Current analyses of metacommunity data largely focus on global attributes across the entire metacommunity, such as mean alpha, beta, and gamma diversity, as well as the partitioning of compositional variation into single estimates of contributions of space and environmental effects and, more recently, possible contributions of species interactions. However, this view neglects the fact that different species and sites in the landscape can vary widely in how they contribute to these metacommunity‐wide attributes. We argue for a new conceptual framework with matched analytics with the goals of studying the complex and interactive relations between process and pattern in metacommunities that is focused on the variation among species and among sites which we call the ‘internal structure' of the metacommunity. To demonstrate how the internal structure could be studied, we create synthetic data using a process‐based colonization–extinction metacommunity model. We then use joint species distribution models to estimate how the contributions of space, environment, and biotic interactions driving metacommunity assembly differ among species and sites. We find that this approach to the internal structure of metacommunities provides useful information about the distinct ways that different species and different sites contribute to metacommunity structure. Although it has limitations, our work points at a more general approach to understand how other possible complexities might affect internal structure and might thus be incorporated into a more cohesive metacommunity theory.

ABSTRACTMetacommunity ecology has become an important subdiscipline of ecology, but it is increasingly evident that its foundational theoretical and analytical frameworks do not adequately incorporate a realistic continuum of environmental and biotic process at play. We propose an approach that develops stronger links between theoretical and statistical frameworks to shift the focus towards the study of the ‘internal structure’ of metacommunities by dissecting how different species and different sites contribute to overall metacommunity structure. To illustrate this, we simulate data from a model that includes environmental variation, dispersal, biotic interactions, and stochasticity as the basic ecological processes that influence species’ (co)-distributions. We analyze the simulated data with hierarchical community models and propose a new method to visualize and analyze the simultaneous role of species co-distribution, environment, space, and stochasticity in this emerging statistical approach. We focus in particular on quantifying how species affect the overall structure of the metacommunity via differences in their dispersal and niche traits, and how environmental filtering, dispersal and species interactions varies from site to site in relation to environmental conditions and connectivity. Although there are still challenges ahead, this framework provides a roadmap for a more comprehensive approach by jointly developing more mechanistic theory based on community assembly processes and the analytical tools needed to map these concepts onto data in diverse landscapes and systems.

In December 2009, countries meet in Copenhagen to establish a new global climate agreement. This article links the need for reducing transport-related greenhouse gas emissions in developing countries with the current international climate negotiations. Arguing that a sustainable transport approach requires comprehensive policy packages, it assesses the suitability of current climate negotiation proposals in promoting sustainable transport. The project-based approach under the current climate regime incentivises neither comprehensive sustainable transport and mobility policies, nor sufficient numbers of local projects. Current proposals to increase efforts by developing countries, to reform the Clean Development Mechanism, and to create new emission trading mechanisms are promising but still have to overcome several obstacles. One obstacle involves how to properly assess the impact of actions while maintaining streamlined procedures. The authors conclude from their analysis that the best way forward would be to establish an international mitigation fund with a dedicated transport window financed by industrialised countries. This fund would enable developing countries to implement national policies and local projects. Developing countries would outline low-carbon development strategies, including a sectoral strategy for low-carbon transport.

The paper examines policies and measures that promote the usage of pedelecs and that contribute to climate friendly passenger transportation thereby. As pedelecs allow the rider to pedal at lower efforts, pedelecs provide the potential to increase the share of bicycle trips in metropolitan regions with hilly landscapes and with a significant share of medium commuting distances. The paper develops attitude-based mobility types and defines their specific pedelec affinity based upon differentiated reasons to use a pedelec. Thereafter policies and measures are examined that foster purchase and usage of pedelecs, and factors influencing the modal behaviour of (potential) attitude-based target groups are defined. Quantification of climate protection effects is conducted based on two scenarios for the German city of Wuppertal, a city known for its steep slopes. The first scenario assumes business as usual, and the second scenario is based on the introduction of ambitious policies and measures to encourage purchase and usage of pedelecs. Following a mixed-method approach, qualitative scenario assumptions are calculated by a quantitative model, which incorporates the analyses on attitude-based mobility types respective pedelec affinities.The results indicate that ambitious promotion of pedelecs significantly contributes to climate change mitigation. Compared to business as usual, ambitious policies and measures to purchase and use pedelecs reduce CO2-emissions of passenger transport in Wuppertal by 11 per cent in 2050. A spatially inclusive and comprehensive 30 kph speed limit proves to be particularly effective. In the scenario of ambitious promotion of pedelecs, interventions solely fostering the purchase of pedelecs significantly increase the modal share of pedelecs, whereas in a business as usual case such efforts remain ineffective. The traditional bicycle profits from the promotion of pedelecs, but its increased usage does not bring about similar climate protection effects.

Abstract