“Why not pitch the whole enterprise at the highest level possible?”: Speculative Radicalism and the Planetary Topics

This dissertation problematizes the hegemony of “critique” within the humanities in general and communication studies in particular. I argue that critique in the current mode, a reading and engagement practice that valorizes suspicion and purports to unmask allegedly concealed ideologies, does not equip scholars or students with the imaginative capacity necessary to confront the problems of the Anthropocene. Drawing upon the resources of speculative realism and speculative fiction, I propose speculative radicalism as an alternative practice. Speculative radicalism is an affirmative mode of reading, engagement, and theorizing that encourages the imagining of alternative future ways of living and modes of production, proceeding stepwise from a posited point of difference, or “novum.” Kim Stanley Robinson’s Mars Trilogy is offered as a model of invention in the speculative radicalist mode. With the goal of elaborating how speculative radicalism operates in this context, I repurpose the rhetorical topics of invention, or topoi. I argue that to fully appreciate the Mars Trilogy, one must understand that its applicable topics are, in fact, the planetary features of Mars itself: its gravity, landforms, and more. I develop and analyze this list of the planetary topics in the context of the Trilogy. In addition, I use the planetary topics to reevaluate established critical readings of the strategy video game series Sid Meier’s Civilization, as well as Robert Zubrin’s nonfiction space advocacy monograph The Case for Mars. I conclude that a reading of these artifacts informed by the planetary topics can yield more nuanced judgements than those produced by the prevailing style of academic critique; furthermore, this conclusion points the way toward the development of a speculative radicalist mode of engagement and imagination that is capable of meeting the challenges of the Anthropocene

Nematode community shifts in response to experimental warming and canopy conditions are associated with plant community changes in the temperate-boreal forest ecotone

Global climate warming is one of the key forces driving plant community shifts, such as range shifts of temperate species into boreal forests. As plant community shifts are slow to observe, ecotones, boundaries between two ecosystems, are target areas for providing early evidence of ecological responses to warming. The role of soil fauna is poorly explored in ecotones, although their positive and negative effects on plant species can influence plant community structure. We studied nematode communities in response to experimental warming (ambient, +1.7, +3.4 °C) in soils of closed and open canopy forest in the temperate-boreal ecotone of Minnesota, USA and calculated various established nematode indices. We estimated species-specific coverage of understory herbaceous and shrub plant species from the same experimental plots and tested if changes in the nematode community are associated with plant cover and composition. Individual nematode trophic groups did not differ among warming treatments, but the ratio between microbial-feeding and plant-feeding nematodes increased significantly and consistently with warming in both closed and open canopy areas and at both experimental field sites. The increase in this ratio was positively correlated with total cover of understory plant species, perhaps due to increased predation pressure on soil microorganisms causing higher nutrient availability for plants. Multivariate analyses revealed that temperature treatment, canopy conditions and nematode density consistently shaped understory plant communities across experimental sites. Our findings suggest that warming-induced changes in nematode community structure are associated with shifts in plant community composition and productivity in the temperate-boreal forest ecotones

Effects of soil warming history on the performances of congeneric temperate and boreal herbaceous plant species and their associations with soil biota

Aims. Climate warming raises the probability of range expansions of warm-adapted temperate species into areas currently dominated by cold-adapted boreal species. Warming-induced plant range expansions could partly depend on how warming modifies relationships with soil biota that promote plant growth, such as by mineralizing nutrients. Here, we grew two pairs of congeneric herbaceous plants species together in soil with a five-year warming history (ambient, +1.7°C, +3.4°C) and related their performances to plant-beneficial soil biota. Methods. Each plant pair belonged to either the mid-latitude temperate climate or the higher latitude southern boreal climate. Warmed soils were extracted from a chamberless heating experiment at two field sites in the temperate-boreal ecotone of North America. To isolate potential effects of different soil warming histories, air temperature for the greenhouse experiment was identical across soils. We hypothesized that soil with a five-year warming history in the field would enhance the performance of temperate plant species more than boreal plant species, and expected improved plant performances to have positive associations with plant-growth promoting soil biota (microbial-feeding nematodes and arbuscular mycorrhizal fungi). Main findings. Our main hypothesis was partly confirmed as only one temperate species performed better in soil with warming history than in soil with history of ambient temperature. Further, this effect was restricted to the site with higher soil water content in the growing season of the sampling year (prior to soil collection). One of the boreal species performed consistently worse in previously warmed soil, whereas the other species showed neutral responses to soil warming history. We found a positive correlation between the density of microbial-feeding nematodes and the performance of one of the temperate species in previously wetter soils, but this correlation was negative at the site with previously drier soil. We found no significant correlations between the performance of the other temperate species as well as the two boreal species and any of the studied soil biota. Our results indicate that soil warming can modify the relation between certain plant species and microbial-feeding nematodes in given soil edaphic conditions, which might be important for plant performance in the temperate-boreal ecotone