Habitat conditions of the endangered species Salix myrtilloides in Eastern Poland

Abstract

Changes in habitat conditions in the area of Eastern Poland (Polesie Podlaskie), often associated with anthropopressure, cause a reduction in the number of locations and population size of valuable and rare bog plant species, including a Pleistocene boreal relict, Salix myrtilloides. The aim of this study was to determine the current conditions of occurrence of this species based on the physico-chemical parameters of peatland piezometric groundwater. The results confirm the declining trend in the number of locations and abundance of this species in the past few decades, but at the same time they confirm the wide range of amplitude of the many investigated factors. Among the groundwater parameters studied, the low level of nitrogen fractions, phosphorus fractions, cations, and DOC can be considered to be a set of conditions promoting the preservation of the Salix myrtilloides population. The higher concentrations of phosphates, sulfates, Na, Ca, and Mg as well as higher pH and electrolytic conductivity can be considered to be presumably unfavorable. The lack of significant differences in the values of the piezometric water factors investigated for the sites with different population sizes of the studied species requires the identification of other limiting factors and the implementation of programs for its active protection in Poland.

To What Degree Can the Specifics of Occurrence of Glacial Relic Betula humilis Schrank Be an Indicator of Habitat Conditions of Moderate Climate Peatlands?

“…The character of the research covers a number of different dependencies, e.g., susceptibility to the extinction of small isolated populations [42]; the heterogeneity of habitats and their effect on species richness, and the effect of the fragmentation of anthropogenic habitats on the number and state of rare plant species [14]; or the analysis of habitat indices with respect to attempts to actively protect such species [8,9].…”

“…Coal extraction from deposits at a depth of 1 km results in breaking through aquifers. Due to the hydraulic connections of parts of fossil deposits with overlying waters, this causes outflow, the elimination of surface stagnation, and a decrease in natural water retention [8,9,52].…”

“…The particular habitat requirements related to the evolutional adjustment of the effect of the northern continental climate are observed here in the case of rare and protected Pleistocene boreal relics such as e.g., Betula humilis, Salix lapponum, or Salix myrtilloides [3][4][5][6][7][8][9]. In spite of numerous morphological, anatomical, physiological, and ecological adaptations permitting their survival in often extreme environmental conditions [3,[10][11][12], the rate of environmental transformations related to the fluctuations of the moderate climate and progressing human pressure are occurring too fast for the species.…”

“…The effect of environmental transformations can therefore be a decrease in the number of sites of occurrence of glacial relics, and a successive shrinking of their populations. Local populations of such species are therefore under actual threat of extinction and the further restriction of their range of occurrence [5,8,9].…”

“…In such conditions, the specificity of the occurrence of boreal relics can reflect changes in their habitats, particularly in reference to hydrological conditions that are often modified anthropogenically [3,[6][7][8][9].…”