TY - JOUR A1 - Allan, Eric A1 - Bossdorf, Oliver A1 - Dormann, Carsten F. A1 - Prati, Daniel A1 - Gossner, Martin M. A1 - Tscharntke, Teja A1 - Blüthgen, Nico A1 - Bellach, Michaela A1 - Birkhofer, Klaus A1 - Boch, Steffen A1 - Böhm, Stefan A1 - Börschig, Carmen A1 - Chatzinotas, Antonis A1 - Christ, Sabina A1 - Daniel, Rolf A1 - Diekötter, Tim A1 - Fischer, Christiane A1 - Friedl, Thomas A1 - Glaser, Karin A1 - Hallmann, Christine A1 - Hodac, Ladislav A1 - Hölzel, Norbert A1 - Jung, Kirsten A1 - Klein, Alexandra-Maria A1 - Klaus, Valentin H. A1 - Kleinebecker, Till A1 - Krauss, Jochen A1 - Lange, Markus A1 - Morris, E. Kathryn A1 - Müller, Jörg A1 - Nacke, Heiko A1 - Pasalic, Esther A1 - Rillig, Matthias C. A1 - Rothenwoehrer, Christoph A1 - Schally, Peter A1 - Scherber, Christoph A1 - Schulze, Waltraud X. A1 - Socher, Stephanie A. A1 - Steckel, Juliane A1 - Steffan-Dewenter, Ingolf A1 - Türke, Manfred A1 - Weiner, Christiane N. A1 - Werner, Michael A1 - Westphal, Catrin A1 - Wolters, Volkmar A1 - Wubet, Tesfaye A1 - Gockel, Sonja A1 - Gorke, Martin A1 - Hemp, Andreas A1 - Renner, Swen C. A1 - Schöning, Ingo A1 - Pfeiffer, Simone A1 - König-Ries, Birgitta A1 - Buscot, Francois A1 - Linsenmair, Karl Eduard A1 - Schulze, Ernst-Detlef A1 - Weisser, Wolfgang W. A1 - Fischer, Markus T1 - Interannual variation in land-use intensity enhances grassland multidiversity JF - Proceedings of the National Academy of Sciences of the United States of America N2 - Although temporal heterogeneity is a well-accepted driver of biodiversity, effects of interannual variation in land-use intensity (LUI) have not been addressed yet. Additionally, responses to land use can differ greatly among different organisms; therefore, overall effects of land-use on total local biodiversity are hardly known. To test for effects of LUI (quantified as the combined intensity of fertilization, grazing, and mowing) and interannual variation in LUI (SD in LUI across time), we introduce a unique measure of whole-ecosystem biodiversity, multidiversity. This synthesizes individual diversity measures across up to 49 taxonomic groups of plants, animals, fungi, and bacteria from 150 grasslands. Multidiversity declined with increasing LUI among grasslands, particularly for rarer species and aboveground organisms, whereas common species and belowground groups were less sensitive. However, a high level of interannual variation in LUI increased overall multidiversity at low LUI and was even more beneficial for rarer species because it slowed the rate at which the multidiversity of rare species declined with increasing LUI. In more intensively managed grasslands, the diversity of rarer species was, on average, 18% of the maximum diversity across all grasslands when LUI was static over time but increased to 31% of the maximum when LUI changed maximally over time. In addition to decreasing overall LUI, we suggest varying LUI across years as a complementary strategy to promote biodiversity conservation. KW - biodiversity loss KW - agricultural grasslands KW - Biodiversity Exploratories Y1 - 2014 U6 - https://doi.org/10.1073/pnas.1312213111 SN - 0027-8424 VL - 111 IS - 1 SP - 308 EP - 313 PB - National Acad. of Sciences CY - Washington ER - TY - JOUR A1 - Penone, Caterina A1 - Allan, Eric A1 - Soliveres, Santiago A1 - Felipe-Lucia, Maria R. A1 - Gossner, Martin M. A1 - Seibold, Sebastian A1 - Simons, Nadja K. A1 - Schall, Peter A1 - van der Plas, Fons A1 - Manning, Peter A1 - Manzanedo, Ruben D. A1 - Boch, Steffen A1 - Prati, Daniel A1 - Ammer, Christian A1 - Bauhus, Juergen A1 - Buscot, Francois A1 - Ehbrecht, Martin A1 - Goldmann, Kezia A1 - Jung, Kirsten A1 - Mueller, Joerg A1 - Mueller, Joerg C. A1 - Pena, Rodica A1 - Polle, Andrea A1 - Renner, Swen C. A1 - Ruess, Liliane A1 - Schoenig, Ingo A1 - Schrumpf, Marion A1 - Solly, Emily F. A1 - Tschapka, Marco A1 - Weisser, Wolfgang W. A1 - Wubet, Tesfaye A1 - Fischer, Markus T1 - Specialisation and diversity of multiple trophic groups are promoted by different forest features JF - Ecology letters N2 - While forest management strongly influences biodiversity, it remains unclear how the structural and compositional changes caused by management affect different community dimensions (e.g. richness, specialisation, abundance or completeness) and how this differs between taxa. We assessed the effects of nine forest features (representing stand structure, heterogeneity and tree composition) on thirteen above- and belowground trophic groups of plants, animals, fungi and bacteria in 150 temperate forest plots differing in their management type. Canopy cover decreased light resources, which increased community specialisation but reduced overall diversity and abundance. Features increasing resource types and diversifying microhabitats (admixing of oaks and conifers) were important and mostly affected richness. Belowground groups responded differently to those aboveground and had weaker responses to most forest features. Our results show that we need to consider forest features rather than broad management types and highlight the importance of considering several groups and community dimensions to better inform conservation. KW - biodiversity exploratories KW - dark diversity KW - forest management KW - global change KW - land-use KW - multidiversity KW - specialisation KW - temperate forests Y1 - 2018 U6 - https://doi.org/10.1111/ele.13182 SN - 1461-023X SN - 1461-0248 VL - 22 IS - 1 SP - 170 EP - 180 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Tucker, Marlee A. A1 - Boehning-Gaese, Katrin A1 - Fagan, William F. A1 - Fryxell, John M. A1 - Van Moorter, Bram A1 - Alberts, Susan C. A1 - Ali, Abdullahi H. A1 - Allen, Andrew M. A1 - Attias, Nina A1 - Avgar, Tal A1 - Bartlam-Brooks, Hattie A1 - Bayarbaatar, Buuveibaatar A1 - Belant, Jerrold L. A1 - Bertassoni, Alessandra A1 - Beyer, Dean A1 - Bidner, Laura A1 - van Beest, Floris M. A1 - Blake, Stephen A1 - Blaum, Niels A1 - Bracis, Chloe A1 - Brown, Danielle A1 - de Bruyn, P. J. Nico A1 - Cagnacci, Francesca A1 - Calabrese, Justin M. A1 - Camilo-Alves, Constanca A1 - Chamaille-Jammes, Simon A1 - Chiaradia, Andre A1 - Davidson, Sarah C. A1 - Dennis, Todd A1 - DeStefano, Stephen A1 - Diefenbach, Duane A1 - Douglas-Hamilton, Iain A1 - Fennessy, Julian A1 - Fichtel, Claudia A1 - Fiedler, Wolfgang A1 - Fischer, Christina A1 - Fischhoff, Ilya A1 - Fleming, Christen H. A1 - Ford, Adam T. A1 - Fritz, Susanne A. A1 - Gehr, Benedikt A1 - Goheen, Jacob R. A1 - Gurarie, Eliezer A1 - Hebblewhite, Mark A1 - Heurich, Marco A1 - Hewison, A. J. Mark A1 - Hof, Christian A1 - Hurme, Edward A1 - Isbell, Lynne A. A1 - Janssen, Rene A1 - Jeltsch, Florian A1 - Kaczensky, Petra A1 - Kane, Adam A1 - Kappeler, Peter M. A1 - Kauffman, Matthew A1 - Kays, Roland A1 - Kimuyu, Duncan A1 - Koch, Flavia A1 - Kranstauber, Bart A1 - LaPoint, Scott A1 - Leimgruber, Peter A1 - Linnell, John D. C. A1 - Lopez-Lopez, Pascual A1 - Markham, A. Catherine A1 - Mattisson, Jenny A1 - Medici, Emilia Patricia A1 - Mellone, Ugo A1 - Merrill, Evelyn A1 - Mourao, Guilherme de Miranda A1 - Morato, Ronaldo G. A1 - Morellet, Nicolas A1 - Morrison, Thomas A. A1 - Diaz-Munoz, Samuel L. A1 - Mysterud, Atle A1 - Nandintsetseg, Dejid A1 - Nathan, Ran A1 - Niamir, Aidin A1 - Odden, John A1 - Oliveira-Santos, Luiz Gustavo R. A1 - Olson, Kirk A. A1 - Patterson, Bruce D. A1 - de Paula, Rogerio Cunha A1 - Pedrotti, Luca A1 - Reineking, Bjorn A1 - Rimmler, Martin A1 - Rogers, Tracey L. A1 - Rolandsen, Christer Moe A1 - Rosenberry, Christopher S. A1 - Rubenstein, Daniel I. A1 - Safi, Kamran A1 - Said, Sonia A1 - Sapir, Nir A1 - Sawyer, Hall A1 - Schmidt, Niels Martin A1 - Selva, Nuria A1 - Sergiel, Agnieszka A1 - Shiilegdamba, Enkhtuvshin A1 - Silva, Joao Paulo A1 - Singh, Navinder A1 - Solberg, Erling J. A1 - Spiegel, Orr A1 - Strand, Olav A1 - Sundaresan, Siva A1 - Ullmann, Wiebke A1 - Voigt, Ulrich A1 - Wall, Jake A1 - Wattles, David A1 - Wikelski, Martin A1 - Wilmers, Christopher C. A1 - Wilson, John W. A1 - Wittemyer, George A1 - Zieba, Filip A1 - Zwijacz-Kozica, Tomasz A1 - Mueller, Thomas T1 - Moving in the Anthropocene BT - global reductions in terrestrial mammalian movements JF - Science N2 - Animal movement is fundamental for ecosystem functioning and species survival, yet the effects of the anthropogenic footprint on animal movements have not been estimated across species. Using a unique GPS-tracking database of 803 individuals across 57 species, we found that movements of mammals in areas with a comparatively high human footprint were on average one-half to one-third the extent of their movements in areas with a low human footprint. We attribute this reduction to behavioral changes of individual animals and to the exclusion of species with long-range movements from areas with higher human impact. Global loss of vagility alters a key ecological trait of animals that affects not only population persistence but also ecosystem processes such as predator-prey interactions, nutrient cycling, and disease transmission. Y1 - 2018 U6 - https://doi.org/10.1126/science.aam9712 SN - 0036-8075 SN - 1095-9203 VL - 359 IS - 6374 SP - 466 EP - 469 PB - American Assoc. for the Advancement of Science CY - Washington ER - TY - JOUR A1 - Noonan, Michael J. A1 - Tucker, Marlee A. A1 - Fleming, Christen H. A1 - Akre, Thomas S. A1 - Alberts, Susan C. A1 - Ali, Abdullahi H. A1 - Altmann, Jeanne A1 - Antunes, Pamela Castro A1 - Belant, Jerrold L. A1 - Beyer, Dean A1 - Blaum, Niels A1 - Boehning-Gaese, Katrin A1 - Cullen Jr, Laury A1 - de Paula, Rogerio Cunha A1 - Dekker, Jasja A1 - Drescher-Lehman, Jonathan A1 - Farwig, Nina A1 - Fichtel, Claudia A1 - Fischer, Christina A1 - Ford, Adam T. A1 - Goheen, Jacob R. A1 - Janssen, Rene A1 - Jeltsch, Florian A1 - Kauffman, Matthew A1 - Kappeler, Peter M. A1 - Koch, Flavia A1 - LaPoint, Scott A1 - Markham, A. Catherine A1 - Medici, Emilia Patricia A1 - Morato, Ronaldo G. A1 - Nathan, Ran A1 - Oliveira-Santos, Luiz Gustavo R. A1 - Olson, Kirk A. A1 - Patterson, Bruce D. A1 - Paviolo, Agustin A1 - Ramalho, Emiliano Estero A1 - Rosner, Sascha A1 - Schabo, Dana G. A1 - Selva, Nuria A1 - Sergiel, Agnieszka A1 - da Silva, Marina Xavier A1 - Spiegel, Orr A1 - Thompson, Peter A1 - Ullmann, Wiebke A1 - Zieba, Filip A1 - Zwijacz-Kozica, Tomasz A1 - Fagan, William F. A1 - Mueller, Thomas A1 - Calabrese, Justin M. T1 - A comprehensive analysis of autocorrelation and bias in home range estimation JF - Ecological monographs : a publication of the Ecological Society of America. N2 - Home range estimation is routine practice in ecological research. While advances in animal tracking technology have increased our capacity to collect data to support home range analysis, these same advances have also resulted in increasingly autocorrelated data. Consequently, the question of which home range estimator to use on modern, highly autocorrelated tracking data remains open. This question is particularly relevant given that most estimators assume independently sampled data. Here, we provide a comprehensive evaluation of the effects of autocorrelation on home range estimation. We base our study on an extensive data set of GPS locations from 369 individuals representing 27 species distributed across five continents. We first assemble a broad array of home range estimators, including Kernel Density Estimation (KDE) with four bandwidth optimizers (Gaussian reference function, autocorrelated‐Gaussian reference function [AKDE], Silverman's rule of thumb, and least squares cross‐validation), Minimum Convex Polygon, and Local Convex Hull methods. Notably, all of these estimators except AKDE assume independent and identically distributed (IID) data. We then employ half‐sample cross‐validation to objectively quantify estimator performance, and the recently introduced effective sample size for home range area estimation ( N̂ area ) to quantify the information content of each data set. We found that AKDE 95% area estimates were larger than conventional IID‐based estimates by a mean factor of 2. The median number of cross‐validated locations included in the hold‐out sets by AKDE 95% (or 50%) estimates was 95.3% (or 50.1%), confirming the larger AKDE ranges were appropriately selective at the specified quantile. Conversely, conventional estimates exhibited negative bias that increased with decreasing N̂ area. To contextualize our empirical results, we performed a detailed simulation study to tease apart how sampling frequency, sampling duration, and the focal animal's movement conspire to affect range estimates. Paralleling our empirical results, the simulation study demonstrated that AKDE was generally more accurate than conventional methods, particularly for small N̂ area. While 72% of the 369 empirical data sets had >1,000 total observations, only 4% had an N̂ area >1,000, where 30% had an N̂ area <30. In this frequently encountered scenario of small N̂ area, AKDE was the only estimator capable of producing an accurate home range estimate on autocorrelated data. KW - animal movement KW - kernel density estimation KW - local convex hull KW - minimum convex polygon KW - range distribution KW - space use KW - telemetry KW - tracking data Y1 - 2018 U6 - https://doi.org/10.1002/ecm.1344 SN - 0012-9615 SN - 1557-7015 VL - 89 IS - 2 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Müller, Jörg A1 - Boch, Steffen A1 - Prati, Daniel A1 - Socher, Stephanie A. A1 - Pommer, Ulf A1 - Hessenmöller, Dominik A1 - Schall, Peter A1 - Schulze, Ernst Detlef A1 - Fischer, Markus T1 - Effects of forest management on bryophyte species richness in Central European forests JF - Forest ecology and management N2 - We studied the effect of three major forest management types (unmanaged beech, selection beech, and age class forests) and stand variables (SMId, soil pH, proportion of conifers, litter cover, deadwood cover, rock cover and cumulative cover of woody trees and shrubs) on bryophyte species richness in 1050 forest plots in three regions in Germany. In addition, we analysed the species richness of four ecological guilds of bryophytes according to their colonized substrates (deadwood, rock, soil, bark) and the number of woodland indicator bryophyte species. Beech selection forests turned out to be the most species rich management type, whereas unmanaged beech forests revealed even lower species numbers than age-class forests. Increasing conifer proportion increased bryophyte species richness but not the number of woodland indicator bryophyte species. The richness of the four ecological guilds mainly responded to the abundance of their respective substrate. We conclude that the permanent availability of suitable substrates is most important for bryophyte species richness in forests, which is not stringently linked to management type. Therefore, managed age-class forests and selection forests may even exceed unmanaged forests in bryophyte species richness due to higher substrate supply and therefore represent important habitats for bryophytes. Typical woodland indicator bryophytes and their species richness were negatively affected by SMId (management intensity) and therefore better indicate forest integrity than the species richness of all bryophytes. Nature conservation efforts should focus on the reduction of management intensity. Moreover, maintaining and increasing a variability of substrates and habitats, such as coarse woody debris, increasing structural heterogeneity by retaining patches with groups of old, mature to over-mature trees in managed forests, maintaining forest climate conditions by silvicultural methods that assure stand continuity, e.g. by selection cutting rather than clear cutting and shelterwood logging might promote bryophyte diversity and in particular the one of woodland indicator bryophytes. KW - Beech forests KW - Conifer plantations KW - Cryptogams KW - Ecological guilds KW - Forest management KW - Temperate forests KW - Selection vs. age-class forests KW - Unmanaged vs. managed forests KW - Woodland indicator species Y1 - 2018 U6 - https://doi.org/10.1016/j.foreco.2018.10.019 SN - 0378-1127 SN - 1872-7042 VL - 432 SP - 850 EP - 859 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Laschewsky, André A1 - Mallwitz, Frank A1 - Baussard, Jean-Francois A1 - Cochin, Didier A1 - Fischer, Peter A1 - Habib-Jiwan, Jean-Louis A1 - Wischerhoff, Erik T1 - Aggregation phenomena in polyelectrolyte multilayers made from polyelectrolytes bearing bulky functional, hydrophobic fragments N2 - The functionalization of polyelectrolyte multilayers often implies the use of bulky functional fragments, attached to a standard polyelectrolyte matrix. Despite of the high density of non-charged, often hydrophobic substituents, regular film growth by sequential adsorption proceeds easily when an appropriate polyelectrolyte counter ion is chosen. However, the functional fragments may cluster or aggregate. This complication is particularly evident when using chromophores and fluorophores as bulky pendant groups. Attention has to be paid to this phenomenon for the design of functional polyelectrolyte films, as aggregation may modify crucially the properties. The use of charged spacer groups does not necessarily suppress the aggregation of functional side groups. Still, clustering and aggregation depend on the detailed system employed, and are not obligatory. In the case of cationic poly(acrylamide)s labeled with naphthalene and pyrene fluorophores, for instance, the polymers form intramolecular hydrophobic associates in solution, as indicated by strong excimer formation. But the polymers can undergo a conformational rearrangement upon adsorption so that they are decoiled in the adsorbed films. Analogous observations are made for polyanions bearing mesogenic biphenyls fragments. In contrast, polycations functionalized with the dye coumarin 343 show little aggregation in solution, but a marked aggregation in the ESA films Y1 - 2004 ER - TY - JOUR A1 - Jessel, Beate A1 - Fischer-Hüftle, Peter T1 - Bewältigung von Eingriffen durch Verkehrsvorhaben in das Landschaftsbild : rechtliche Rahmenbedingungen und fachliche Anforderungen N2 - Zusammenfassung In der naturschutzrechtlichen Eingriffsregelung wird das Landschaftsbild gegenüber den Belangen des Naturhaushalts oft nachrangig behandelt, obwohl es von den Voraussetzungen des Bundesnaturschutzgesetzes her gleichermaßen in alle Schritte der Folgenbewältigung einzubeziehen ist. Für diese Schritte werden exemplarisch rechtliche Rahmenbedingungen und fachliche Anforderungen aufgezeigt. Ingesamt wird so eine strukturierte Herangehensweise deutlich, die über die einzelnen Arbeitsschritte der Erfassung des Ist-Zustandes, der Aufstellung eines Zielkonzeptes, der Ableitung von Vorkehrungen zur Vermeidung sowie der Begründung von Maßnahmen zur landschaftsgerechten Wiederherstellung und Neugestaltung des Landschaftsbildes hinweg durchgängig auf denselben Beschreibungsmerkmalen aufbaut und damit einen durchgängigen Ableitungszusammenhang von den ermittelten Beeinträchtigungen des Landschaftsbildes zu darauf Bezug nehmenden Maßnahmen begründet. Wesentlich ist, dass dabei die Charakteristik des jeweiligen Landschaftsraumes im Vordergrund steht und dass nicht nur einzelne Beeinträchtigungen betrachtet, sondern diese jeweils in ihrem Zusammenwirken auf den wahrgenommenen Raumeindruck beleuchtet werden. Ein wichtiger Aspekt ist zudem die Rechtssicherheit, weshalb sich der verwendete Rahmen eng an die Terminologie des Bundesnaturschutzgesetzes anlehnt Summary How to deal with Disturbance of the Visual Landscape by Traffic Projects? Legal framework conditions and special requirements The impact regulation of nature conservation only gives inferior treatment to the visual landscape compared to other natural resources although nature conservation legislation requires its equal integration into all steps of consequential dealing. For these steps the study shows exemplary legal framework conditions and specialist requirements. They should make clearer a structural approach including individual working steps, such as recording of present site conditions, establishment of a target concept, derivation of measures of avoidance and justification of measures for a sensitive regeneration and design of the visual landcape. The approach continuously bases on the same features of description, leading to a consistent connection between identified disturbances of the visual landscape and related measures. The focus of attemtion should be given to the characteristics of the respective landscape and the analysis should not only consider disturbances or compensation measures individually but also in combination with the general spatial perception. Another important aspect is the legal security; therefore the text closely follows the terminology of the Federal Nature Conservation Legislation. Y1 - 2003 ER - TY - BOOK A1 - Jessel, Beate A1 - Fischer-Hüftle, Peter A1 - Jenny, Daniel A1 - Zschalich, Andrea T1 - Erarbeitung von Ausgleichs- und Ersatzmaßnahmen für Beeinträchtigungen des Landschaftsbildes : Ergebnisse aus dem F+E-Vorhaben 89982130 des Bundesamtes für Naturschutz T3 - Angewandte Landschaftsökologie N2 - Auch nach über 25 Jahren Anwendung der Eingriffsregelung nehmen landschaftsästhetische Aspekte häufig noch eine deutlich schwächere Stellung gegenüber den Belangen des Naturhaushalts ein. Als besonders schwierig erweist sich die Erfassung und Bewertung des Landschaftsbildes und - ausgehend von den konkreten Beeinträchtigungen, die vom Vorhaben ausgehen - die Ableitung wirkungsbezogener Kompensationsmaßnahmen. Mit der vorliegenden Veröffentlichung wird eine Handlungsanleitung zur Erfassung und Beschreibung des Landschaftsbildes vorgelegt, die insbesondere auf eine schlüssige Begründung und Herleitung von Vorkehrungen zur Vermeidung sowie von Ausgleichs- und Ersatzmaßnahmen zur landschaftsgerechten Wiederhertsellung und Neugestaltung des Landschaftsbildes abzielt. Wesentlich ist, dass dabei der notwendige Bezug auf die Charakteristik des jeweiligen Landschaftsraums im Vordergrund steht. Daneben werden die Einsetzbarkeit verschiedener Methoden der Landschaftsvisualisierung im Arbeitsablauf der Eingriffsregelung beleuchtet, Hinweise für entsprechende Standards begründet sowie Empfehlungen für Nachkontrollen von Kompensationsmaßnahmen begründet. Y1 - 2003 SN - 3-7843-3732-5 VL - 53 PB - Bundesamt für Naturschutz CY - Bonn-Bad Godesberg ER - TY - JOUR A1 - Arys, Xavier A1 - Fischer, Peter A1 - Jonas, Alain M. A1 - Koetse, Marc M. A1 - Legras, Roger A1 - Laschewsky, André A1 - Wischerhoff, Erik T1 - Ordered polyelectrolyte multilayers : rules governing layering in organic binary multilayers Y1 - 2003 ER - TY - JOUR A1 - Zalden, Peter A1 - Quirin, Florian A1 - Schumacher, Mathias A1 - Siegel, Jan A1 - Wei, Shuai A1 - Koc, Azize A1 - Nicoul, Matthieu A1 - Trigo, Mariano A1 - Andreasson, Pererik A1 - Enquist, Henrik A1 - Shu, Michael J. A1 - Pardini, Tommaso A1 - Chollet, Matthieu A1 - Zhu, Diling A1 - Lemke, Henrik A1 - Ronneberger, Ider A1 - Larsson, Jörgen A1 - Lindenberg, Aaron M. A1 - Fischer, Henry E. A1 - Hau-Riege, Stefan A1 - Reis, David A. A1 - Mazzarello, Riccardo A1 - Wuttig, Matthias A1 - Sokolowski-Tinten, Klaus T1 - Femtosecond x-ray diffraction reveals a liquid-liquid phase transition in phase-change materials JF - Science N2 - In phase-change memory devices, a material is cycled between glassy and crystalline states. The highly temperature-dependent kinetics of its crystallization process enables application in memory technology, but the transition has not been resolved on an atomic scale. Using femtosecond x-ray diffraction and ab initio computer simulations, we determined the time-dependent pair-correlation function of phase-change materials throughout the melt-quenching and crystallization process. We found a liquid-liquid phase transition in the phase-change materials Ag4In3Sb67Te26 and Ge15Sb85 at 660 and 610 kelvin, respectively. The transition is predominantly caused by the onset of Peierls distortions, the amplitude of which correlates with an increase of the apparent activation energy of diffusivity. This reveals a relationship between atomic structure and kinetics, enabling a systematic optimization of the memory-switching kinetics. Y1 - 2019 U6 - https://doi.org/10.1126/science.aaw1773 SN - 0036-8075 SN - 1095-9203 VL - 364 IS - 6445 SP - 1062 EP - 1067 PB - American Assoc. for the Advancement of Science CY - Washington, DC ER -