Thoughts on the processes that maintain local species diversity of ectomycorrhizal fungi

• Published in: Plant and soil Vol. 170; no. 1; pp. 63 - 73
• Main Author: Bruns, Thomas D.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Dordrecht Kluwer Academic Publishers 01-03-1995; Springer
• Subjects: Agronomy. Soil science and plant productions; Animal and plant ecology; Animal, plant and microbial ecology; biodiversidad; biodiversite; biodiversity; Biological and medical sciences; Economic plant physiology; Forest soils; Fundamental and applied biological sciences. Psychology; Fungi; MICROBIAL POPULATION DYNAMICS; microorganisme; microorganismos; microorganisms; Mycology; mycorhize; Mycorrhizae; Mycorrhizal fungi; Nitrogen; Pine trees; Plant roots; Soil fungi; Species diversity; Symbiosis (nodules, symbiotic nitrogen fixation, mycorrhiza...); Synecology; Terrestrial ecosystems; Forests; Organic matter; Theory; Resource allocation; Biological model; Forest soil; Review; Guild; Biodiversity; Inorganic element; Modeling; Monoculture; Fungi; Species diversity; Ecosystem; Network; Interspecific competition; Ectomycorrhiza; Mathematical model; Thallophyta; Symbiosis; Partition; Root; Mycoflora; Carbon; Biodynamics; Artificial forest stand; Biocenosis; Forestry; Mycorrhiza; Circular configuration; Patch
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/BF02183055

Ectomycorrhizal fungi exhibit high diversity even in small monoculture forests. Roughly 20 to 35 species typically occupy such sites. Explanations for this diversity can be based on resource partitioning, disturbance, competition, or interaction with other organisms. Mycorrhizal fungi compete for two general classes of resources: host-derived carbon and soil or detritus derived mineral nutrients. Both types of resources are arrayed in space (e.g., soil depth, distance from tree) and time (e.g., season, host successional series). Some species seem to be partitioned in space and time at these scales, but the question of how widespread these patterns are remains largely unanswered. Mineral resources are distributed in discrete substrates in soil, litter, and within other soil microorganisms; the biochemical diversity exhibited by fungi may translate into differences in access to these resources among species. Small-scale natural disturbances that sever roots, mix soil horizons and litter layers, or change local pH and nutrient availability, are likely to create additional habitats for ectomycorrhizal fungi. Evidence from fruiting patterns and differences in colonization strategies suggest that such disturbances may be important for establishment of some species. Competitive replacement networks among species have the theoretical potential to increase diversity. The frequency of species replacements, observed co-infections of ectomycorrhizal fungi on single host roots, and high rates of rootlet turn-over all suggest that competition is important, but whether it plays a creative role in maintaining diversity remains to be demonstrated. Other organisms could be important in the maintenance of diversity, if they effect competition among mycorrhizal fungi. Bacteria and soil invertebrates are the most likely groups for such interactions. Technological advances in root observation and PCR methods for identification of mycorrhizae make many of these theories testable.