Physico-chemical groundwater conditions at Salix lapponum stands in Eastern Poland

Abstract

A subarctic-boreal relict species, Salix lapponum, found within the area of the Łęczna-Włodawa Lakeland (Eastern Poland), is particularly threatened with extinction due to the southern limit of its range and the specific conditions of its occurrence. This conclusion is evidenced by a systematic reduction in the number of its locations, which is accompanied by a decrease in the numbers of individuals making up its populations. The aim of the present study was to determine habitat conditions of the occurrence of Salix lapponum populations on the basis of an analysis of physico-chemical factors of groundwater at the sites associated with various stages of succession taking place in small peatland water bodies. The results of this study confirm the trend that the stands and population numbers of this species are decreasing with the intensification of ecological succession and the degree of its progress and at the same time show that this species exhibits a wide amplitude of many of the investigated factors. Among the groundwater parameters under investigation, the low level of total nitrogen, phosphorus fraction and DOC as well as the high level of Ca, pH and electrolytic conductivity can be considered to be a set of conditions that promote the maintenance of Salix lapponum populations. On the other hand, in the case of nitrates, nitrites, sulphates as well as the Na, K and Mg ions, the Kruskal-Wallis statistical test showed that the distribution of their values was invariant in relation to the studied habitats, which is probably evidence that they do not determine the development or extinction of the investigated populations in these habitats.

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 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].…”

Salix lapponum L. vs. phytophagous insects – an assessment of the risks and the reaction of plants

“…It is a dioecious plant blooming in May and June. Downy willow has specific leaves with silvery grey napped underside characterized by long, thin-walled, tubular, twisted, very sinuous trichomes and a thick indumentum (Binns & Blunden, 1980;Pogorzelec, 2008a;Serafin et al, 2015). Salix lapponum frequently occurs in subarctic and boreal regions of northern and north-eastern Europe and western Siberia.…”

“…Some isolated populations are also recorded in the mountains of Central and South Europe and in Scotland (Kaźmierczakowa & Zarzycki, 2001;Podbielkowski, 2002). It grows in sunny or partially shaded locations, and prefers oligotrophic or mesotrophic habitats rich in organic matter with a pH value of 4-6 (Pogorzelec, 2008;Serafin et al, 2015). In Poland, the S. lapponum species is on the verge of extinction and, as a glacial relict, it has the status of an endangered species in Poland (EN; 'Red Data Book' status) as well as a vulnerable plant (EN by IUCN) (Kaźmierczakowa & Zarzycki, 2001;Mirek et al, 2006).…”

“…Its main causes are attributed to changes in habitat conditions in natural stands of this species. These are primarily changes in water relations, which result in the process of ecological succession in peatland ecosystems (Serafin et al, 2015). The appearance of expanding species, i.e.…”