The role of humans in the global dispersal of free‐living terrestrial microorganisms has received surprisingly little attention in the literature, compared with the frequent discussions of human dispersal for aquatic microbes. Here I argue that this area needs more study, using examples from the ecology of testate amoebae to illustrate the nature of the problem. The techniques of molecular ecology now make these ideas open to investigation in a way that would have been difficult in the past, and, in the case of testate amoebae, palaeoecological approaches may also be valuable.
Aims To use the ecosystem on Green Mountain, Ascension Island, to illustrate aspects of ecosystem construction and function as well as possible mitigation of human caused global environmental change. Location Ascension Island, tropical south Atlantic. Main conclusions The cloud forest on Green Mountain is a man-made system that has produced a tropical forest without any coevolution between its constituent species. This has implications for the way we think about ecosystems and provides a striking example of Janzen's idea of 'ecological fitting'. This system provides ecosystem services, such as carbon sequestration, and illustrates the possible role of man-made ecosystems in the mitigation of global warming.
Two recent studies have cast new light on the evolutionary history of MYCORRHIZAE. New fossil evidence has pushed the date for the appearance of ARBUSCULAR MYCORRHIZAE back to 460 million years ago, predating vascular plants. A phylogenetic tree for the Basidiomycota shows that these fungi have gained (and lost) the ectomycorrhizal condition repeatedly during their history. These studies help highlight the paleoecological importance of mycorrhizae and add to our understanding of the evolution of mutualisms.
