2016
Afkhami, Michelle E.; Strauss, Sharon Y.
Native fungal endophytes suppress an exotic dominant and increase plant diversity over small and large spatial scales Journal Article
In: Ecology, vol. 97, no. 5, pp. 1159–1169, 2016.
Abstract | Links | BibTeX | Tags: biodiversity, Bromus laevipes, Epichloë, evenness, fungal endophyte, grass, hidden players, invasive species, keystone species, mutualism, richness, symbiosis
@article{Afkhami2016,
title = {Native fungal endophytes suppress an exotic dominant and increase plant diversity over small and large spatial scales},
author = {Michelle E. Afkhami and Sharon Y. Strauss},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Afkhami_2016_Eco.pdf},
doi = {10.1890/15-1166.1},
year = {2016},
date = {2016-01-01},
journal = {Ecology},
volume = {97},
number = {5},
pages = {1159–1169},
abstract = {Understanding community dynamics and processes, such as the factors that
generate and maintain biodiversity, drive succession, and affect invasion susceptibility, is
a central goal in ecology and evolution. While most studies of how species interactions
affect communities have focused on highly visible macroorganisms, we show that mutualistic
microfungal endophytes have community-level effects across their host plant’s range and
provide the first example of fungal endophytes enhancing plant diversity. A three-year
field study in which we experimentally manipulated endophyte abundance in a native
Californian grass showed that despite their minute biomass, endophytes dramatically increased
plant community diversity (~110% greater increase with endophytes) by suppressing a
dominant invasive grass, Bromus diandrus. This effect was also detectable, but smaller,
across five additional common gardens spanning ecologically diverse habitats, different
climates, and >400 km of the host grass’ range as well as at microspatial scales within
gardens. Our study illustrates that mutualistic microbes, while often hidden players, can
have unexpectedly large ecological impacts across a wide range of habitats and scales and
may be important for promoting diverse communities and ecosystems.},
keywords = {biodiversity, Bromus laevipes, Epichloë, evenness, fungal endophyte, grass, hidden players, invasive species, keystone species, mutualism, richness, symbiosis},
pubstate = {published},
tppubtype = {article}
}
Understanding community dynamics and processes, such as the factors that
generate and maintain biodiversity, drive succession, and affect invasion susceptibility, is
a central goal in ecology and evolution. While most studies of how species interactions
affect communities have focused on highly visible macroorganisms, we show that mutualistic
microfungal endophytes have community-level effects across their host plant’s range and
provide the first example of fungal endophytes enhancing plant diversity. A three-year
field study in which we experimentally manipulated endophyte abundance in a native
Californian grass showed that despite their minute biomass, endophytes dramatically increased
plant community diversity (~110% greater increase with endophytes) by suppressing a
dominant invasive grass, Bromus diandrus. This effect was also detectable, but smaller,
across five additional common gardens spanning ecologically diverse habitats, different
climates, and >400 km of the host grass’ range as well as at microspatial scales within
gardens. Our study illustrates that mutualistic microbes, while often hidden players, can
have unexpectedly large ecological impacts across a wide range of habitats and scales and
may be important for promoting diverse communities and ecosystems.
generate and maintain biodiversity, drive succession, and affect invasion susceptibility, is
a central goal in ecology and evolution. While most studies of how species interactions
affect communities have focused on highly visible macroorganisms, we show that mutualistic
microfungal endophytes have community-level effects across their host plant’s range and
provide the first example of fungal endophytes enhancing plant diversity. A three-year
field study in which we experimentally manipulated endophyte abundance in a native
Californian grass showed that despite their minute biomass, endophytes dramatically increased
plant community diversity (~110% greater increase with endophytes) by suppressing a
dominant invasive grass, Bromus diandrus. This effect was also detectable, but smaller,
across five additional common gardens spanning ecologically diverse habitats, different
climates, and >400 km of the host grass’ range as well as at microspatial scales within
gardens. Our study illustrates that mutualistic microbes, while often hidden players, can
have unexpectedly large ecological impacts across a wide range of habitats and scales and
may be important for promoting diverse communities and ecosystems.
2012
Afkhami, Michelle E.
Fungal endophyte-grass symbioses are rare in the California floristic province and other regions with Mediterranean-influenced climates Journal Article
In: Fungal Ecology, vol. 5, no. 3, pp. 345-352, 2012.
Abstract | Links | BibTeX | Tags: fungal endophyte, grass, symbiosis
@article{Afkhami2012,
title = {Fungal endophyte-grass symbioses are rare in the California floristic province and other regions with Mediterranean-influenced climates},
author = {Michelle E. Afkhami},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Afkami_2012-FungEco.pdf},
doi = {10.1016/j.funeco.2011.09.006},
year = {2012},
date = {2012-06-01},
journal = {Fungal Ecology},
volume = {5},
number = {3},
pages = {345-352},
abstract = {Research on agronomic grasses has shown that Class 1 fungal endophytes (Neotyphodium/Epichloë; Clavicipitaceae) can have profound effects on host plant fitness. However, in natural systems, even basic ecological knowledge of most endophyte symbioses is lacking. Here, I describe the distribution and abundance of endophytes across 36 native (or naturalized) grasses in a previously unsurveyed region, the California Floristic Province. Symbiosis was generally low: 8.33 % of species and 18.75 % of genera hosted endophytes. I then compared the proportions of symbiotic species and genera found in California and other Mediterranean regions to the proportions found in non-Mediterranean regions. Surveys of Mediterranean-influenced regions showed significantly lower proportions of species (∼66 % lower) and genera (∼65 % lower) hosting endophyte than surveys of non-Mediterranean regions. This pattern suggests that selection in Mediterranean climates may not favor endophyte symbioses.},
keywords = {fungal endophyte, grass, symbiosis},
pubstate = {published},
tppubtype = {article}
}
Research on agronomic grasses has shown that Class 1 fungal endophytes (Neotyphodium/Epichloë; Clavicipitaceae) can have profound effects on host plant fitness. However, in natural systems, even basic ecological knowledge of most endophyte symbioses is lacking. Here, I describe the distribution and abundance of endophytes across 36 native (or naturalized) grasses in a previously unsurveyed region, the California Floristic Province. Symbiosis was generally low: 8.33 % of species and 18.75 % of genera hosted endophytes. I then compared the proportions of symbiotic species and genera found in California and other Mediterranean regions to the proportions found in non-Mediterranean regions. Surveys of Mediterranean-influenced regions showed significantly lower proportions of species (∼66 % lower) and genera (∼65 % lower) hosting endophyte than surveys of non-Mediterranean regions. This pattern suggests that selection in Mediterranean climates may not favor endophyte symbioses.
2004
Bidartondo, Martin I.; Burghardt, Bastian; Gebauer, Gerhard; Bruns, Thomas D.; Read, David J.
Changing partners in the dark: isotopic and molecular evidence of ectomycorrhizal liaisons between forest orchids and trees. Journal Article
In: Proceedings of the Royal Society of London: Biological Sciences, vol. 271, no. Series B, 1550, pp. 1799-1806, 2004, ISSN: 09628452.
Abstract | Links | BibTeX | Tags: Cephalanthera, Epipactis, mycorrhizae, partial myco-heterotrophy, symbiosis, Tuber
@article{Bidartondo2004,
title = {Changing partners in the dark: isotopic and molecular evidence of ectomycorrhizal liaisons between forest orchids and trees.},
author = {Martin I. Bidartondo and Bastian Burghardt and Gerhard Gebauer and Thomas D. Bruns and David J. Read},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Changing-Partners-in-the-Dark-Isotopic-and-Molecular-Evidence-of-Ectomycorrhizal-Liaisons-between-Forest-Orchids-and-Trees_Bidartondo.pdf},
doi = {10.1098/rspb.2004.2807},
issn = {09628452},
year = {2004},
date = {2004-09-07},
journal = {Proceedings of the Royal Society of London: Biological Sciences},
volume = {271},
number = {Series B, 1550},
pages = {1799-1806},
abstract = {In the mycorrhizal symbiosis, plants exchange photosynthates for mineral nutrients acquired by fungi from the soil. This mutualistic arrangement has been subverted by hundreds of mycorrhizal plant species that lack the ability to photosynthesize. The most numerous examples of this behaviour are found in the largest plant family, the Orchidaceae. Although non-photosynthetic orchid species are known to be highly specialized exploiters of the ectomycorrhizal symbiosis, photosynthetic orchids are thought to use free-living saprophytic or pathogenic fungal lineages. However, we present evidence that putatively photosynthetic orchids from five species that grow in the understorey of forests (i) form mycorrhizas with ectomycorrhizal fungi of forest trees and (ii) have stable-isotope signatures indicating distinctive pathways for nitrogen and carbon acquisition approaching those of non-photosynthetic orchids that associate with ectomycorrhizal fungi of forest trees. These findings represent a major shift in our understanding of both orchid ecology and evolution because they explain how orchids can thrive in low-irradiance niches and they show that a shift to exploiting ectomycorrhizal fungi precedes viable losses of photosynthetic ability in orchid lineages.},
keywords = {Cephalanthera, Epipactis, mycorrhizae, partial myco-heterotrophy, symbiosis, Tuber},
pubstate = {published},
tppubtype = {article}
}
In the mycorrhizal symbiosis, plants exchange photosynthates for mineral nutrients acquired by fungi from the soil. This mutualistic arrangement has been subverted by hundreds of mycorrhizal plant species that lack the ability to photosynthesize. The most numerous examples of this behaviour are found in the largest plant family, the Orchidaceae. Although non-photosynthetic orchid species are known to be highly specialized exploiters of the ectomycorrhizal symbiosis, photosynthetic orchids are thought to use free-living saprophytic or pathogenic fungal lineages. However, we present evidence that putatively photosynthetic orchids from five species that grow in the understorey of forests (i) form mycorrhizas with ectomycorrhizal fungi of forest trees and (ii) have stable-isotope signatures indicating distinctive pathways for nitrogen and carbon acquisition approaching those of non-photosynthetic orchids that associate with ectomycorrhizal fungi of forest trees. These findings represent a major shift in our understanding of both orchid ecology and evolution because they explain how orchids can thrive in low-irradiance niches and they show that a shift to exploiting ectomycorrhizal fungi precedes viable losses of photosynthetic ability in orchid lineages.