Please use this identifier to cite or link to this item:
|Title:||The role of bryophytes for tree seedling responses to winter climate change : implications for the stress gradient hypothesis||Authors:||Lett, Signe
Wardle, David A.
Teuber, Laurenz M.
|Issue Date:||2017||Source:||Lett, S., Wardle, D. A., Nilsson, M.-C., Teuber, L. M., & Dorrepaal, E. (2018). The role of bryophytes for tree seedling responses to winter climate change : implications for the stress gradient hypothesis. Journal of Ecology, 106(3), 1142-1155. doi:10.1111/1365-2745.12898||Series/Report no.:||Journal of Ecology||Abstract:||1. When tree seedlings establish beyond the current tree line due to climate warming, they encounter existing vegetation, such as bryophytes that often dominate in arctic and alpine tundra. The stress gradient hypothesis (SGH) predicts that plant interactions in tundra become increasingly negative as climate warms and conditions become less harsh. However, for seedlings, climate warming might not result in lower winter stress, if insulating snow cover is reduced. 2. We aimed to understand if bryophytes facilitate seedling survival in a changing winter climate and if these effects of bryophytes on tree seedlings comply with the SGH along elevational gradients under contrasting snow conditions. 3. In the Swedish subarctic, we transplanted intact bryophyte cores covered by each of three bryophyte species and bryophyte‐free control soil from above the tree line to two field common garden sites, representing current and future tree line air temperature conditions (i.e. current tree line elevation and a lower, warmer, elevation below the tree line). We planted seedlings of Betula pubescens and Pinus sylvestris into these cores and subjected them to experimental manipulation of snow cover during one winter. 4. In agreement with the SGH, milder conditions caused by increased snow cover enhanced the generally negative or neutral effects of bryophytes on seedlings immediately after winter. Furthermore, survival of P. sylvestris seedlings after one full year was higher at lower elevation, especially when snow cover was thinner. However, in contrast with the SGH, impacts of bryophytes on over‐winter survival of seedlings did not differ between elevations, and impacts on survival of B. pubescens seedlings after 1 year was more negative at lower elevation. Bryophyte species differed in their effect on seedling survival after winter, but these differences were not related to their insulating capacity. 5. Synthesis. Our study demonstrates that interactions from bryophytes can modify the impacts of winter climate change on tree seedlings, and vice versa. These responses do not always comply with SGH, but could ultimately have consequences for large‐scale ecological processes such as tree line shifts. These new insights need to be taken into account in predictions of plant species responses to climate change.||URI:||https://hdl.handle.net/10356/107519
|ISSN:||0022-0477||DOI:||http://dx.doi.org/10.1111/1365-2745.12898||Rights:||© 2017 The Authors (Journal of Ecology). © 2017 British Ecological Society. All rights reserved. This paper was published in Journal of Ecology and is made available with permission of The Authors (Journal of Ecology) and British Ecological Society.||Fulltext Permission:||open||Fulltext Availability:||With Fulltext|
|Appears in Collections:||ASE Journal Articles|
Files in This Item:
|The role of bryophytes for tree seedling responses.pdf||742.37 kB||Adobe PDF|
Items in DR-NTU are protected by copyright, with all rights reserved, unless otherwise indicated.