In situ growth of Sphagnum riparium Ångstr. shoots were monitored during the 2015 and 2016 growing seasons in Karelia, Russia. It was established that shoot growth rates fluctuated with a period of around 30 days, that is, showed a circatrigintan rhythm. Such rhythms from mosses have not been previously reported. Correlation of growth rates with the percentage of the illuminated portion of the Moon was statistically significant (p<0.01) in both years. Shoot growth rates were reliably higher around the new Moon compared to the full Moon. This phenomenon may be due either to causality or to a pure coincidence of processes with similar rhythms.

According to background data, bog systems can be successfully surveyed using the ground penetrating radar (GPR). The high contrast resolution of peat due to its electrical characteristics accounts for this. This paper demonstrates the results of the GPR usage in the Republic of Karelia (Russia). Data collection was carried out by the OKO-2 radar with the 150M antenna unit (150 MHz frequency). Data from stratigraphic columns was used as reference information. The brightest element on the radar profile is the boundary line of the bog mineral base, comprising of sand. All of the GPR traces allow to reliably identify facies, which can be correlated with peat types. The radar profiles were compared with the peat decomposition level indicators. It was defined that change in levels of peat decomposition leads to emergence of new reflective boundary lines. The research conducted demonstrates the high efficiency of GPR in identifying the composition and structure of peat deposits. It is established that different peat types generate specific GPR facies, which can be used as search attributes. The comparison between the GPR interpretation results and core section drilling materials confirms the reliability of the conclusions reached.

Temperature plays an essential role in a plant’s life. The current investigation reveals that photoreceptors, whose activity is affected by the geomagnetic field, are a critical element of its perception. This knowledge suggests that plants’ responses to temperature could shift in different geomagnetic conditions. To test this hypothesis, we studied the change in the growth response of the peat moss Sphagnum riparium to temperature with a gradual increase in the geomagnetic K_p index. Growth data for this species were collected from Karelian mires by detailed monitoring over eight full growing seasons. The growth of 209,490 shoots was measured and 1439 growth rates were obtained for this period. The analysis showed a strong positive dependence of sphagnum growth on temperature (r = 0.58; n = 1439; P = 1.7 × 10⁻¹¹⁹), which is strongest in the K_p range from 0.87 to 1.61 (r = 0.65; n = 464; P = 4.5 × 10⁻⁵⁸). This K_p interval is clearer after removing the seasonal contributions from the growth rate and temperature and is preserved when diurnal temperature is used. Our results are consistent with the hypothesis and show the unknown contribution of the geomagnetic field to the temperature responses of plants.