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Juha M. Alatalo

Bio: Juha M. Alatalo is an academic researcher from Qatar University. The author has contributed to research in topics: Tundra & Climate change. The author has an hindex of 28, co-authored 121 publications receiving 5280 citations. Previous affiliations of Juha M. Alatalo include Uppsala University & Florida State University College of Arts and Sciences.


Papers
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Journal ArticleDOI
TL;DR: Warming increased height and cover of deciduous shrubs and graminoids, decreased cover of mosses and lichens, and decreased species diversity and evenness, which predict that warming will cause a decline in biodiversity across a wide variety of tundra, at least in the short term.
Abstract: Recent observations of changes in some tundra ecosystems appear to be responses to a warming climate. Several experimental studies have shown that tundra plants and ecosystems can respond strongly to environmental change, including warming; however, most studies were limited to a single location and were of short duration and based on a variety of experimental designs. In addition, comparisons among studies are difficult because a variety of techniques have been used to achieve experimental warming and different measurements have been used to assess responses. We used metaanalysis on plant community measurements from standardized warming experiments at 11 locations across the tundra biome involved in the International Tundra Experiment. The passive warming treatment increased plant-level air temperature by 1-3°C, which is in the range of predicted and observed warming for tundra regions. Responses were rapid and detected in whole plant communities after only two growing seasons. Overall, warming increased height and cover of deciduous shrubs and graminoids, decreased cover of mosses and lichens, and decreased species diversity and evenness. These results predict that warming will cause a decline in biodiversity across a wide variety of tundra, at least in the short term. They also provide rigorous experimental evidence that recently observed increases in shrub cover in many tundra regions are in response to climate warming. These changes have important implications for processes and interactions within tundra ecosystems and between tundra and the atmosphere.

1,232 citations

Journal ArticleDOI
TL;DR: Results indicate that key phenological events such as leaf bud burst and flowering occurred earlier in warmed plots throughout the study period; however, there was little impact on growth cessation at the end of the season.
Abstract: The International Tundra Experiment (ITEX) is a collaborative, multisite experiment using a common temperature manipulation to examine variability in species response across climatic and geographic gradients of tundra ecosystems. ITEX was designed specifically to examine variability in arctic and alpine species response to increased temperature. We compiled from one to four years of experimental data from 13 different ITEX sites and used meta-analysis to analyze responses of plant phenology, growth, and reproduction to experimental warming. Results indicate that key phenological events such as leaf bud burst and flowering occurred earlier in warmed plots throughout the study period; however, there was little impact on growth cessation at the end of the season. Quantitative measures of vegetative growth were greatest in warmed plots in the early years of the experiment, whereas reproductive effort and success increased in later years. A shift away from vegetative growth and toward reproductive effort and success in the fourth treatment year suggests a shift from the initial response to a secondary response. The change in vegetative response may be due to depletion of stored plant reserves, whereas the lag in reproductive response may be due to the formation of flower buds one to several seasons prior to flowering. Both vegetative and reproductive responses varied among life-forms; herbaceous forms had stronger and more consistent vegetative growth responses than did woody forms. The greater responsiveness of the herbaceous forms may be attributed to their more flexible morphology and to their relatively greater proportion of stored plant reserves. Finally, warmer, low arctic sites produced the strongest growth responses, but colder sites produced a greater reproductive response. Greater resource investment in vegetative growth may be a conservative strategy in the Low Arctic, where there is more competition for light, nutrients, or water, and there may be little opportunity for successful germination or seedling development. In contrast, in the High Arctic, heavy investment in producing seed under a higher temperature scenario may provide an opportunity for species to colonize patches of unvegetated ground. The observed differential response to warming suggests that the primary forces driving the response vary across climatic zones, functional groups, and through time.

854 citations

Journal ArticleDOI
TL;DR: Cornelissen et al. as discussed by the authors showed that lichen decline in arctic ecosystems is a function of increases in vascular plant biomass, and proposed a global change and arctic ecology model.
Abstract: Cornelissen, J. H. C., Callaghan, T. V., Alatalo, J. M., Michelsen, A., Graglia, E., Hartley, A. E., Hik, D. S., Hobbie, S. E., Press, M. C., Robinson, C. H., Henry, G. H. R. (2001). Global change and arctic ecosystems: is lichen decline a function of increases in vascular plant biomass. Journal of Ecology, 89, (6), 984-994. Sponsorship: Swedish Natural Science Research Council (NFR)/Swedish Environmental Protection Agency (two grants)/ US National Science Foundation (four grants)/ the Danish Natural Science Research Council (two grants)/ NASA (Global Change Fellowship), NSERC (Canada, two grants)/the Natural Environment Research Council (UJ, two grants)/ the 'Stiftelse for Oscar & Lilli Lamms Minne' (Sweden) / ESRC (Global Change Research Council).

452 citations

Journal ArticleDOI
TL;DR: It is demonstrated that longer-term, large-scale changes to leaf litter decomposition will be driven primarily by both direct warming effects and concomitant shifts in plant growth form composition, with a much smaller role for changes in litter quality within species.
Abstract: Whether climate change will turn cold biomes from large long-term carbon sinks into sources is hotly debated because of the great potential for ecosystem-mediated feedbacks to global climate. Critical are the direction, magnitude and generality of climate responses of plant litter decomposition. Here, we present the first quantitative analysis of the major climate-change-related drivers of litter decomposition rates in cold northern biomes worldwide. Leaf litters collected from the predominant species in 33 global change manipulation experiments in circum-arctic-alpine ecosystems were incubated simultaneously in two contrasting arctic life zones. We demonstrate that longer-term, large-scale changes to leaf litter decomposition will be driven primarily by both direct warming effects and concomitant shifts in plant growth form composition, with a much smaller role for changes in litter quality within species. Specifically, the ongoing warming-induced expansion of shrubs with recalcitrant leaf litter across cold biomes would constitute a negative feedback to global warming. Depending on the strength of other (previously reported) positive feedbacks of shrub expansion on soil carbon turnover, this may partly counteract direct warming enhancement of litter decomposition.

427 citations

Journal ArticleDOI
Anne D. Bjorkman1, Anne D. Bjorkman2, Isla H. Myers-Smith2, Sarah C. Elmendorf3, Sarah C. Elmendorf4, Sarah C. Elmendorf5, Signe Normand1, Nadja Rüger6, Pieter S. A. Beck, Anne Blach-Overgaard1, Daan Blok7, J. Hans C. Cornelissen8, Bruce C. Forbes9, Damien Georges2, Scott J. Goetz10, Kevin C. Guay11, Gregory H. R. Henry12, Janneke HilleRisLambers13, Robert D. Hollister14, Dirk Nikolaus Karger15, Jens Kattge16, Peter Manning, Janet S. Prevéy, Christian Rixen, Gabriela Schaepman-Strub17, Haydn J.D. Thomas2, Mark Vellend18, Martin Wilmking19, Sonja Wipf, Michele Carbognani20, Luise Hermanutz21, Esther Lévesque22, Ulf Molau23, Alessandro Petraglia20, Nadejda A. Soudzilovskaia24, Marko J. Spasojevic25, Marcello Tomaselli20, Tage Vowles23, Juha M. Alatalo26, Heather D. Alexander27, Alba Anadon-Rosell19, Alba Anadon-Rosell28, Sandra Angers-Blondin2, Mariska te Beest29, Mariska te Beest30, Logan T. Berner10, Robert G. Björk23, Agata Buchwal31, Agata Buchwal32, Allan Buras33, Katherine S. Christie34, Elisabeth J. Cooper35, Stefan Dullinger36, Bo Elberling37, Anu Eskelinen38, Anu Eskelinen39, Esther R. Frei12, Esther R. Frei15, Oriol Grau40, Paul Grogan41, Martin Hallinger, Karen A. Harper42, Monique M. P. D. Heijmans33, James I. Hudson, Karl Hülber36, Maitane Iturrate-Garcia17, Colleen M. Iversen43, Francesca Jaroszynska44, Jill F. Johnstone45, Rasmus Halfdan Jørgensen37, Elina Kaarlejärvi46, Elina Kaarlejärvi30, Rebecca A Klady12, Sara Kuleza45, Aino Kulonen, Laurent J. Lamarque22, Trevor C. Lantz47, Chelsea J. Little48, Chelsea J. Little17, James D. M. Speed49, Anders Michelsen37, Ann Milbau50, Jacob Nabe-Nielsen1, Sigrid Schøler Nielsen1, Josep M. Ninot28, Steven F. Oberbauer51, Johan Olofsson30, Vladimir G. Onipchenko52, Sabine B. Rumpf36, Philipp R. Semenchuk35, Philipp R. Semenchuk36, Rohan Shetti19, Laura Siegwart Collier21, Lorna E. Street2, Katharine N. Suding4, Ken D. Tape53, Andrew J. Trant54, Andrew J. Trant21, Urs A. Treier1, Jean-Pierre Tremblay55, Maxime Tremblay22, Susanna Venn56, Stef Weijers57, Tara Zamin41, Noémie Boulanger-Lapointe12, William A. Gould58, David S. Hik59, Annika Hofgaard, Ingibjörg S. Jónsdóttir60, Ingibjörg S. Jónsdóttir61, Janet C. Jorgenson62, Julia A. Klein63, Borgthor Magnusson, Craig E. Tweedie64, Philip A. Wookey65, Michael Bahn66, Benjamin Blonder67, Benjamin Blonder68, Peter M. van Bodegom24, Benjamin Bond-Lamberty69, Giandiego Campetella70, Bruno Enrico Leone Cerabolini71, F. Stuart Chapin53, William K. Cornwell72, Joseph M. Craine, Matteo Dainese, Franciska T. de Vries73, Sandra Díaz74, Brian J. Enquist75, Brian J. Enquist76, Walton A. Green77, Rubén Milla78, Ülo Niinemets79, Yusuke Onoda80, Jenny C. Ordoñez81, Wim A. Ozinga33, Wim A. Ozinga82, Josep Peñuelas40, Hendrik Poorter83, Hendrik Poorter84, Peter Poschlod85, Peter B. Reich86, Peter B. Reich87, Brody Sandel88, Brandon S. Schamp89, Serge N. Sheremetev90, Evan Weiher91 
Aarhus University1, University of Edinburgh2, National Ecological Observatory Network3, University of Colorado Boulder4, Institute of Arctic and Alpine Research5, Smithsonian Institution6, Lund University7, VU University Amsterdam8, University of Lapland9, Northern Arizona University10, Bigelow Laboratory For Ocean Sciences11, University of British Columbia12, University of Washington13, Grand Valley State University14, Swiss Federal Institute for Forest, Snow and Landscape Research15, Max Planck Society16, University of Zurich17, Université de Sherbrooke18, University of Greifswald19, University of Parma20, Memorial University of Newfoundland21, Université du Québec à Trois-Rivières22, University of Gothenburg23, Leiden University24, University of California, Riverside25, Qatar University26, Mississippi State University27, University of Barcelona28, Utrecht University29, Umeå University30, Adam Mickiewicz University in Poznań31, University of Alaska Anchorage32, Wageningen University and Research Centre33, Alaska Department of Fish and Game34, University of Tromsø35, University of Vienna36, University of Copenhagen37, Helmholtz Centre for Environmental Research - UFZ38, University of Oulu39, Spanish National Research Council40, Queen's University41, Saint Mary's University42, Oak Ridge National Laboratory43, University of Aberdeen44, University of Saskatchewan45, Vrije Universiteit Brussel46, University of Victoria47, Swiss Federal Institute of Aquatic Science and Technology48, Norwegian University of Science and Technology49, Research Institute for Nature and Forest50, Florida International University51, Moscow State University52, University of Alaska Fairbanks53, University of Waterloo54, Laval University55, Deakin University56, University of Bonn57, United States Forest Service58, Simon Fraser University59, University of Iceland60, University Centre in Svalbard61, United States Fish and Wildlife Service62, Colorado State University63, University of Texas at El Paso64, University of Stirling65, University of Innsbruck66, University of Oxford67, Rocky Mountain Biological Laboratory68, Pacific Northwest National Laboratory69, University of Camerino70, University of Insubria71, University of New South Wales72, University of Manchester73, National University of Cordoba74, University of Arizona75, Santa Fe Institute76, Harvard University77, King Juan Carlos University78, Estonian University of Life Sciences79, Kyoto University80, World Agroforestry Centre81, Radboud University Nijmegen82, Macquarie University83, Forschungszentrum Jülich84, University of Regensburg85, University of Minnesota86, University of Sydney87, Santa Clara University88, Algoma University89, Komarov Botanical Institute90, University of Wisconsin–Eau Claire91
04 Oct 2018-Nature
TL;DR: Biome-wide relationships between temperature, moisture and seven key plant functional traits across the tundra and over time show that community height increased with warming across all sites, whereas other traits lagged behind predicted rates of change.
Abstract: The tundra is warming more rapidly than any other biome on Earth, and the potential ramifications are far-reaching because of global feedback effects between vegetation and climate. A better understanding of how environmental factors shape plant structure and function is crucial for predicting the consequences of environmental change for ecosystem functioning. Here we explore the biome-wide relationships between temperature, moisture and seven key plant functional traits both across space and over three decades of warming at 117 tundra locations. Spatial temperature-trait relationships were generally strong but soil moisture had a marked influence on the strength and direction of these relationships, highlighting the potentially important influence of changes in water availability on future trait shifts in tundra plant communities. Community height increased with warming across all sites over the past three decades, but other traits lagged far behind predicted rates of change. Our findings highlight the challenge of using space-for-time substitution to predict the functional consequences of future warming and suggest that functions that are tied closely to plant height will experience the most rapid change. They also reveal the strength with which environmental factors shape biotic communities at the coldest extremes of the planet and will help to improve projections of functional changes in tundra ecosystems with climate warming.

425 citations


Cited by
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Journal Article
TL;DR: In this article, the authors present a document, redatto, voted and pubblicato by the Ipcc -Comitato intergovernativo sui cambiamenti climatici - illustra la sintesi delle ricerche svolte su questo tema rilevante.
Abstract: Cause, conseguenze e strategie di mitigazione Proponiamo il primo di una serie di articoli in cui affronteremo l’attuale problema dei mutamenti climatici. Presentiamo il documento redatto, votato e pubblicato dall’Ipcc - Comitato intergovernativo sui cambiamenti climatici - che illustra la sintesi delle ricerche svolte su questo tema rilevante.

4,187 citations

Journal Article
TL;DR: In this paper, a documento: "Cambiamenti climatici 2007: impatti, adattamento e vulnerabilita" voteato ad aprile 2007 dal secondo gruppo di lavoro del Comitato Intergovernativo sui Cambiamentsi Climatici (Intergovernmental Panel on Climate Change).
Abstract: Impatti, adattamento e vulnerabilita Le cause e le responsabilita dei cambiamenti climatici sono state trattate sul numero di ottobre della rivista Cda. Approfondiamo l’argomento presentando il documento: “Cambiamenti climatici 2007: impatti, adattamento e vulnerabilita” votato ad aprile 2007 dal secondo gruppo di lavoro del Comitato Intergovernativo sui Cambiamenti Climatici (Intergovernmental Panel on Climate Change). Si tratta del secondo di tre documenti che compongono il quarto rapporto sui cambiamenti climatici.

3,979 citations

Book
01 Jan 1999
TL;DR: In this article, a taxonomic index (genera) of alpine plants is presented, with a brief review of water relations and water relations of alpin plants in the alpine life zone.
Abstract: 1 Plant ecology at high elevations.- The concept of limitation.- A regional and historical account.- The challenge of alpine plant research.- 2 The alpine life zone.- Altitudinal boundaries.- Global alpine land area.- Alpine plant diversity.- Origin of alpine floras.- Alpine growth forms.- 3 Alpine climate.- Which alpine climate.- Common features of alpine climates.- Regional features of alpine climates.- 4 The climate plants experience.- Interactions of relief, wind and sun.- How alpine plants influence their climate.- The geographic variation of alpine climate.- 5 Life under snow: protection and limitation.- Temperatures under snow.- Solar radiation under snow.- Gas concentrations under snow.- Plant responses to snowpack.- 6 Alpine soils.- Physics of alpine soil formation.- The organic compound.- The interaction of organic and inorganic compounds.- 7 Alpine treelines.- About trees and lines.- Current altitudinal positions of climatic treelines.- Treeline-climate relationships.- Intrazonal variations and pantropical plateauing of alpine treelines.- Treelines in the past.- Attempts at a functional explanation of treelines.- A hypothesis for treeline formation.- Growth trends near treelines.- Evidence for sink limitation.- 8 Climatic stress.- Survival of low temperature extremes.- Avoidance and tolerance of low temperature extremes.- Heat stress in alpine plants.- Ultraviolet radiation - a stress factor.- 9 Water relations.- Ecosystem water balance.- Soil moisture at high altitudes.- Plant water relations - a brief review of principles.- Water relations of alpine plants.- Desiccation stress.- Water relations of special plant types.- 10 Mineral nutrition.- Soil nutrients.- The nutrient status of alpine plants.- Nutrient cycling and nutrient budgets.- Nitrogen fixation.- Mycorrhiza.- Responses of vegetation to variable nutrient supply.- 11 Uptake and loss of carbon.- Photosynthetic capacity of alpine plants.- Photosynthetic responses to the environment.- Daily carbon gain of leaves.- The seasonal carbon gain of leaves.- C4 and CAM photosynthesis at high altitudes.- Tissue respiration of alpine plants.- Ecosystem carbon balance.- 12 Carbon investments.- Non-structural carbohydrates.- Lipids and energy content.- Carbon costs of leaves and roots.- Whole plant carbon allocation.- 13 Growth dynamics and phenology.- Seasonal growth.- Diurnal leaf extension.- Rates of plant dry matter accumulation.- Functional duration of leaves and roots.- 14 Cell division and tissue formation.- Cell size and plant size.- Mitosis and the cell cycle.- From meristem activity to growth control.- 15 Plant biomass production.- The structure of alpine plant canopies.- Primary productivity of alpine vegetation.- Plant dry matter pools.- Biomass losses through herbivores.- 16 Plant reproduction.- Flowering and pollination.- Seed development and seed size.- Germination.- Alpine seed banks and natural recruitment.- Clonal propagation.- Alpine plant age.- Community processes.- 17 Global change at high elevation.- Alpine land use.- The impact of altered atmospheric chemistry.- Climatic change and alpine ecosystems.- References (with chapter annotation).- Taxonomic index (genera).- Geographical index.- Color plates.- Plant life forms.- The alpine life zone.- Environmental stress.- The human dimension.

2,971 citations

Journal ArticleDOI
TL;DR: This new handbook has a better balance between whole-plant traits, leaf traits, root and stem traits and regenerative traits, and puts particular emphasis on traits important for predicting species’ effects on key ecosystem properties.
Abstract: Plant functional traits are the features (morphological, physiological, phenological) that represent ecological strategies and determine how plants respond to environmental factors, affect other trophic levels and influence ecosystem properties. Variation in plant functional traits, and trait syndromes, has proven useful for tackling many important ecological questions at a range of scales, giving rise to a demand for standardised ways to measure ecologically meaningful plant traits. This line of research has been among the most fruitful avenues for understanding ecological and evolutionary patterns and processes. It also has the potential both to build a predictive set of local, regional and global relationships between plants and environment and to quantify a wide range of natural and human-driven processes, including changes in biodiversity, the impacts of species invasions, alterations in biogeochemical processes and vegetation–atmosphere interactions. The importance of these topics dictates the urgent need for more and better data, and increases the value of standardised protocols for quantifying trait variation of different species, in particular for traits with power to predict plant- and ecosystem-level processes, and for traits that can be measured relatively easily. Updated and expanded from the widely used previous version, this handbook retains the focus on clearly presented, widely applicable, step-by-step recipes, with a minimum of text on theory, and not only includes updated methods for the traits previously covered, but also introduces many new protocols for further traits. This new handbook has a better balance between whole-plant traits, leaf traits, root and stem traits and regenerative traits, and puts particular emphasis on traits important for predicting species’ effects on key ecosystem properties. We hope this new handbook becomes a standard companion in local and global efforts to learn about the responses and impacts of different plant species with respect to environmental changes in the present, past and future.

2,744 citations

01 Feb 2016

1,970 citations