@inproceedings{BoldtBurischNaeth, author = {Boldt-Burisch, Katja and Naeth, M. Anne}, title = {The influence of arbuscular mycorrhizae on root precision nutrient foraging of two pioneer plant species during early reclamation}, series = {European Geosciences Union General Assembly 2017 Vienna, Austria, 23-28 April 2017}, booktitle = {European Geosciences Union General Assembly 2017 Vienna, Austria, 23-28 April 2017}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {On many post mining sites in the Lusatian Mining District (East Germany) soil heterogeneity consists of sandy soil with embedded clay-silt fragments. Those clays silt fragments might act as nutrient hotspots. Arbuscular mycorrhizal fungi in an infertile ecosystem could enhance a plant's ability to selectively forage for those nutrients and thus to improve plants nutrient supply. In our study we investigated whether silt-clay fragments within a sandy soil matrix induced preferential root growth of Lotus corniculatus and Calamagrostis epigeios, whether arbuscular mycorrhizae influenced root foraging patterns, and to what extent selective rooting in clay silt fragments influenced plant growth were addressed in this research. Soil types were sterile and non-sterile sandy soil and clay-silt fragments. Treatments were with and without arbuscular mycorrhizae, with and without soil solution, and soil solution and mycorrhizal inoculum combined. Root biomass, root density and intraradical fungal alkaline phosphatase activity and frequency were determined in fragments relative to sandy soil. Furthermore, temporal relationship of number of roots in fragments and plant height was assessed. Lotus corniculatus showed strong selective rooting into fragments especially with those plants treated with commercial cultivated arbuscular mycorrhizae; Calamagrostis epigeios did not. Without arbuscular mycorrhizae, L. corniculatus growth was significantly reduced and selective rooting did not occur. Selective rooting induced significant growth spurts of L. corniculatus. Roots in fragments had higher fungal alkaline phosphatase activity suggesting that mycorrhizal efficiency and related plants phosphorus supply is enhanced in roots in fragments. The application of cultivated arbuscular mycorrhizal fungi significantly and quickly influenced root foraging patterns, especially those of L. corniculatus, suggesting mycorrhizae may also enhance the ability of other plants to selectively forage for nutrients and could therefore play an important role in early plant establishment on infertile reclamation sites.}, language = {en} } @misc{BoldtBurischSchneiderNaethetal., author = {Boldt-Burisch, Katja and Schneider, Bernd Uwe and Naeth, M. Anne and H{\"u}ttl, Reinhard F.}, title = {Root exudation of organic acids of herbaceous pioneer plants and their growth in steriled and non-steriled nutrient-poor, sandy soils from post-mining sites}, series = {Pedosphere}, volume = {29}, journal = {Pedosphere}, number = {1}, issn = {1002-0160}, doi = {10.1016/S1002-0160(18)60056-6}, pages = {34 -- 44}, abstract = {Nutrient-poor, sandy soils form the prevailing substrate at post-mining sites and present a challenge for plants. We studied the organic acid quantity and composition of three commonly occurring pioneer plant species, the legumes Lotus corniculatus L. and Trifolium arvense L. and the grass Calamagrostis epigeios (L.) Roth, to determine if plant growth and exudation differed with (nonsterile soil) and without (sterile soil) an indigenous soil microbial community. We investigated whether organic acids were found in the rhizosphere and surrounding soil and whether this influenced nutrient mobilization. This study consists of linked field investigations and a greenhouse experiment. Plants were grown in the greenhouse in either steriled or non-steriled sandy soil from a reclamation site in the Lusatian mining landscape (Welzow S¨ud, East Germany). After seven months, the plant biomass, root morphology, organic acids, and water-soluble nutrients and root colonization with arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE) were analyzed. Roots of all three plants in the field and greenhouse experiments were highly colonized with AMF. Calamagrostis epigeios and T. arvense had a significantly higher colonization frequency with DSE than L. corniculatus. The quantity and composition of organic acids strongly differed among plant species, with the highest number of organic acids found for L. corniculatus and lowest for C. epigeios. The quantity of organic acids was greatly reduced in all plants under steriled soil conditions. However, the composition of organic acids and plant growth in steriled soil were reduced for both legumes, but not for C. epigeios, which had a higher biomass under steriled conditions. Changes in nutrient concentrations in the field rhizosphere soil relative to those in the control were measurable after seven months. While the spectrum of organic acids and the growth of legumes seemed to be dependent on a highly diverse soil microbial community and a symbiotic partner, the grass C. epigeios appeared capable of mobilizing enough nutrients without an indigenous microbial community, and might be more competitive on sites where soil microbial diversity and activity are low.}, language = {en} } @misc{BoldtBurischNaethSchneideretal., author = {Boldt-Burisch, Katja and Naeth, M. Anne and Schneider, Bernd Uwe and H{\"u}ttl, Reinhard F.}, title = {Linkage between root system development of three pioneer plant species and soil nitrogen during the initial phase of ecosystem development of the artificial watershed H{\"u}hnerwasser}, series = {Geophysical Research Abstracts}, volume = {21}, journal = {Geophysical Research Abstracts}, pages = {1}, abstract = {ln 2005, a 7-ha artificial watershed (H{\"u}hnerwasser) was built an a post mined Iandscape in Lusatia, Germany from sandy Substrates of Pleistocene origin, commonly used in reclamation. The watershed was developed to investigate the initial phase of soil and ecosystem development under natural conditions. At this early stage, nutrients in young sandy soils are limited and pioneer plants become key components of natural succession. Local abundant pioneering legumes Lotus corniculatus and Trifolium arvense and one pioneer grass species Calamagrostis epigeios were investigated 5 years after watershed construction. ln the present study, we investigated the influence of spatial root distribution of these species an soil nitrogen accumulation and on nutrient redistribution. Soil, including roots, was sampled from field monoliths covered with the aforementioned plant species. Root systems of both legumes were mainly restricted to the upper 20 cm of soil, whereas roots of C. epigeios also developed strongly at greater depths. A positive relationship was found, with higher plant densities associated with higher root densities, which were related with higher nodule densities for legumes and which were all associated with significantly higher soil nitrogen concentration relative to non-vegetated areas. This research provides rare information on the role root systems of pioneer legumes play in soil nitrogen input and development of nutrient patterns in the early stage of soil and ecosystem development during revegetation by natural succession.}, language = {en} } @misc{BoldtBurischNaethSchneideretal., author = {Boldt-Burisch, Katja and Naeth, M. Anne and Schneider, Bernd Uwe and H{\"u}ttl, Reinhard F.}, title = {Linkage between root systems of three pioneer plant species and soil nitrogen during early reclamation of a mine site in Lusatia, Germany}, series = {Restoration Ecology}, volume = {23}, journal = {Restoration Ecology}, number = {4}, issn = {1526-100X}, doi = {10.1111/rec.12190}, pages = {357 -- 365}, abstract = {In 2005, a 7-ha artificial watershed (Chicken Creek) was built on a post mined landscape in Lusatia, Germany from sandy substrates of Pleistocene origin, commonly used in reclamation. The watershed was developed to investigate the initial phase of soil and ecosystem development under natural conditions. At this early stage, mineral nitrogen in young sandy soils is primarily limited and nitrogen fixing legumes become key components of natural succession. Local abundant pioneering legumes Lotus corniculatus and Trifolium arvense and one pioneer grass species Calamagrostis epigeios were investigated 5 years after watershed construction. In this study, we investigated the influence of spatial root and nodule distribution of these species on soil nitrogen accumulation. Soil, including roots, was sampled from field monoliths covered with the aforementioned plant species. Root systems of both legumes were mainly restricted to the upper 20 cm of soil, whereas roots of C. epigeios also developed strongly at greater depths. A positive relationship was found, with higher plant densities associated with higher root densities which were associated with higher nodule densities for legumes and which were all associated with significantly higher soil nitrogen content relative to non-vegetated areas. This research provides rare information on the role root systems of pioneer legumes play in soil nitrogen input in the early stage of soil and ecosystem development during revegetation by natural succession.}, language = {en} } @misc{BoldtBurischNaeth, author = {Boldt-Burisch, Katja and Naeth, M. Anne}, title = {Early colonization of root associated fungal communities on reclamation substrates at a diamond mine in the Canadian Sub-Arctic}, series = {Applied Soil Ecology}, volume = {110}, journal = {Applied Soil Ecology}, issn = {0929-1393}, doi = {10.1016/j.apsoil.2016.10.006}, pages = {118 -- 126}, abstract = {Mining sites are harsh environments and establishment of root associated symbiotic fungi may be crucial for plant establishment and long term community development. Diamond mining in the Northwest Territories produces large amounts of processed kimberlite, and in some cases lake bed sediment and reclamation is needed for re-establishment of ecosystem function. This study investigated early fungal colonization with arbuscular mycorrhizae and dark septate endophytes on common reclamation substrates of different ages, relative to native tundra. Natural colonization of vegetation free sites with mycorrhizal spores on a trajectory associated with substrate age and type was very low. Fungal spore quantity and diversity was significantly accelerated by establishment of vegetation. Dark septate endophytes dominated native site Cyperaceae whereas reclamation site grasses were dominated by arbuscular mycorrhizae. Topsoil amendment was most effective for fungal colonization on reclamation substrates suggesting that a single application of topsoil can have a long term effect on the soil fungal community.}, language = {en} } @misc{BoldtBurischNaeth, author = {Boldt-Burisch, Katja and Naeth, M. Anne}, title = {Mycorrhization affects root distribution of Lotus corniculatus and Calamagrostis epigeios in a nutrient poor heterogeneous soil in a rhizotron experiment}, series = {Rhizosphere}, volume = {4}, journal = {Rhizosphere}, issn = {2452-2198}, doi = {10.1016/j.rhisph.2017.06.003}, pages = {36 -- 47}, abstract = {Plant growth can be highly dependent on symbiotic partners, such as arbuscular mycorrhizal fungi (AMF) that improve the plant's nutrient uptake. However, less is known about whether AMF can beneficially influence spatial root distribution, especially in soils with patchy nutrient concentrations. This study was conducted to evaluate root distribution and plant response of Lotus corniculatus and Calamagrostis epigeios in a heterogeneous nutrient poor soil under different mycorrhizal conditions. Heterogeneous soil conditions of a reclamation site in the Lusation mining district, consisting of a nutrient poor sandy soil with embedded large silt-clay fragments, were used for this rhizotron experiment. Treatments were non-mycorrhizal and mycorrhizal L. corniculatus and C. epigeios in sterile soil and in sterile soil with a fungal free soil solution and mycorrhizal plants in a non-sterile soil. Mycorrhizal fungi were exogenous (Funneliformis mosseae and Rhizophagus irregularis) in sterile soil and indigenous mycorrhizal fungi in non-sterile soil. Plants were grown in rhizotrons, with clay-silt fragments in a sandy soil matrix. Treatment response variables were root density, root and shoot biomass, shoot tissue nutrient concentrations, and percentage of roots in clay-silt fragments relative to total root biomass, mycorrhizal colonization and intraradical fungal alkaline phosphatase (ALP) activity. Exogenous mycorrhizal L. corniculatus plants had higher root mass density in clay-silt fragments than indigenous mycorrhizal and non-mycorrhizal plants while C. epigeios had only higher root mass density in clay-silt fragments relative to sandy soil only in exogenous mycorrhizal plants in sterile soil with soil solution. Nonmycorrhizal C. epigeios shoot biomass in sterile soil did not significantly differ from that of exogenous mycorrhizal treatments. The greatest shoot biomass for both plant species, was with the highest percentage of roots in clay-silt fragments relative to the total root system. Exogenous mycorrhizal plants of both species had highest shoot phosphorus concentrations in sterile soil with soil solution. However, intraradical fungal ALP activity was highest in indigenous mycorrhizal plants. The results indicate that mycorrhizal conditions can have a strong influence on spatial root development. The consequences are that conditions, which promote root growth, lead to more roots in nutrient rich clay-silt fragments and thus enhance plant exploitation of heterogeneously distributed soil nutrients.}, language = {en} } @misc{BoldtBurischNaethSchneideretal., author = {Boldt-Burisch, Katja and Naeth, M. Anne and Schneider, Uwe and Schneider, Beate and H{\"u}ttl, Reinhard F.}, title = {Plant growth and arbuscular mycorrhizae development in oil sands processing by-products}, series = {Science of the Total Environment}, volume = {621}, journal = {Science of the Total Environment}, issn = {1879-1026}, doi = {10.1016/j.scitotenv.2017.11.188}, pages = {30 -- 39}, abstract = {Soil pollutants such as hydrocarbons can induce toxic effects in plants and associated arbuscular mycorrhizal fungi (AMF). This study was conducted to evaluate if the legume Lotus corniculatus and the grass Elymus trachycaulus and arbuscular mycorrhizal fungi could growin two oil sands processing by-products after bitumen extraction fromthe oil sands in northern Alberta, Canada. Substrate treatmentswere coarse tailings sand (CTS), a mix of dry mature fine tailings (MFT) with CTS (1:1) and Pleistocene sandy soil (hydrocarbon free); microbial treatments were without AMF, with AMF and AMF plus soil bacteria isolated from oil sands reclamation sites. Plant biomass, root morphology, leaf water content, shoot tissue phosphorus content and mycorrhizal colonization were evaluated. Both plant species had reduced growth in CTS and tailings mix relative to sandy soil. AMF frequency and intensity in roots of E. trachycaulus was not influenced by soil hydrocarbons; however, it decreased significantly over time in roots of L. corniculatus without bacteria in CTS. Mycorrhizal inoculation alone did not significantly improve plant growth in CTS and tailings mix; however, inoculation with mycorrhizae plus bacteria led to a significantly positive response of both plant species in CTS. Thus, combined inoculationwith selected mycorrhizae and bacteria led to synergistic effects. Such combinations may be used in future to improve plant growth in reclamation of CTS and tailings mix.}, language = {en} } @misc{BoldtBurischNaeth, author = {Boldt-Burisch, Katja and Naeth, M. Anne}, title = {Heterogeneous soil conditions influence fungal alkaline phosphatase activity in roots of Lotus corniculatus}, series = {Applied Soil Ecology}, volume = {116}, journal = {Applied Soil Ecology}, issn = {0929-1393}, doi = {10.1016/j.apsoil.2017.03.024}, pages = {55 -- 63}, abstract = {Extremes in soil water, temperature, pH and inorganic nutrient availability can highly influence mycorrhizal formation and nutrient acquisition. However, the influence of soil heterogeneity and seasonal soil changes on fungal alkaline phosphatase (ALP) activity in mycorrhizal roots is unknown. Whether the activity of intraradical fungal ALP is influenced by soil texture heterogeneity, soil depth, nutrient concentrations and root density during the growing season were addressed in this research. The root system of Lotus corniculatus grown on a reclamation site was analyzed for intraradical mycorrhizal ALP activity in 0-10, 10-20 and 20-30 cm depth increments of sandy soil and in clay-silt fragments (mostly localized in 10-20 cm) from May to September. Root length density and water soluble nutrient contents in sandy soil and clay-silt fragments were determined for each sample. Soil water content and soil temperature data of a nearby site were used for climate conditions on sampling dates. Fungal ALP activity in roots growing in clay-silt fragments was higher than in those growing in sandy soil, independent of sampling date. Fungal ALP activity in sandy soil increased with soil depth which is related to decreasing root densities and lower nutrient concentrations. However, nutrient dense clay-silt fragments significantly positively influenced local mycorrhizal ALP activity in L. corniculatus roots, suggesting that the ability of mycorrhizae to selectively take up phosphorus and other nutrients from those nutrient hot spots is enhanced and could play a significant role in successful establishment of pioneer plant species on infertile reclamation sites.}, language = {en} } @misc{StoverNaethBoldtBurisch, author = {Stover, Holly J. and Naeth, M. Anne and Boldt-Burisch, Katja}, title = {Soil disturbance changes arbuscular mycorrhizal fungi richness and composition in a fescue grassland in Alberta Canada}, series = {Applied Soil Ecology}, volume = {Vol. 131}, journal = {Applied Soil Ecology}, issn = {0929-1393}, doi = {10.1016/j.apsoil.2018.07.008}, pages = {29 -- 37}, abstract = {Native grasslands are endangered by non-native plant invasion worldwide, including foothills fescue grasslands in North America. Large populations of non-native plant species have established in these disturbed fescue grasslands, forming dense monocultures and spreading into undisturbed areas. Soil disturbance and plant invasion can alter the arbuscular mycorrhizal fungi (AMF) community, an important symbiotic partner of most land plants, which could negatively affect native plant reestablishment. The objective of this study was to assess whether AMF communities on a fescue grassland shifted in response to disturbances by landfill storage and gravel quarrying and with invasion of non-native plant species relative to undisturbed grassland. Soil and root-AMF samples were procured from disturbed and undisturbed areas at three sites. Plant canopy cover and species richness were assessed. Soils were analyzed for pH; electrical conductivity; total nitrogen, carbon and phosphorus; and available nutrients. For relative AMF taxa abundance assessment, NS31 and AMF specific primer AML2 were used to amplify a central fragment of the V3 and V4 region of the 18S rRNA gene. AMF were characterized using 454 pyrosequencing and multiplexed barcoded samples amplified from genomic DNA isolated from roots. There were 92 AMF, including 15 potentially novel taxa detected. AMF communities in disturbed and undisturbed sampling locations were distinct except for one site, and indicator AMF virtual taxa (VT) for undisturbed grassland and disturbed sites were identified. AMF richness was higher in undisturbed (72 VT) than disturbed (64 VT) sites and AMF richness was positively correlated with plant species richness, diversity and native plant cover, and negatively correlated with non-native plant cover. There were 43 AMF VT on undisturbed and disturbed sites, 62\% with higher relative abundance on disturbed sites. Site disturbance shifted AMF communities relative to undisturbed native fescue grassland; thus restoration success with native plants might be highly dependent on reintroducing native AMF.}, language = {en} } @misc{BoldtBurischNaeth, author = {Boldt-Burisch, Katja and Naeth, M. Anne}, title = {Phosphogypsum significantly alters root growth and fungal colonization of smooth brome and sheep fescue on a reclamation site}, series = {Rhizosphere}, volume = {9}, journal = {Rhizosphere}, issn = {2452-2198}, doi = {10.1016/j.rhisph.2018.12.003}, pages = {106 -- 109}, abstract = {Phosphogypsum (PG) is a by-product of phosphate fertilizer production. This study is the first to investigate Bromis inermis and Festuca ovina root morphology and colonization with arbuscular mycorrhizal fungi and dark septate endophytes (DSE) in pure PG and PG with a soil cap (soil). Root length density was significantly lower for plants on PG than on soil and both plant species were colonized with AMF and DSE, with lower frequency and intensity in PG. Phosphorus (20 times), calcium (35 times) and sulphur (50 times) were significantly higher in PG than in soil; resulting higher root tissue concentrations were significantly negatively correlated with mycorrhizal colonization for Festuca but not Bromus. Higher fungal colonization of Bromus, especially with DSE known to be prevalent in extreme environments, may be responsible for its better performance on PG relative to Festuca.}, language = {en} } @inproceedings{BoldtBurischNaethSchneideretal., author = {Boldt-Burisch, Katja and Naeth, M. Anne and Schneider, Bernd Uwe and H{\"u}ttl, Reinhard F.}, title = {Root growth, mycorrhization and physiological effects of plants growing on oil tailing sands}, series = {European Geosciences Union, General Assembly 2015, Vienna, Austria, 13 April - 17 May 2015}, booktitle = {European Geosciences Union, General Assembly 2015, Vienna, Austria, 13 April - 17 May 2015}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, language = {en} }