![FIGURE 4.4 Principle coordinate analysis of ectomycorrhizae in protozoan species space, showing the difference in protozoan community structure of different ectomycorrhizal fungal species on roots of ponderosa pine. Four groupings appear from this analysis with similar protozoan communities on group 1 [Rhizopogon subcaerulenscens (Rs), R. ellenae (Re), and R. truncates (Rt)] from group 2 [R. arctostaphylii (Ra), R. smithii (Rsm), and R. flavofibrillosus (Rf)], from group 3 [R. vulgaris (Rvu), R. rubescens (Rr), Thelephora terrestris (Thel), and Mycelium radicis atrovirens (MRA)] from the outlier R. occidentalis (Ro). Source: The data have been reworked from Ingham and Massicotte (1994), and the first two axes account for 23% and 18.2% of the variation, respectively.](https://images.tandf.co.uk/common/jackets/crclarge/978082474/9780824742447.jpg "FIGURE 4.4 Principle coordinate analysis of ectomycorrhizae in protozoan species space, showing the difference in protozoan community structure of different ectomycorrhizal fungal species on roots of ponderosa pine. Four groupings appear from this analysis with similar protozoan communities on group 1 [Rhizopogon subcaerulenscens (Rs), R. ellenae (Re), and R. truncates (Rt)] from group 2 [R. arctostaphylii (Ra), R. smithii (Rsm), and R. flavofibrillosus (Rf)], from group 3 [R. vulgaris (Rvu), R. rubescens (Rr), Thelephora terrestris (Thel), and Mycelium radicis atrovirens (MRA)] from the outlier R. occidentalis (Ro). Source: The data have been reworked from Ingham and Massicotte (1994), and the first two axes account for 23% and 18.2% of the variation, respectively.")
ABSTRACT
As it is believed that mycorrhizal plants direct much more of their photosynthates into the soil than nonmycorrhizal plants, it is anticipated that where the growth of organisms that are energy-limited, the detrital food web would benefit from the flow of C through mycorrhizal plants into the below-ground ecosystem. Setälä (2000) investigated the potential benefit of the presence of ectomycorrhizal fungi on the roots of Scots pine (Pinus sylvestris) on fungiverous and micobiverous representatives of soil mesofauna. Soil was defaunated and then reinoculated with 10 species of soil bacteria, 11 species of saprotrophic soil fungi, and pine seedlings, either infected or notinfected with four ectomycorrhizal fungi. Soil fauna were added with increasing levels of community complexity, including the omnivorous enchytraeid species Cognettia sphagnetorum, a Collembola (Hypogastrura assimilis), and four species of oribatid mites. After 60 weeks, pine biomass production was significantly greater in the mycorrhizal systems, the total biomass being 1.43 times higher in the presence than absence of ectomycorrhizal fungi. Similarly, almost 10 times more fungal biomass was detected on pine roots growing in the mycorrhizal than in the nonmycorrhizal systems. Despite the larger biomass of both the pines and their associated fungal community, however, neither the numbers nor biomasses of the mesofauna differed significantly between the mycorrhizal and nonmycorrhizal systems (Table 4.11). The presence of Collembola and C. sphagnetorum had a positive influence on pine growth,
Faunal density (number per experimental system)
Faunal group No mycorrhiza With mycorrhiza Enchytraeid 83 98
Collembola 62 18
Faunal groups alone
Mite 630 1372
Enchytraeid 339 44
Collembola 14 20
Faunal groups in combination
Mite 90 1235
Note: There are no statistically significant differences among the number of animals between mycorrhizal treatments because of the high variance around the mean values. Source: Data from Setälä (2000).
