| 1. |
- Lett, Signe, et al.
(författare)
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Can bryophyte groups increase functional resolution in tundra ecosystems?
- 2022
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Ingår i: Arctic Science. - Ottawa : Canadian Science Publishing. - 2368-7460. ; 8:3, s. 609-637
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Tidskriftsartikel (refereegranskat)abstract
- The relative contribution of bryophytes to plant diversity, primary productivity, and ecosystem functioning increases towards colder climates. Bryophytes respond to environmental changes at the species level, but because bryophyte species are relatively difficult to identify, they are often lumped into one functional group. Consequently, bryophyte function remains poorly resolved. Here, we explore how higher resolution of bryophyte functional diversity can be encouraged and implemented in tundra ecological studies. We briefly review previous bryophyte functional classifications and the roles of bryophytes in tundra ecosystems and their susceptibility to environmental change. Based on shoot morphology and colony organization, we then propose twelve easily distinguishable bryophyte functional groups. To illustrate how bryophyte functional groups can help elucidate variation in bryophyte effects and responses, we compiled existing data on water holding capacity, a key bryophyte trait. Although plant functional groups can mask potentially high interspecific and intraspecific variability, we found better separation of bryophyte functional group means compared with previous grouping systems regarding water holding capacity. This suggests that our bryophyte functional groups truly represent variation in the functional roles of bryophytes in tundra ecosystems. Lastly, we provide recommendations to improve the monitoring of bryophyte community changes in tundra study sites.
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| 2. |
- van Zuijlen, Kristel, et al.
(författare)
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Extinction risk of European bryophytes predicted by bioclimate and traits
- 2024
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Ingår i: Biological Conservation. - 0006-3207 .- 1873-2917. ; 293
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Tidskriftsartikel (refereegranskat)abstract
- Extinction risk is not randomly distributed among species but depends on species traits, their relationship to climate and land use, and corresponding threats by global change. While knowledge of which factors influence extinction risk is increasingly available for some taxonomic groups, this is still largely lacking for bryophytes. Here, we used random forest models to study which biological and ecological traits and bioclimatic variables are important predictors for extinction risk in European bryophytes. We hypothesized that species with a high extinction risk have a short life span, low dispersal capacities, and are more likely specialists than generalists in terms of ecological traits and bioclimate. Overall, we found bioclimatic variables to be the most important predictors for extinction risk, most notably precipitation seasonality, and related ecological traits such as continentality and elevational range. Important biological traits were plant size, life strategy and sporophyte production. In general, species living at climatic extremes and/or those with a narrow environmental range are more likely to be threatened. In addition, small-sized species and/or species with low reproductive effort and/or larger spore size are more likely to be threatened. Our findings imply that climate change may become an important driver of bryophytes extinction risk and that biological and ecological traits will be most relevant for species in coping with future threats.
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| 3. |
- van Zuijlen, Kristel, et al.
(författare)
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Frost damage measured by electrolyte leakage in subarctic bryophytes increases with climate warming
- 2024
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Ingår i: Journal of Ecology. - : John Wiley & Sons. - 0022-0477 .- 1365-2745. ; 112:2, s. 220-232
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Tidskriftsartikel (refereegranskat)abstract
- Observed climate change in northern high latitudes is strongest in winter, but still relatively little is known about the effects of winter climate change on tundra ecosystems. Ongoing changes in winter climate and snow cover will change the intensity, duration and frequency of frost events. Bryophytes form a major component of northern ecosystems but their responses to winter climate changes are largely unknown.Here, we studied how changes in overall winter climate and snow regime affect frost damage in three common bryophyte taxa that differ in desiccation tolerance in a subarctic tundra ecosystem. We used a snow manipulation experiment where bryophyte cores were transplanted from just above the tree line to similar elevation (i.e. current cold climate) and lower elevation (i.e. near-future warmer climate scenario) in Abisko, Sweden. Here, we measured frost damage in shoots of Ptilidium ciliare, Hylocomium splendens and Sphagnum fuscum with the relative electrolyte leakage (REL) method, during late winter and spring in two consecutive years. We hypothesized that frost damage would be lower in a milder climate (low site) and higher under reduced snow cover and that taxa from moister habitats with assumed low desiccation tolerance would be more sensitive to lower temperature and thinner snow cover than those from drier and more exposed habitats.Contrary to our expectations, frost damage was highest at low elevation, while the effect of snow treatment differed across sites and taxa. At the high site, frost damage was reduced under snow addition in the taxon with the assumed lowest desiccation tolerance, S. fuscum. Surprisingly, frost damage increased with mean temperature in the bryophyte core of the preceding 14 days leading up to REL measurements and decreased with higher frost degree sums, that is, was highest in the milder climate at the low site.Synthesis Our results imply that climate warming in late winter and spring increases frost damage in bryophytes. Given the high abundance of bryophytes in tundra ecosystems, higher frost damage could alter the appearance and functioning of the tundra landscape, although the short and long-term effects on bryophyte fitness remain to be studied.
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