Exploring Trait Trade-Offs for Fungal Decomposers in a Southern California Grassland

Microbial drought resistance may destabilize soil carbon

Droughts are becoming more frequent and intense with climate change. As plants and microbes respond to drought, there may be consequences for the vast stocks of organic carbon stored in soils. If microbes sustain their activity under drought, soils could lose carbon, especially if inputs from plants decline. Empirical and theoretical studies reveal multiple mechanisms of microbial drought resistance, including tolerance and avoidance. Physiological responses allow microbes to acclimate to drought within minutes to days. Along with dispersal, shifts in community composition could allow microbiomes to maintain functioning despite drought. Microbes might also adapt to drier conditions through evolutionary processes. Together, these mechanisms could result in soil carbon losses larger than currently anticipated under climate change.

Sympoietic growth: living and producing with fungi in times of ecological distress

Drawing upon ethnographic research on human living and producing with fungi, and Haraway's theorization of sympoiesis and the model ecosystems of mycorrhizae developed in current mycological research, we offer a concept of sympoietic growth. Sympoiesis is a concept that suggests a way of thinking about growth as a more-than-human process and provides an alternative political imaginary both to current forms of economic growth and to the idea of "degrowth." We explore human-fungi co-operation in forests, an urban park, and a shopping mall, on a miso production farm, and in a Catholic parish to provide insights into the logic and relationships involved in sympoietic growth in the field of agriculture and food production. We argue that this form of food provision has a sustainable, (re)generative potential not only in ecological and social but also economic terms. In conclusion, we highlight three patterns of sympoietic growth: the absence of any urge to "take (back) control" over the multispecies dynamic on the part of the humans; a non-instrumental passion for more-than-human life; and a combination of intellectual and manual labor as a form of attachment to the more-than-human world.

Phenotypic plasticity of fungal traits in response to moisture and temperature

Phenotypic plasticity of traits is commonly measured in plants to improve understanding of organismal and ecosystem responses to climate change but is far less studied for microbes. Specifically, decomposer fungi are thought to display high levels of phenotypic plasticity and their functions have important implications for ecosystem dynamics. Assessing the phenotypic plasticity of fungal traits may therefore be important for predicting fungal community response to climate change. Here, we assess the phenotypic plasticity of 15 fungal isolates (12 species) from a Southern California grassland. Fungi were incubated on litter at five moisture levels (ranging from 4-50% water holding capacity) and at five temperatures (ranging from 4-36 °C). After incubation, fungal biomass and activities of four extracellular enzymes (cellobiohydrolase (CBH), β-glucosidase (BG), β-xylosidase (BX), and N-acetyl-β-D-glucosaminidase (NAG)) were measured. We used response surface methodology to determine how fungal phenotypic plasticity differs across the moisture-temperature gradient. We hypothesized that fungal biomass and extracellular enzyme activities would vary with moisture and temperature and that the shape of the response surface would vary between fungal isolates. We further hypothesized that more closely related fungi would show more similar response surfaces across the moisture-temperature gradient. In support of our hypotheses, we found that plasticity differed between fungi along the temperature gradient for fungal biomass and for all the extracellular enzyme activities. Plasticity also differed between fungi along the moisture gradient for BG activity. These differences appear to be caused by variation mainly at the moisture and temperature extremes. We also found that more closely related fungi had more similar extracellular enzymes activities at the highest temperature. Altogether, this evidence suggests that with global warming, fungal biodiversity may become increasingly important as functional traits tend to diverge along phylogenetic lines at higher temperatures.