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The composition and properties of soil cover in three experimental areas in Estonia were analysed in terms of soil forming processes and land management practises. These areas were Jõgeva (JEA), Kuusiku (KEA) and Olustvere (OEA). Pedodiversity, humus forms and agrochemical status were analysed within seven arable land parcels. The soil cover of JEA was relatively homogenous. Dominant soil species were Cutanic Luvisols and Haplic Cambisols and the dominant soil texture of epipedons were slightly stony (pebbley) loams. The soil of KEA was much more heterogeneous, with five contrasting soil species in terms of soil genesis and four soil moisture states. The soil species in KEA were Mollic Gleysols, Haplic Cambisols, Gleyic Luvisols and Rendzic Cambisols (with relatively heterogeneous soils textures; from sands to loams). OEA was predominantly Stagnic Albeluvisol, with the topsoil texture consisting of sandy loam textures. In terms of soil species and properties JEA is representative of Central Estonian, OEA of South Estonian and KEA of North Estonian pedo-ecological conditions. These areas are generally representative of arable soils of the eastern part of the North European Plain. Soil cover is treated as a medium through which it is possible to improve the environmental status of an area. The 'environment protection value' (EPV) of soils were evaluated and detailed EPV categories were derived. Soils of JEA have high EPV due to neutral to slightly acid reaction, optimum humus contents, high cation exchange capacity, sufficient soil depth and the physical properties of subsoils are optimal. The EPV of KEA soil cover is less, due to high content of rock fragments in soil and and low biological activity within epipedons.

<p>Methane (CH<sub>4</sub>) has high global warming potential, and its atmospheric concentration is increasing rapidly at the present rate of 0.3% yr<sup>-1</sup>. Forest ecosystems cover a large part of the biosphere and play a significant role in climate change. Upland forest soils are considered as important terrestrial sinks for atmospheric CH<sub>4</sub>; however, the complex interactions between microbial processes of CH<sub>4</sub> production and oxidation, and environmental drivers are not well understood. Balance of CH<sub>4</sub> in the forest ecosystems depends on two main natural processes, i.e., anaerobic methanogenesis and aerobic methanotrophy, driven by multiple environmental factors. A forest ecosystem's ability to exchange CH<sub>4</sub> depends on the soil type, environmental conditions, species composition, living trees and deadwood, age and health conditions of the tree stand, and their CH<sub>4</sub> balance can vary between seasons and years.</p><p>In this study, we present long-term CH<sub>4</sub> fluxes (from 2015 to 2019) in a 60-200-year-old coniferous forest site of Scots pine (Pinus sylvestris) grown on loose sandy soil in Soontaga research station (58°01'N 26°04'E) in Estonia. The fluxes of CH<sub>4</sub> were measured every two weeks, using a manual static soil chamber (n = 6) and gas chromatography method. Air temperature, precipitation and humidity, and soil moisture and temperature (10 cm depth) were measured continuously. The average annual temperature and precipitation recorded were 7.3 + 1.0 °C and 54.3 + 3.9 mm, respectively.</p><p>The results showed that mature pine forest soil was an annual net sink of CH<sub>4</sub>: −21.14 + 0.59 g ha<sup>−‍1</sup> yr<sup>-1 </sup>(mean + SE). No significant difference (p < 0.05) was found between the soil CH<sub>4</sub> uptake and tree age. Methane uptake correlated negatively (r<sup>2 </sup>= 0.61, p < 0.05) with soil temperature and showed similar seasonal dynamics being highest during the vegetation period (Apr-Oct) and lowest during the non-vegetation period (Nov-Mar). The highest CH<sub>4</sub> uptake (−36.93 g ha<sup>−‍1</sup>) was observed in July 2018, the warmest and driest month during the overall period. Even though soil moisture was only weakly correlated (r<sup>2</sup> = 0.15, p < 0.05) with CH<sub>4</sub> uptake, the CH<sub>4</sub> flux was affected by precipitation. As a result of this, it is noticed that CH<sub>4</sub> uptake in the cold and wet conditions decreased with increasing precipitation in winter and increased with warming during warm and dry conditions in summer.</p><p>Concluded, our coniferous pine forest was sequestering CH<sub>4</sub> during the investigated five years. The soil CH<sub>4</sub> uptake could be explained by CH<sub>4</sub> oxidation at optimal temperature in the water-unsaturated surface soil regulating the soil's microbial activity.</p>

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