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L. 1999. Chemical and mineral composition of ectomycorrhizosphere soils of subalpine fir (Abies lasiocarpa (Hook.) Nutt.) in the Ae horizon of a Luvisol. Can. J. Soil Sci. 79: [25][26][27][28][29][30][31][32][33][34][35]. Differences in the properties of bulk forest and rhizosphere soils are often attributed to ectomycorrhizal association, or the symbiosis characterized by a fungal sheath surrounding the root (mantle) and intercellular root colonization (Hartig net). We compared the soil pH, total C, N, cation exchange capacity, and the contents of mica, chlorite, kaolinite, 2:1 expandable clays, feldspars and amorphous materials between two ectomycorrhizosphere soils (or soil environment in the vicinity of ectomycorrhizae (ECM)) and non-ectomycorrhizosphere soils to study the influence of ectomycorrhizae on chemical and mineralogical properties of soils. The two ectomycorrhizosphere soils were characterized by ectomycorrhizal colonization dominated by (1) Piloderma spp., and (2) Mycelium radicis atrovirens and cottony yellow-brown (MRA-CYB) types or where Piloderma spp. colonization was <2%. Our results showed that total C and N were higher in ectomycorrhizosphere than non-ectomycorrhizosphere soils, and the ectomycorrhizosphere soils dominated by Piloderma spp. had almost twice the total C and N as ectomycorrhizosphere soils with MRA-CYB. Soil pH was lower by half a pH unit in ectomycorrhizosphere soils compared to non-ectomycorrhizosphere soils. Cation exchange capacity as well as exchangeable Ca 2+ , Mg 2+ and K + were lower in non-ectomycorrhizosphere soil compared to ectomycorrhizosphere soils. We also found that cation exchange capacity, exchangeable Ca 2+ , Mg 2+ and K + values in soils dominated by Piloderma spp. were higher compared to ectomycorrhizosphere soils with insignificant Piloderma spp. Our results suggest that transformation rate of mica and chlorite to 2:1 expandable clays was predominant in ectomycorrhizosphere compared to non-ectomycorrhizosphere soils, likely as a result of high production of organic acids and direct extraction of K + and Mg 2+ by fungal hyphae. In ectomycorrhizoplane samples, it is suggested that K + and possibly amorphous Al 2 O 3 and Fe 2 O 3 could reconstitute the degraded mica and chlorite through the formation of hydroxy-interlayered 2:1 clays. Soil properties and biogeochemical processes in bulk forest soils are often different from those of the rhizosphere or the narrow soil environment affected by activities of living roots (Foster et al. 1983;Curl and Truelove 1986

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[91][92][93][94][95][96][97][98][99][100][101][102]. Soil properties of rhizosphere zones in coniferous forests are influenced by the presence of ectomycorrhizae. To elucidate the role of ectomycorrhizae (ECM) on the alteration of chemical and mineralogical properties of soils, soil pH, total C and N, cation exchange capacity, and the contents of mica, chlorite, and kaolinite, 2:1 type expandable clays, and amorphous minerals were compared in two soils, soils influenced by ectomycorrhizal fungi (ECS) and non-ectomycorrhizosphere soils (N-ECM) of Picea glauca x engelmannii (Moench.) Voss. Specifically, the two ECS soils were dominated by (1) Piloderma spp. (ECS-A) and (2) Inocybe lacera-like and Hebeloma-like morphotypes or where Piloderma spp. colonization was <1% (ECS-B). Our results showed that pH was lower in ECS compared to N-ECM samples. Total C and N were significantly higher in ECS soils than N-ECM samples. Cation exchange capacity as well as exchangeable K + , and Na + were higher in ECS compared to N-ECM soils. X-ray diffraction analysis showed that the amount of 2:1 expanding clays (vermiculite and smectite) was higher in ECS than N-ECM samples and results suggest that there is an enhanced transformation of mica and chlorite to 2:1 type expandable clays in ECS samples when compared to N-ECM samples. The differences in chemical and mineralogical properties between ECS and N-ECM soils, in our study, support earlier studies that show ectomycorrhizal fungi can alter the properties of soils in the rhizosphere zone.