The politics of national SDG indicator systems: A comparison of four European countries.

The sustainable development goals (SDGs) constitute an ambitious comprehensive global framework including monitoring mechanisms and indicators to evaluate progress towards precise targets of sustainable development. Most European countries have adapted their national sustainability indicator systems to conform to the UN Agenda 2030 for sustainable development, introducing new indicators and monitoring frameworks and governance processes in which these are embedded. What do we know about the political processes and struggles of implementing this important global framework? How does the politics of indicators differ in national contexts? We propose a classification of national indicator systems along dimensions of indicator selection, appraisal landscape, participatory nature, and political communication.

Sustainable Development Goals and risks: The Yin and the Yang of the paths towards sustainability.

The United Nations 2030 Agenda and Sustainable Development Goals (SDGs) define a path towards a sustainable future, but given that uncertainty characterises the outcomes of any SDG-related actions, risks in the implementation of the Agenda need to be addressed. At the same time, most risk assessments are narrowed to sectoral approaches and do not refer to SDGs. Here, on the basis of a literature review and workshops, it is analysed how SDGs and risks relate to each other's in different communities.

The Hierarchy-of-Hypotheses Approach: A Synthesis Method for Enhancing Theory Development in Ecology and Evolution.

In the current era of Big Data, existing synthesis tools such as formal meta-analyses are critical means to handle the deluge of information. However, there is a need for complementary tools that help to (a) organize evidence, (b) organize theory, and (c) closely connect evidence to theory. We present the hierarchy-of-hypotheses (HoH) approach to address these issues.

"Organismic" positions in early German-speaking ecology and its (almost) forgotten dissidents.

In early German ecology, the key concept used to refer to a synecological unit was Biozönose (biocoenosis). Taken together with the concept of the Biotop (biotope), it was also understood as an integrated higher-order unit of life, sometimes called a "Holozön" (holocoen). These units were often perceived as having properties similar to those of individual organisms, and they informed the mainstream of German ecology until at least the late 1960s.

Conceptual frameworks and methods for advancing invasion ecology.

Invasion ecology has much advanced since its early beginnings. Nevertheless, explanation, prediction, and management of biological invasions remain difficult. We argue that progress in invasion research can be accelerated by, first, pointing out difficulties this field is currently facing and, second, looking for measures to overcome them.

Can we define ecosystems? On the confusion between definition and description of ecological concepts.

Sound definitions of its basic concepts are fundamental to every scientific discipline. In some instances, like in the case of the ecosystem concept, the question arises if we can define such concepts at all. And if we can define them, how should we choose from the multiple definitions available? And what are the preconditions for a scientifically sound and useful definition? On the basis of the ecosystem concept, this paper illustrates a major, often neglected distinction in the definition of ecological concepts, namely that between defining criteria and additional descriptive statements connected to those definitions.

Ecological units: definitions and application.

Concepts of ecological units, such as population, community, and ecosystem, are at the basis of ecological theory and research and have increasingly become the focus of conservation strategies. Concepts of these units still suffer from inconsistencies and confusions over terminology. The different concepts are treated here together as a common "conceptual cluster," with similar ecological functions (roles) and similar problems in their definition and use.