Search

Your search keyword '"Jónsdóttir, I. S."' showing total 24 results
Start Over Author "Jónsdóttir, I. S."
24 results on '"Jónsdóttir, I. S."'

2. Environmental drivers of increased ecosystem respiration in a warming tundra

Author

Maes, S. L., Dietrich, J., Midolo, G., Schwieger, S., Kummu, M., Vandvik, V., Aerts, R., Althuizen, I. H. J., Biasi, C., Björk, R. G., Böhner, H., Carbognani, M., Chiari, G., Christiansen, C. T., Clemmensen, K. E., Cooper, E. J., Cornelissen, J. H. C., Elberling, B., Faubert, P., Fetcher, N., Forte, T. G. W., Gaudard, J., Gavazov, K., Guan, Z., Guðmundsson, J., Gya, R., Hallin, S., Hansen, B. B., Haugum, S. V., He, J.-S., Hicks Pries, C., Hovenden, M. J., Jalava, M., Jónsdóttir, I. S., Juhanson, J., Jung, J. Y., Kaarlejärvi, E., Kwon, M. J., Lamprecht, R. E., Le Moullec, M., Lee, H., Marushchak, M. E., Michelsen, A., Munir, T. M., Myrsky, E. M., Nielsen, C. S., Nyberg, M., Olofsson, J., Óskarsson, H., Parker, T. C., Pedersen, E. P., Petit Bon, M., Petraglia, A., Raundrup, K., Ravn, N. M. R., Rinnan, R., Rodenhizer, H., Ryde, I., Schmidt, N. M., Schuur, E. A. G., Sjögersten, S., Stark, S., Strack, M., Tang, J., Tolvanen, A., Töpper, J. P., Väisänen, M. K., van Logtestijn, R. S. P., Voigt, C., Walz, J., Weedon, J. T., Yang, Y., Ylänne, H., Björkman, M. P., Sarneel, J. M., and Dorrepaal, E.

Published
2024
Full Text
View/download PDF

3. Responses of Tundra Plants to Experimental Warming: Meta-Analysis of the International Tundra Experiment

Author

Arft, A. M., Walker, M. D., Gurevitch, J., Alatalo, J. M., Bret-Harte, M. S., Dale, M., Diemer, M., Gugerli, F., Henry, G. H. R., Jones, M. H., Hollister, R. D., Jonsdottir, I. S., Laine, K., Levesque, E., Marion, G. M., Molau, U., Molgaard, P., Nordenhall, U., Raszhivin, V., Robinson, C. H., Starr, G., Stenstrom, A., Stenstrom, M., Totland, O., Turner, P. L., Walker, L. J., Webber, P. J., Welker, J. M., and Wookey, P. A.

Published
1999
Full Text
View/download PDF

4. Biotic interactions mediate patterns of herbivore diversity in the Arctic

Author

Barrio, I. C., Bueno, C. G., Gartzia, M., Soininen, E. M., Christie, K. S., Speed, J. D. M., Ravolainen, V. T., Forbes, B. C., Gauthier, G., Horstkotte, T., Hoset, K. S., Høye, T. T., Jónsdóttir, I. S., Lévesque, E., Mörsdorf, M. A., Olofsson, J., Wookey, P. A., and Hik, D. S.

Published
2016

5. Phenological response of tundra plants to background climate variation tested using the International Tundra Experiment

Author

Oberbauer, S. F., Elmendorf, S. C., Troxler, T. G., Hollister, R. D., Rocha, A. V., Bret-Harte, M. S., Dawes, M. A., Fosaa, A. M., Henry, G. H. R., Høye, T. T., Jarrad, F. C., Jónsdóttir, I. S., Klanderud, K., Klein, J. A., Molau, U., Rixen, C., Schmidt, N. M., Shaver, G. R., Slider, R. T., Totland, Ø., Wahren, C.-H., and Welker, J. M.

Published
2013
Full Text
View/download PDF

6. Developing common protocols to measure tundra herbivory across spatial scales

Author

Barrio, I. C., Angerbjörn, Anders, Jónsdóttir, I. S., Barrio, I. C., Angerbjörn, Anders, and Jónsdóttir, I. S.

Abstract

Understanding and predicting large-scale ecological responses to global environmental change requires comparative studies across geographic scales with coordinated efforts and standardized methodologies. We designed, applied, and assessed standardized protocols to measure tundra herbivory at three spatial scales: plot, site (habitat), and study area (landscape). The plot-and site-level protocols were tested in the field during summers 2014–2015 at 11 sites, nine of them consisting of warming experimental plots included in the International Tundra Experiment (ITEX). The study area protocols were assessed during 2014–2018 at 24 study areas across the Arctic. Our protocols provide comparable and easy to implement methods for assessing the intensity of invertebrate herbivory within ITEX plots and for characterizing vertebrate herbivore communities at larger spatial scales. We discuss methodological constraints and make recommendations for how these protocols can be used and how sampling effort can be optimized to obtain comparable estimates of herbivory, both at ITEX sites and at large landscape scales. The application of these protocols across the tundra biome will allow characterizing and comparing herbivore communities across tundra sites and at ecologically relevant spatial scales, providing an important step towards a better understanding of tundra ecosystem responses to large-scale environmental change.

Published
2022
Full Text
View/download PDF

7. Evolutionary history of grazing and resources determine herbivore exclusion effects on plant diversity

Author

Price, J. N. (Jodi N.), Sitters, J. (Judith), Ohlert, T. (Timothy), Tognetti, P. M. (Pedro M.), Brown, C. S. (Cynthia S.), Seabloom, E. W. (Eric W.), Borer, E. T. (Elizabeth T.), Prober, S. M. (Suzanne M.), Bakker, E. S. (Elisabeth S.), MacDougall, A. S. (Andrew S.), Yahdjian, L. (Laura), Gruner, D. S. (Daniel S.), Olde Venterink, H. (Harry), Barrio, I. C. (Isabel C.), Graff, P. (Pamela), Bagchi, S. (Sumanta), Arnillas, C. A. (Carlos Alberto), Bakker, J. D. (Jonathan D.), Blumenthal, D. M. (Dana M.), Boughton, E. H. (Elizabeth H.), Brudvig, L. A. (Lars A.), Bugalho, M. N. (Miguel N.), Cadotte, M. W. (Marc W.), Caldeira, M. C. (Maria C.), Dickman, C. R. (Chris R.), Donohue, I. (Ian), Grégory, S. (Sonnier), Hautier, Y. (Yann), Jónsdóttir, I. S. (Ingibjörg S.), Lannes, L. S. (Luciola S.), McCulley, R. L. (Rebecca L.), Moore, J. L. (Joslin L.), Power, S. A. (Sally A.), Risch, A. C. (Anita C.), Schütz, M. (Martin), Standish, R. (Rachel), Stevens, C. J. (Carly J.), Veen, G. F. (G. F.), Virtanen, R. (Risto), Wardle, G. M. (Glenda M.), Price, J. N. (Jodi N.), Sitters, J. (Judith), Ohlert, T. (Timothy), Tognetti, P. M. (Pedro M.), Brown, C. S. (Cynthia S.), Seabloom, E. W. (Eric W.), Borer, E. T. (Elizabeth T.), Prober, S. M. (Suzanne M.), Bakker, E. S. (Elisabeth S.), MacDougall, A. S. (Andrew S.), Yahdjian, L. (Laura), Gruner, D. S. (Daniel S.), Olde Venterink, H. (Harry), Barrio, I. C. (Isabel C.), Graff, P. (Pamela), Bagchi, S. (Sumanta), Arnillas, C. A. (Carlos Alberto), Bakker, J. D. (Jonathan D.), Blumenthal, D. M. (Dana M.), Boughton, E. H. (Elizabeth H.), Brudvig, L. A. (Lars A.), Bugalho, M. N. (Miguel N.), Cadotte, M. W. (Marc W.), Caldeira, M. C. (Maria C.), Dickman, C. R. (Chris R.), Donohue, I. (Ian), Grégory, S. (Sonnier), Hautier, Y. (Yann), Jónsdóttir, I. S. (Ingibjörg S.), Lannes, L. S. (Luciola S.), McCulley, R. L. (Rebecca L.), Moore, J. L. (Joslin L.), Power, S. A. (Sally A.), Risch, A. C. (Anita C.), Schütz, M. (Martin), Standish, R. (Rachel), Stevens, C. J. (Carly J.), Veen, G. F. (G. F.), Virtanen, R. (Risto), and Wardle, G. M. (Glenda M.)

Abstract

Ecological models predict that the effects of mammalian herbivore exclusion on plant diversity depend on resource availability and plant exposure to ungulate grazing over evolutionary time. Using an experiment replicated in 57 grasslands on six continents, with contrasting evolutionary history of grazing, we tested how resources (mean annual precipitation and soil nutrients) determine herbivore exclusion effects on plant diversity, richness and evenness. Here we show that at sites with a long history of ungulate grazing, herbivore exclusion reduced plant diversity by reducing both richness and evenness and the responses of richness and diversity to herbivore exclusion decreased with mean annual precipitation. At sites with a short history of grazing, the effects of herbivore exclusion were not related to precipitation but differed for native and exotic plant richness. Thus, plant species’ evolutionary history of grazing continues to shape the response of the world’s grasslands to changing mammalian herbivory.

Published
2022

8. The tundra phenology database:more than two decades of tundra phenology responses to climate change

Author

Prevéy, J. S. (Janet S.), Elmendorf, S. C. (Sarah Claire), Bjorkman, A. (Anne), Alatalo, J. M. (Juha M.), Ashton, I. (Isabel), Assmann, J. J. (Jakob J.), Björk, R. G. (Robert G.), Björkman, M. P. (Mats P.), Cannone, N. (Nicoletta), Carbognani, M. (Michele), Chisholm, C. (Chelsea), Clark, K. (Karin), Collins, C. G. (Courtney G.), Cooper, E. J. (Elisabeth J.), Elberling, B. (Bo), Frei, E. R. (Esther R.), Henry, G. R. (Gregory R.H.), Hollister, R. D. (Robert D.), Høye, T. T. (Toke Thomas), Jónsdóttir, I. S. (Ingibjörg Svala), Kerby, J. T. (Jeffrey T.), Klanderud, K. (Kari), Kopp, C. (Christopher), Levesque, E. (Esther), Mauritz, M. (Marguerite), Molau, U. (Ulf), Myers-Smith, I. H. (Isla H.), Natali, S. M. (Susan M.), Oberbauer, S. F. (Steven F.), Panchen, Z. (Zoe), Petraglia, A. (Alessandro), Post, E. (Eric), Rixen, C. (Christian), Rodenhizer, H. (Heidi), Rumpf, S. B. (Sabine B.), Schmidt, N. M. (Niels Martin), Schuur, T. (Ted), Semenchuk, P. (Philipp), Smith, J. G. (Jane Griffin), Suding, K. (Katharine), Totland, Ø. (Ørjan), Troxler, T. (Tiffany), Wahren, H. (Henrik), Welker, J. M. (Jeffrey M.), Wipf, S. (Sonja), Yang, Y. (Yue), Prevéy, J. S. (Janet S.), Elmendorf, S. C. (Sarah Claire), Bjorkman, A. (Anne), Alatalo, J. M. (Juha M.), Ashton, I. (Isabel), Assmann, J. J. (Jakob J.), Björk, R. G. (Robert G.), Björkman, M. P. (Mats P.), Cannone, N. (Nicoletta), Carbognani, M. (Michele), Chisholm, C. (Chelsea), Clark, K. (Karin), Collins, C. G. (Courtney G.), Cooper, E. J. (Elisabeth J.), Elberling, B. (Bo), Frei, E. R. (Esther R.), Henry, G. R. (Gregory R.H.), Hollister, R. D. (Robert D.), Høye, T. T. (Toke Thomas), Jónsdóttir, I. S. (Ingibjörg Svala), Kerby, J. T. (Jeffrey T.), Klanderud, K. (Kari), Kopp, C. (Christopher), Levesque, E. (Esther), Mauritz, M. (Marguerite), Molau, U. (Ulf), Myers-Smith, I. H. (Isla H.), Natali, S. M. (Susan M.), Oberbauer, S. F. (Steven F.), Panchen, Z. (Zoe), Petraglia, A. (Alessandro), Post, E. (Eric), Rixen, C. (Christian), Rodenhizer, H. (Heidi), Rumpf, S. B. (Sabine B.), Schmidt, N. M. (Niels Martin), Schuur, T. (Ted), Semenchuk, P. (Philipp), Smith, J. G. (Jane Griffin), Suding, K. (Katharine), Totland, Ø. (Ørjan), Troxler, T. (Tiffany), Wahren, H. (Henrik), Welker, J. M. (Jeffrey M.), Wipf, S. (Sonja), and Yang, Y. (Yue)

Abstract

Observations of changes in phenology have provided some of the strongest signals of the effects of climate change on terrestrial ecosystems. The International Tundra Experiment (ITEX), initiated in the early 1990s, established a common protocol to measure plant phenology in tundra study areas across the globe. Today, this valuable collection of phenology measurements depicts the responses of plants at the colder extremes of our planet to experimental and ambient changes in temperature over the past decades. The database contains 150 434 phenology observations of 278 plant species taken at 28 study areas for periods of 1–26 years. Here we describe the full data set to increase the visibility and use of these data in global analyses and to invite phenology data contributions from underrepresented tundra locations. Portions of this tundra phenology database have been used in three recent syntheses, some data sets are expanded, others are from entirely new study areas, and the entirety of these data are now available at the Polar Data Catalogue (https://doi.org/10.21963/13215).

Published
2022

9. Winters are changing:snow effects on Arctic and alpine tundra ecosystems

Author

Rixen, C. (Christian), Høye, T. T. (Toke Thomas), Macek, P. (Petr), Aerts, R. (Rien), Alatalo, J. M. (Juha M.), Anderson, J. T. (Jill T.), Arnold, P. A. (Pieter A.), Barrio, I. C. (Isabel C), Bjerke, J. W. (Jarle W.), Björkman, M. P. (Mats P.), Blok, D. (Daan), Blume-Werry, G. (Gesche), Boike, J. (Julia), Bokhorst, S. (Stef), Carbognani, M. (Michele), Christiansen, C. T. (Casper T.), Convey, P. (Peter), Cooper, E. J. (Elisabeth J.), Cornelissen, J. H. (J. Hans C.), Coulson, S. J. (Stephen J.), Dorrepaal, E. (Ellen), Elberling, B. (Bo), Elmendorf, S. C. (Sarah C.), Elphinstone, C. (Cassandra), Forte, T. G. (T’ai G.W.), Frei, E. R. (Esther R.), Geange, S. R. (Sonya R.), Gehrmann, F. (Friederike), Gibson, C. (Casey), Grogan, P. (Paul), Halbritter, A. H. (Aud Helen), Harte, J. (John), Henry, G. H. (Gregory H.R.), Inouye, D. W. (David W.), Irwin, R. E. (Rebecca E.), Jespersen, G. (Gus), Jónsdóttir, I. S. (Ingibjörg Svala), Jung, J. Y. (Ji Young), Klinges, D. H. (David H.), Kudo, G. (Gaku), Lämsä, J. (Juho), Lee, H. (Hanna), Lembrechts, J. J. (Jonas J.), Lett, S. (Signe), Lynn, J. S. (Joshua Scott), Mann, H. M. (Hjalte M.R.), Mastepanov, M. (Mikhail), Morse, J. (Jennifer), Myers-Smith, I. H. (Isla H.), Olofsson, J. (Johan), Paavola, R. (Riku), Petraglia, A. (Alessandro), Phoenix, G. K. (Gareth K.), Semenchuk, P. (Philipp), Siewert, M. B. (Matthias B.), Slatyer, R. (Rachel), Spasojevic, M. J. (Marko J.), Suding, K. (Katharine), Sullivan, P. (Patrick), Thompson, K. L. (Kimberly L.), Väisänen, M. (Maria), Vandvik, V. (Vigdis), Venn, S. (Susanna), Walz, J. (Josefine), Way, R. (Robert), Welker, J. M. (Jeffrey M.), Wipf, S. (Sonja), Zong, S. (Shengwei), Rixen, C. (Christian), Høye, T. T. (Toke Thomas), Macek, P. (Petr), Aerts, R. (Rien), Alatalo, J. M. (Juha M.), Anderson, J. T. (Jill T.), Arnold, P. A. (Pieter A.), Barrio, I. C. (Isabel C), Bjerke, J. W. (Jarle W.), Björkman, M. P. (Mats P.), Blok, D. (Daan), Blume-Werry, G. (Gesche), Boike, J. (Julia), Bokhorst, S. (Stef), Carbognani, M. (Michele), Christiansen, C. T. (Casper T.), Convey, P. (Peter), Cooper, E. J. (Elisabeth J.), Cornelissen, J. H. (J. Hans C.), Coulson, S. J. (Stephen J.), Dorrepaal, E. (Ellen), Elberling, B. (Bo), Elmendorf, S. C. (Sarah C.), Elphinstone, C. (Cassandra), Forte, T. G. (T’ai G.W.), Frei, E. R. (Esther R.), Geange, S. R. (Sonya R.), Gehrmann, F. (Friederike), Gibson, C. (Casey), Grogan, P. (Paul), Halbritter, A. H. (Aud Helen), Harte, J. (John), Henry, G. H. (Gregory H.R.), Inouye, D. W. (David W.), Irwin, R. E. (Rebecca E.), Jespersen, G. (Gus), Jónsdóttir, I. S. (Ingibjörg Svala), Jung, J. Y. (Ji Young), Klinges, D. H. (David H.), Kudo, G. (Gaku), Lämsä, J. (Juho), Lee, H. (Hanna), Lembrechts, J. J. (Jonas J.), Lett, S. (Signe), Lynn, J. S. (Joshua Scott), Mann, H. M. (Hjalte M.R.), Mastepanov, M. (Mikhail), Morse, J. (Jennifer), Myers-Smith, I. H. (Isla H.), Olofsson, J. (Johan), Paavola, R. (Riku), Petraglia, A. (Alessandro), Phoenix, G. K. (Gareth K.), Semenchuk, P. (Philipp), Siewert, M. B. (Matthias B.), Slatyer, R. (Rachel), Spasojevic, M. J. (Marko J.), Suding, K. (Katharine), Sullivan, P. (Patrick), Thompson, K. L. (Kimberly L.), Väisänen, M. (Maria), Vandvik, V. (Vigdis), Venn, S. (Susanna), Walz, J. (Josefine), Way, R. (Robert), Welker, J. M. (Jeffrey M.), Wipf, S. (Sonja), and Zong, S. (Shengwei)

Abstract

Snow is an important driver of ecosystem processes in cold biomes. Snow accumulation determines ground temperature, light conditions, and moisture availability during winter. It also affects the growing season’s start and end, and plant access to moisture and nutrients. Here, we review the current knowledge of the snow cover’s role for vegetation, plant-animal interactions, permafrost conditions, microbial processes, and biogeochemical cycling. We also compare studies of natural snow gradients with snow experimental manipulation studies to assess time scale difference of these approaches. The number of tundra snow studies has increased considerably in recent years, yet we still lack a comprehensive overview of how altered snow conditions will affect these ecosystems. Specifically, we found a mismatch in the timing of snowmelt when comparing studies of natural snow gradients with snow manipulations. We found that snowmelt timing achieved by snow addition and snow removal manipulations (average 7.9 days advance and 5.5 days delay, respectively) were substantially lower than the temporal variation over natural spatial gradients within a given year (mean range 56 days) or among years (mean range 32 days). Differences between snow study approaches need to be accounted for when projecting snow dynamics and their impact on ecosystems in future climates.

Published
2022

10. The tundra phenology database: More than two decades of tundra phenology responses to climate change

Author

Prevéy, J. S., Elmendorf, S. C., Bjorkman, A., Alatalo, J. M., Ashton, I., Assmann, J. J., Björk, R. G., Björkman, M. P., Cannone, N., Carbognani, M., Chisholm, C., Clark, K., Collins, C. G., Cooper, E. J., Elberling, B., Frei, E. R., Henry, G. R. H., Hollister, R. D., Høye, T. T., Jónsdóttir, I. S., Kerby, J. T., Klanderud, K., Kopp, C., Levesque, E., Mauritz, M., Molau, U., Myers-Smith, I. H., Natali, S. M., Oberbauer, S. F., Panchen, Z., Petraglia, A., Post, E., Rixen, C., Rodenhizer, H., Rumpf, S. B., Schmidt, N. M., Schuur, T., Semenchuk, P., Smith, J. G., Suding, K., Totland, Ø, Troxler, T., Wahren, H., Welker, J. M., Wipf, S., Yang, Y., Prevéy, J. S., Elmendorf, S. C., Bjorkman, A., Alatalo, J. M., Ashton, I., Assmann, J. J., Björk, R. G., Björkman, M. P., Cannone, N., Carbognani, M., Chisholm, C., Clark, K., Collins, C. G., Cooper, E. J., Elberling, B., Frei, E. R., Henry, G. R. H., Hollister, R. D., Høye, T. T., Jónsdóttir, I. S., Kerby, J. T., Klanderud, K., Kopp, C., Levesque, E., Mauritz, M., Molau, U., Myers-Smith, I. H., Natali, S. M., Oberbauer, S. F., Panchen, Z., Petraglia, A., Post, E., Rixen, C., Rodenhizer, H., Rumpf, S. B., Schmidt, N. M., Schuur, T., Semenchuk, P., Smith, J. G., Suding, K., Totland, Ø, Troxler, T., Wahren, H., Welker, J. M., Wipf, S., and Yang, Y.

Abstract

Observations of changes in phenology have provided some of the strongest signals of the effects of climate change on terrestrial ecosystems. The International Tundra Experiment (ITEX), initiated in the early 1990s, established a common protocol to measure plant phenology in tundra study areas across the globe. Today, this valuable collec-tion of phenology measurements depicts the responses of plants at the colder extremes of our planet to experimental and ambient changes in temperature over the past decades. The database contains 150 434 phenology observations of 278 plant species taken at 28 study areas for periods of 1–26 years. Here we describe the full data set to increase the visibility and use of these data in global analyses and to invite phenology data contributions from underrepresented tundra locations. Portions of this tundra phenology database have been used in three recent syntheses, some data sets are expanded, others are from entirely new study areas, and the entirety of these data are now available at the Polar Data Catalogue (https://doi.org/10.21963/13215). Résumé Les observations des changements dans la phénologie ont fourni certains des signaux les plus forts des effets du changement climatique sur les écosystèmes terrestres. L’expérience internationale sur la toundra ITEX (International Tundra Experiment), lancée au début des années 1990, a établi un protocole commun pour mesurer la phénologie des plantes dans les zones d’étude de la toundra à travers le monde. Aujourd’hui, cette précieuse collection de mesures phénologiques décrit les réponses des plantes des régions les plus froides de notre planète aux changements expérimentaux et ambiants de température au cours des dernières décennies. La base de données contient 150 434 observations phénologiques de 278 espèces de plantes prises dans 28 zones d’étude sur des périodes allant de 1 à 26 ans. Les auteurs décrivent ici l’ensemble des données afin d’accroître la visibilité et l’utilisat

Published
2022

11. Can bryophyte groups increase functional resolution in tundra ecosystems?

Author

Lett, S., Jónsdóttir, I. S., Becker-Scarpitta, A., Christiansen, C. T., During, H., Ekelund, F., Henry, G. H. R., Lang, S. I., Michelsen, A., Rousk, K., Alatalo, J. M., Betway, K. R., Rui, S. B., Callaghan, T., Carbognani, M., Cooper, E. J., Cornelissen, J. H. C., Dorrepaal, E., Egelkraut, D., Elumeeva, T. G., Haugum, S. V., Hollister, R. D., Jägerbrand, A. K., Keuper, F., Klanderud, K., Lévesque, E., Liu, X., May, J., Michel, P., Mörsdorf, M., Petraglia, A., Rixen, C., Robroek, B. J. M., Rzepczynska, A. M., Soudzilovskaia, N. A., Tolvanen, A., Vandvik, V., Volkov, I., Volkova, I., van Zuijlen, K., Lett, S., Jónsdóttir, I. S., Becker-Scarpitta, A., Christiansen, C. T., During, H., Ekelund, F., Henry, G. H. R., Lang, S. I., Michelsen, A., Rousk, K., Alatalo, J. M., Betway, K. R., Rui, S. B., Callaghan, T., Carbognani, M., Cooper, E. J., Cornelissen, J. H. C., Dorrepaal, E., Egelkraut, D., Elumeeva, T. G., Haugum, S. V., Hollister, R. D., Jägerbrand, A. K., Keuper, F., Klanderud, K., Lévesque, E., Liu, X., May, J., Michel, P., Mörsdorf, M., Petraglia, A., Rixen, C., Robroek, B. J. M., Rzepczynska, A. M., Soudzilovskaia, N. A., Tolvanen, A., Vandvik, V., Volkov, I., Volkova, I., and van Zuijlen, K.

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. Résumé La contribution relative des bryophytes à la diversité végétale, à la productivité primaire et au fonctionnement des écosystèmes s’accroît vers les climats plus froids. Les bryophytes répondent aux changements environnementaux au niveau de l’espèce, mais puisque les espèces de bryophytes sont relativement difficiles à identifier, elles sont souvent regroupées en un seul groupe fonctionnel. Par conséquent, la fonction des bryophytes reste mal résolue. Les auteurs explorent ici comment une m

Published
2022

13. Stomping in silence:conceptualizing trampling effects on soils in polar tundra

Author

Tuomi, M. (Maria), Väisänen, M. (Maria), Ylänne, H. (Henni), Brearley, F. Q. (Francis Q.), Barrio, I. C. (Isabel C.), Bråthen, K. A. (Kari Anne), Eischeid, I. (Isabell), Forbes, B. C. (Bruce C.), Jónsdóttir, I. S. (Ingibjörg S.), Kolstad, A. L. (Anders L.), Macek, P. (Petr), Petit Bon, M. (Matteo), Speed, J. D. (James D. M.), Stark, S. (Sari), Svavarsdóttir, K. (Kristin), Thórsson, J. (Jóhann), and Bueno, C. G. (C. Guillermo)

Subjects
Arctic ecosystems, herbivory, non‐trophic interactions, physical disturbance, grazing, herbivore–soil interactions, treading
Abstract

1. Ungulate trampling modifies soils and interlinked ecosystem functions across biomes. Until today, most research has focused on temperate ecosystems and mineral soils while trampling effects on cold and organic matter‐rich tundra soils remain largely unknown. 2. We aimed to develop a general model of trampling effects on soil structure, biota, microclimate and biogeochemical processes, with a particular focus on polar tundra soils. To reach this goal, we reviewed literature about the effects of trampling and physical disturbances on soils across biomes and used this to discuss the knowns and unknowns of trampling effects on tundra soils. 3. We identified the following four pathways through which trampling affects soils: (a) soil compaction; (b) reductions in soil fauna and fungi; (c) rapid losses in vegetation biomass and cover; and (d) longer term shifts in vegetation community composition. 4. We found that, in polar tundra, soil responses to trampling pathways 1 and 3 could be characterized by nonlinear dynamics and tundra‐specific context dependencies that we formulated into testable hypotheses. 5. In conclusion, trampling may affect tundra soil significantly but many direct, interacting and cascading responses remain unknown. We call for research to advance the understanding of trampling effects on soils to support informed efforts to manage and predict the functioning of tundra systems under global changes.

Published
2021

14. Species loss due to nutrient addition increases with spatial scale in global grasslands

Author

Seabloom, E. W. (Eric W.), Batzer, E. (Evan), Chase, J. M. (Jonathan M.), Harpole, W. S. (W. Stanley), Adler, P. B. (Peter B.), Bagchi, S. (Sumanta), Bakker, J. D. (Jonathan D.), Barrio, I. C. (Isabel C.), Biederman, L. (Lori), Boughton, E. H. (Elizabeth H.), Bugalho, M. N. (Miguel N.), Caldeira, M. C. (Maria C.), Catford, J. A. (Jane A.), Daleo, P. (Pedro), Eisenhauer, N. (Nico), Eskelinen, A. (Anu), Haider, S. (Sylvia), Hallett, L. M. (Lauren M.), Jónsdóttir, I. S. (Ingibjörg Svala), Kimmel, K. (Kaitlin), Kuhlman, M. (Marirose), MacDougall, A. (Andrew), Molina, C. D. (Cecilia D.), Moore, J. L. (Joslin L.), Morgan, J. W. (John W.), Muthukrishnan, R. (Ranjan), Ohlert, T. (Timothy), Risch, A. C. (Anita C.), Roscher, C. (Christiane), Schütz, M. (Martin), Sonnier, G. (Grégory), Tognetti, P. M. (Pedro M.), Virtanen, R. (Risto), Wilfahrt, P. A. (Peter A.), Borer, E. T. (Elizabeth T.), Seabloom, E. W. (Eric W.), Batzer, E. (Evan), Chase, J. M. (Jonathan M.), Harpole, W. S. (W. Stanley), Adler, P. B. (Peter B.), Bagchi, S. (Sumanta), Bakker, J. D. (Jonathan D.), Barrio, I. C. (Isabel C.), Biederman, L. (Lori), Boughton, E. H. (Elizabeth H.), Bugalho, M. N. (Miguel N.), Caldeira, M. C. (Maria C.), Catford, J. A. (Jane A.), Daleo, P. (Pedro), Eisenhauer, N. (Nico), Eskelinen, A. (Anu), Haider, S. (Sylvia), Hallett, L. M. (Lauren M.), Jónsdóttir, I. S. (Ingibjörg Svala), Kimmel, K. (Kaitlin), Kuhlman, M. (Marirose), MacDougall, A. (Andrew), Molina, C. D. (Cecilia D.), Moore, J. L. (Joslin L.), Morgan, J. W. (John W.), Muthukrishnan, R. (Ranjan), Ohlert, T. (Timothy), Risch, A. C. (Anita C.), Roscher, C. (Christiane), Schütz, M. (Martin), Sonnier, G. (Grégory), Tognetti, P. M. (Pedro M.), Virtanen, R. (Risto), Wilfahrt, P. A. (Peter A.), and Borer, E. T. (Elizabeth T.)

Abstract

The effects of altered nutrient supplies and herbivore density on species diversity vary with spatial scale, because coexistence mechanisms are scale dependent. This scale dependence may alter the shape of the species–area relationship (SAR), which can be described by changes in species richness (S) as a power function of the sample area (A): S = cAz, where c and z are constants. We analysed the effects of experimental manipulations of nutrient supply and herbivore density on species richness across a range of scales (0.01–75 m²) at 30 grasslands in 10 countries. We found that nutrient addition reduced the number of species that could co-occur locally, indicated by the SAR intercepts (log c), but did not affect the SAR slopes (z). As a result, proportional species loss due to nutrient enrichment was largely unchanged across sampling scales, whereas total species loss increased over threefold across our range of sampling scales.

Published
2021

15. Experimental warming differentially affects vegetative and reproductive phenology of tundra plants

Author

Collins, C. G. (Courtney G.), Elmendorf, S. C. (Sarah C.), Hollister, R. D. (Robert D.), Henry, G. H. (Greg H. R.), Clark, K. (Karin), Bjorkman, A. D. (Anne D.), Myers-Smith, I. H. (Isla H.), Prevéy, J. S. (Janet S.), Ashton, I. W. (Isabel W.), Assmann, J. J. (Jakob J.), Alatalo, J. M. (Juha M.), Carbognani, M. (Michele), Chisholm, C. (Chelsea), Cooper, E. J. (Elisabeth J.), Forrester, C. (Chiara), Jónsdóttir, I. S. (Ingibjörg Svala), Klanderud, K. (Kari), Kopp, C. W. (Christopher W.), Livensperger, C. (Carolyn), Mauritz, M. (Marguerite), May, J. L. (Jeremy L.), Molau, U. (Ulf), Oberbauer, S. F. (Steven F.), Ogburn, E. (Emily), Panchen, Z. A. (Zoe A.), Petraglia, A. (Alessandro), Post, E. (Eric), Rixen, C. (Christian), Rodenhizer, H. (Heidi), Schuur, E. A. (Edward A. G.), Semenchuk, P. (Philipp), Smith, J. G. (Jane G.), Steltzer, H. (Heidi), Totland, Ø. (Ørjan), Walker, M. D. (Marilyn D.), Welker, J. M. (Jeffrey M.), Suding, K. N. (Katharine N.), Collins, C. G. (Courtney G.), Elmendorf, S. C. (Sarah C.), Hollister, R. D. (Robert D.), Henry, G. H. (Greg H. R.), Clark, K. (Karin), Bjorkman, A. D. (Anne D.), Myers-Smith, I. H. (Isla H.), Prevéy, J. S. (Janet S.), Ashton, I. W. (Isabel W.), Assmann, J. J. (Jakob J.), Alatalo, J. M. (Juha M.), Carbognani, M. (Michele), Chisholm, C. (Chelsea), Cooper, E. J. (Elisabeth J.), Forrester, C. (Chiara), Jónsdóttir, I. S. (Ingibjörg Svala), Klanderud, K. (Kari), Kopp, C. W. (Christopher W.), Livensperger, C. (Carolyn), Mauritz, M. (Marguerite), May, J. L. (Jeremy L.), Molau, U. (Ulf), Oberbauer, S. F. (Steven F.), Ogburn, E. (Emily), Panchen, Z. A. (Zoe A.), Petraglia, A. (Alessandro), Post, E. (Eric), Rixen, C. (Christian), Rodenhizer, H. (Heidi), Schuur, E. A. (Edward A. G.), Semenchuk, P. (Philipp), Smith, J. G. (Jane G.), Steltzer, H. (Heidi), Totland, Ø. (Ørjan), Walker, M. D. (Marilyn D.), Welker, J. M. (Jeffrey M.), and Suding, K. N. (Katharine N.)

Abstract

Rapid climate warming is altering Arctic and alpine tundra ecosystem structure and function, including shifts in plant phenology. While the advancement of green up and flowering are well-documented, it remains unclear whether all phenophases, particularly those later in the season, will shift in unison or respond divergently to warming. Here, we present the largest synthesis to our knowledge of experimental warming effects on tundra plant phenology from the International Tundra Experiment. We examine the effect of warming on a suite of season-wide plant phenophases. Results challenge the expectation that all phenophases will advance in unison to warming. Instead, we find that experimental warming caused: (1) larger phenological shifts in reproductive versus vegetative phenophases and (2) advanced reproductive phenophases and green up but delayed leaf senescence which translated to a lengthening of the growing season by approximately 3%. Patterns were consistent across sites, plant species and over time. The advancement of reproductive seasons and lengthening of growing seasons may have significant consequences for trophic interactions and ecosystem function across the tundra.

Published
2021

17. Circumpolar Arctic Vegetation Classification

Author

Walker, D. A., Daniëls, F. J. A., Matveyeva, N. V., Šibík, J., Walker, M. D., Breen, A. L., Druckenmiller, L. A., Raynolds, M. K., Bültmann, H., Hennekens, S., Buchhorn, M., Epstein, H. E., Ermokhina, K., Fosaa, A. M., Heidmarsson, S., Heim, B., Jónsdóttir, I. S., Koroleva, N., Lévesque, E., MacKenzie, W. H., Henry, G. H. R., Nilsen, L., Peet, R., Razzhivin, V., Talbot, S. S., Telyatnikov, M., Thannheiser, D., Webber, P. J., Wirth, L. M., Walker, D. A., Daniëls, F. J. A., Matveyeva, N. V., Šibík, J., Walker, M. D., Breen, A. L., Druckenmiller, L. A., Raynolds, M. K., Bültmann, H., Hennekens, S., Buchhorn, M., Epstein, H. E., Ermokhina, K., Fosaa, A. M., Heidmarsson, S., Heim, B., Jónsdóttir, I. S., Koroleva, N., Lévesque, E., MacKenzie, W. H., Henry, G. H. R., Nilsen, L., Peet, R., Razzhivin, V., Talbot, S. S., Telyatnikov, M., Thannheiser, D., Webber, P. J., and Wirth, L. M.

Abstract

Aims: An Arctic Vegetation Classification (AVC) is needed to address issues related to rapid Arctic-wide changes to climate, land-use, and biodiversity. Location: The 7.1 million km2 Arctic tundra biome. Approach and conclusions: The purpose, scope and conceptual framework for an Arctic Vegetation Archive (AVA) and Classification (AVC) were developed during numerous workshops starting in 1992. The AVA and AVC are modeled after the European vegetation archive (EVA) and classification (EVC). The AVA will use Turboveg for data management. The AVC will use a Braun-Blanquet (Br.-Bl.) classification approach. There are approximately 31,000 Arctic plots that could be included in the AVA. An Alaska AVA (AVA-AK, 24 datasets, 3026 plots) is a prototype for archives in other parts of the Arctic. The plan is to eventually merge data from other regions of the Arctic into a single Turboveg v3 database. We present the pros and cons of using the Br.-Bl. classification approach compared to the EcoVeg (US) and Biogeoclimatic Ecological Classification (Canada) approaches. The main advantages are that the Br.-Bl. approach already has been widely used in all regions of the Arctic, and many described, well-accepted vegetation classes have a pan-Arctic distribution. A crosswalk comparison of Dryas octopetala communities described according to the EcoVeg and the Braun-Blanquet approaches indicates that the non-parallel hierarchies of the two approaches make crosswalks difficult above the plantcommunity level. A preliminary Arctic prodromus contains a list of typical Arctic habitat types with associated described syntaxa from Europe, Greenland, western North America, and Alaska. Numerical clustering methods are used to provide an overview of the variability of habitat types across the range of datasets and to determine their relationship to previously described Braun-Blanquet syntaxa. We emphasize the need for continued maintenance of the Pan-Arctic Species List, and additional plot data to

Published
2018

20. RESPONSES OF TUNDRA PLANTS TO EXPERIMENTAL WARMING:META-ANALYSIS OF THE INTERNATIONAL TUNDRA EXPERIMENT

Author

Arft, A. M., primary, Walker, M. D., additional, Gurevitch, J., additional, Alatalo, J. M., additional, Bret-Harte, M. S., additional, Dale, M., additional, Diemer, M., additional, Gugerli, F., additional, Henry, G. H. R., additional, Jones, M. H., additional, Hollister, R. D., additional, Jónsdóttir, I. S., additional, Laine, K., additional, Lévesque, E., additional, Marion, G. M., additional, Molau, U., additional, Mølgaard, P., additional, Nordenhäll, U., additional, Raszhivin, V., additional, Robinson, C. H., additional, Starr, G., additional, Stenström, A., additional, Stenström, M., additional, Totland, Ø., additional, Turner, P. L., additional, Walker, L. J., additional, Webber, P. J., additional, Welker, J. M., additional, and Wookey, P. A., additional

Published
1999
Full Text
View/download PDF

21. Responses to mineral nutrient availability and heterogeneity in physiologically integrated sedges from contrasting habitats.

Author

D'Hertefeldt, T., Falkengren-Grerup, U., and Jónsdóttir, I. S.

Subjects
PLANT nutrients, PLANT physiology, CAREX, HABITATS, PLANT clones, PLANT cellular signal transduction, PLANT biomass, BIOMASS production
Abstract

Clonal plants from poor habitats benefit less from morphologically plastic responses to heterogeneity than plants from more productive sites. In addition, physiological integration has been suggested to either increase or decrease the foraging efficiency of clonal plants. We tested the capacity for biomass production and morphological response in two closely related, rhizomatous species from habitats that differ in resource availability, Carex arenaria (from poor sand dunes) and C. disticha (from nutrient-richer, moister habitats). We expected lower total biomass production and reduced morphological plasticity in C. arenaria, and that both species would produce more ramets in high nutrient patches, either in response to signals transported through physiological integration, or by locally determined responses to nutrient availability. To investigate mineral nutrient heterogeneity, plants were grown in boxes divided into two compartments with homogeneous or heterogeneous supply of high (H) or low (L) nutrient levels, resulting in four treatments, H-H, H-L, L-H and L-L. Both C. arenaria and C. disticha produced similar biomass in high nutrient treatments. C. disticha responded to high nutrients by increased biomass production and branching of the young parts and by altering root:shoot ratio and rhizome lengths, while C. arenaria showed localised responses to high nutrients in terms of local biomass and branch production in high nutrient patches. The results demonstrated that although it has a conservative morphology, C. arenaria responded to nutrient heterogeneity through morphological plasticity. An analysis of costs and benefits of integration on biomass production showed that young ramets of both species benefited significantly from physiological integration, but no corresponding costs were found. This suggests that plants from resource-poor but dynamic habitats like sand dunes respond morphologically to high nutrient patches. The two species responded to nutrient heterogeneity in different traits, and this is discussed in terms of local and distant signalling of plant status. [ABSTRACT FROM AUTHOR]

Published
2011
Full Text
View/download PDF

23. Climate Change and Goose Grazing on Svalbard’s Tundra

Author

Cooper, E., Jónsdóttir, I. S., Chaput, D., Dries Kuijper, Maarten J.J.E. Loonen, Pahud, A., Sjögersten, S., Richard Ubels, Wal, R., Woodin, Sarah J., Huiskes, A., Groningen Institute of Archaeology, and Arctic and Antarctic studies

24. Genetic variation and clonal diversity in four clonal sedges (Carex) along the Arctic coast of Eurasia.

Author

Stenström A, Jonsson BO, Jónsdóttir IS, Fagerström T, and Augner M

Subjects
Arctic Regions, Isoenzymes genetics, Magnoliopsida enzymology, Phylogeny, Plant Leaves chemistry, Polymorphism, Genetic genetics, Regression Analysis, Genes, Plant genetics, Genetic Variation, Magnoliopsida genetics
Abstract

We studied the structure of genetic variation (at both ramet- and genet-level) and clonal diversity within and among populations in the four closely related arctic clonal sedges Carex bigelowii, C. ensifolia, C. lugens and C. stans by use of allozyme markers. Compared to other sedges and arctic plants, the studied taxa all had high levels of genetic variation, both within populations and taxa. These taxa contained most of the total gene diversity (H(T)) within populations and a small part of the diversity among populations (G(ST) ranged 0.05--0.43). Carex bigelowii had genetic variation (H(S) = 0.173, mean for populations) at a comparable level to other outbreeding arctic plants and to other widespread, rhizomatous and mainly outbreeding Carex species. In contrast, C. ensifolia (H(S) = 0.335), C. lugens (H(S) = 0.339) and C. stans (H(S) = 0.294) had within-population variations that were higher than in most other studied Carex species and for arctic plants in general. Genetic variation was not related to any tested environmental variable, but it was lower in areas deglaciated only 10,000 years BP compared to areas deglaciated 60,000 years BP or not glaciated at all during the Weichselian. All the populations were multiclonal, except for two populations of C. stans that were monoclonal. In contrast to genetic variation, clonal diversity decreased with latitude and did not differ between areas with different times of deglaciation. In accordance with previous studies, C. bigelowii and C. lugens were found to be outbreeding, while C. ensifolia and C. stans had mixed mating systems.

Published
2001
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results