Parker Bartz

Introduction Unlike other major plant nutrients, N is naturally brought into most ecosystems through lightning and the biological fixation of atmospheric N gas by microbes, a process known as N fixation. Given that N limits plant growth in many ecosystems (LeBauer & Treseder, 2008), biological N fixation is a critical process to study (Reed et al., 2011). N-fixing microbes are divided into two groups: asymbiotic (free-living) and symbiotic.

1 Introduction During the last century, the global temperature has increased by 1°C, and climate models predict that it will increase by 3.5°C–4.0°C by the end of the century (Parry et al. 2007), which is a possible turning point in plant metabolic function (Doughty et al. 2023). Leaf temperature is altered by sunlight, wind, and water availability and usually exceeds air temperature during periods of intense sunlight (Matsui and Eguchi 1971; Perera et al.

Abstract Tropical forests are increasingly threatened by climate change. Yet, it is still unclear how tropical plants respond to increasing temperatures. Leaf heat tolerance (LHT) in tropical plants is often at its upper limit, suggesting that climate change might negatively impact tropical forests. We hypothesized that intraspecific variation in this leaf trait might be associated with changes in the soil microbiome, which might also respond to climate.