[PDF] The Effects Of Mycorrhizal Inoculation In Valley Oak And Grassland Restoration Plantings In The Central Valley California eBook

Author : Brett Joseph Fisher
Publisher :
Page : 78 pages
File Size : 10,40 MB
Release : 2011
Category : Mycorrhizas
ISBN :

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One factor used to determine wetland mitigation success is the establishment of native wetland plant species. Although mycorrhizal associations are known to be present in 70 to 95% of all plant species and have been linked to seedling establishment as well as nutrient and carbon flux within plant communities, the presence or absence of mycorrhizal fungi are not assessed or addressed during wetland mitigation work. Three experiments were devised to examine the effects of mycorrhizal fungi on the germination and growth of native wetland plant species in soils and field sites from natural, restored, and created wetlands. Greenhouse experiment I was a small scale greenhouse experiment in which soil from Siebenthaler Fen (SF), a high quality wetland, was used to inoculate plants with mycorrhizal fungi to determine its effect on germination and growth. Inoculation significantly affected shoot height of 30% of plant species and fresh weight of 100% of plant species. Field soils significantly affected both fresh and dry weight of 70% of plant species independent of inoculation. Greenhouse experiment II was a large-scale greenhouse experiment in which a produced soil inoculum was used to infect plants with mycorrhizal fungi to determine its effect on the growth of four native wetland plants. Inoculation significantly affected shoot height, dry weight, and arbuscular colonization of Mimulus ringens L. The overall affect of field soils were few and highly varied. In the field experiment, native wetland plants were inoculated with MycoGrow Soluble in the greenhouse prior to transplantation into natural, restored, and created wetlands to determine the effect of soil inoculation containing mycorrhizal fungi on plant growth and establishment. Soil inoculation significantly decreased shoot dry weight of M. ringens but did not impact the shoot height, leaf count, or shoot count of any species. Field site location significantly affected shoot height of M. ringens, C. vulpinoidea, and C. stipata. In this study, the effects of soil inoculation containing mycorrhizal fungi varied greatly between plant species and field sites and soils throughout all three experiments. When inoculated, the growth of some plants increased, some were not affected, and others decreased. Though not true for all species, M. ringens displayed clear correlations between inoculation and growth in the greenhouse. The plant shoot height, dry weight, and arbuscular colonization of M. ringens were all significantly affected by inoculation. For M. ringens, inoculation increased arbuscular colonization while reducing plant shoot height and dry weight. In the field, shoot dry weight of M. ringens was once again significantly decreased by inoculation; however, a direct correlation to arbuscular colonization was not found. However, the shoot dry weight of all four species combined reflected the level of site disturbance originally used to choose these field sites, independent of mycorrhizal treatment. While certain plant species may in fact benefit from the presence of mycorrhizal fungi in the soil, the degree to which the plants are impacted by mycorrhizae is strongly dependent on the condition of the site and soil in which they are grown. Therefore, it appears to be more beneficial to select a mitigation site with minimally disturbed, hydric soils that will support the growth of native wetland plants than it is to attempt the re-introduction of mycorrhizal fungi to disturbed areas through soil inoculation.

Author : Susanne Arnold
Publisher :
Page : 33 pages
File Size : 48,10 MB
Release : 2012
Category : Mycorrhizal fungi
ISBN :

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Mycorrhizal fungi form symbiotic relationships with plant roots, increasing nutrient and water availability to plants and improving soil stability. Mechanical disturbance of soil has been found to reduce mycorrhizal inoculum in soils, but findings have been inconsistent. To examine the impact of restoration practices on riparian mycorrhizal inoculum potential, soil samples were collected at the Tres Rios Ecosystem Restoration and Flood Control Project located at the confluence of the Salt, Gila, and Agua Fria rivers in central Arizona. The project involved the mechanical removal of invasive Tamarix spp.(tamarisk, salt cedar) and grading prior to revegetation. Soil samples were collected from three stages of restoration: pre-restoration, soil banks with chipped vegetation, and in areas that had been graded in preparation for revegetation. Bioassay plants were grown in the soil samples and roots analyzed for arbuscular mycorrhizal (AM) and ectomycorrhizal (EM) infection percentages. Vegetations measurements were also taken for woody vegetation at the site. The mean number of AM and EM fungal propagules did not differ between the three treatment area, but inoculum levels did differ between AM and EM fungi with AM fungal propagules detected at moderate levels and EM fungi at very low levels. These differences may have been related to availability of host plants since AM fungi form associations with a variety of desert riparian forbs and grasses and EM fungi only form associations with Populus spp. and Salix spp. which were present at the site but at low density and canopy cover. Prior studies have also found that EM fungi may be more affected by tamarisk invasions than AM fungi. Our results were similar to other restoration projects for AM fungi suggesting that it may not be necessary to add AM fungi to soil prior to planting native vegetation because of the moderate presence of AM fungi even in soils dominated by tamarisk and exposed to soil disturbance during the restoration process. In contrast when planting trees that form EM associations, it may be beneficial to augment soil with EM fungi collected from riparian areas or to pre-inoculate plants prior to planting.

Author : David J. Gibson
Publisher : Cambridge University Press
Page : 363 pages
File Size : 36,25 MB
Release : 2019-03-21
Category : Nature
ISBN : 1107195268

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A comprehensive assessment of the effects of climate change on global grasslands and the mitigating role that ecologists can play.