Publications

Scientific publications

Mironov V.L., Grabovik S.I., Ignashov P.A., Kantserova L.V.
Geotropic curvatures of Sphagnum: environmental features of their genesis and trial application for estimation shoot length increment
// Arctoa. Vol. 25 (2). 2016. Pp. 353-363
Keywords: Karelia, tied thread method, method of natural markers, artefacts, geotropism, snow
load, mire water level, mosses, nival, aqueous, length increment, coefficient of variation
The genesis of geotropic curvatures in the natural habitat of Sphagnum mosses is described in
detail on the basis of in situ observations. A novel method of estimation of length increment of Sphagna
shoots is developed, based on their geotropic curvatures, which are the markers of physical impacts.
The snow load in northern areas is an example of the most typical impact on Sphagnum cover and
further geotropic response of stems. Deviation in stem growth causes the curves which may form after
snowmelt or under the snow layer. First attempt to use the snow induced markers, named further as
“nival geotropic curvatures”, for estimation of shoot increment rate of Sphagna stems were made in
the late 20th century. However, first researchers ignored other than snow cover common factors that
are responsible for the formation of similar markers during the growing season. Therefore, measuring
increment from these markers may result in incorrect estimation, because they could be formed neither
due to the snow load nor the beginning of the growing season. Our method takes into account these
shortcomings. Several Sphagnum species were involved in the research for experimental comparison
of the novel method with the classical tied thread method. Experimental plots were studied during a
two-year period on Karelian mires. The length increment values obtained by both methods show some
differences. Shoot increment values obtained by the method of the nival geotropic curvatures markedly
exceed values obtained by the classical tied thread method in all cases. The difference ranged from 7.5
to 18.6 % in 2014 and from 20.8 to 45.8 % in 2015. The results could be explained by the negative
effect of the tied thread method on the growth of moss, that was described in the literature. The
coefficients of variation estimated by the method of nival curvatures are reliably lower than those
obtained by the tied thread method for practically all samples. In 2014, mean value of the coefficients
of variation were 20.3±4.2 % for samples obtained by tied thread method and 13.0±4.7 % for samples
obtained by nival geotropic curvatures method. In 2015, the coefficients of variation were estimated at 21.1±5.3 % and 8.7±2.2 %, respectively.The differences are assumed to be due to the difference in the degree of impact on the structure of Sphagnum cover.
Indexed at Web of Science, RSCI
Last modified: January 27, 2017