Using a new database of plant macrofossils of the Czech and Slovak Republics to compare past and present distribution of hypothetically relict fen mosses

Abstract

M. (2018): Using a new database of plant macrofossils of the Czech and Slovak Republics to compare past and present distribution of hypothetically relict fen mosses. -Preslia 90: 367-386.Modern databases containing large amounts of botanical data are a promising source of new results based on large data analyses. We used a new database of plant macrofossils of the Czech and Slovak Republics to compare the recent distributions of putative relict species of fen bryophytes with their past distributions since the late glacial. All the species studied occur in lateglacial sediments, but mostly in regions where they are recently recorded (19-21st centuries). There are specific regions rich in putative relict species of fen bryophytes both in late glacial / early Holocene times and recently. In some cases the target species were, however, found outside the recent distribution range where environmental conditions are no longer suitable for their occurrence. We further found that the total number of the glacial and early-Holocene records greatly exceeds the total number of records for the middle Holocene, when succession to woodlands or bogs resulted in a reduction in species of bryophytes that are specific to open rich fens. The observed patterns may imply a relict status of the target species. We especially documented a substantial decline in the abundance of species requiring a high and stable water level (Drepanocladus trifarius, Meesia triquetra and Scorpidium scorpioides), both throughout the Holocene and during the most recent transformations of the landscape. In contrast, those species that tolerate transient decreases in water level persisted into recent times at more localities (Calliergon giganteum, Hamatocaulis vernicosus, Paludella squarrosa). Macrofossil data cannot, however, provide a quantitative analysis of the distribution of a species, because the number of recent data usually greatly exceeds the number of fossil records. The reason is that the area sampled in palaeoecological research is very small as it is time-consuming and expensive; cores or excavations usually are of only a few square centimetres. Despite this shortcoming, macrofossil data are an important, but not the only, source of evidence for the identification of the relict status of a species.

Characteristics, Main Impacts, and Stewardship of Natural and Artificial Freshwater Environments: Consequences for Biodiversity Conservation

“…Rich and calcareous fens act as important biodiversity hotspots. Many species considered as a relict from late glacial and Early Holocene times occur here [351][352][353], and they are significantly associated with old fens initiating before the Middle Holocene [354]. Such fens are richer in plant specialists than younger ones, and when they are large enough, also in snail species [355].…”

Welcome to the Czech Republic again! Rare northern mosses Calliergon megalophyllum and Drepanocladus sordidus (Amblystegiaceae) in South Bohemia in light of their European distribution and habitat preferences

“…(Holá et al 2010). Many of them were also documented in the Třeboň Basin as macrofossils in Late-Glacial and Early-Holocene peat deposits (Hájková et al 2018). Ptačí blato fishpond is located within the Třeboň Biosphere Reserve and Protected Landscape Area.…”

The ratio between bryophyte functional groups impacts vascular plants in rich fens

“…These latent variables may include biotic interactions such as the competition with generalist vascular plants, the type of nutrient limitation (Pawlikowski, Abramczyk, Szczepaniuk, & Kozub, ) and spatial effects (Hájek et al., ). These spatial effects largely coincide with the poor ability of some species, the hypothetically relict species, to disperse from old ancient fens to younger fens (Hájek et al., ; Hajkova et al., ; Peterka et al., ). Since Sphagnum ‐rich fens started to occur more frequently in the second half of the Holocene (Kuhry, Nicholson, Gignac, Vitt, & Bayley, ; Gajewski, Viau, Sawada, Atkinson, & Wilson,; Väliranta et al., ) we expect that many hypothetically relict species are better adapted to brown‐moss than Sphagnum patches.…”

“…These spatial effects largely coincide with the poor ability of some species, the hypothetically relict species, to disperse from old ancient fens to younger fens (Hájek et al, 2011;Hajkova et al, 2018;Peterka et al, 2018). Since Sphagnum-rich fens started to occur more frequently in the second half of the Holocene (Kuhry, Nicholson, Gignac, Vitt, & Bayley, 1993;Gajewski, Viau, Sawada, Atkinson, & Wilson,2001;Väliranta et al, 2017) we expect that many hypothetically relict species are better adapted to brown-moss than Sphagnum patches.…”