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Jan Frouz - One of the best experts on this subject based on the ideXlab platform.
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low root biomass and occurrence of ectomycorrhizal exploration types in inhabited wood Ant formica polyctena Nests in a temperate spruce forest
2017Co-Authors: Veronika Jilkova, Jan Frouz, Martin Vohnik, Jens Dauber, Andreas Marten, Hana SimackovaAbstract:Trees growing in nutrient-limited temperate forest soils can gain nutrients by root proliferation into nutrient-rich hotspots and/or by forming mycorrhizal symbioses. In this study we investigated the effects of nutrient-rich hotspots (inhabited wood Ant Nests) on Norway spruce root biomass and occurrence of ectomycorrhizal (EcM) exploration types. Substrates were collected from the mineral soil layer in a temperate middle-European spruce forest (Nationalpark Harz, Germany) from four micro-regions within each of the five wood Ant Nests sampled, i.e. 1) centre of the belowground part of a nest, 2) nest's rim, 3) nest's run-off zone (ca. 20 cm from nest's rim), and 4) from the surrounding forest soil (>10 m from nest's rim). Root biomass, EcM exploration types, moisture and nutrient contents were determined in all substrates. Although naturally enriched, wood Ant Nests had neither root biomass nor occurrence of EcM exploration types higher compared to the surrounding forest soil. The probable main reasons were high phosphorus content and low moisture maintained inside inhabited Nests, although the effect was not significAnt. Apparently, other substrate properties not determined in our study also affect the occurrence of exploration types in wood Ant nest substrates. Inhabited wood Ant Nests thus seem unfavourable for root proliferation and their subsequent EcM colonization. However, roots can gain nutrients from the run-off zone around Nests where low moisture is not maintained and nutrient contents are higher due to leaching from the nest substrate.
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methane and carbon dioxide flux in the profile of wood Ant formica aquilonia Nests and the surrounding forest floor during a laboratory incubation
2016Co-Authors: Veronika Jilkova, Jan Frouz, Tomas Picek, Martina Sestauberova, Vaclav Kristůfek, Tomas CajthamlAbstract:We compared methane (CH4) and carbon dioxide (CO2) fluxes in samples collected from the aboveground parts of wood Ant Nests and in the organic and mineral layer of the surrounding forest floor. Gas fluxes were measured during a laboratory incubation, and microbial properties (abundance of fungi, bacteria, and methanotrophic bacteria) and nutrient contents (total and available carbon and nitrogen) were also determined. Both CO2 and CH4 were produced from Ant nest samples, indicating that the aboveground parts of wood Ant Nests act as sources of both gases; in comparison, the forest floor produced about four-times less CO2 and consumed rather than produced CH4. Fluxes of CH4 and CO2 were positively correlated with contents of available carbon and nitrogen. The methanotrophic community was represented by type II methanotrophic bacteria, but their abundance did not explain CH4 flux. Fungal abundance was greater in Ant nest samples than in forest floor samples but bacterial abundance was similar in both kinds of samples, suggesting that the organic materials in the Nests may have been too recalcitrAnt for bacteria to decompose. The results indicate that the aboveground parts of wood Ant Nests are hot spots of CO2 and CH4 production in the forest floor.
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effects of nutrient rich substrate and ectomycorrhizal symbiosis on spruce seedling biomass in abandoned Nests of the wood Ant formica polyctena a laboratory experiment
2015Co-Authors: Veronika Jilkova, Jan Frouz, Martin Vohnik, Ondřej MudrakAbstract:Abstract Coniferous trees can take up mineral nutrients either non-symbiotically from nutrient-rich hotspots in the forest floor or via symbiosis with ectomycorrhizal (EcM) fungi; EcM symbiosis also enables the trees to obtain nutrients from organic substances. Excellent examples of nutrient-rich forest-floor hotspots are abandoned wood Ant Nests, which accumulate significAnt amounts of inorganic substances that are readily accessible to roots as well as organic substances that are not accessible to non-mycorrhizal roots. We examined the effects of substrates from abandoned Nests of the wood Ant Formica polyctena and EcM symbiosis on the growth of Norway spruce (Picea abies) seedlings. The tested substrates originated from the centers and rims of wet and dry Ant Nests, and from the surrounding forest floor. Aseptic spruce seedlings were grown in these substrates in a growth chamber, and after 7 months, seedling biomass, the chemical and microbiological properties of the substrates, and EcM colonization and diversity were determined. Spruce seedlings grew better and had a more diverse spectra of EcM fungi in the Ant nest substrates than in the forest floor substrate. Substrate nutrient content, especially phosphorus and basic cations, positively correlated with spruce biomass, EcM diversity, and fungal biomass. Contrary to conventional wisdom, high nutrient contents in Ant Nests apparently enhanced EcM abundance and diversity. Although abandoned wood Ant Nests in temperate and boreal forests are not abundAnt and thus are unlikely to have ecosystem level effects, they may cause significAnt local variations in tree growth and in the occurrence of root-symbiotic fungi.
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mechanisms of ph change in wood Ant formica polyctena Nests
2012Co-Authors: Veronika Jilkova, O Sebek, Jan FrouzAbstract:Abstract We conducted a study to determine why the pH of wood Ant nest materials is typically higher than that of the surrounding forest soil. An experiment with litter bags demonstrated that the pH of litter increased significAntly (after only 7 months) in Ant Nests. Because the food that foraging Ants bring into the nest contains easily decomposed carbohydrates and basic cations (largely in the form of honeydew and prey) that can cause increases in pH, we then estimated the amount of this influ of basic cations and easily decomposed carbohydrates. Based on these estimates, we conducted a second experiment to determine whether addition of field-determined quAntities of an easily decomposed carbohydrate (glucose) or a basic cation (Ca2+) would increase the pH of the litter in artificial Ant Nests in the forest. Both glucose and Ca2+ additions significAntly increased the pH of the litter but the increase was greater with Ca2+. The rate of pH increase in the artificial Nests was similar to the rate of increase in natural Nests. According to our study, Ants collect substAntial amounts of mineral-enriched materials in this ecosystem, which collectively increase the pH of nest material.
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influence of the wood Ant formica polyctena on soil nutrient and the spruce tree growth
2008Co-Authors: Jan Frouz, M Rybnicek, P Cudlin, E ChmelikovaAbstract:The effect of Formica polyctena Ant Nests on the distribution of soil nutrients, soil pH and the growth of Norway spruce trees was studied in the southern part of the Czech Republic. Soil nutrient content (exchangeable P, N, K and pH) and growth of mature spruce trees were measured at four distances from the nearest Ant hill (0-1, 3-5, 10-50 and >200 m). Trees at all distances were visited by Ants, except for those >200 m from the nearest nest. Soil pH and of P, K and NO 3 concentrations were higher near Ant Nests ( 200 m from the Nests, where no significAnt differences in these variables were detected. In contrast, tree ring analyses (1974-2004) showed that trees >200 m from the Ant Nests grew significAntly faster than trees at other distances, followed by trees within 1 m of the Nests. No growth differences were found between the growth of trees at 3-5 and 10-50 m from Ant Nests. We postulate that nutrient and carbohydrate removal of honeydew collected by Ant-tended aphids are slowing growth of tree. However, trees may partly compensate for this depletion by having access to a larger supply of soil nutrients near Ant Nests.
Veronika Jilkova - One of the best experts on this subject based on the ideXlab platform.
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gradients of labile carbon inputs into the soil surrounding wood Ant Nests in a temperate forest
2020Co-Authors: Veronika Jilkova, Kateřina Jandova, Anna Vaciřova, Jaroslav KuklaAbstract:Wood Ants are common in temperate forests, and while building their Nests and foraging for food, they transfer large amounts of organic matter and nutrients. Here, we tested the hypothesis that wood Ants generate natural gradients of labile carbon (C) inputs into the soil surrounding their Nests. We selected five medium-sized wood Ant (Formica aquilonia) Nests in a coniferous temperate forest and established sampling points at distances of 4, 30 and 70 m from each nest. Throughfall (honeydew + aboveground vegetation leachates) and litterfall were collected regularly during a vegetative season and were analysed for labile organic C content. In addition, soil from the organic horizon (Oe + Oa), surface mineral horizon (A) and subsoil mineral horizon (B) was collected and analysed for organic matter and nutrient contents. The labile C input in throughfall increased with distance from the nest (it was 1.5-fold greater at 70 m than at 4 m). C input changed during the vegetative season and was highest in June. Litterfall was not affected by the distance from the nest. Organic matter and nutrient contents were unaffected by distance from the nest in surface soil horizons but were significAntly higher near the nest (4 m) than 70 m from the nest in the subsoil mineral horizon, suggesting that surface soils are less affected by the labile C inputs than subsoils. Finally, we suggest that the gradients in labile C input surrounding wood Ant Nests can be used to study the effects of labile C input changes on soil properties.
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low root biomass and occurrence of ectomycorrhizal exploration types in inhabited wood Ant formica polyctena Nests in a temperate spruce forest
2017Co-Authors: Veronika Jilkova, Jan Frouz, Martin Vohnik, Jens Dauber, Andreas Marten, Hana SimackovaAbstract:Trees growing in nutrient-limited temperate forest soils can gain nutrients by root proliferation into nutrient-rich hotspots and/or by forming mycorrhizal symbioses. In this study we investigated the effects of nutrient-rich hotspots (inhabited wood Ant Nests) on Norway spruce root biomass and occurrence of ectomycorrhizal (EcM) exploration types. Substrates were collected from the mineral soil layer in a temperate middle-European spruce forest (Nationalpark Harz, Germany) from four micro-regions within each of the five wood Ant Nests sampled, i.e. 1) centre of the belowground part of a nest, 2) nest's rim, 3) nest's run-off zone (ca. 20 cm from nest's rim), and 4) from the surrounding forest soil (>10 m from nest's rim). Root biomass, EcM exploration types, moisture and nutrient contents were determined in all substrates. Although naturally enriched, wood Ant Nests had neither root biomass nor occurrence of EcM exploration types higher compared to the surrounding forest soil. The probable main reasons were high phosphorus content and low moisture maintained inside inhabited Nests, although the effect was not significAnt. Apparently, other substrate properties not determined in our study also affect the occurrence of exploration types in wood Ant nest substrates. Inhabited wood Ant Nests thus seem unfavourable for root proliferation and their subsequent EcM colonization. However, roots can gain nutrients from the run-off zone around Nests where low moisture is not maintained and nutrient contents are higher due to leaching from the nest substrate.
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methane and carbon dioxide flux in the profile of wood Ant formica aquilonia Nests and the surrounding forest floor during a laboratory incubation
2016Co-Authors: Veronika Jilkova, Jan Frouz, Tomas Picek, Martina Sestauberova, Vaclav Kristůfek, Tomas CajthamlAbstract:We compared methane (CH4) and carbon dioxide (CO2) fluxes in samples collected from the aboveground parts of wood Ant Nests and in the organic and mineral layer of the surrounding forest floor. Gas fluxes were measured during a laboratory incubation, and microbial properties (abundance of fungi, bacteria, and methanotrophic bacteria) and nutrient contents (total and available carbon and nitrogen) were also determined. Both CO2 and CH4 were produced from Ant nest samples, indicating that the aboveground parts of wood Ant Nests act as sources of both gases; in comparison, the forest floor produced about four-times less CO2 and consumed rather than produced CH4. Fluxes of CH4 and CO2 were positively correlated with contents of available carbon and nitrogen. The methanotrophic community was represented by type II methanotrophic bacteria, but their abundance did not explain CH4 flux. Fungal abundance was greater in Ant nest samples than in forest floor samples but bacterial abundance was similar in both kinds of samples, suggesting that the organic materials in the Nests may have been too recalcitrAnt for bacteria to decompose. The results indicate that the aboveground parts of wood Ant Nests are hot spots of CO2 and CH4 production in the forest floor.
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effects of nutrient rich substrate and ectomycorrhizal symbiosis on spruce seedling biomass in abandoned Nests of the wood Ant formica polyctena a laboratory experiment
2015Co-Authors: Veronika Jilkova, Jan Frouz, Martin Vohnik, Ondřej MudrakAbstract:Abstract Coniferous trees can take up mineral nutrients either non-symbiotically from nutrient-rich hotspots in the forest floor or via symbiosis with ectomycorrhizal (EcM) fungi; EcM symbiosis also enables the trees to obtain nutrients from organic substances. Excellent examples of nutrient-rich forest-floor hotspots are abandoned wood Ant Nests, which accumulate significAnt amounts of inorganic substances that are readily accessible to roots as well as organic substances that are not accessible to non-mycorrhizal roots. We examined the effects of substrates from abandoned Nests of the wood Ant Formica polyctena and EcM symbiosis on the growth of Norway spruce (Picea abies) seedlings. The tested substrates originated from the centers and rims of wet and dry Ant Nests, and from the surrounding forest floor. Aseptic spruce seedlings were grown in these substrates in a growth chamber, and after 7 months, seedling biomass, the chemical and microbiological properties of the substrates, and EcM colonization and diversity were determined. Spruce seedlings grew better and had a more diverse spectra of EcM fungi in the Ant nest substrates than in the forest floor substrate. Substrate nutrient content, especially phosphorus and basic cations, positively correlated with spruce biomass, EcM diversity, and fungal biomass. Contrary to conventional wisdom, high nutrient contents in Ant Nests apparently enhanced EcM abundance and diversity. Although abandoned wood Ant Nests in temperate and boreal forests are not abundAnt and thus are unlikely to have ecosystem level effects, they may cause significAnt local variations in tree growth and in the occurrence of root-symbiotic fungi.
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mechanisms of ph change in wood Ant formica polyctena Nests
2012Co-Authors: Veronika Jilkova, O Sebek, Jan FrouzAbstract:Abstract We conducted a study to determine why the pH of wood Ant nest materials is typically higher than that of the surrounding forest soil. An experiment with litter bags demonstrated that the pH of litter increased significAntly (after only 7 months) in Ant Nests. Because the food that foraging Ants bring into the nest contains easily decomposed carbohydrates and basic cations (largely in the form of honeydew and prey) that can cause increases in pH, we then estimated the amount of this influ of basic cations and easily decomposed carbohydrates. Based on these estimates, we conducted a second experiment to determine whether addition of field-determined quAntities of an easily decomposed carbohydrate (glucose) or a basic cation (Ca2+) would increase the pH of the litter in artificial Ant Nests in the forest. Both glucose and Ca2+ additions significAntly increased the pH of the litter but the increase was greater with Ca2+. The rate of pH increase in the artificial Nests was similar to the rate of increase in natural Nests. According to our study, Ants collect substAntial amounts of mineral-enriched materials in this ecosystem, which collectively increase the pH of nest material.
Matthew I Hutchings - One of the best experts on this subject based on the ideXlab platform.
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A Single Streptomyces Symbiont Makes Multiple Antifungals to Support the Fungus Farming Ant
2016Co-Authors: Acromyrmex Octospinosus, Ryan F Seipke, Lionel Hill, Rebecca J M Goss, Charles Brearley, Matthew I HutchingsAbstract:Attine Ants are dependent on a cultivated fungus for food and use Antibiotics produced by symbiotic Actinobacteria as weedkillers in their fungus gardens. Actinobacterial species belonging to the genera Pseudonocardia, Streptomyces and Amycolatopsis have been isolated from attine Ant Nests and shown to confer protection against a range of microfungal weeds. In previous work on the higher attine Acromyrmex octospinosus we isolated a Streptomyces strain that produces candicidin, consistent with another report that attine Ants use Streptomyces-produced candicidin in their fungiculture. Here we report the genome analysis of this Streptomyces strain and identify multiple Antibiotic biosynthetic pathways. We demonstrate, using gene disruptions and mass spectrometry, that this single strain has the capacity to make candicidin and multiple Antimycin compounds. Although Antimycins have been known for.60 years we report the sequence of the biosynthetic gene cluster for the first time. Crucially, disrupting the candicidin and Antimycin gene clusters in the same strain had no effect on bioactivity against a co-evolved nest pathogen called Escovopsis that has been identified in,30 % of attine Ant Nests. Since the Streptomyces strain has strong bioactivity against Escovopsis we conclude that it must make additional Antifungal(s) to inhibit Escovopsis. However, candicidin and Antimycins likely offer protection against other microfungal weeds that infect the attine fungal gardens. Thus, we propose that the selection of this biosynthetically prolific strain from the natural environment provides A. octospinosus with broad spectrum activity against Escovopsis and othe
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a single streptomyces symbiont makes multiple Antifungals to support the fungus farming Ant acromyrmex octospinosus
2011Co-Authors: Ryan F Seipke, Jörg Barke, Lionel Hill, Charles A Brearley, Douglas W Yu, Rebecca J M Goss, Matthew I HutchingsAbstract:Attine Ants are dependent on a cultivated fungus for food and use Antibiotics produced by symbiotic Actinobacteria as weedkillers in their fungus gardens. Actinobacterial species belonging to the genera Pseudonocardia, Streptomyces and Amycolatopsis have been isolated from attine Ant Nests and shown to confer protection against a range of microfungal weeds. In previous work on the higher attine Acromyrmex octospinosus we isolated a Streptomyces strain that produces candicidin, consistent with another report that attine Ants use Streptomyces-produced candicidin in their fungiculture. Here we report the genome analysis of this Streptomyces strain and identify multiple Antibiotic biosynthetic pathways. We demonstrate, using gene disruptions and mass spectrometry, that this single strain has the capacity to make candicidin and multiple Antimycin compounds. Although Antimycins have been known for >60 years we report the sequence of the biosynthetic gene cluster for the first time. Crucially, disrupting the candicidin and Antimycin gene clusters in the same strain had no effect on bioactivity against a co-evolved nest pathogen called Escovopsis that has been identified in ∼30% of attine Ant Nests. Since the Streptomyces strain has strong bioactivity against Escovopsis we conclude that it must make additional Antifungal(s) to inhibit Escovopsis. However, candicidin and Antimycins likely offer protection against other microfungal weeds that infect the attine fungal gardens. Thus, we propose that the selection of this biosynthetically prolific strain from the natural environment provides A. octospinosus with broad spectrum activity against Escovopsis and other microfungal weeds.
Martin Vohnik - One of the best experts on this subject based on the ideXlab platform.
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low root biomass and occurrence of ectomycorrhizal exploration types in inhabited wood Ant formica polyctena Nests in a temperate spruce forest
2017Co-Authors: Veronika Jilkova, Jan Frouz, Martin Vohnik, Jens Dauber, Andreas Marten, Hana SimackovaAbstract:Trees growing in nutrient-limited temperate forest soils can gain nutrients by root proliferation into nutrient-rich hotspots and/or by forming mycorrhizal symbioses. In this study we investigated the effects of nutrient-rich hotspots (inhabited wood Ant Nests) on Norway spruce root biomass and occurrence of ectomycorrhizal (EcM) exploration types. Substrates were collected from the mineral soil layer in a temperate middle-European spruce forest (Nationalpark Harz, Germany) from four micro-regions within each of the five wood Ant Nests sampled, i.e. 1) centre of the belowground part of a nest, 2) nest's rim, 3) nest's run-off zone (ca. 20 cm from nest's rim), and 4) from the surrounding forest soil (>10 m from nest's rim). Root biomass, EcM exploration types, moisture and nutrient contents were determined in all substrates. Although naturally enriched, wood Ant Nests had neither root biomass nor occurrence of EcM exploration types higher compared to the surrounding forest soil. The probable main reasons were high phosphorus content and low moisture maintained inside inhabited Nests, although the effect was not significAnt. Apparently, other substrate properties not determined in our study also affect the occurrence of exploration types in wood Ant nest substrates. Inhabited wood Ant Nests thus seem unfavourable for root proliferation and their subsequent EcM colonization. However, roots can gain nutrients from the run-off zone around Nests where low moisture is not maintained and nutrient contents are higher due to leaching from the nest substrate.
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effects of nutrient rich substrate and ectomycorrhizal symbiosis on spruce seedling biomass in abandoned Nests of the wood Ant formica polyctena a laboratory experiment
2015Co-Authors: Veronika Jilkova, Jan Frouz, Martin Vohnik, Ondřej MudrakAbstract:Abstract Coniferous trees can take up mineral nutrients either non-symbiotically from nutrient-rich hotspots in the forest floor or via symbiosis with ectomycorrhizal (EcM) fungi; EcM symbiosis also enables the trees to obtain nutrients from organic substances. Excellent examples of nutrient-rich forest-floor hotspots are abandoned wood Ant Nests, which accumulate significAnt amounts of inorganic substances that are readily accessible to roots as well as organic substances that are not accessible to non-mycorrhizal roots. We examined the effects of substrates from abandoned Nests of the wood Ant Formica polyctena and EcM symbiosis on the growth of Norway spruce (Picea abies) seedlings. The tested substrates originated from the centers and rims of wet and dry Ant Nests, and from the surrounding forest floor. Aseptic spruce seedlings were grown in these substrates in a growth chamber, and after 7 months, seedling biomass, the chemical and microbiological properties of the substrates, and EcM colonization and diversity were determined. Spruce seedlings grew better and had a more diverse spectra of EcM fungi in the Ant nest substrates than in the forest floor substrate. Substrate nutrient content, especially phosphorus and basic cations, positively correlated with spruce biomass, EcM diversity, and fungal biomass. Contrary to conventional wisdom, high nutrient contents in Ant Nests apparently enhanced EcM abundance and diversity. Although abandoned wood Ant Nests in temperate and boreal forests are not abundAnt and thus are unlikely to have ecosystem level effects, they may cause significAnt local variations in tree growth and in the occurrence of root-symbiotic fungi.
Douglas W Yu - One of the best experts on this subject based on the ideXlab platform.
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a single streptomyces symbiont makes multiple Antifungals to support the fungus farming Ant acromyrmex octospinosus
2011Co-Authors: Ryan F Seipke, Jörg Barke, Lionel Hill, Charles A Brearley, Douglas W Yu, Rebecca J M Goss, Matthew I HutchingsAbstract:Attine Ants are dependent on a cultivated fungus for food and use Antibiotics produced by symbiotic Actinobacteria as weedkillers in their fungus gardens. Actinobacterial species belonging to the genera Pseudonocardia, Streptomyces and Amycolatopsis have been isolated from attine Ant Nests and shown to confer protection against a range of microfungal weeds. In previous work on the higher attine Acromyrmex octospinosus we isolated a Streptomyces strain that produces candicidin, consistent with another report that attine Ants use Streptomyces-produced candicidin in their fungiculture. Here we report the genome analysis of this Streptomyces strain and identify multiple Antibiotic biosynthetic pathways. We demonstrate, using gene disruptions and mass spectrometry, that this single strain has the capacity to make candicidin and multiple Antimycin compounds. Although Antimycins have been known for >60 years we report the sequence of the biosynthetic gene cluster for the first time. Crucially, disrupting the candicidin and Antimycin gene clusters in the same strain had no effect on bioactivity against a co-evolved nest pathogen called Escovopsis that has been identified in ∼30% of attine Ant Nests. Since the Streptomyces strain has strong bioactivity against Escovopsis we conclude that it must make additional Antifungal(s) to inhibit Escovopsis. However, candicidin and Antimycins likely offer protection against other microfungal weeds that infect the attine fungal gardens. Thus, we propose that the selection of this biosynthetically prolific strain from the natural environment provides A. octospinosus with broad spectrum activity against Escovopsis and other microfungal weeds.