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Category: Microbial Genetics and Molecular Biology; Environmental Microbiology
Fungal Ecology: Principles and Mechanisms of Colonization and Competition by Saprotrophic Fungi, Page 1 of 2
< Previous page | Next page > /docserver/preview/fulltext/10.1128/9781555819583/9781555819576_Chap13-1.gif /docserver/preview/fulltext/10.1128/9781555819583/9781555819576_Chap13-2.gifAbstract:
Decomposer fungi, by their very nature, continually deplete the organic resources in which they grow and feed. They therefore rely on continual successful spread to new resources. In terrestrial ecosystems resources are distributed heterogeneously in space and time ( 1 , 2 ). They are often discrete, ranging in size from small fragments, e.g., bud scales, to large tree trunks, though discrete leaves en masse can form a continuous layer on the forest floor. The processes of arrival and spread are thus crucial to the success of saprotrophic fungi. Following arrival at a resource, their competitive ability determines whether they are successful in colonization and how long they retain that territory. Colonization and competition are the main focus of this paper and are discussed separately below, largely drawing on wood decay fungi for illustrative examples.
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How R-C-S characteristics relate to r-K strategies.
How R-C-S characteristics relate to r-K strategies.
Foraging strategies of cord-forming basidiomycetes growing out of precolonized beech wood blocks across compacted soil. (A) Hypholoma fasciculare, a short-range forager, produces highly dense hyphae and mycelia. (B) Phanerochaete velutina is a longer-range forager with a more open cord system. (C) Resinicium bicolor has an even more open system than P. velutina, with thicker cords.
Foraging strategies of cord-forming basidiomycetes growing out of precolonized beech wood blocks across compacted soil. (A) Hypholoma fasciculare, a short-range forager, produces highly dense hyphae and mycelia. (B) Phanerochaete velutina is a longer-range forager with a more open cord system. (C) Resinicium bicolor has an even more open system than P. velutina, with thicker cords.
Sectioned beech trunk showing decay columns running longitudinally through the wood. Arrows indicate dark zone lines (pseudosclerotial plates) surrounding different decay columns.
Sectioned beech trunk showing decay columns running longitudinally through the wood. Arrows indicate dark zone lines (pseudosclerotial plates) surrounding different decay columns.
Fungal community development pathways in woody resources. Newly available wood (top) becomes progressively colonized, initially through primary resource capture in an open community stage where there is still unoccupied territory, until all territory becomes occupied, resulting in a closed community where further colonization occurs as secondary resource capture. As the community moves from open to closed, combat becomes the driving force for change. Finally, communities in well-decayed wood are characterized by substrate modification and invasion by soil invertebrates. The ecological characteristics of the dominant organisms are indicated in boxes: R, ruderal; C, combative; S, stress-tolerant. Driving forces are indicated in italic, and direction of community change is indicated by arrows. The community may be driven toward the left by stress aggravation or to the right by stress alleviation, although destructive disturbance will drive the community toward species with R-selected characteristics. (Adapted from references 5 and 58 .)
Fungal community development pathways in woody resources. Newly available wood (top) becomes progressively colonized, initially through primary resource capture in an open community stage where there is still unoccupied territory, until all territory becomes occupied, resulting in a closed community where further colonization occurs as secondary resource capture. As the community moves from open to closed, combat becomes the driving force for change. Finally, communities in well-decayed wood are characterized by substrate modification and invasion by soil invertebrates. The ecological characteristics of the dominant organisms are indicated in boxes: R, ruderal; C, combative; S, stress-tolerant. Driving forces are indicated in italic, and direction of community change is indicated by arrows. The community may be driven toward the left by stress aggravation or to the right by stress alleviation, although destructive disturbance will drive the community toward species with R-selected characteristics. (Adapted from references 5 and 58 .)
Interspecific interactions of fungi growing in natural and artificial media. (A) Cross section of a decaying beech branch with dark zone lines (pseudosclerotial plates) surrounding competing mycelia. (B, C) Growth of Trametes versicolor when exposed to the diffusible organic compounds (DOCs) from uncolonized malt broth (control) (B) or DOCs from Fomes fomentarius (C). (D, E) Phallus impudicus cord systems growing across compacted soil when exposed to volatile organic compounds (VOCs) from uncolonized soil (control) (D) or VOCs from Hypholoma fasciculare growing across soil (E). (F) Interaction between H. fasciculare and Resinicium bicolor cord systems across compacted soil. (G) Accumulation of reactive oxygen species (ROS) at the interaction zone between Bjerkandera adusta (left) and T. versicolor (left) on 2% malt agar (MA). ROS are stained purple using nitro blue tetrazolium (methods in reference 92 ). (H) Three-way interaction between mycelia of H. fasciculare (left), P. velutina (center), and Stereum hirsutum (right) growing on 2% malt agar (MA). H. fasciculare cords are beginning to encroach over the P. velutina mycelium, while H. fasciculare itself is overgrown by P. velutina cords. A thick barrage separates the mycelia of S. hirsutum and P. velutina, with a distinct orange/yellow band of pigment deposited in the agar at the regions of contact between the two mycelia.
Interspecific interactions of fungi growing in natural and artificial media. (A) Cross section of a decaying beech branch with dark zone lines (pseudosclerotial plates) surrounding competing mycelia. (B, C) Growth of Trametes versicolor when exposed to the diffusible organic compounds (DOCs) from uncolonized malt broth (control) (B) or DOCs from Fomes fomentarius (C). (D, E) Phallus impudicus cord systems growing across compacted soil when exposed to volatile organic compounds (VOCs) from uncolonized soil (control) (D) or VOCs from Hypholoma fasciculare growing across soil (E). (F) Interaction between H. fasciculare and Resinicium bicolor cord systems across compacted soil. (G) Accumulation of reactive oxygen species (ROS) at the interaction zone between Bjerkandera adusta (left) and T. versicolor (left) on 2% malt agar (MA). ROS are stained purple using nitro blue tetrazolium (methods in reference 92 ). (H) Three-way interaction between mycelia of H. fasciculare (left), P. velutina (center), and Stereum hirsutum (right) growing on 2% malt agar (MA). H. fasciculare cords are beginning to encroach over the P. velutina mycelium, while H. fasciculare itself is overgrown by P. velutina cords. A thick barrage separates the mycelia of S. hirsutum and P. velutina, with a distinct orange/yellow band of pigment deposited in the agar at the regions of contact between the two mycelia.
Characteristics defining the life history strategies of ruderal, combative, and stress-tolerant species
Characteristics defining the life history strategies of ruderal, combative, and stress-tolerant species
Secondary metabolite production during antagonistic interactions a
Secondary metabolite production during antagonistic interactions a
Extracellular enzyme production during antagonistic interactions a
Extracellular enzyme production during antagonistic interactions a