Water Holding Capacity of Some Bryophyta Species from Tundra and North Taiga of the West Siberia

Abstract

Functional traits are a set of characteristics that are expressed in the phenotype of an individual organism as a response to the environment and their impact on the ecosystem’s properties. They are positioned at the crossroads between the response and influence of the organisms, creating a certain interest in functional ecological and evolutionary fields. Due to this unique position, they are divided into two categories: effect functional traits and response functional traits. Effect traits describe the influence of the species on the environment regardless of whether such traits are an adaptive advantage to the individual or not. In Bryophyta, one of the most important effect traits is water holding capacity (WHC), which is their means of regulating ecosystem hydrology. On a global scale, mosses’ WHC is manifested in the slowdown of the large water cycle, in the storage of huge volumes of fresh water by peatlands and in the enormous paludification of Western Siberia. The main goal of our research was to obtain the water holding capacity measurements of tundra and taiga moss species to establish the base and foundation for environmental monitoring in the north of Siberia—the region with the most rapidly changing climate. Both the capacity to hold water within the moss tissues (WHC) and the capacity to hold water externally between the morphological structures (leaves, branches, rhizoids, etc.) (WHCe) were measured. In total, 95 samples of 9 Sphagnum and 5 true mosses species were involved to the research; some species were collected at two or three sampling sites within two natural zones/subzones that gave us the opportunity to compare the WHC along the meridional transection. In average, the northern taiga samples showed slightly higher WHC than tundra samples, probably due to the environmental specifics of the habitat—the taiga habitats were more moist, while the tundra was drier. Overall, in the majority of species, the standard deviation calculation revealed that the variability of WHCe is significantly higher than that of WHC. Such high variability in WHCe may be explained in regard to the morphological features of each individual considerably shifting between the samples of the same species while the anatomical features retain more stable results.