(Dis)entangling Barad: Materialisms and ethics

In the wake of the widespread uptake of and debate surrounding the work of Karen Barad, this article revisits her core conceptual contributions. We offer descriptions, elaborations, problematizations and provocations for those intrigued by or invested in this body of work. We examine Barad’s use of quantum physics, which underpins her conception of the material world. We discuss the political strengths of this position but also note tensions associated with applying quantum physics to phenomena at macro-scales. We identify both frictions and unacknowledged affinities with science and technology studies in Barad’s critique of reflexivity and her concept of diffraction. We flesh out Barad’s overarching position of ‘agential realism’, which contains a revised understanding of scientific apparatuses. Building upon these discussions, we argue that inherent in agential realism is both an ethics of inclusion and an ethics of exclusion. Existing research has, however, frequently emphasized entanglement and inclusion to the detriment of foreclosure and exclusion. Nonetheless, we contend that it is in the potential for an ethics of exclusion that Barad’s work could be of greatest utility within science and technology studies and beyond

Leaf Trait-Environment Relationships in a Subtropical Broadleaved Forest in South-East China

Although trait analyses have become more important in community ecology, trait-environment correlations have rarely been studied along successional gradients. We asked which environmental variables had the strongest impact on intraspecific and interspecific trait variation in the community and which traits were most responsive to the environment. We established a series of plots in a secondary forest in the Chinese subtropics, stratified by successional stages that were defined by the time elapsed since the last logging activities. On a total of 27 plots all woody plants were recorded and a set of individuals of every species was analysed for leaf traits, resulting in a trait matrix of 26 leaf traits for 122 species. A Fourth Corner Analysis revealed that the mean values of many leaf traits were tightly related to the successional gradient. Most shifts in traits followed the leaf economics spectrum with decreasing specific leaf area and leaf nutrient contents with successional time. Beside succession, few additional environmental variables resulted in significant trait relationships, such as soil moisture and soil C and N content as well as topographical variables. Not all traits were related to the leaf economics spectrum, and thus, to the successional gradient, such as stomata size and density. By comparing different permutation models in the Fourth Corner Analysis, we found that the trait-environment link was based more on the association of species with the environment than of the communities with species traits. The strong species-environment association was brought about by a clear gradient in species composition along the succession series, while communities were not well differentiated in mean trait composition. In contrast, intraspecific trait variation did not show close environmental relationships. The study confirmed the role of environmental trait filtering in subtropical forests, with traits associated with the leaf economics spectrum being the most responsive ones