| 1. |
- Arnqvist, Goran, et al.
(författare)
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Falsk marknadsföring om hållbart skogsbruk
- 2022
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Ingår i: Svenska Dagbladet Debatt. - 1101-2412.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Dagens svenska skogsbruk är inte ekologiskt hållbart. Att saluföra det som hållbart är därför – för att tala klarspråk – falsk marknadsföring, skriver forskare.
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| 2. |
- Beche, Dinkissa, et al.
(författare)
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Prevalence of major pests and diseases in wild and cultivated coffee in Ethiopia
- 2023
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Ingår i: Basic and Applied Ecology. - 1439-1791 .- 1618-0089. ; 73, s. 3-9
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Tidskriftsartikel (refereegranskat)abstract
- The study of pests and diseases on crops and crop relatives in the wild is valuable from both a theoretical and an applied point of view. Few studies have addressed multiple pests and diseases in such ecosystems. Our objectives were to (1) compare the prevalence of multiple pests and diseases on coffee in forests and more managed landscapes and (2) assess how spatial, environmental, host density and management factors affect the incidence and severity of coffee pests and diseases across forests.To achieve these objectives we studied different pests, diseases and one hyperparasite on wild and semi-wild coffee from 84 plots of 20 × 20 m across a forested landscape in southwest Ethiopia and compared the results to previous studies of more intensively managed adjacent landscapes.The prevalence of all surveyed coffee leaf pests and diseases was high (>71% of investigated plots) and very similar to the levels in more intensively managed landscapes reported in the literature. The incidence rates of all pests, diseases and the hyperparasite showed a high variation among the plots, and correlation with each other in some cases. However, this variation was weakly related to the measured environmental and management variables, but coffee pests and diseases were often positively related to high coffee density.One possible explanation for the similar prevalence is that, although the landscapes are different, the local environmental conditions have much in common since coffee is also grown under indigenous shade trees in more intensively managed landscapes. However, the variability in pest and disease levels among sites was large and it is difficult to predict where they attain high levels. There is a need of detailed investigations on drivers of spatio-temporal population dynamics of these species, including their natural enemies, to be able to provide advice for development of sustainable coffee disease management.
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| 3. |
- Burger, H. F., et al.
(författare)
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Bottom-up and top-down drivers of herbivory on Arabica coffee along an environmental and management gradient
- 2022
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Ingår i: Basic and Applied Ecology. - : Elsevier BV. - 1439-1791 .- 1618-0089. ; 59, s. 21-32
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Tidskriftsartikel (refereegranskat)abstract
- While sustainable agriculture relies on natural pest control, we lack insights into the relative importance of bottom-up and top-down factors on pest levels, especially along broad environmental and management gradients. To this aim, we focused on bottom-up and top-down control of herbivore damage in sixty sites in the centre of origin of Arabica coffee in southwestern Ethiopia, where coffee grows along a management gradient ranging from little or no management in the natural forest to commercial plantations. More specifically, we examined how canopy cover, percentage of surrounding forest and management intensity affected caffeine and chlorogenic acid concentration (bottom-up process) and attack of dummy caterpillars by ants and birds (top-down process), and how these in turn affected pest levels. Caffeine and chlorogenic acid concentrations were negatively related to canopy cover, while ant attack rate was positively related to canopy cover. Both ant and bird attack rate increased with the percentage of surrounding forest. Yet, secondary chemistry and caterpillar attack rates were unrelated to herbivory, and herbivory was only directly and positively affected by management intensity. Our study highlights that canopy cover can have contrasting effects on plant defence and predation, and that changes in bottom-up and top-down factors do – unlike often assumed – not necessarily translate into reduced pest levels. Instead, direct effects of management on pest levels may be more important than bottom-up or top-down mediated effects.
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| 4. |
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| 5. |
- Christiansen, Ditte Marie, 1990-, et al.
(författare)
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Effects of past and present microclimates on northern and southern plant species in a managed forest landscape
- 2023
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Ingår i: Journal of Vegetation Science. - 1100-9233 .- 1654-1103. ; 34:4
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Tidskriftsartikel (refereegranskat)abstract
- Questions: Near-ground temperatures can vary substantially over relatively short distances, enabling species with different temperature preferences and geographical distributions to co-exist within a small area. In a forest landscape, the near-ground temperatures may change due to management activities that alter forest density. As a result of such management activities, current species distributions and performances might not only be affected by current microclimates, but also by past conditions due to time-lagged responses.Location: Sweden.Methods: We examined the effects of past and current microclimates on the distributions and performances of two northern, cold-favoured, and two southern, warm-favoured, plant species in 53 managed forest sites. Each pair was represented by one vascular plant and one bryophyte species. We used temperature logger data and predictions from microclimate models based on changes in basal area to relate patterns of occurrence, abundance, and reproduction to current and past microclimate.Results: The two northern species were generally favoured by microclimates that were currently cold, characterised by later snowmelt and low accumulated heat over the growing season. In contrast, the two southern species were generally favoured by currently warm microclimates, characterised by high accumulated heat over the growing season. Species generally had higher abundance in sites with a preferred microclimate both in the past and present, and lower abundance than expected from current conditions, if the past microclimate had changed from warm to cold or vice versa, indicating time-lags in abundance patterns of the species.Conclusions: Our results show a potential importance of past and present microclimate heterogeneity for the co-existence of species with different temperature preferences in the same landscape and highlight the possibility to manage microclimates to mitigate climate change impacts on forest biodiversity.
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| 6. |
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| 7. |
- Christiansen, Ditte Marie, 1990-
(författare)
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Responses of boreal forest understory plant communities to climate and forestry
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A warming climate is altering species distributions and community compositions. To understand and predict changes in species distributions to climate change, we often use species occurrences together with large-scale regional climate data. This can be problematic for several reasons. Species living near the ground experience small-scale spatial variation in temperatures, i.e., microclimate, that are influenced by topography and vegetation and can therefore deviate a lot from regional temperatures. Further, climate often affects species indirectly via species interactions, and such interactions can also change with climate. And last, species may respond slower than climate changes. Ignoring these aspects can complicate our understanding of species-climate relationships.In this thesis, I examined how microclimate and changes in microclimate due to forest management impact performances, interactions, and distributions of plant species in boreal forest understory communities. First, I quantified the importance of microclimate for species performances and distributions. Specifically, I compared the effects of spring temperatures measured on local and regional scales on the population dynamics of a southern forest herb (I). I also tested how small-scale spatial microclimate variation contributed to the regional co-existence of northern and southern understory plant species (II). Second, I examined the role of species interactions in driving abundance patterns of two moss species with different temperature niches across their Swedish ranges by transplanting them separately and together across a climate gradient (III). Lastly, I investigated how understory plant communities respond to changes in microclimate caused by forest management (IV), and how past microclimates influence current patterns of species occurrence, abundance, and reproduction (II).I found that local spring temperatures had a significant effect on the population dynamics of the southern forest herb that could not be detected using regional spring temperatures (I). Spatial variation in microclimate explained the regional co-existence of two northern and two southern species, where the northern species were favoured by cold microclimates and the southern species by warm microclimates (II). In the transplant experiment (III), I found that climate-mediated competition can override the direct effects of climate and limit abundances across ranges. Lastly, I found that microclimate changes caused by forest management activities had a large effect on understory communities (IV), and that current abundances of northern and southern species were partly explained by past microclimate (II).Overall, I demonstrated that, to understand how species (particularly understory plants) respond to climate, we need to replace the standard use of regional climate data with locally measured climate data or down-scaled gridded climate data that account for variation in topography as well as vegetation. To predict how species will respond to climate change, we also need to include species interactions and how these interactions change with a changing climate. Finally, changes in microclimate following changes in forest structure have large effects on understory species. The last finding is important to consider when studying changes in understory communities in a climate context and could be used to mitigate climate effects on forest biodiversity.
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| 8. |
- Cronberg, Nils, et al.
(författare)
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Mossor
- 2005
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Ingår i: The 2005 Red List of Swedish species. - 9188506304 ; , s. 191-204
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Bokkapitel (populärvet., debatt m.m.)
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| 9. |
- Dahlberg, C. Johan, 1978-, et al.
(författare)
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Performance of Forest Bryophytes with Different Geographical Distributions Transplanted across a Topographically Heterogeneous Landscape
- 2014
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:11
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Tidskriftsartikel (refereegranskat)abstract
- Most species distribution models assume a close link between climatic conditions and species distributions. Yet, we know little about the link between species’ geographical distributions and the sensitivity of performance to local environmental factors. We studied the performance of three bryophyte species transplanted at south- and north-facing slopes in a boreal forest landscape in Sweden. At the same sites, we measured both air and ground temperature. We hypothesized that the two southerly distributed species Eurhynchium angustirete and Herzogiella seligeri perform better on south-facing slopes and in warm conditions, and that the northerly distributed species Barbilophozia lycopodioides perform better on north-facing slopes and in relatively cool conditions. The northern, but not the two southern species, showed the predicted relationship with slope aspect. However, the performance of one of the two southern species was still enhanced by warm temperatures. An important reason for the inconsistent results can be that microclimatic gradients across landscapes are complex and influenced by many climate-forcing factors. Therefore, comparing only north- and south-facing slopes might not capture the complexity of microclimatic gradients. Population growth rates and potential distributions are the integrated results of all vital rates. Still, the study of selected vital rates constitutes an important first step to understand the relationship between population growth rates and geographical distributions and is essential to better predict how climate change influences species distributions.
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| 10. |
- Dahlberg, C. Johan, 1978-, et al.
(författare)
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Population differentiation in timing of development in a forest herb associated with local climate and canopy closure
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Our knowledge of how plant seasonal development is related to local versus larger-scale environmental variation is limited. We investigated differentiation in the timing of vegetative and reproductive development among populations of the forest herb Lathyrus vernus over different spatial scales. We predicted earlier development and shorter development time for populations from a colder, northern region compared to populations from a warmer, southern region. Also, we predicted earlier and shorter development within regions to be associated with colder temperatures and higher proportions of deciduous trees at their sites of origin. Lastly, we predicted that earlier flowering is strongly correlated with earlier start of development. To examine these predictions, we conducted a common garden study, and compared the development of 10 northern and 10 southern Swedish L. vernus populations. Start of development, development time and start of flowering did not differ between populations from the two regions in contrast to our prediction. Within the southern region, start of flowering was earlier in populations from colder sites, while start of development was earlier with colder temperatures within the northern region. Start of flowering occurred earlier in southern populations from sites with higher proportion of deciduous trees. Thus, the prediction for the timing of development within regions was partly confirmed. However, vegetative and reproductive development was not simultaneously influenced by temperature and proportion of deciduous trees within regions, possibly due to the negative correlation between vegetative growth and development time. This implies that earlier start of development or shorter development time not necessarily correspond to earlier start of flowering or vice versa. Overall, the results suggest that smaller scale effects within region, such as temperature and interspecific competition for light, was more important for the timing of development than the larger scale gradients between regions. Lastly, the population differentiation across gradients of temperature and proportion of deciduous trees implies that populations may adapt to long-term changes in light or climatic conditions, and differ in their short-term response to climate change.
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