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The relationships of soil CO2 flux with selected Norway spruce root parameters and sterol content in the soil
Holub, Filip ; Fabiánek, Tomáš ; Večeřová, Kristýna ; Moos, Martin ; Oravec, Michal ; Tříska, Jan ; Marková, I. ; Edwards, Magda ; Cudlín, Pavel
The flow of CO2 from the soil is a very important part of the carbon cycle in an ecosystem. The aim of our work was to determine how roots and rhizospheric fungi contribute to CO2 flux from the soil. Preliminary results from two years of research are presented. The research on how root biomass as well as ergosterol and phytosterol contents in roots and soil affected CO2 flux from the soil was conducted in a 108-year-old Norway spruce (Picea abies (L.) Karst.) forest in the Drahany Highlands during 2010 and 2011. CO2 flow was measured using a LI-8100 portable closed gasometric system (Li-Cor, USA). The dry weight and volume of individual root categories (< 1 mm, 1–2 mm, 2–5 mm, > 5 mm), C and N contents in the roots, as well as ergosterol, β-sitosterol, and campesterol contents in the soil and roots were determined from root-containing soil samples located in the circular measurement chamber. In addition, sterol content was determined in the soil only. Our soil respiration results correspond with the findings of Buchman (2000) who found respiration values between 5–7 μmol CO2 m−2 s−1 in a 111-year-old spruce forest. A significant influence on soil respiration was proven only for sitosterol content in the soil. The relationships among soil CO2 flux, root characteristics, and nitrogen and sterol contents in the roots and soil are discussed.
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Treeline shift under global change - ectomycorrhizas as a limiting factor?
Vašutová, Martina ; Holub, Filip ; Čermák, Martin ; Cudlín, Pavel
It is assumed that global change will cause a treeline shift . Because competitive abilities and natural regeneration of trees are infl uenced by ectomycorrhizal (ECM) symbiosis and fi ne roots and ECM mycelia play a key role in belowground carbon turnover, we have studied the ECM associations of treeline ecosystems. We aim to fi nd out how resistant and resilient current ECM associations of these ecosystems are and whether the absence of appropriate ECM symbionts could be a limiting factor of an ecosystem shift . We have focused on natural mountain spruce forests and spruce forests on the treeline; dwarf pine stands with scattered spruce trees above the treeline will be studied in years to come. Ectomycorrhizas were described by morphological features and sequenced to identify fungal species. In the case of taxonomically complicated ECM fungal groups, sequences from microscopically identifi ed sporocarps were used for the identifi cation of ectomycorrhizas. A disproportion between ECM fungi diversity in spruce stands and dwarf pine stands revealed based on a literature review can indicate diff erent ectomycorrhiza patterns at the treeline. According to preliminary results from the Giant Mts. there is an adequate ECM fungal species diversity in mountain spruce forest and spruce forests on the treeline.
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