ALBERT

Description: The search for predictions of species diversity across environmental gradients has challenged ecologists for decades. The humped-back model (HBM) suggests that plant diversity peaks at intermediate productivity; at low productivity few species can tolerate the environmental stresses, and at high productivity a few highly competitive species dominate. Over time the HBM has become increasingly controversial, and recent studies claim to have refuted it. Here, by using data from coordinated surveys conducted throughout grasslands worldwide and comprising a wide range of site productivities, we provide evidence in support of the HBM pattern at both global and regional extents. The relationships described here provide a foundation for further research into the local, landscape, and historical factors that maintain biodiversity.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Fraser, Lauchlan H -- Pither, Jason -- Jentsch, Anke -- Sternberg, Marcelo -- Zobel, Martin -- Askarizadeh, Diana -- Bartha, Sandor -- Beierkuhnlein, Carl -- Bennett, Jonathan A -- Bittel, Alex -- Boldgiv, Bazartseren -- Boldrini, Ilsi I -- Bork, Edward -- Brown, Leslie -- Cabido, Marcelo -- Cahill, James -- Carlyle, Cameron N -- Campetella, Giandiego -- Chelli, Stefano -- Cohen, Ofer -- Csergo, Anna-Maria -- Diaz, Sandra -- Enrico, Lucas -- Ensing, David -- Fidelis, Alessandra -- Fridley, Jason D -- Foster, Bryan -- Garris, Heath -- Goheen, Jacob R -- Henry, Hugh A L -- Hohn, Maria -- Jouri, Mohammad Hassan -- Klironomos, John -- Koorem, Kadri -- Lawrence-Lodge, Rachael -- Long, Ruijun -- Manning, Pete -- Mitchell, Randall -- Moora, Mari -- Muller, Sandra C -- Nabinger, Carlos -- Naseri, Kamal -- Overbeck, Gerhard E -- Palmer, Todd M -- Parsons, Sheena -- Pesek, Mari -- Pillar, Valerio D -- Pringle, Robert M -- Roccaforte, Kathy -- Schmidt, Amanda -- Shang, Zhanhuan -- Stahlmann, Reinhold -- Stotz, Gisela C -- Sugiyama, Shu-ichi -- Szentes, Szilard -- Thompson, Don -- Tungalag, Radnaakhand -- Undrakhbold, Sainbileg -- van Rooyen, Margaretha -- Wellstein, Camilla -- Wilson, J Bastow -- Zupo, Talita -- New York, N.Y. -- Science. 2015 Jul 17;349(6245):302-5. doi: 10.1126/science.aab3916.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Natural Resource Sciences, Thompson Rivers University, Kamloops, BC, Canada. lfraser@tru.ca. ; Department of Biology, University of British Columbia, Okanagan campus, Kelowna, BC, Canada. ; Department of Disturbance Ecology, BayCEER, Uni- versity of Bayreuth, Bayreuth, Germany. ; Department of Molecular Biology and Ecology of Plants, Tel Aviv University, Tel-Aviv, Israel. ; Department of Botany, Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia. ; Faculty of Natural Resources College of Agriculture and Natural Resources, University of Tehran, Iran. ; MTA Centre for Ecological Research, Institute of Ecology and Botany, Vacratot, Hungary, and School of Plant Biology, University of Western Australia, Crawley, Australia. ; Department of Biogeography, BayCEER, University of Bayreuth, Bayreuth, Germany. ; Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada. ; Department of Ecology and Evolutionary Biology, University of Kansas, Manhattan, KS 66047, USA. ; Department of Biology, National University of Mongolia, Ulaanbaatar, Mongolia. ; Department of Botany, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil. ; Department of Agricultural, Food and Nutritional Sciences, University of Alberta, Edmonton, AB, Canada. ; Applied Behavioural Ecology and Ecosystem Research Unit, University of South Africa, Johannesberg, South Africa. ; Instituto Multidisciplinario de Biologia Vegetal (IMBIV-CONICET) and Facultad de Ciencias Exactas, Fisicas y Naturales, Universidad Nacional de Cordoba, Cordoba, Espana. ; School of Biosciences and Veterinary Medicine, University of Camerino, Camerino, Italy. ; School of Natural Sciences, Trinity College Dublin, Dublin, Ireland. ; Departamento de Botanica, UNESP - Univ. Estadual Paulista, Rio Claro, Brazil. ; Department of Biology, Syracuse University, Syracuse, NY 13210, USA. ; Department of Biology, University of Akron, Akron, OH 44325, USA. ; Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA. ; Department of Biology, University of Western Ontario, London, ON, Canada. ; Department of Botany, Corvinus University of Budapest, Budapest, Hungary. ; Department of Natural Resources, Islamic Azad University, Nour Branch, Iran. ; Department of Botany, University of Otago, Dunedin, New Zealand. ; International Centre for Tibetan Plateau Ecosystem Management, Lanzhou University, Lanzhou, China. ; Institute of Plant Sciences, University of Bern, Altenbergrain 21, CH-3013, Bern, Switzerland. ; Department of Ecology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil. ; Faculty of Agronomy, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil. ; Department of Range and Watershed Management, Ferdowsi University of Mashhad, Iran. ; Department of Biology, University of Florida, Gainesville, FL 32611, USA. ; Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA. ; Department of Natural Resource Sciences, Thompson Rivers University, Kamloops, BC, Canada. ; Laboratory of Plant Ecology, Hirosaki University, Hirosaki, Japan. ; Institute of Plant Production, Szent Istvan University, Godollo, Hungary. ; Agriculture and Agri-Food Canada, Lethbridge Research Centre, Lethbridge, AB, Canada. ; Department of Plant Science, University of Pretoria, Pretoria, South Africa. ; Faculty of Science and Technology, Free University of Bozen-Bolzano, Bolzano, Italy. ; Department of Botany, University of Otago, Dunedin, New Zealand. Landcare Research, Dunedin, New Zealand.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26185249" target="_blank"〉PubMed〈/a〉

Description: Tredennick et al. criticize one of our statistical analyses and emphasize the low explanatory power of models relating productivity to diversity. These criticisms do not detract from our key findings, including evidence consistent with the unimodal constraint relationship predicted by the humped-back model and evidence of scale sensitivities in the form and strength of the relationship.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Pither, Jason -- Fraser, Lauchlan H -- Jentsch, Anke -- Sternberg, Marcelo -- Zobel, Martin -- Cahill, James -- Beierkuhnlein, Carl -- Bartha, Sandor -- Bennett, Jonathan A -- Boldgiv, Bazartseren -- Brown, Leslie R -- Cabido, Marcelo -- Campetella, Giandiego -- Carlyle, Cameron N -- Chelli, Stefano -- Csergo, Anna Maria -- Diaz, Sandra -- Enrico, Lucas -- Ensing, David -- Fidelis, Alessandra -- Garris, Heath W -- Henry, Hugh A L -- Hohn, Maria -- Klironomos, John -- Koorem, Kadri -- Lawrence-Lodge, Rachael -- Manning, Peter -- Mitchell, Randall J -- Moora, Mari -- Pillar, Valerio D -- Stotz, Gisela C -- Sugiyama, Shu-ichi -- Szentes, Szilard -- Tungalag, Radnaakhand -- Undrakhbold, Sainbileg -- Wellstein, Camilla -- Zupo, Talita -- New York, N.Y. -- Science. 2016 Jan 29;351(6272):457. doi: 10.1126/science.aad8019.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biology, University of British Columbia, Okanagan Campus, Kelowna, BC, Canada. jason.pither@ubc.ca. ; Department of Natural Resource Sciences, Thompson Rivers University, Kamloops, BC, Canada. ; Department of Disturbance Ecology, BayCEER, University of Bayreuth, Bayreuth, Germany. ; Department of Molecular Biology and Ecology of Plants, Tel Aviv University, Tel-Aviv, Israel. ; Department of Botany, Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia. ; Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada. ; Department of Biogeography, Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, Bayreuth, Germany. ; Hungarian Academy of Sciences Centre for Ecological Research, Institute of Ecology and Botany, Vacratot, Hungary. School of Plant Biology, University of Western Australia, Crawley, Australia. ; Department of Botany, Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia. Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada. ; Ecology Group, Department of Biology, National University of Mongolia, Ulaanbaatar, Mongolia. ; Department of Environmental Sciences, University of South Africa, Florida, South Africa. ; Facultad de Ciencias Exactas, Fisicas y Naturales, Universidad Nacional de Cordoba, Cordoba, Argentina. ; School of Biosciences and Veterinary Medicine, Plant Diversity and Ecosystems Management Unit, University of Camerino, Camerino, Italy. ; Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Canada. ; School of Natural Sciences, Trinity College Dublin, The University of Dublin, Dublin, Ireland. ; Instituto Multidisciplinario de Biologia Vegetal (IMBIV), National Scientific and Technical Research Council and Facultad de Ciencias Exactas, Fisicas y Naturales, Universidad Nacional de Cordoba, Cordoba, Argentina. ; Department of Biology, Queen's University, Kingston, Ontario, Canada. ; Departamento de Botanica, UNESP - Universidade Estadual Paulista, Rio Claro, SP, Brazil. ; Department of Biology, University of Western Ontario, London, Ontario, Canada. ; Department of Botany, Faculty of Horticultural Science, Corvinus University of Budapest, Hungary. ; Department of Biology, University of British Columbia, Okanagan Campus, Kelowna, BC, Canada. ; Department of Botany, University of Otago, Dunedin, New Zealand. ; Biodiversity and Climate Research Centre, Senckenberg Gesellschaft fur Naturforschung, Germany. ; Department of Biology, University of Akron, Akron, OH, USA. ; Department of Ecology, Federal University of Rio Grande do Sul, Porto Alegre, Brazil. ; Faculty of Agriculture and Life Science, Hirosaki University, Aomori, Japan. ; Institute of Plant Production, Szent Istvan University, Godollo, Hungary. ; Faculty of Science and Technology, Free University of Bozen-Bolzano, Bolzano, Italy.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26823419" target="_blank"〉PubMed〈/a〉

Description: Aims Increasing evidence worldwide indicates that high mountain regions are not immune to invasion by alien plants. Here, we aimed to address whether three major woody invaders of low-mountain areas are constrained to lower altitudes due to climatic restrictions or just by low propagule pressure. We hypothesize that the increasing climatic harshness towards higher altitudes restricts seedling establishment and survival of these woody invaders and thus their potential for altitudinal expansion. Methods The study was carried out in the Sierras Grandes Mountains, Córdoba, central Argentina (32º50'S, 64º90'W). We addressed the hypothesis with an experimental approach, dissociating the effect of the environmental gradient from that of propagule pressure, by discarding the influence of seed sources. We translocated seeds of Gleditsia triacanthos L. , Ligustrum lucidum W.T. Aiton. and Pyracantha angustifolia (Franch.) C.K.Schneid. along the altitudinal gradient (from 900 to 2700 m asl). Seven sites were selected along the altitudinal gradient, spaced every 200–400 m. Three plots (4 x 4 m) were selected within each altitudinal site and excluded from livestock; 100 seeds of each species were sown within each plot (6300 seeds in total). Seedling emergence and survival was monitored during two growing seasons and soil temperature and moisture was recorded as well. The field experiment was complemented with lab assays. Important Findings Climate along this altitudinal gradient might be least restrictive at mid elevations, as a result of the intersection between opposite soil temperature and moisture gradients. Sown seeds germinated along the whole altitudinal gradient and seedlings successfully established and over-wintered well above their current altitudinal distribution (up to 2200 m for Ligustrum and 2400 m for Gleditsia and Pyracantha ). Additional lab assays confirmed field patterns and gave some insights into contrasting regeneration strategies between these invaders that might help to overcome stochastic environmental constraints in the germination stage. Overall, seedlings of three major woody invaders of low-mountain woodlands can establish and survive at higher elevations than their current distribution. In contrast to natives, they seem to be broad climate tolerators, rather than specialized stress tolerators, capable of germinating and growing across a wide elevational range. While long-term experiments might be necessary to fully address the potentials for altitudinal expansion, out results on early lifecycle stage suggest that the invaders studied here would have mostly a dispersal barrier rather than a climate barrier to establish in the upper belt of the Sierras Grandes.