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- Alatalo, Juha M., et al.
(författare)
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Bryophyte cover and richness decline after 18 years of experimental warming in Alpine Sweden
- 2024
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- 1. Bryophytes in the Arctic and Alpine regions are important in terms of biodiversity, cover and biomass. However, climate change and widespread shrubification of alpine and arctic tundra is predicted to increase in the future, with potentially large impacts on bryophyte communities.2. We studies the impact of 18 years of experimental warming with open top chambers (OTCs) on bryophyte cover, richness and diversity in an alpine mesic meadow and a heath plant community in Northern Sweden. In addition we investigated the relationship between deciduous shrubs and bryophytes.3. Cover and richness of bryophytes both declined due to long-term warming, while diversity did not show any significant responses. After 18 years, bryophyte cover had decreased by 71% and 26 in the heath and meadow, while richness declined by 39% and 26%, respectively.4. Synthesis. Decline in total bryophyte cover in both communities in response to long-term warming was driven by a general decline in many species, with only two individual species showing significant declines. Although most of the species included in the individual analyses did not show any detectable changes, the cumulative change in all species was significant. In addition, species loss was slower than the general decline in bryophyte abundance. As hypothesized, we found significant negative relationship between deciduous shrub cover and bryophyte cover, but not bryophyte richness, in both plant communities. This is likely due to a more delayed decline in species richness compared to abundance, similar to what was observed in response to long-term warming.
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| 2. |
- Muscarella, Robert, et al.
(författare)
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The global abundance of tree palms
- 2020
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Ingår i: Global Ecology and Biogeography. - : Wiley. - 1466-822X .- 1466-8238. ; 29:9, s. 1495-1514
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Tidskriftsartikel (refereegranskat)abstract
- AimPalms are an iconic, diverse and often abundant component of tropical ecosystems that provide many ecosystem services. Being monocots, tree palms are evolutionarily, morphologically and physiologically distinct from other trees, and these differences have important consequences for ecosystem services (e.g., carbon sequestration and storage) and in terms of responses to climate change. We quantified global patterns of tree palm relative abundance to help improve understanding of tropical forests and reduce uncertainty about these ecosystems under climate change.LocationTropical and subtropical moist forests.Time periodCurrent.Major taxa studiedPalms (Arecaceae).MethodsWe assembled a pantropical dataset of 2,548 forest plots (covering 1,191 ha) and quantified tree palm (i.e., ≥10 cm diameter at breast height) abundance relative to co‐occurring non‐palm trees. We compared the relative abundance of tree palms across biogeographical realms and tested for associations with palaeoclimate stability, current climate, edaphic conditions and metrics of forest structure.ResultsOn average, the relative abundance of tree palms was more than five times larger between Neotropical locations and other biogeographical realms. Tree palms were absent in most locations outside the Neotropics but present in >80% of Neotropical locations. The relative abundance of tree palms was more strongly associated with local conditions (e.g., higher mean annual precipitation, lower soil fertility, shallower water table and lower plot mean wood density) than metrics of long‐term climate stability. Life‐form diversity also influenced the patterns; palm assemblages outside the Neotropics comprise many non‐tree (e.g., climbing) palms. Finally, we show that tree palms can influence estimates of above‐ground biomass, but the magnitude and direction of the effect require additional work.ConclusionsTree palms are not only quintessentially tropical, but they are also overwhelmingly Neotropical. Future work to understand the contributions of tree palms to biomass estimates and carbon cycling will be particularly crucial in Neotropical forests.
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