Population Growth and the Landscape Ecology of Microbes on Leaf Surfaces

摘要

The leaf surfaces of terrestrial plants, with a total surface area estimated at 4-6 chi 10~8 km~2 (Morris and Kinkel, 2002) represent one of the largest and most significant microbial habitats. Epicuticular colonists, including yeasts, filamentous fungi and protists, live on nutrients that are either deposited as fallout from the atmosphere or exuded from within the leaf. The epiphytic community is remarkably variable in several ways and at many levels of scale. This reflects the unknown but presumably relatively large influence of underlying habitat heterogeneity. Virtually from the emergence of phyllosphere microbiology as a discipline more than 50 years ago, research has focused on the well known but unexplained phenomenon of extreme leaf-to-leaf variability in microbe population densities (Woody et al, 2003). Here we consider how this arises and how it is shaped by microscale processes. There are clear analogies and implications to other microbial systems and to macro-ecology.