Above and belowground community strategies respond to different global change drivers

Environmental changes alter the diversity and structure of communities. By shifting the range of species traits that will be successful under new conditions, environmental drivers can also dramatically impact ecosystem functioning and resilience. Above and belowground communities jointly regulate whole-ecosystem processes and responses to change, yet they are frequently studied separately. To determine whether these communities respond similarly to environmental changes, we measured taxonomic and trait-based responses of plant and soil microbial communities to four years of experimental warming and nitrogen deposition in a temperate grassland. Plant diversity responded strongly to N addition, whereas soil microbial communities responded primarily to warming, likely via an associated decrease in soil moisture. These above and belowground changes were associated with selection for more resource-conservative plant and microbe growth strategies, which reduced community functional diversity. Functional characteristics of plant and soil microbial communities were weakly correlated (P = 0.07) under control conditions, but not when above or belowground communities were altered by either global change driver. These results highlight the potential for global change drivers operating simultaneously to have asynchronous impacts on above and belowground components of ecosystems. Assessment of a single ecosystem component may therefore greatly underestimate the whole-system impact of global environmental changes

A conceptual map of invasion biology: Integrating hypotheses into a consensus network

Background and aims Since its emergence in the mid‐20th century, invasion biology has matured into a productive research field addressing questions of fundamental and applied importance. Not only has the number of empirical studies increased through time, but also has the number of competing, overlapping and, in some cases, contradictory hypotheses about biological invasions. To make these contradictions and redundancies explicit, and to gain insight into the field’s current theoretical structure, we developed and applied a Delphi approach to create a consensus network of 39 existing invasion hypotheses. Results The resulting network was analysed with a link‐clustering algorithm that revealed five concept clusters (resource availability, biotic interaction, propagule, trait and Darwin’s clusters) representing complementary areas in the theory of invasion biology. The network also displays hypotheses that link two or more clusters, called connecting hypotheses, which are important in determining network structure. The network indicates hypotheses that are logically linked either positively (77 connections of support) or negatively (that is, they contradict each other; 6 connections). Significance The network visually synthesizes how invasion biology’s predominant hypotheses are conceptually related to each other, and thus, reveals an emergent structure – a conceptual map – that can serve as a navigation tool for scholars, practitioners and students, both inside and outside of the field of invasion biology, and guide the development of a more coherent foundation of theory. Additionally, the outlined approach can be more widely applied to create a conceptual map for the larger fields of ecology and biogeography

Les habitats rocheux intertidaux sous l'influence d'activités anthropiques (structure, dynamique et enjeux de conservation)

Les activités humaines, de loisir et professionnelles, vont en s intensifiant sur les zones rocheuses intertidales. Le piétinement associé à ces activités, le remaniement des blocs pour rechercher des espèces consommables, ne sont pas sans incidence sur les biocénoses des milieux rocheux. Les conséquences de ces activités sur la structure et la dynamique des roches du médiolittoral et des champs de blocs de bas d estran en particulier, nécessitent d'être caractérisées. A travers l identification des espèces et descripteurs qui répondent le plus aux perturbations "piétinement des platiers rocheux" et "retournement des blocs par les pêcheurs à pied", des indicateurs écologiques simplifiés peuvent être dégagés et faciliter, à terme, le diagnostic de l état de conservation de ces habitats. Les processus écologiques de dégradation et de déstructuration des biocénoses sous l'effet du piétinement passent par des interactions entre espèces très complexes. Les résultats d expérimentations in situ soulignent des phénomènes de seuils très marqués, liés en particulier à la protection jouée par les algues brunes structurantes sur les autres espèces. L'étude du retournement des blocs par les pêcheurs à pied met en évidence une phase de mortalité presque totale des organismes fixés ou peu mobiles des blocs et une faible résilience de l habitat. Le choix de stations de référence appropriées et l utilisation des espèces et descripteurs les plus sensibles au retournement des blocs ont permis la création de deux indicateurs de perturbation. Déclinés à deux échelles spatiales différentes, ils sont applicables en routine par les scientifiques et les gestionnaires d aires marines protégées.Recreational and professional activities are intensifying on the rocky intertidal. The overturning of boulders and the trampling associated with human activities, have consequences on the structure and dynamic of rocky intertidal communities. Through the identification of species and descriptors that respond more to the disturbances trampling of mediolittoral rock platforms and the overturning of low eulittoral boulders by hand-fishermen , SMART indicators (Simple, Measurable, Achievable, Realistic, and Time limited indicator) can be created for the assessment of the conservation status of these habitats. The effects of trampling were tested with control approach. Experiments in situ underlined very complex interactions between species during the ecological processes of degradation of biocenoses. High thresholds of disturbance were also observed. They were particularly related to the protection played by structuring brown algae on other species. The study of boulder s overturning highlighted a step of almost total mortality of fixed or low mobile organisms that live on upper or lower surfaces of boulders. Results also showed a low resilience of the habitat. The use of appropriate reference situations and of the most sensitive species to the boulder s overturning, led to the creation of two ecological indicators. Declined to two different spatial scales, they may be applied routinely by scientists and managers of marine protected areas.BREST-SCD-Bib. electronique (290199901) / SudocSudocFranceF

Grassland allergenicity increases with urbanisation and plant invasions

Pollen allergies have been on the rise in cities, where anthropogenic disturbances, warmer climate and introduced species are shaping novel urban ecosystems. Yet, the allergenic potential of these urban ecosystems, in particular spontaneous vegetation outside parks and gardens, remains poorly known. We quantified the allergenic properties of 56 dry grasslands along a double gradient of urbanisation and plant invasion in Berlin (Germany). 30% of grassland species were classified as allergenic, most of them being natives. Urbanisation was associated with an increase in abundance and diversity of pollen allergens, mainly driven by an increase in allergenic non-native plants. While not inherently more allergenic than native plants, the pool of non-natives contributed a larger biochemical diversity of allergens and flowered later than natives, creating a broader potential spectrum of allergy. Managing novel risks to urban public health will involve not only targeted action on allergenic non-natives, but also policies at the habitat scale favouring plant community assembly of a diverse, low-allergenicity vegetation. Similar approaches could be easily replicated in other cities to provide a broad quantification and mapping of urban allergy risks and drivers

The Ecologist's Career Compass: A game to explore career paths

One of the most challenging endeavors for students is choosing a career path that best fits their interests, wills and skills, and setting their professional goals accordingly. Such decisions are often made from within the culture of academia, in which mentors and peers are mainly familiar with the academic job market and lack the knowledge necessary to consult about other types of careers. We aimed to address this gap for ecology and related fields by creating an engaging and effective tool to help students and professionals to familiarize themselves with the diversity of potential career paths available to ecologists. The tool is an applied card game – the Ecologist's Career Compass – which is provided here freely. The game is played as a trump card game and includes 33 cards, each representing a combination of one of four job-market sectors and one of nine types of positions. Each card indicates the level of seven skill categories required to likely be hired and succeed in the focal position at the focal sector, as well as more specific examples for typical jobs in the focal combination. The information in the game largely relies on input from a global survey we conducted among 315 ecologists from 35 countries. While the challenges faced by early-career ecologists in developing their professional path are substantial and diverse, this game can assist in gaining a broad comparative overview of the whole ecology job market and the skills required to likely excel in different paths. We hope this applied game will act as a conversation starter about the diversity of aspirations and opportunities in ecology classrooms and labs.Alexander von Humboldt‐Stiftung http://dx.doi.org/10.13039/100005156Deutsche Bundesstiftung Umwelt http://dx.doi.org/10.13039/100007636Peer Reviewe

Closing the loop as an inverse problem: the real-time control of THEMIS adaptive optics

We have taken advantage of the implementation of an adaptive optics system on the Themis solar telescope to implement innovative strategies based on an inverse problem formulation for the control loop. Such an approach encompassing the whole system implies the estimation of the pixel variances of the Shack-Hartmann wavefront sensor, a novel real-time method to extract the wavefront slopes as well as their associated noise covariance, and the computation of pseudo-open loop data. The optimal commands are computed by iteratively solving a regularized inverse problem with spatio-temporal constraints including Kolmogorov statistics. The latency of the dedicated real-time control software with conventional CPU is shorter than 300 $\mu$s from the acquisition of the raw 400 x 400 pixel wavefront sensor image to the sending of the commands

Immunogenicity of long-lasting recombinant factor VIII products

International audienceReplacement therapy for patients with hemophilia A using plasma-derived or recombinant factor VIII (FVIII) is complicated by the short half-life of the FVIII products and by the occurrence of neutralizing antibodies in a substantial number of patients. In the recent years, enormous efforts have been invested to develop new generations of coagulation factors with extended half-lives. Presumably, the use of long-lasting FVIII products should reduce the frequency of administration to the patients and drastically improve their quality of life. The question of their immunogenicity remains however unanswered as yet. The present review proposes a summary of the different strategies developed to enhance the half-life of FVIII, including fusion of FVIII to the Fc fragment of the human IgG1 or to human serum albumin, or attachment of polyethylene glycol. Based on the available literature, we hypothesize on the potential benefits or risks associated with each of the latter strategies in terms of immunogenicity of the newly derived hemostatic drugs

A Wearable Sensor Network for Gait Analysis: A 6-Day Experiment of Running Through the Desert

International audienceThis paper presents a new system for analysis of walking and running gaits. The system is based on a network of wireless nodes with various types of embedded sensors. It has been designed to allow long-term recording in outdoor environments and was tested during the 2010 "Sultan Marathon des Sables" desert race. A runner was fitted with the sensory network for six days of the competition. Although technical problems have limited the amount of data recorded, the experiment was nevertheless suc- cessful: the system did not interfere with the runner, who finished with a high ranking, the concept was validated and high quality data were ac- quired. It should be noted that the loss of some of the measurements was mainly due to problems with the cable connectors between the nodes and batteries. In this paper, we describe the technical aspects of the system developed, the experimental conditions under which it was validated, and give examples of the data obtained with some preliminary processing

A common framework for identifying linkage rules across different types of interactions

Species interactions, ranging from antagonisms to mutualisms, form the architecture of biodiversity and determine ecosystem functioning. Understanding the rules responsible for who interacts with whom, as well as the functional consequences of these interspecific interactions, is central to predict community dynamics and stability. Species traits sensu lato may affect different ecological processes by determining species interactions through a two-step process. First, ecological and life-history traits govern species distributions and abundance, and hence determine species co-occurrence and the potential for species to interact. Secondly, morphological or physiological traits between co-occurring potential interaction partners should match for the realization of an interaction. Here, we review recent advances on predicting interactions from species co-occurrence and develop a probabilistic model for inferring trait matching. The models proposed here integrate both neutral and trait-matching constraints, while using only information about known interactions, thereby overcoming problems originating from undersampling of rare interactions (i.e. missing links). They can easily accommodate qualitative or quantitative data and can incorporate trait variation within species, such as values that vary along developmental stages or environmental gradients. We use three case studies to show that the proposed models can detect strong trait matching (e.g. predator‿prey system), relaxed trait matching (e.g. herbivore‿plant system) and barrier trait matching (e.g. plant‿pollinator systems). Only by elucidating which species traits are important in each process (i.e. in determining interaction establishment and frequency), we can advance in explaining how species interact and the consequences of these interactions for ecosystem functioning. A lay summary is available for this articlePeer Reviewe