| 1. |
- Auffret, Alistair, et al.
(författare)
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Can field botany be effectively taught as a distance course? Experiences and reflections from the COVID-19 pandemic
- 2022
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Ingår i: AoB PLANTS. - : Oxford University Press (OUP). - 2041-2851. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- The COVID-19 pandemic that started in 2020 forced a rapid change in university teaching, with large numbers of courses switching to distance learning with very little time for preparation. Courses involving many practical elements and field excursions required particular care if students were to fulfil planned learning outcomes. Here, we present our experiences in teaching field botany in 2020 and 2021. Using a range of methods and tools to introduce students to the subject, promote self-learning and reflection and give rapid and regular feedback, we were able to produce a course that allowed students to achieve the intended learning outcomes and that obtained similarly positive student evaluations to previous years. The course and its outcomes were further improved in 2021. We describe how we structured field botany as a distance course in order that we could give the best possible learning experience for the students. Finally, we reflect on how digital tools can aid teaching such subjects in the future, in a world where public knowledge of natural history is declining.In an era of large-scale biodiversity change and reductions in basic knowledge of natural history, it is important that practical courses in subjects like field botany continue to be taught effectively. Forced by the COVID-19 pandemic to teach plant identification with no direct contact with students, we used a range of methods and tools to promote self-learning and reflection in students, and to facilitate rapid feedback by teachers. Here, we present our method for producing a course that allowed students to achieve the intended learning outcomes and that obtained positive student evaluations.
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| 2. |
- Hämäläinen, Aino, et al.
(författare)
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Conservation value of low-productivity forests measured as the amount and diversity of dead wood and saproxylic beetles
- 2018
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Ingår i: Ecological Applications. - : Wiley. - 1051-0761 .- 1939-5582. ; 28, s. 1011-1019
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Tidskriftsartikel (refereegranskat)abstract
- In many managed landscapes, low-productivity land comprises most of the remaining relatively untouched areas, and is often over-represented within protected areas. The relationship between the productivity and conservational value of a site is poorly known; however, it has been hypothesized that biodiversity increases with productivity due to higher resource abundance or heterogeneity, and that the species communities of low-productivity land are a nested subset of communities from more productive land. We tested these hypotheses for dead-wood-dependent beetles by comparing their species richness and composition, as well as the amount and diversity of dead wood, between low-productivity (potential forest growth <1 m(3)center dot ha(-1)center dot yr(-1)) and high-productivity Scots pine-dominated stands in Sweden. We included four stand types: stands situated on (1) thin soils and (2) mires (both low-productivity), (3) managed stands, and (4) unmanaged stands set aside for conservation purposes (both high-productivity). Beetle species richness and number of red-listed species were highest in the high-productivity set-asides. Species richness was positively correlated with the volume and diversity of dead wood, but volume appeared to be a better predictor than diversity for the higher species richness in set-asides. Beetle species composition was similar among stand types, and the assemblages in low-productivity stands were largely subsets of those in high-productivity set-asides. However, 11% of all species and 40% of red-listed species only occurred in high-productivity stands, while no species were unique to low-productivity stands. We conclude that low-productivity forests are less valuable for conservation than high-productivity forest land. Given the generally similar species composition among stand types, a comparable conservational effect could be obtained by setting aside a larger area of low-productivity forest in comparison to the high-productivity. In terms of dead wood volumes, 1.8-3.6 ha of low-productivity forest has the same value as 1 ha of unmanaged high-productivity forest. This figure can be used to estimate the conservation value of low-productivity forests; however, as high-productivity forests harbored some unique species, they are not completely exchangeable.
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| 3. |
- Hämäläinen, Aino
(författare)
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Freezing tolerance of seeds can explain differences in the distribution of two widespread mistletoe subspecies in Europe
- 2021
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Ingår i: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 482
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Tidskriftsartikel (refereegranskat)abstract
- The ability of plants to tolerate freezing limits their geographical distribution. Therefore, winter warming may shift a species' occurrence northwards and/or to higher altitudes. In Europe, the hemiparasitic vascular plant Viscum album (mistletoe) has two common and widespread subspecies: V. a. ssp. album and V. a. ssp. austriacum. The former has a more northern geographic distribution than the latter. Therefore we hypothesised that seeds of V. a. ssp. album are more tolerant to freezing than those of V. a. ssp. austriacum. From these two mistletoe subspecies V. a. ssp. austriacum is, in some managed forest areas, considered a novel threat to tree growth and forest health.Berries of V. a. ssp. album were collected from Sweden, Poland and Switzerland and berries of V. a. ssp. austriacum were collected from Poland, Switzerland and Spain. After storage at -3 degrees C, seeds were extracted from the pulp of berries and exposed to eight different temperatures between -8 degrees C and -30 degrees C, with the storage temperature serving as the control. After freezing treatments, germination of seeds was monitored. In addition, differential thermal analysis was used to measure freeze tolerance of seeds.The seeds of V. a. ssp. album tolerated lower temperatures than seeds of V. a. ssp. austriacum. The temperature at which 50% of seeds lost their ability to germinate (LT50) was -15 degrees C in V. a. ssp. austriacum and between -15 degrees C and - 19 degrees C in V. a. ssp. album. The results of differential thermal analysis to determine the freezing point of seeds supported these findings.The freezing tolerance of mistletoe seeds was relatively well coupled with the winter climate at the edge of their current geographic distribution. Based on our results, the warming of winters may eliminate the abiotic barrier that has thus far limited mistletoes' expansion, opening a window of opportunity for these parasites to increase their abundance and shift their distribution range towards higher latitudes and altitudes.Although mistletoes play important ecological roles in forest ecosystems, their recent increase has raised concern among forest managers, because they may cause a substantial reduction in tree growth in single species dominated stands. Increasing tree species diversity might be an effective method for limiting future mass infestations in homogeneous managed forests.
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| 4. |
- Hämäläinen, Aino, et al.
(författare)
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Increasing the amount of dead wood by creation of high stumps has limited value for lichen diversity
- 2021
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Ingår i: Journal of Environmental Management. - : Elsevier BV. - 0301-4797 .- 1095-8630. ; 280
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Tidskriftsartikel (refereegranskat)abstract
- Artificial creation of dead wood in managed forests can be used to mitigate the negative effects of forestry on biodiversity. For this to be successful, it is essential to understand the conservation value that the created dead wood has in comparison to naturally occurring dead wood, and, furthermore, where in the landscape addition of dead wood is most beneficial, i.e. how landscape composition influences species occurrence on dead wood. We examined these questions by surveying epixylic lichens on artificially created high stumps of Scots pine (Pinus sylvestris) in 3-17 years old clear-cuts. We compared lichen assemblages on high stumps to those on other types of pine dead wood in mature forests, and examined how stump age, the amount of dead wood at the clear-cuts, and landscape composition at 500 m - 2.5 km scale influenced the assemblages. In comparison to other dead wood types, high stumps hosted lower lichen richness and less variable assemblages containing mainly common generalist species. Species richness increased with stump age, whereas dead wood amount and landscape composition were not important; only the total amount of forests in the landscape had a minor positive effect. We conclude that at the studied timescale high stumps of Scots pine are not particularly valuable for epixylic lichens and provide a poor substitute for naturally occurring dead wood in mature forests, although their value may increase with age. Furthermore, directing dead wood creation to specific stands or landscapes does not appear beneficial for lichen biodiversity, given the minor effect of landscape composition found at scales below 2.5 km.
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| 5. |
- Hämäläinen, Aino, et al.
(författare)
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Living Trees and Biodiversity
- 2023
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Ingår i: Boreal Forests in the Face of Climate Change : Sustainable Management. - Cham : Springer International Publishing. - 9783031159879 ; :74, s. 145-166
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Bokkapitel (refereegranskat)abstract
- Living trees are fundamental for boreal forest biodiversity. They contribute to stand structural diversity, which determines the range of habitat niches available for forest-dwelling species. Specific characteristics of living trees, such as species, age, and presence of microhabitats, determine how species utilize trees for food, as nesting places, or as growing substrates. This chapter explores the associations between living trees and aboveground biodiversity, reviews the factors such as soil productivity, hydrological regime, stand successional stage, and forestry activities that influence the characteristics of living trees and stand structural diversity, and presents the consequences of current and future climate change on boreal biodiversity.
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| 6. |
- Hämäläinen, Aino, et al.
(författare)
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Low-productivity boreal forests have high conservation value for lichens
- 2020
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Ingår i: Journal of Applied Ecology. - : Wiley. - 0021-8901 .- 1365-2664. ; 57, s. 43-54
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Tidskriftsartikel (refereegranskat)abstract
- 1. Land set aside for preservation of biodiversity often has low productivity. As biodiversity generally increases with productivity, due to higher or more diverse availability of resources, this implies that some of the biodiversity may be left unprotected. Due to a lack of knowledge on the species diversity and conservation value of low-productivity habitats, the consequences of the biased allocation of low-productivity land for set-asides are unknown.2. We examined the conservation value of boreal low-productivity forests (potential tree growth <1 m(3) ha(-1) year(-1)) by comparing assemblages of tree- and deadwood-dwelling lichens and forest stand structure between productive and low-productivity forest stands. We surveyed 84 Scots pine-dominated stands in three regions in Sweden, each including four stand types: two productive (managed and unman-aged) and two low-productivity stands (on mires and on thin, rocky soils).3. Lichen species richness was the highest in low-productivity stands on thin soil, which had similar amounts and diversity of resources (living trees and dead wood) to productive unmanaged stands. Stands in low-productivity mires, which had low abundance of living trees and dead wood, hosted the lowest lichen richness. Lichen species composition differed among stand types, but none of them hosted unique species. The differences in both species richness and composition were more pronounced in northern than in southern Sweden, likely due to shorter history of intensive forestry.4. Synthesis and applications. Boreal low-productivity forests can have as high conservation value as productive forests, which should be reflected in conservation strategies. However, their value is far from uniform, and conservation planning should acknowledge this variation and not treat all low-productivity forests as a uniform group. Some types of low-productivity forest (e.g. on rocky soil) are more valuable than others (e.g. on mires), and should thus be prioritized in conservation. It is also important to consider the landscape context: low-productivity forests may have higher value in landscapes where high-productivity forests are highly influenced by forestry. Finally, although low-productivity forests can be valuable for some taxa, productive forests may still be important for other taxa.
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| 7. |
- Hämäläinen, Aino
(författare)
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The response of epiphytic lichens on living and dead Pinus sylvestris to prescribed fires of varying severity
- 2024
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Ingår i: Forest Ecology and Management. - 0378-1127 .- 1872-7042. ; 551
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Tidskriftsartikel (refereegranskat)abstract
- Prescribed burning can be used to restore forest ecosystems degraded by anthropogenic pressures. However, some species such as epiphytic lichens may be vulnerable to fire. We studied the effects of fire on epiphytic lichens on living and dead Pinus sylvestris (Scots pine) by surveying lichens up to two meters on the trunks 21 years after experimental and replicated prescribed burnings in pine-dominated boreal forests in Finland. We investigated three types of stands that had faced different levels of fire severity: 1) unburned semi-natural mature stands (i.e., control sites), 2) burned semi-natural mature stands, and 3) burned retention groups on clearcut sites. In the semi-natural mature stands, the fires were low-severity surface fires and induced negligible mortality in P. sylvestris. In the retention groups, the fires induced high tree mortality and made fresh deadwood the dominant substrate type. Low-severity fires reduced the occurrence of several species, but usually did not eliminate them. High-severity fires eliminated some species, but the abundant deadwood frequently hosted some species that were absent or infrequent on the unburned sites. Thus, the fires had only small effects on total species richness. However, fires substantially changed species composition: they reduced the occurrence of species associated with late-successional habitats, while increasing the occurrence of early-successional species. We also found fires to decrease the occurrence of microlichens and increase that of macrolichens. The magnitude of the compositional changes increased with fire severity. Our findings indicate that the high quantities of fresh deadwood in post-disturbance forests provide habitat only to a limited portion of deadwood-associated lichens. Fire can increase landscape-scale variation in epiphytic lichen communities, but we observed negative effects, which increased with fire severity, on lichen flora of conservation concern. Thus, we recommend prescribed burning to be applied primarily in sites with a history of intensive management. Fire should be avoided in sites with substrates that are fire-sensitive and important to lichen diversity.
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| 8. |
- Hämäläinen, Aino
(författare)
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Time-lag effects of habitat loss, but not fragmentation, on deadwood-dwelling lichens
- 2024
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Ingår i: Landscape Ecology. - 0921-2973 .- 1572-9761. ; 39
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Tidskriftsartikel (refereegranskat)abstract
- Context Landscape habitat amount is known to increase biodiversity, while the effects of habitat fragmentation are still debated. It has been suggested that negative fragmentation effects may occur with a time lag, which could explain inconsistent results. However, there is so far no empirical support for this idea.Objectives We evaluated whether habitat amount and fragmentation at the landscape scale affect the species density of deadwood-dwelling lichens, and whether these effects occur with a time lag.Methods We surveyed deadwood-dwelling lichens in woodland key habitats in two regions in northern Sweden, and modelled their species density as a function of past (1960s) and present (2010s) habitat amount (old forest area) and fragmentation (edge density) in the surrounding landscapes.Results Present habitat amount generally had weak positive effects on lichen species density. Positive effects of the past habitat amount were stronger, indicating a time lag in habitat amount effects. Habitat fragmentation effects were generally weak and similar whether fragmentation was measured in the past or the present landscapes, indicating no time lag in fragmentation effects.Conclusions We found a time lag effect of habitat amount, but not fragmentation. This result is not consistent with suggestions that time lags explain the mixed observations of fragmentation effects. Time-lag effects of habitat amount suggest that the studied lichen communities face an extinction debt. Conservation should therefore prioritize increasing the amount of old forest, for example by creating forest reserves, to maintain the current lichen diversity. More generally, our results imply that studies examining only the present habitat amount risk under-estimating its importance.
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| 9. |
- Ranius, Thomas, et al.
(författare)
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Protected area designation and management in a world of climate change: A review of recommendations
- 2023
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Ingår i: AMBIO: A Journal of the Human Environment. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 52, s. 68-80
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Forskningsöversikt (refereegranskat)abstract
- Climate change is challenging conservation strategies for protected areas. To summarise current guidance, we systematically compiled recommendations from reviews of scientific literature (74 reviews fitting inclusion criteria) about how to adapt conservation strategies in the face of climate change. We focussed on strategies for designation and management of protected areas in terrestrial landscapes, in boreal and temperate regions. Most recommendations belonged to one of five dominating categories: (i) Ensure sufficient connectivity; (ii) Protect climate refugia; (iii) Protect a few large rather than many small areas; (iv) Protect areas predicted to become important for biodiversity in the future; and (v) Complement permanently protected areas with temporary protection. The uncertainties and risks caused by climate change imply that additional conservation efforts are necessary to reach conservation goals. To protect biodiversity in the future, traditional biodiversity conservation strategies should be combined with strategies purposely developed in response to a warming climate.
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| 10. |
- Ranius, Thomas, et al.
(författare)
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The effects of logging residue extraction for energy on ecosystem services and biodiversity : a synthesis
- 2018
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Ingår i: Journal of Environmental Management. - : Elsevier. - 0301-4797 .- 1095-8630. ; 209, s. 409-425
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Forskningsöversikt (refereegranskat)abstract
- We review the consequences for biodiversity and ecosystem services from the industrial-scale extraction of logging residues (tops, branches and stumps from harvested trees and small-diameter trees from thinnings) in managed forests. Logging residue extraction can replace fossil fuels, and thus contribute to climate change mitigation. The additional biomass and nutrients removed, and soils and other structures disturbed, have several potential environmental impacts. To evaluate potential impacts on ecosystem services and biodiversity we reviewed 279 scientific papers that compared logging residue extraction with non-extraction, the majority of which were conducted in Northern Europe and North America. The weight of available evidence indicates that logging residue extraction can have significant negative effects on biodiversity, especially for species naturally adapted to sun-exposed conditions and the large amounts of dead wood that are created by large-scaled forest disturbances. Slash extraction may also pose risks for future biomass production itself, due to the associated loss of nutrients. For water quality, reindeer herding, mammalian game species, berries, and natural heritage the results were complicated by primarily negative but some positive effects, while for recreation and pest control positive effects were more consistent. Further, there are initial negative effects on carbon storage, but these effects are transient and carbon stocks are mostly restored over decadal time perspectives. We summarize ways of decreasing some of the negative effects of logging residue extraction on specific ecosystem services, by changing the categories of residue extracted, and site or forest type targeted for extraction. However, we found that suggested pathways for minimizing adverse outcomes were often in conflict among the ecosystem services assessed. Compensatory measures for logging residue extraction may also be used (e.g. ash recycling, liming, fertilization), though these may also be associated with adverse environmental impacts.
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| 11. |
- Ranius, Thomas, et al.
(författare)
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The evolutionary species pool concept does not explain occurrence patterns of dead-wood-dependent organisms: implications for logging residue extraction
- 2019
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Ingår i: Oecologia. - : Springer Science and Business Media LLC. - 0029-8549 .- 1432-1939. ; 191, s. 241-252
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Tidskriftsartikel (refereegranskat)abstract
- Emulation of natural disturbances is often regarded as a key measure to make forestry biodiversity-oriented. Consequently, extraction of logging residues is assumed to have little negative effect in comparison to extraction of dead wood mainly formed at natural disturbances. This is consistent with the evolutionary species pool hypothesis, which suggests that most species are evolutionary adapted to the naturally most abundant habitats. We tested this hypothesis for dead-wood-dependent macrofungi, lichens, and beetles in a boreal forest landscape in central Sweden, assuming that species are adapted to conditions similar to today's unmanaged forest. No occurrence patterns, for the species groups which we investigated, were consistent with the hypothesis. Overall, stumps and snags had the highest habitat quality (measured as average population density with equal weight given to each species) and fine woody debris the lowest, which was unexpected, since stumps were the rarest dead-wood type in unmanaged forest. We conclude that the evolutionary species pool concept did not explain patterns of species' occurrences, and for two reasons, the concept is not reliable as a general rule of thumb: (1) what constitute habitats harbouring different species communities can only be understood from habitat-specific studies and (2) the suitability of habitats is affected by their biophysical characteristics. Thus, emulation of natural disturbances may promote biodiversity, but empirical studies are needed for each habitat to understand how natural disturbances should be emulated. We also conclude that stump extraction for bioenergy is associated with larger risks for biodiversity than fine woody debris extraction.
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