1 Introduction

It is increasingly expected from landscape research and from environmental research in general that science directly contributes to the solving of pressing societal problems (e.g. Bocking, 2004*). More and more problem-oriented research is funded that is explicitly designed to contribute to the solving of particular problems in society. However, despite increased efforts to direct environmental research towards problem-oriented research it is not obvious if science has become more effective in supporting environmental problem solving (Bocking, 2004*; Cash et al., 2003*). We present in this article a theoretical framework that facilitates the analysis of the problem-orientation of research fields, and helps to design more effective problem-oriented research. Our theoretical framework is based on scholarship that developed over the past few decades among theoreticians and practitioners of problem-oriented research (Bammer, 2005*; Cash et al., 2003*; Hirsch Hadorn, 2003*; Klein et al., 2001; Nowotny et al., 2001*; Pohl and Hirsch Hadorn, 2007*). In the second part of the article we apply the proposed framework to a concrete example of a problem-oriented landscape research field – namely research on biotic invasions. Some organisms that have been introduced through human transportation to new geographic areas, where they were previously not present, have spread in the landscape and can have negative impacts. Such biotic invasions can lead to massive economic and ecologic costs (Mack et al., 2000*; MEA, 2005*; Pimentel et al., 2005*), and the management of invasive species is therefore a high priority in national and international environmental policies (McNeely et al., 2001; Mooney et al., 2005*). Our review is intended to comprehensively discuss invasion research since the late 1950s, but is necessarily incomplete and simplifies the structure and diversity of the research field for the purpose of our analysis. We think that invasion research is typical for landscape research in several ways, and that therefore our analysis will also help to design more effective science in other fields of problem-oriented landscape research. Particularly, biotic invasions are processes that take place on multiple spatial scales with a particular relevance of the landscape scale. Further, biotic invasions represent a complex societal issue because scientific knowledge is highly uncertain, and both conflicts of interests and values are prominent in the problem-solving context (post-normal situation sensu Funtowicz and Ravetz (1993*)), and such post-normal situations are common in environmental research. In the case of invasion research, for instance, many different actors (and their particular interests) from a wide range of professional fields are involved in problem-solving (Mooney et al., 2005*; Wittenberg and Cock, 2001*), and debates about the value judgments implicated in the issue are vivid (e.g. Simberloff, 2003*; Theodoropoulos, 2003*).