Global distribution of forest soil dictyostelids

Abstract

Aim The goal of this project was to compile, organize, and present the known distributional data on the dictyostelid cellular slime moulds (CSMs) found in forest soils worldwide. The question of what factors influence CSM distribution patterns was also addressed.Location CSMs have been recovered from soils of temperate deciduous forest, tropical deciduous and seasonal evergreen rainforest, boreal coniferous forest, and tundra by various investigators around the world.Methods Within each of these four biomes, various locations around the world have been sampled by a number of investigators. The current study attempts to synthesize the known dictyostelid distributional data and present specific patterns of distribution.Results Worldwide, sixty-five species of CSM were found to occupy various forest soils. These species' distributions fell into one of four categories: cosmopolitan, disjunct, restricted, and pantropical.Main conclusions Global CSM distribution patterns are influenced by a variety of factors other than the biota (including but not restricted to climate, latitude, altitude, soil pH, and soil-forming parent materials). The current study supports the thesis that organic inputs from specific plant associations and animal vectors have an important role as well.

What’s on your boots: an investigation into the role we play in protist dispersal

“…This structure can vary widely in shape, size and coloration among species and displays most of the characters used for species identification (Raper, 1984). Within the dictyostelids some of the c. 150 species appear to have restricted or disjunct distributions, while others are cosmopolitan (Swanson et al, 1999). This distribution pattern is consistent with the Ômoderate endemicity modelÕ proposed by Foissner (1999Foissner ( , 2006, under which some microorganisms exhibit biogeographical patterns similar to those seen in macroorganisms.…”

“…However, in the dictyostelids there does not appear to be a clear correlation between size and ubiquity of distribution (Swanson et al, 1999). This is in contrast to the situation found in testate amoebae, where smaller amoebae are more likely to be cosmopolitan (Wilkinson, 2001;Yang et al, 2010).…”

“…Two of the species recovered, D. sphaerocephalum and D. minutum, are considered cosmopolitan in distribution (Raper, 1984;Swanson et al, 1999), and have previously been recorded in Sweden (A.L. Perrigo & M. Romeralo, unpublished data).…”

“…In terms of size, it is interesting to note that D. sphaerocephalum, the only species encountered more than once here (Table 1), has robust sorophores, with sori that are among the largest known for dictyostelids. Swanson et al (1999) note that D. sphaerocephalum is often found in disturbed or cultivated soils. This suggests a species with high dispersal capabilities and colonization potential.…”

An Unusually Low Microsatellite Mutation Rate in Dictyostelium discoideum, an Organism With Unusually Abundant Microsatellites

“…However, selection ought to be potent in D. discoideum. It has a large geographic range ½eastern North America and part of eastern Asia (Swanson et al 1999) and therefore should have a large effective population size. Molecular evidence suggests that it is typical of unicellular eukaryotes to have a population size (estimated as N e m) large enough to make selection a very potent force relative to drift (Lynch and Conery 2003).…”