Abstract
Environmental flows have primarily a practical purpose, being an important part of water management. Despite the widespread use of environmental flows, current studies rarely describe ...practical insights of the methods or consider environmental flows based on ecological traits, especially regarding macroinvertebrates. In addition to hydraulic parameters, the ecological traits may also indicate processes that drive the distribution of organisms. Nevertheless, so far the habitat suitability criteria for functional feeding groups, the most commonly used ecological trait for macroinvertebrates, have not been described. In this study, we performed a detailed analysis of habitat suitability curves for the macroinvertebrate community and for FFGs. The criteria were determined based on data collected during two field campaigns (2018 and 2019) from the Flinta River, a lowland, dynamic, sandy stream located in western Poland. The method of habitat preference curves (HPCs) for flow velocities, depths and substrate was adopted. Before determining the final habitat suitability criteria, for all considered groups the habitat preference curves and habitat utilization curves were determined separately for the data collected in 2018 and 2019. The results showed that this step was key in developing the final habitat suitability criteria. Additionally, considering FFGs provided insight into the mechanisms that drove the distribution of organisms and resultant suitability.
Most European riverine ecosystems suffer from the negative influence of impoundments on flow regime. Downstream effects of dams lead to a number of environmental and socioeconomic risks and, ...therefore, should be thoroughly examined in specific contexts. Our study aims to quantify the downstream effects of the Siemianówka Reservoir (Upper Narew, Poland), using statistical analysis of key elements of the river’s flow regime, such as the flow duration and recurrence of floods and droughts. In a comparative study on control catchments not influenced by impoundments (the Supraśl and Narewka Rivers), we revealed the following downstream effects of the analyzed dam: significant shortening of spring floods, reduction of the duration and depth of summer droughts, decrease of the maximum discharge, and homogenization of the discharge hydrographs. Although we determined a significant decrease in the duration of summer floods in the “before” and “after” dam function periods, we showed that this issue is regional, climate-related, and replicated in control catchments, rather than an evident downstream effect of the dam. We conclude that significant hydrological downstream effects of the Siemianówka dam–reservoir system could have been the main driver inducing the deterioration of the anastomosing stretch of the Narew River downstream of the dam.
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•Ranunculus prefers drainage conditions, i.e., upward flow in hyporheic zone.•Developing Ranunculus modifies hydraulic properties of the riverbed.•Ranunculus clumps decreased ...filtration flow in the hyporheic zone five-fold.•Ranunculus habitats must be managed properly to remain in a healthy state.•Recognition of hyporheic flows is required in Ranunculus habitat conservation.
The study attempted to assess the influence of the filtration stream and hydraulic gradient in the hyporheic zone on the distribution of water crowfoot (Ranunculus sect. Batrachium) in common temperate lowland river type in two European ecoregions: (14) Central Plains and (16) Eastern Plains. A novel filtrometer and a gradient meter were employed for water flow measurements in the hyporheic zone at 24 study sites distributed throughout Central Europe between 2017 and 2019. At the majority of the study sites, hyporheic zones covered with Ranunculus vegetation were found to be dominated by groundwater drainage. Moreover, the intensity of groundwater filtration supplied via the hyporheic zone varied, ranging from 0.0017 m3 d−1·m−2 to 0.4118 m3 d−1·m−2. It was also determined that the average stream of filtration in the non-vegetated parts of the riverbed was 0.6065 m3 d-1·m−2, whereas it was five times lower in the zones overgrown with Ranunculus clumps, amounting to 0.1190 m3 d−1 m−2. The study provides quantification of the interactions between water exchange in the hyporheic zone and the growth and distribution of Ranunculus species, indicating that the exchange of surface water and groundwater is an important environmental factor that stimulates the growth of various Ranunculus taxa. The study provides evidence for a new environmental indicator, specifically the importance of surface water and groundwater exchange in the hyporheic zone of rivers for Ranunculus vegetation conservation and for planning and implementing nature-based river management methods.
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•Remote sensing-based approach to indicate vertical displacement of the peat.•Annualpeatland subsidencein the BiebrzaValleypeatlands = 1.44 cm.•Verifying this approach vs. field ...observations (R2 = 0.7, RMSE = 0. 23 cm)•∼ 46 tones of peat per hectare lost per annum.•Subsidence due to artificial drainage and climate change at the regional scale.
Peatlands play a crucial role in carbon storage, but drainage and climate change-induced hydrological changes drivers degrade peat soils, followed by negative vertical displacement of the soil surface, referred to in the literature as peat subsidence. Assessing peatland subsidence is an important indicator of peatland status that allows the development of peatlands to be revealed over a given period. However, traditional methods are limited in their applicability to large and inaccessible peatlands. In this study, we introduce a remote sensing framework for easily indicating peat subsidence at a large scale. Our framework utilizes the Alaska Satellite Facility (ASF) Interferometry Synthetic Aperture Radar (InSAR) with on-demand cloud computing, employing an optimization process including a Small Baseline Set technique and seasonal-annual search approach. By implementing this approach in the Biebrza Valley, Poland, covering the period from April 2015 to April 2022, we unveiled a tragedy, an annual subsidence rate of 1.44 cm. It means a peat loss between 58.1 and 89.6 million cubic meters over seven years, an annual loss of 86.4 to 132.5 (average 109) m3, approximately 46 tons, of dry matter peat per hectare. This finding was verified through field surveys, with high accuracy. An R2 value of 0.7, and an RMSE value of 0.23 cm determine the reliability of this approach in estimating the vertical displacement. The potential of this tool as a robust method to assess large-scale peatlands would allow for the assessment of average water levels as well as greenhouse gas emissions over large areas of peatlands, even at the continental scale.
Mesotrophic rich fens, that is, groundwater-fed mires, may be long-lasting, as well as transient ecosystems, displaced in time by poor fens, bogs, forests or eutrophic reeds. We hypothesized that fen ...stability is controlled by plant stress caused by waterlogging with calcium-rich and nutrient-poor groundwater, which limits expansion of hummock mosses, tussock sedges and trees. We analysed 32 European Holocene macrofossil profiles of rich fens using plant functional traits (PFTs) which indicate the level of plant stress in the environment: canopy height, clonal spread, diaspore mass, specific leaf area, leaf dry matter content, Ellenberg moisture value, hummock-forming ability, mycorrhizal status and plant functional groups. Six PFTs, which formed long-term significant trends during mire development, were compiled as rich fen stress indicator (RFSI). We found that RFSI values at the start of fen development were correlated with the thickness of subsequently accumulated rich fen peat. RFSI declined in fens approaching change into another mire type, regardless whether it was shifting into bog, forest or eutrophic reeds. RFSI remained comparatively high and stable in three rich fens, which have not terminated naturally until present times. By applying PFT analysis to macrofossil data, we demonstrated that fens may undergo a gradual autogenic process, which lowers the ecosystem’s resistance and enhances shifts to other mire types. Long-lasting rich fens, documented by deep peat deposits, are rare. Because autogenic processes tend to alleviate stress in fens, high levels of stress are needed at initial stages of rich fen development to enable its long persistence and continuous peat accumulation.
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•Two years of CH4 and CO2 flux measurements in a wetland in north-east Poland.•CH4 emissions 29±4gm−2yr−1 in wetter year and 20±1gm−2yr−1 in drier year.•CO2 uptake 980±150gm−2yr−1 in ...wetter year and 560±130gm−2yr−1 in drier year.•These annual exchanges are well within ranges found for other temperate wetlands.
Observational data on greenhouse gases exchange between ecosystems and the atmosphere are crucial in understanding the global climate mechanisms. Among different methods of estimation of this exchange, the eddy-covariance (EC) technique provides a direct measure of the net flux density across the atmosphere-ecosystem interface. Still, such data are highly scarce for Central European wetlands. In this work, we present the results of two years (2013–2014) of continuous open-path EC measurements of methane (CH4) and carbon dioxide (CO2) fluxes at the wetlands of the Biebrza National Park in northeastern Poland – one of the biggest coherent lowland wetland area in Central Europe. The measurement site (53°35′30.8″N, 22°53′32.4″E) was located near the Kopytkówka river in a fen peatland, whose soils are slightly decomposed due to dehydration. The mean annual sum of CH4 release equaled 29±4gCH4m−2yr−1 in wetter year 2013 and 20±1gCH4m−2yr−1 in drier year 2014. The mean annual uptake of CO2 reached 980±150gCO2m−2yr−1 and 560±130gCO2m−2yr−1 in 2013 and 2014, respectively. Both fluxes show a clear annual pattern with maximum CH4 release in June and July (at a level of 130nmolm−2s−1) and maximum CO2 uptake in June (at a level of 4.2μmolm−2s−1). The considerable C–CO2 uptake in comparison to C–CH4 emissions suggests that the Biebrza river wetlands are a significant carbon sink, but the net contribution of the Biebrza mires to the climate forcing is unclear because of different metrics which can be used to specify the relative weights of CO2 and CH4.
Nitrogen load is crucial for its application in various fields such as agriculture and improving water quality control for authorities responsible for establishing agricultural policies in the area. ...The calculation of nitrogen load using existing equations is not applicable for all types of rivers, thus requiring the development of a new equation that can be applied to lakes and rivers in the Biebrza river catchment. To determine the new equation, extensive mapping of the catchment area was conducted, which was adjusted to precipitation and runoff in the area, allowing the observed results to be compared. Based on several analyses, the new equation has better accuracy, RMSE of the new model-based estimation decreased by 65.9% in 2005–2015 and 62.2% in 2016–2021 for river and 92% in 2008–2019 and 95% in 2020–2021 for lakes. Therefore, the application of the new calibrated empirical model provides results close to the real values and it can be used in the Biebrza river basin to simulate the total nitrogen runoff.
A massive shift in agricultural practices over the past decades, to support exceptionally high yields and productivities involving intensive agriculture, have led to unsustainable agriculture ...practices across the globe. Sustenance of such high yields and productivities demand high use of organic and industrial fertilizers. This acts as a negative pressure on the environment. Excessive use of fertilizers leads to nutrient surplus in the fields, which, as a part of catchment runoff, flows into the water bodies as diffuse pollution. These nutrients through rivers are eventually passed into seas. High nutrients ending up into water bodies cause eutrophication. The situation is worsened when such unsustainable agricultural activities are carried out on drained peatlands. As a result, the nutrients that were not part of the nutrient cycle in the landscape for years begin to leach out due to mineralization of peatlands, thereby putting an additional load of nutrients on the environment, that was already under the negative impact of nutrient surplus. In view of the above, a small lowland catchment of the Ryck river in northeast Germany was assessed for its nitrogen losses from agricultural lands through empirical modelling. Initial empirical modelling resulted in an average annual total nitrogen loss of 14.7 kg ha−1 year−1. After a comparative analysis of these results with procured data, the empirical equation was modified to suit the catchment, yielding more accurate results. The study showed that 75.6% of peatlands in the catchment are under agricultural use. Subsequently, a proposal was made for potential wetland buffer zones in the Ryck catchment. Altogether, 13 peatland sites across 8 sub-catchments were recommended for mitigation of high nutrient runoff. In the end, nutrient efficiency of proposed WBZs in one of the sub-catchments of Ryck has been discussed. The results show that (i) the modified empirical equation can act as a key tool in application-based future strategies for nitrogen reduction in the Ryck catchment, (ii) restoration of peatlands and introduction of WBZs can help in mitigating the nutrient runoff for improved water quality of Ryck, and subsequently (ii) contribute to efficient reduction of riverine loads of nutrients into the Baltic Sea.
One of the most commonly used methods of environmental flows assessment is the approach based on Habitat Suitability Modeling (HSM) and habitat preferences curves (HPCs). Relationships between ...organisms and physical parameters describing the habitat remain strongly nonlinear and vary depending on several factors. The most common comparisons concern analyses between natural and regulated rivers, where the degree of river channel alterations is undefined and usually refers to all forms of hydromorphological degradation. Additionally, spatial scale and computational range of such a research mostly focus on longer river reaches and statistical analysis of HPC transferability, without detailed estimation of environmental flows values. The main aim of our research was assessment and comparison of environmental flows’ values for macroinvertebrates at two reaches of one river with different degrees of hydromorphological alteration. Two research hypotheses were verified: 1) morphological conditions impact on values of environmental flows and weighted usable area; 2) the mean value of environmental flows at the regulated river reach is higher compared to the natural reach. In order to put the obtained values of environmental flows into a broader context, the analyses of hydrological data and calculation of hydrology-based environmental flows were performed. Additionally, before determination of environmental flows, the transferability of habitat suitability criteria between reaches was verified. The obtained results confirmed research hypotheses, revealing strong dependence of environmental flows values to morphological conditions. Additionally, for both studied sections the lower limits of environmental flows were greater than hydrology-based values.
This publication contains data on geophysical measurements taken in the Szuszalewo wetlands located in northern Poland. The measurements were made using the electrical resistivity imaging (ERI) ...method. The ERI data was collected during two survey expeditions – March 30th, 31st (two ERI profiles), April 1st (one ERI profile), and May 12th (two prospection lines) 2023. The reason goal was to illustrate the arrangement of geological layers creating this wetland. The data repository contains detailed data descriptions for each survey site. This Electrical Resistivity Imaging (ERI) data from the selected survey sites can be used to perform numerical modeling of groundwater and surface water interaction in this environmentally valuable area, which is, to a certain extent a scientific terra incognita, hydrogeological investigation of hydraulic conductivity and hydrodynamic field, identify geological structure, and characterize engineering properties of the organic soils.
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