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This dataset contains all data on which the following publication below is based. Paper Citation: Risch Anita C., Zimmermann, Stefan, Schütz, Martin, Borer, Elizabeth T., Broadbent, Arthur A.D., Caldeira, Maria C., Davies, Kendi F., Eisenhauer, Nico, Eskelinen, Anu, Fay, Philip A., Hagedorn, Frank, Knops, Johannes M.H., Lembrechts, Jonas, J., MacDougall, Andrew S., McCulley, Rebecca L., Melbourne, Brett A., Moore, Joslin L., Power, Sally A., Seabloom, Eric W., Silveira, Maria L., Virtanen, Risto, Yahdjian, Laura, Ochoa-Hueso, Raul (accepted). Drivers of the microbial metabolic quotient across global grasslands. Global Ecology and Biogeography Please cite this paper together with the citation for the datafile. The microbial metabolic quotient (MMQ; mg CO2-C mg MBC-1 h-1), defined as the amount of microbial CO2 respired (MR; mg CO2-C kg soil-1 h-1) per unit of microbial biomass C (MBC; mg C kg soil-1), is a key parameter for understanding the microbial regulation of the carbon (C) cycle, including soil C sequestration. Here, we experimentally tested hypotheses about the individual and interactive effects of multiple nutrient addition (NPK+micronutrients) and herbivore exclusion on MR, MBC, and MMQ across 23 sites (5 continents). Our sites encompassed a wide range of edaphoclimatic conditions, thus we assessed which edaphoclimatic variables affected MMQ the most and how they interacted with our treatments. Soils were collected in plots with established experimental treatments. MR was assessed in a five-week laboratory incubation without glucose addition, MBC via substrate-induced respiration. MMQ was calculated as MR/MBC and corrected for soil temperatures (MMQsoil). Using LMMs and SEMs, we analysed how edaphoclimatic characteristics and treatments interactively affected MMQsoil. MMQsoil was higher in locations with higher mean annual temperature, lower water holding capacity, and soil organic C concentration, but did not respond to our treatments across sites as neither MR nor MBC changed. We attributed this relative homeostasis to our treatments to the modulating influence of edaphoclimatic variables. For example, herbivore exclusion, regardless of fertilization, led to greater MMQsoil only at sites with lower soil organic C (-1.7%). Our results pinpoint the main variables related to MMQsoil across grasslands and emphasize the importance of the local edaphoclimatic conditions in controlling the response of the C cycle to anthropogenic stressors. By testing hypotheses about MMQsoil across global edaphoclimatic gradients, this work also helps to align the conflicting results of prior studies.

Nutrients and herbivores are well-known drivers of grassland diversity and stability in local communities. However, whether they interact to impact the stability of aboveground biomass and whether these effects depend on spatial scales remain unknown. It is also unclear whether nutrients and herbivores impact stability via different facets of plant diversity including species richness, evenness, and changes in community composition through time and space. We used a replicated experiment adding nutrients and excluding herbivores for 5 years in 34 global grasslands to explore these questions. We found that both nutrient addition and herbivore exclusion alone reduced stability at the larger spatial scale (aggregated local communities; gamma stability), but through different pathways. Nutrient addition reduced gamma stability primarily by increasing changes in local community composition over time, which was mainly driven by species replacement. Herbivore exclusion reduced gamma stability primarily by decreasing asynchronous dynamics among local communities (spatial asynchrony). Their interaction weakly increased gamma stability by increasing spatial asynchrony. Our findings indicate that disentangling the processes operating at different spatial scales may improve conservation and management aiming at maintaining the ability of ecosystems to reliably provide functions and services for humanity.

In the version of this Article originally published, there were unit conversion errors in the dataset when calculating specific leaf area (SLA) values at 10 of the 27 sites; errors were made when converting SLA from cm 2 g –1 to mm 2 g –1 and from mm 2 mg –1 to mm 2 g –1. This resulted in two incorrect data points: Phleum pratense in plot 27 at the Frue.ch site (SLA >300,000 mm 2 g –1) and Poa secunda in plot 31 at the shps.us site (SLA >60 mm 2 g –1). These two values were changed to ‘NA’ in the dataset, and therefore some reported estimates were changed, resulting in changes to the data points in Fig. 2a, the top bar of Fig. 3 and several values in the text.

This project is aimed at investigating trophic cascades originating from the successive exclusion of herbivores of various sizes from subalpine grasslands of the Swiss National Park (SNP). Historical grazing patterns in the SNP have developed two distinct vegetation types – heavily grazed short grass vegetation and lightly grazed tall grass vegetation – derived from former land use which differ in vegetation quality, community composition and usage by herbivores. This poster presents some of the methods we use to study how herbivore exclusion affects ecosystem properties and processes.

Although diverse herbivore communities utilise grasslands, many previous studies only excluded the largest animals. Thus, little is known about how smaller herbivores, including invertebrates, affect grassland processes. We find that sequentially excluding different sized herbivores strongly impacts soil properties such as moisture, temperature and respiration. Such changes have potential implications for ecosystem nutrient cycling (e.g. C storage). This poster was presented at the British Ecological Society 2012 Annual Meeting in Birmingham between the 17th and 20th December.

Although diverse herbivore communities utilise grasslands, many previous studies only exclude largest animals. Thus, little is known about how smaller herbivores, including invertebrates, affect grassland processes. We find that sequentially excluding different sized herbivores strongly impacts vegetation quantity/quality; depending on original grassland grazing pressures. This has implications for ecosystem nutrient cycling (e.g. C storage) and pattern reinforcing feedbacks. This presentation was presented at the British Ecological Society Annual Meeting 2012 on the 18th December.

In order to understand how different herbivore guilds based on body size affect ecosystem processes, we designed an experimental setup in the Swiss Alps. Using differing mesh sizes we sequentially exclude large herbivores (ungulates), medium mammals (hare and marmots), small mammals (mice and voles) and small herbivores (invertebrates). The fencing method has the potential to change ecosystem parameters such as air humidity and temperature, soil moisture and temperature and light levels. This is a supplement to go with the poster "Does size matter? Effects of herbivore exclusion on soil properties" presented at the British Ecological Society 2012 Annual Meeting in Birmingham between the 17th and 20th of December.

Mitosis is the essential process during which a cell divides into two viable daughter cells. To allow a faithful segregation of the chromosomes into each daughter, the cell forms the bipolar spindle. The NIMA-like kinase family member Nek9 has been previously proposed to play a role in bipolar spindle assembly and in the chromosomal pathway of microtubule assembly. We aimed at gaining a better understanding of Nek9 function by characterizing Xenopus Nek9, xNek9, using the Xenopus egg extract system. We have shown that xNek9 may not act through the kinase cascade xNek9 – xNek6 in meiosis as described for human Nek9 in somatic cells and therefore may have different substrates. Furthermore, we have demonstrated by depletion, increased addition of Flag-hNek9 and a dominant-negative approach that xNek9 is important for bipolar spindle formation. In addition, we have shown that xNek9 depletion causes decreased microtubule density in bipolar spindles and slower RanGTP induced aster formation. We identified xNedd1, the adaptor protein for the γTuRC, as a novel interactor and substrate of xNek9. xNek9 depletion reduces the recruitment of xNedd1 to sperm nuclei induced aster and decreases the number and length of nucleated microtubules. These data suggest that one role of xNek9 in spindle assembly is exerted through xNedd1 regulation. We propose a model for xNek9 – xNedd1 interaction and a putative mechanism for the regulation of xNek9 – xNedd1 explaining how they fulfil their role in bipolar spindle assembly., La mitosis es el proceso esencial durante el cual una célula se divide en dos células hijas viables. Para permitir una segregación fiable de los cromosomas en cada hija, la célula forma el huso bipolar. Nek9, el miembro de la familia de quinasas NIMA-like ha sido propuesto para desempeñar un papel en el la asamblea del huso bipolar y en la vía cromosómica de ensamblaje de los microtúbulos. Nuestro objetivo era lograr una mejor comprensión de la función Nek9 caracterizando Nek9 de Xenopus, xNek9, utilizando el sistema de extracto de huevos de Xenopus. Hemos demostrado que xNek9 probablemente no actuará a través de la cascada de las quinasas xNek9 - xNek6 en la meiosis como se describe para Nek9 humano en células somáticas y por lo tanto pueden tener diferentes sustratos. Además, hemos demostrado por el agotamiento, la adición incrementada de Flag-hNek9 y un enfoque dominante-negativas que xNek9 es importante para la formación del huso bipolar. Además, hemos demostrado que el agotamiento xNek9 causa una disminución de la densidad de los microtúbulos en los husos bipolares y una formación más lenta de asteres inducidos por RanGTP. Se identificó xNedd1, la proteína adaptadora para el γTuRC, como un interactor y sustrato novedoso de xNek9. El agotamiento de xNek9 reduce la contratación de xNedd1 a los asteres inducidas por núcleos de espermatozoides y disminuye el número y longitud de microtúbulos nucleados. Estos datos sugieren que un papel de xNek9 en el conjunto del huso se husorce a través de la regulación de xNedd1. Proponemos un modelo para la interacción xNek9 – xNedd1 y un supuesto mecanismo para la regulación de xNek9 – xNedd1 explicando cómo cumplen su papel en la ensamblaje del huso bipolar.

In diesem Beitrag werden die ersten Ergebnisse eines Forschungsprojekts zur räumlichen Trennung von Altersgruppen vorgestellt. Ziel dieses Projekts ist es, eine teilweise Erklärung für die ungleiche Verteilung von Altersgruppen in der Stadt Hamburg zu finden, eine ausführliche Beschreibung der empirisch feststellbaren Segregation zu liefern und eine empirisch begründete Analyse zu versuchen. Die Studie basiert auf den Ergebnissen der Volksbefragung von 1960 und 1971, der Bevölkerungsstatistik von 1977 und den Ergebnissen des Gebäude- und Haushaltszensus von 1968. Die Darstellung der empirischen Daten zeigt, daß - bezogen auf ganz Hamburg - die Segregation in altersspezifische Gruppen zwischen 1961 und 1977 zugenommen hat, während die Einwohnerzahl zurückgegangen ist. Zugleich wird festgestellt, daß die altersspezifische Segregation in Stadtbezirken am stärksten, in den ländlichen Bezirken am schwächsten ausgeprägt ist. Abschließend werden die Ergebnisse in einer Arbeitshypothese für weitere Forschungen zusammengefaßt: Der Charakter der in einer Stadt zur Verfügung stehenden Wohnmöglichkeiten bestimmt die Alterszusammensetzung der Bevölkerung. (RW)

An den Wanderungen innerhalb der Städte sind nicht alle Altersgruppen der Bevölkerung gleichmäßig beteiligt. Der daraus resultierende Entmischungsprozeß führt zur altersspezifischen Segregation der städtischen Bevölkerung. Der Aufsatz stellt den theoretischen Zusammenhang dar zwischen den je nach Stellung im Lebenszyklus unterschiedlichen Wohnbedürfnissen, der innerstädtischen Migration und der altersabhängigen Wahl der Lage, Größe, Art und Ausstattung der Wohnung. Im empirischen Teil wird versucht, das Ausmaß der altersspezifischen Segregation zu bestimmen am Beispiel unterschiedlicher Altersgruppen der Wohnbevölkerung Hamburgs der Jahre 1961, 1970 und 1977, zusätzlich je nach Entfernung der betrachteten Ortsteile zur Innenstadt. Die Hamburger Bevölkerung ist über alle Altersgruppen segregiert; diese altersspezifische Segregation hat zunehmende Tendenz; die Segregationswerte zeigen in Abhängigkeit von der Entfernung zur Innenstadt unterschiedliche Muster. Die gleichzeitige Betrachtung der Altersstruktur- Veränderung und der Einwohnerzahlen ergibt Hinweise auf die Auswirkungen der zurückliegenden innerstädtischen Wanderungen. Die sich aus der zunehmenden Segregation ergebenden Folgerungen für die kommunale Planung werden anhand ausgewählter Probleme im abschließenden Kapitel diskutiert: altersspezifische Infrastruktur-Ausstattung, Veränderungen im Wohnungsbestand, Zuzugsbarrieren für Familien. Migration within the towns does not involve every age group to the same extent. The resulting process of dissociation is therefore leading to an age-specific segregation of the urban population. The article shows the theoretical connection among the housing needs - which differ according to the position within the life cycle -, the intra-urban migration and the age-dependent choice of location, dimension, kind and equipment of the apartment. The empirical part tries to determine the dimension of age-specific segregation taking as example different age groups of the population in Hamburg in 1961, 1970 and 1977, and showing, in addition, the function of the distance between the discussed quarters and the city. Segregation concerns all age groups of the population of Hamburg and has an increasing trend; the segregation values differ according to the distance from the city. When considering the changes in the age structure and, simultaneously, the number of inhabitants, the effects of the past intra-urban migration become obvious. The consequences from increasing segregation for local planning are discussed in the last chapter on the basis of the following problems: age-specific infrastructural equipment, changes of housing stock, migration bans for families. Aux migrations à l’intérieur de la ville ne participent pas de la même façon toutes les couches d’âge de la population. Le processus de séparation qui en résulte entraîne le phénomène spécifique de répartition par couches d’âge de la population urbaine. Le traité décrit le lien qui existe en théorie entre les besoins de logement, considérés toujours sous l’aspect de la place occupée dans le cycle de vie, de la migration à l’intérieur de la ville, et le choix de l’emplacement, des dimensions, du type et de l’équipement du logement qui dépend de l’âge. Dans la partie empirique, l’auteur essaie de définir les proportions de la répartition spécifique p ar couches d’âge des années 1961,1970 et 1977 sur le modèle de différents groupes d’âge de la population de Hambourg. Celle-ci s’effectue en outre en considérant la distance des lieux en question au centre ville. C ’est à Hambourg que la répartition en couches d ’âge est la plus forte; celle-ci va en s’intensifiant. Les valeurs de la répartition diffèrent selon la distance au centre ville. La considération parallèle de la transform ation structurelle selon l’âge et du nombre d’habitants fournit des indications sur les conséquences des migrations à l’intérieur de la ville. Les conséquences de la répartition croissante selon l’âge sur la planification communale sont traitées à l’appui de problèmes sélectionnés dans le chapitre final: infrastructure et équipement selon l’âge, changements dans le nombre des logements existants et difficultés d’accès pour des familles.

Gegenstand der Untersuchung ist die Tatsache, dass die städtische Bevölkerung nicht nur nach ihrem sozialökonomischen Status getrennt voneinander wohnt, sondern auch nach ihrem Alter: Segregation von Altersgruppen in der Großstadt. Es besteht ein Zusammenhang zwischen Alterstruktur und Wohnungsstruktur in den städtischen Teilgebieten. In der theoretischen Erklärung dieses Zusammenhanges verknüpft der Autor Aussagen über die Bevölkerungs-suburbanisierung mit dem Konzept des Lebenszyklus. Die empirische Analyse erstreckt sich auf die Altersstruktur der Städte Hamburg (1961, 1970, 1981) und Wien (1961, 1971, 1982). Im beschreibenden Teil wird das Ausmaß der Segregation für verschiedene städtische Ebenen bestimmt; es hat in beiden Städten zugenommen. Im erklärenden Teil wird die Altersstruktur der städtischen Teilgebiete für beide Städte mittels des Instruments der Pfadanalyse erklärt. Die Ergebnisse der Kausalmodelle zeigen sowohl stadtspezifische als auch altersgruppenspezifische Unterschiede.

Plant traits are commonly used to predict ecosystem-level processes, but the validity of such predictions is dependent on the assumption that trait variability between species is greater than trait variability within a species—the robustness assumption. Here, we compare leaf trait intraspecific and interspecific variability depending on: geographical differences between sites, and 5 years of experimental herbivore exclusion in two vegetation types of subalpine grasslands in Switzerland. Four-leaf traits were measured from eight herbaceous species common to all 18 sites. Intraspecific trait variability differed significantly depending on site and herbivory. However, the amount and structure of variability depended on the trait measured and whether considering leaf traits separately or multiple leaf traits simultaneously. Leaf phosphorus (P) concentration showed the highest intraspecific variability, while specific leaf area (SLA) showed the highest interspecific variability and displayed intraspecific variability only in response to herbivore exclusion. Species identity based on multiple traits was not predictable. We find intraspecific variability is an essential consideration when using plant functional traits as a common currency not just species mean traits. This is particularly true for leaf nutrient concentrations, which showed high intraspecific variability in response to site differences and herbivore exclusion; a finding which suggests that the robustness assumption does not always hold.