Major terrestrial vegetation shifts (MTVSs) resulting from either human activities or natural processes can exert substantial pressure on lakes mainly through impacts on catchment biogeochemical ...cycles and groundwater circulation. To better understand the links between terrestrial vegetation dynamics and lake ecosystem structure and functions over long temporal scales, in this study, we reconstructed the responses of shallow Lake Spore (N Poland) to major late-Holocene vegetation shifts. We combined newly acquired data from pollen and spores, Cladocera, TOC/N, δ13C, and δ15N analyses of bulk organic matter with the already published results from sediment dating and analyses of several biotic and geochemical proxies. Statistical analysis of the abundance data for all the major terrestrial pollen taxa and reconstruction of vegetation openness derived from the REVEALS model indicated five MTVSs, each followed by a change in the lake environment. Changes in Lake Spore trophic status at MTVS1 (~2.82 kyr BP) and MTVS2 (~2.17 kyr BP) were attributed to the reorganization of the catchment’s nutrient cycling associated with a decline (MTVS1) and subsequent regeneration (MTVS2) of deciduous tree stands in the area. A distinct drop in the CaCO3 content of the lake sediments that started at MTVS4 (~0.57 kyr BP) likely occurred due to the substantial depletion of the water calcium pool following an abrupt transition from a tree-dominated to an herb-dominated landscape. Our record also suggested slight lake acidification following a spread of
Pinus sylvestris
at MTVS1 (~2.82 kyr BP) and MTVS3 (~1.10 kyr BP) and a lake level rise concurrent with the sharp increase in landscape openness at MTVS4 (~0.57 kyr BP).
The Central European area has been extensively studied using qualitative reconstruction techniques focusing on the development of peatlands in the past; however, research based on quantitative ...techniques is still lacking, especially in relation to highlands and mountainous areas. In this study, we focused on the hydrological changes and human-induced disturbances that affected two raised bogs from the Orawa-Nowy Targ Basin (Carpathian region): Puścizna Krauszowska and Puścizna Mała. We aimed to reconstruct the development of peatlands and changes in water table under different intensities of human activities. Two peat sequences from two different bogs, both possessing absolute chronologies based on high-resolution 14C dating, were examined in terms of pollen, non-pollen palynomorphs, plant macrofossils and testate amoeba records. We detected an asynchronous decrease in the water table level on the bogs that took place between the 4th and the 7th century ad, which occurred simultaneously with a global cold period ad 300–600 (Migration Period) in case of the Puścizna Mała bog. A concurrent but insignificant human impact on bogs was recorded. A distinct wet shift corresponding to the Wolf solar minimum (ca. ad 1280–1340) in Puścizna Mała was detected during ca. ad 1300–1350. The effect of this climatic event on bog hydrology is difficult to estimate because of the simultaneous human-induced deforestation. Drainage and substantial acceleration of peat extraction in the 19th and the 20th century ad led to the significant disturbances in peatland; however, these bogs were still susceptible to dry climatic events.
Mountain regions harbour high biodiversity; however, in numerous areas, they are strongly degraded by human activity. Our study reconstructs the development of the submontane forest belt (400 and 650 ...m a.s.l.) in the Beskid Wyspowy Mountains (Western Carpathians, Central Europe) affected by climate, humans, fire, and parasitic fungi during the Holocene. This forest belt is considered the most transformed by the human in the Carpathian region. Our multi-proxy study included analyses of pollen, non-pollen palynomorphs (NPPs), plant macrofossils, micro- and macrocharcoal (size fraction >100 µm, analysed in contiguous sampling), geochemical, and sedimentological markers. The results revealed that Picea abies dominated on the fen subjected to study at ca. 8510–5010 cal. BP. Tilia cordata was a substantial component of the submontane forest between ca. 8510 and 2970 cal. BP and it survived a probable Kretzschmaria deusta outbreak, as well as a period of increased fire activity (ca. 6000 cal. BP). The final retreat of forests with a substantial contribution of Tilia was induced by the expansion of Abies alba, Fagus sylvatica, and partly Carpinus betulus and was preceded by the period of increased fire activity and erosion. From ca. 900 cal. BP human-induced deforestations and agricultural and pastoral activity increased. The modern presence of woodlands with Pinus sylvestris and Larix decidua, in the submontane zone in the Beskid Wyspowy Mountains, is a result of sub-recent anthropogenic afforestation on overgrazed areas. The example of the Zbludza site reveals that changes related to fire and pathogen infections, if they have low magnitudes and new competitive taxa are absent, may be reversible in a forest composed of fire-intolerant tree taxa as Tilia. Nonetheless, the widespread submontane ecosystem degradation and the introduction of alien species hamper the regeneration of forest vegetation typical of the submontane zone.
In the time of the global climate crisis, it is vital to protect and restore peatlands to maintain their functioning as carbon sinks. Otherwise, their transformations may trigger a shift to a carbon ...source state and further contribute to global warming. In this study, we focused on eutrophication, which resulted in the transition from rich fen to poor fen conditions on the Kazanie fen (central Greater Poland, western Poland Central Europe). The prior aim was to decipher how i) climate, ii) human, and iii) autogenic processes influenced the pathway of peatland changes in the last ca. 250 years. We applied a high-resolution palaeoecological analysis, based mainly on testate amoebae (TA) and plant macroremains. Our results imply that before ca. 1950 CE, dry shifts on the fen were generally climate-induced. Later, autogenic processes, human pressure and climate warming synergistically affected the fen, contributing to its transition to poor fen within ca. 30 years. Its establishment not only caused changes in vegetation but also altered TA taxonomic content and resulted in a lower diversity of TA. According to our research Microchlamyspatella is an incredibly sensitive testate amoeba that after ca. 200 years of presence, disappeared within 2 years due to changes in water and nutrient conditions. As a whole, our study provides a long-term background that is desired in modern conservation studies and might be used to define future restoration targets. It also confirms the already described negative consequences connected with unsustainable exploitation of nature.
Display omitted
•Multi-proxy study on the rich fen–poor fen transition during the Anthropocene•New high-resolution data on testate amoebae from fens in Central Europe•Human activity and global warming as the main drivers of rich-fen loss•Long-term palaeoecological record for ecological restoration•Testate amoeba as susceptible indicators of rich fen degradation
In this article, we aim to decipher the effect of fire on the changes in the forest composition during the past ca. 10,700 years in the lower montane zone of the Polish Western Carpathians (Beskid ...Makowski Mountains, Central Europe). The results revealed that during the Early Holocene, the Ulmus population (a fire-intolerant taxon) was well-established under high fire activity, induced by the prominent presence of Pinus sylvestris. Ulmus probably was only slightly affected by fire because it occurred in wetter habitats, whereas P. sylvestris occupied drier ones. The final disruption of Pinus sylvestris–Betula woodlands were linked to a declining trend in fire activity but stable fire frequency, combined with the rapid expansion of Corylus avellana at ca. 9680 cal. BP. A low magnitude of fire disturbance with an increasing fire frequency supported the expansion of Tilia cordata (a fire-sensitive species) and C. avellana (a fire-adapted species) against Picea abies during ca. 7650–7270 cal. BP. Cooler and wetter conditions during the 4.2 and 2.8 ka. BP climatic events probably forced humans to migrate to higher altitudes, which contributed to fire-induced deforestation of a small area, which in turn, together with climatic changes, stimulated the expansion of Abies alba and Fagus sylvatica (both are fire-intolerant taxa). The discontinuities in the deposits of mire might be related to the global climatic changes of the 8.2 and 4.2 ka. BP events and extended deforestations linked to the Wallachian colonisation during the Middle Ages. Such depositional gaps, when remaining undetected during palaeoecological studies, may distort the reconstruction process of fire–vegetation relationships. In this study, we unequivocally show that small disturbances in fire may be an advantageous factor for the expansion of tree taxa devoid of morphological–physiological fire traits.
•The first quantitative fire regime reconstruction in the Polish Western Carpathians.•Early Holocene Ulmus expansion was parallel to high fire activity.•Fire contributed to Tilia cordata and Coylus avellana advantage over Picea abies.•Fire-induced deforestations favoured Fagus sylvatica and Abies alba expansions.•The deposit gaps are linked to ‘8.2’ and ‘4.2’ ka BP events and Wallachian activity.
We explored the past environmental history inferred from a fen located in northwestern Poland, in a historically important location. Pollen, plant macrofossils, micro- and macrocharcoal particles, ...and non-pollen palynomorphs were analyzed continuously in a 1-cm resolution, supplemented with archeological data and historical written sources. The last 1200-year environmental history of the fen was supported with accelerator mass spectrometry (AMS) radiocarbon (14C) dating (19 dates per 172 cm of the profile) and validated by 59 210 Pb dates. Our research showed that primeval oak–hornbeam forests near the Kazanie mire disappeared gradually, starting from 1035 ± 20 cal. yr CE, due to the economic development of the newly formed Polish (Piast) statehood. The pollen data revealed no shortage of oak timber during the 11th century, as recorded by previous studies in the area between Poznań and Gniezno. The Czech invasion in 1039 CE, which was associated with mass depopulation and domestic crisis, seemed to be manifested by the increase of pioneer Betula taking advantage of weaker human impact. Substantial land-use changes started with the further development of Polish statehood between the 15th and the 16th century CE, as reflected by cultivated land, ruderal, and meadow and pasture pollen indicators, as well as the rise of microcharcoal influx. The economy of Poland was disrupted by a noticeable socioeconomic collapse in the 17th century CE, which caused depopulation (by approximately 67.5%) and a decline in arable land (by 35%). Paleoecological data reflect this socio-environmental crisis with a decrease in all anthropogenic indicators, rapid forest regeneration, and secondary succession of pine on the abandoned land. According to palynological data, rapid landscape transformation due to agricultural reforms and industrialization commenced in the 19th century CE and was associated with the expansion of pastures, meadows, and arable lands. The following rapid decrease of cultivated land pollen indicators in 1940 ± 10 cal. yr CE is linked with the economic collapse after World War II and/or the implementation of new crops which produce less pollen.
•Diverse ecological responses to socioeconomic transitions related to Polish state development.•Paleoecological data validate the archeological and historical sources.•The gradual loss of the pristine forest during the development of Polish state.•Post-17th-century crisis triggered 200-year-long, secondary succession of Scots pine on abandoned land.
•Kettle-hole peatlands have a high potential for carbon sequestration.•The recorded mean peat carbon accumulation rate exceeds ca 3 times the European mean.•Sphagnum-dominated environs with ...mixotrophic testate amoebae support carbon uptake.
Understanding carbon sequestration patterns in time and space is crucial for models and future projections of carbon uptake. However, their past provides an insight to this understanding, and peatlands play an essential role in the carbon cycle. Hence, peat carbon accumulation rates (PCAR) were reconstructed for the last ±1500 years in three Polish kettle-hole peatlands (Jaczno, Głęboczek and Pawski Ług bogs). Absolute chronologies, retrieved from the Bayesian age-depth models based on high-resolution 14C AMS dating, provided good time control, whereas the selected time interval spanned a broad spectrum of environmental changes and human activity. An additional variable was connected to climate, as the chosen sites are situated along the west-east gradient of northern Poland.
The aim was to find factors responsible for changes in carbon accumulation, so the results of PCAR were combined with pollen, testate amoebae, plant macrofossil, and charcoal data. The research showed that the investigated peatlands varied regarding local environmental conditions (e.g. water level), peatland development, vegetation changes, and fire activity. Generally, the PCAR values were higher in the Sphagnum-dominated sections of the profiles with high shares of mixotrophic testate amoebae unless fire hampered the carbon sequestration. However, our research showed that the changes in carbon uptake resulted from various overlapping factors rather than just one. Nevertheless, high values of PCAR in Jaczno and Pawski Ług (mean 74.6 and 79.64 g C/m2/yr, respectively) point to kettle-hole peatlands being exceptionally efficient in carbon sequestration.
In this article, we examined the indicative value of a relationship between two non-pollen palynomorphs (NPPs), fungal HdV-10, related to the presence of Calluna vulgaris, and HdV-31A, which is ...testate amoeba – Archerella flavum. Both are frequently present on slides designated for pollen analysis, prepared from Sphagnum peat. We analysed three profiles from three extensive ombrotrophic peatlands in northern Poland, in which the content of testate amoebae (TA) was examined and TA-inferred depth to the water table (DWT) was reconstructed. The new analysis of palynological samples regarding NPPs revealed that strong increases in HdV-10 content were mostly simultaneous to HdV-31A declines. However, the relations between both types were not statistically significant. The rapid increases in HdV-10, despite the fact that this type of conidiospores is related to drier habitats on peatlands, were tentatively interpreted as an indicator of rapid rises in the water table level which, in consequence, might have stimulated the production of these spores by fungi. In addition, a negative correlation between HdV-31A and Arcella discoides and positive one, but weaker, in case of HdV-10 (attributed by some authors to species Trichocladium opacum (Corda) S Hughes) and A. discoides show a link between mutual fluctuations of both NPPs and hydrological instabilities on peatland. The Bagno Kusowo bog, the westernmost peatland subjected to the study, displayed an intriguing agreement between the presence of peat sections with strong increases in HdV-10 and cold climate events affecting Europe. Our study reveals that counting even a limited number of NPP types during the standard pollen analysis of Sphagnum peat may support the interpretation of results, especially, in cases when the investigation lacks testate amoeba analysis. When the reconstruction of TA-inferred DWT is provided, it may introduce additional information about the patterns of hydrological dynamics.
Landslide mountain fens formed in landslide depressions are dynamic environments as their development is disturbed by a number of factors, for example, landslides, slopewash, and surface run-off. ...These processes lead to the accumulation of mineral material and wood in peat. Disturbed peatlands are interesting archives of past environmental changes, but they may be challenging for providing biotic proxy-based quantitative reconstructions. Here we investigate long-term changes in testate amoeba communities from two landslide mountain fens – so far an overlooked habitat for testate amoeba investigations. Our results show that abundances of testate amoebae are extremely low in this type of peatlands, therefore not suitable for providing quantitative depth-to-water table reconstructions. However, frequent shifts of dominant testate amoeba species reflect dynamic lithological situation of the studied fens. We observed that high and stable mineral matter input into the peatlands was associated with high abundances of species producing agglutinated (xenosomic) as well as idiosomic shells which prevailed in the testate amoeba communities in both analyzed profiles. This is the first study that explores testate amoebae of landslide mountain fens in such detail, providing novel information about microbial communities of these ecosystems.
During European states' development, various past societies utilized natural resources, but their impact was not uniformly spatially and temporally distributed. Considerable changes resulted in ...landscape fragmentation, especially during the Middle Ages. Changes in state advances that affected the local economy significantly drove trajectories of ecosystems' development. The legacy of major changes from pristine forest to farming is visible in natural archives as novel ecosystems. Here, we present a high-resolution densely dated multi-proxy study covering the last 1500 years from a peatland located in CE Europe. The economic activity of medieval societies was highly modified by new rulers-the Joannites (the Order of St. John of Jerusalem, Knights Hospitaller). We studied the record of these directorial changes noted in the peat profile. Our research revealed a rapid critical land-use transition in the late Middle Ages and its consequences on the peatland ecosystem. The shift from the virgin forest with regular local fires to agriculture correlates well with the raising of local economy and deforestations. Along with the emerging openness, the wetland switched from alkaline wet fen state to acidic, drier Sphagnum-dominated peatland. Our data show how closely the ecological state of wetlands relates to forest microclimate. We identified a significant impact of the Joannites who used the novel farming organization. Our results revealed the surprisingly fast rate of how feudal economy eliminated pristine nature from the studied area and created novel anthroecosystems.
PDF
