  As the impending consequences of climate change loom over the Earth, it has
become vital for researchers to understand the role microorganisms play in this
process. In this paper, we examine how environmental factors, including
moisture levels and temperature, affect the expression of certain fungal
characteristics on a microscale, and how these in turn affect fungal
biodiversity and ecosystem decomposition rates over time.
  We first present a differential equation model to understand how the
distribution of different fungal isolates depends on regional moisture levels.
We introduce both slow and sudden variations into the environment in order to
represent the various ways climate change will impact fungal ecosystems. This
model demonstrates that increased variability in moisture (both short-term and
long-term) increases biodiversity and that fungal populations will shift
towards more stress-tolerant fungi as aridity increases. The model further
suggests the lack of any direct link between biodiversity and decomposition
rates.
  To better describe fungal competition with respect to space, we develop a
local agent-based model (ABM). Unlike the previous model, our ABM focuses on
individuals, tracking each fungus and the result of its interactions. Our ABM
also features a more accurate spatial combat system, allowing us to precisely
discern the influence of fungal interactions on the environment. This model
corroborates the results of the differential equation model and further
suggests that moisture, through its link with temperature and effects on fungal
population, also plays a strong role in determining fungal decomposition rates.
  Together, these models suggest that climate change, which portends increasing
variability in regional conditions and higher average temperatures worldwide,
will lead to an increase in both wood decomposition rates and, independently,
fungal biodiversity.
