practitioners in conservation, game management, fisheries, epidemiology and other fields involved in restocking of vertebrates, who are likely to benefit from merging their perspectives and adopting a more cross-taxonomical and interdisciplinary attitude when laying out future agendas for evaluation and policy-making in this field.
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| 6. |
- Filyushkina, Anna, et al.
(author)
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Expert assessment of landscape-level conservation strategies in boreal forests for biodiversity, recreation and water quality
- 2022
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In: Journal for Nature Conservation. - : Elsevier BV. - 1617-1381 .- 1618-1093. ; 67
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Journal article (peer-reviewed)abstract
- Determining effects of landscape-level conservation strategies is needed, yet a challenging and costly endeavour. The aim of this study was to evaluate the effects of landscape-level conservation strategies in forests on biodiversity and provision of two ecosystem services (recreation and water quality). Specifically, we focused on the spatial allocation of unmanaged areas in production forests and different levels of "land sharing" or "land sparing". They were represented through seven scenarios constructed for a boreal managed forest landscape in central Sweden. All scenarios had the same total level of conservation effort, but they differed in the combinations of sizes of unmanaged areas and how these areas were spread in the landscape. In one scenario, this was complemented with extended rotation of production areas. Experts (researchers in relevant fields) assessed these scenarios for overall biodiversity, recreation, and water quality. We used the Delphi technique: experts filled out an online survey individually in two rounds. In the second round they were familiarized with anonymized responses of others from the previous round. There was little agreement between experts whether concentration of unmanaged areas in one part of the landscape or dispersion of them around the entire area is more beneficial, for biodiversity as well as for the two ecosystem services. The explanation of the opinions given by biodiversity experts were based on different ecological theories resulting in different conclusions (mainly habitat complementation vs. metapopulation ecology). A few large unmanaged areas were considered more beneficial for biodiversity than many small areas. The main argument was that long-term species persistence becomes higher with larger areas. For recreation and water quality, there were almost no differences in estimates between these two strategies. One "land sharing" approach, retention trees, received the lowest score. The second "land sharing" approach, extended rotation, was scored higher, especially regarding recreation. This may be because extended rotations generate features of high recreational value, such as mature, thinned forests with not so much dead wood. Conclusively, we suggest a strategy of mixed conservation measures, with considerable efforts directed towards establishing and maintaining large unmanaged areas.
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| 7. |
- Hessle, Anna, et al.
(author)
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Use of beef steers for profitable management of biologically valuable semi-natural pastures in Sweden
- 2011
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In: Journal for Nature Conservation. - : Elsevier BV. - 1617-1381 .- 1618-1093. ; 19, s. 131-136
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Journal article (peer-reviewed)abstract
- Cessation of grazing is an increasing threat to the biodiversity rich semi-natural pastures in Sweden due to a decreased number of grazing livestock despite environmental payments for management of these pastures. The aim of this study is to compare the profitability of raising beef breed calves as intact bulls kept indoors after weaning and slaughtered at 15 months to raising them as steers grazing semi-natural pastures and slaughtered at 20, 25 or 30 months of age. The 20 and 25 month steers graze one summer and the 30 month steers two summers post-weaning. Profitability is calculated as gross margin to cover fixed costs of the farm and background data is obtained from an animal experiment and official Swedish standard budgets. The comparisons include alternatives with holdings situated in one out of two districts (plain or forest) and with one out of six types of semi-natural pasture (low-or high-yielding pasture, pasture with payment on a base level only or with extra payment for special values, 100% semi-natural pasture or 50% semi-natural pasture with 50% complementary ley pasture). The result suggests that the 30 month steer is the most profitable production system in most of the studied alternatives provided that the present environmental payments, single farm payment and support for less favoured areas are maintained. Bulls are more profitable than 30 month steers only if the semi-natural pasture is both high-yielding and entitled payment on a base level only. The 20 and 25 month steers have no economical competitiveness in any of the alternatives studied. Steers with two post-weaning grazing seasons seem to be a cost-efficient way to preserve the grazing dependent biodiversity in Sweden and other parts of Europe with increasing shortage of calves. (C) 2010 Elsevier GmbH. All rights reserved.
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| 8. |
- Holmström, Kristina, et al.
(author)
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Economic incentives for preserving biodiverse semi-natural pastures with calves from dairy cows
- 2021
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In: Journal for Nature Conservation. - : Elsevier BV. - 1617-1381 .- 1618-1093. ; 62
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Journal article (peer-reviewed)abstract
- Economical profitability of pasture-based beef production is necessary for continued maintenance of semi-natural pastures. In a situation of decreased cattle stocks, there is a potential to castrate male calves from dairy cows and raise them as grazing steers instead of intact bulls reared indoors, which is the common way in the Nordic countries. We examined the profitability in model enterprises with either grazing steers or indoor bulls. Within the two genders (steer and bull), there were animals of two breed types (pure dairy breed and dairy x beef crossbreed), which were divided into an intensive or extensive production system. The intensive steer system had one summer on grass and slaughter at 21 months of age whereas the extensive steer system had two summers on grass and slaughter at 28 months of age. All bulls were reared indoors and slaughtered at 15 or 18 months of age. The profitability was calculated as contribution margin (CM; sigma revenues - sigma variable costs) in three different herd sizes (50, 100 and 150 slaughtered animals per year) and in three different regions in Sweden (the southern forest districts Gsk, the southern plain districts Gns, and the lower parts of the northern Nn). In the basic calculation, CM for all steers in large herds with 150 slaughtered animals per year was above zero for all cases in Gns, and for one case in Nn and in Gsk respectively. However, all steer cases had lower CM than the comparable bull system in the basic calculation. Sensitivity analyses demonstrate several possible ways of increasing the competitiveness of the grazing steers, compared to the bulls. Utilization of buildings without opportunity cost resulted in a CM above zero for all cases. Increasing the proportion of semi-natural pastures rendering high agrienvironmental payment and support was another effective mean. Decreasing the winter feed cost and labour demand on pasture reduced the costs, whereas producing premium-price certified pasture beef increased the revenue, all measures further contributing to an improved profitability. Pasture-based beef production from dairy-born steers can be economically viable, especially in large herds and with extensive production systems. Thereby, we conclude this system to has a potential to graze large areas of semi-natural pastures and thereby conserve their biodiversity and cultural values.
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| 9. |
- Johanisová, Lucie, et al.
(author)
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Assessing trophy hunting in South Africa by comparing hunting and exporting databases
- 2023
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In: Journal for Nature Conservation. - : Elsevier BV. - 1617-1381 .- 1618-1093. ; 72
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Journal article (peer-reviewed)abstract
- Trophy hunting constitutes a major part of the global wildlife tourism industry and is connected through the export of kills to international wildlife trade. Inconsistencies between kills and exports can contribute to identifying illegal trophy hunting that constitutes a major threat to biodiversity conservation. This paper quantitatively analyses to what extent the data of trophy hunting kills and of trophy exports are consistent using the example of South Africa. Data was extracted from two different sources for the year 2018. These sources were trade data reported under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and its Trade Database on the export of trophy items from South Africa, which is compared with the South African Professional Hunting statistics (SAPHs) containing trophy kills information for each species and the country of origin of the hunter. The data of trophy hunting kills and data of trophy hunting export was found to differ to varying degrees across the countries contributing to trophy hunting and CITES-listed trophy-hunted species. We found that both databases report hunting of the same 28 threatened taxa. On the other hand, the same data reports that hunters of 64 nationalities participated in a total of 4,726 trophy kills, while only 3,131 hunting trophy items were exported from South Africa, to 37 countries as final destinations. Among the possible reasons for the discrepancies found, we suggest that the time required to taxidermize trophy specimens may delay the items being addressed to their final destination, in addition to the dual citizenship of some hunters that should also have some influence on our results, as well as the important commercial destination of Brussels Airport. The USA show the highest absolute number of trophy hunters, followed by Spain, but Denmark is the highest driver per capita. Therefore, greater participation of these countries in conservation policies for endangered species is necessary. Additionally, a more detailed differentiation of the term “trophy” to more specific terms such as claws, skins, skulls, etc. may improve reporting systems to easier identify illegal activities related to hunting.
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| 10. |
- Jonason, Dennis, et al.
(author)
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Monitoring of butterflies within a landscape context in south-eastern Sweden
- 2010
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In: JOURNAL FOR NATURE CONSERVATION. - : Elsevier Science B.V., Amsterdam. - 1617-1381. ; 18:1, s. 22-33
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Journal article (peer-reviewed)abstract
- Monitoring of butterflies is often directed only towards grassland fauna. Species associated with other habitats, as well as the impact of the surrounding landscape, are often neglected. The aim with this study was, in contrast, to perform and evaluate a landscape-based monitoring method for butterflies in diverse habitats and more specifically to (i) evaluate the impact of environmental variables on butterfly abundance; (ii) compare the distribution of butterflies in different habitats; and (iii) analyse data from the study with the aim of improving the method. Eight randomly placed study sites (750 m x 750 m) located in south-eastern Sweden were used. The vegetation composition (tree cover, percentage of coniferous and deciduous forest, shrubs, dry, mesic, damp and wet land) inside the squares was analysed using aerial photos and habitats along transects were categorised in the field. The butterfly composition varied depending on the landscape composition. Tree cover had the largest impact on butterfly abundance with a negative relationship between abundance and increasing tree cover. The most species-rich habitats were other grasslands (abandoned fields and fallows), clear-cuts, semi-natural grasslands, and bogs, each habitat also harbouring unique species. Clear-cut was the habitat harbouring the highest abundance and other grasslands the highest diversity of butterflies. Semi-natural grasslands, where the nationally based monitoring of butterflies in Sweden currently is being performed, constitutes andlt;1% of the total land area in Sweden, indicating a current bias in monitoring directed towards only a part of the species pool. The landscape-based form of monitoring presented here can, if performed regularly, increase our knowledge of how structural changes of landscape affect butterflies and thereby improve conservation efforts.
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