Search results for "Water"

Estimating natal dispersal movement rates of female European ducks with multistate modelling

2003

Summary 1 We used up to 34 years of capture–recapture data from about 22 100 new releases of day-old female ducklings and multistate modelling to test predictions about the influence of environmental, habitat and management factors on natal dispersal probability of three species of ducks within the Engure Marsh, Latvia. 2 The mean natal dispersal distances were very similar (c. 0·6–0·7 km) for all three species and were on average 2·7 times greater than breeding dispersal distances recorded within the same study system. 3 We were unable to confirm the kinship hypothesis and found no evidence that young first-nesting females nested closer to their relatives (either mother or sister) than to …

Factors affecting breeding dispersal of European ducks on Engure Marsh, Latvia

2003

Summary 1 We used up to 35 years of capture–recapture data from nearly 3300 individual female ducks nesting on Engure Marsh, Latvia, and multistate modelling to test predictions about the influence of environmental, habitat and management factors on breeding dispersal probability within the marsh. 2 Analyses based on observed dispersal distances of common pochards and tufted ducks provided no evidence that breeding success in year t influenced dispersal distance between t and t+ 1. 3 Breeding dispersal distances (year t to t+ 1) of pochards and tufted ducks were associated with a delay in relative nest initiation dates in year t+ 1. The delay was greater for pochards (c. 4 days) than for tu…

Tropical Atlantic temperature seasonality at the end of the last interglacial

2015

The end of the last interglacial period, ~118 kyr ago, was characterized by substantial ocean circulation and climate perturbations resulting from instabilities of polar ice sheets. These perturbations are crucial for a better understanding of future climate change. The seasonal temperature changes of the tropical ocean, however, which play an important role in seasonal climate extremes such as hurricanes, floods and droughts at the present day, are not well known for this period that led into the last glacial. Here we present a monthly resolved snapshot of reconstructed sea surface temperature in the tropical North Atlantic Ocean for 117.7±0.8 kyr ago, using coral Sr/Ca and δ18O records. W…

Variation characteristics of soil respiration fluxes in four types of grassland communities under different precipitation intensity

2005

A two consecutive years’ field experiment was carried out on four types of semiarid grassland along precipitation gradient in Xilin River Basin of Inner Mongolia during 2001–2003 using a static enclosed black chamber technique. The variation characteristics of soil respiration fluxes from four different types of grassland along precipitation gradient were compared. The possible effect of water-heat factors on characteristics of grassland soil respiration was statistically analyzed and the numerical relational model between soil respiration and water-heat factors was established. Meanwhile the soil CO2 annual emissions of different types of grassland were estimated based on the consecutive a…

Toxicity of waste dump leachates and sugar factory effluents and their impact on groundwater and surface water quality in the Opole Province in Poland

2000

A battery of Toxkit microbiotests with 4 aquatic species from different trophic levels has been used to evaluate the toxicity of 2 types of point source pollution in the Voivoidship of Opole in Poland: percolating waters from drainage systems of 4 municipal waste dumps and the effluents of a sugar factory. In addition, the toxicity of groundwaters from 2 wells near 2 waste dumps was also assessed. All the drainage waters of the waste dumps and the groundwaters near one dump (an unprotected landfill) showed toxic effects on all the test species, for samples taken in spring as well as in autumn. The well water of the (more recent) waste dump of the City of Opole in turn did not show any toxic…

Substrate quality of drained organic soils—Implications for carbon dioxide fluxes

2021

Modelling of piping collapses and gully headcut landforms: Evaluating topographic variables from different types of DEM

2021

Abstract The geomorphic studies are extremely dependent on the quality and spatial resolution of digital elevation model (DEM) data. The unique terrain characteristics of a particular landscape are derived from DEM, which are responsible for initiation and development of ephemeral gullies. As the topographic features of an area significantly influences on the erosive power of the water flow, it is an important task the extraction of terrain features from DEM to properly research gully erosion. Alongside, topography is highly correlated with other geo-environmental factors i.e. geology, climate, soil types, vegetation density and floristic composition, runoff generation, which ultimately inf…

Passive degassing at Nyiragongo (D.R. Congo) and Etna (Italy) volcanoes

2014

Volcanoes are well known as an impressive large natural source of trace elements into the troposphere. Etna (Italy) and Nyiragongo (D.R. Congo) are two stratovolcanoes located in different geological settings, both characterized by persistent passive degassing from their summit craters. Here, we present some results on trace element composition in volcanic plume emissions, atmospheric bulk deposition (rainwater) and their uptake by the surrounding vegetation, with the aim to compare and identify differences and similarities between these two volcanoes. Volcanic emissions were sampled by using active filter-packs for acid gases (sulfur and halogens) and specific teflon filters for particulat…

Using 81Kr and Noble Gases to Characterize and Date Groundwater and Brines in the Baltic Artesian Basin on the One-Million-Year Timescale

2017

Analyses for $^{81}$Kr and noble gases on groundwater from the deepest aquifer system of the Baltic Artesian Basin (BAB) were performed to determine groundwater ages and uncover the flow dynamics of the system on a timescale of several hundred thousand years. We find that the system is controlled by mixing of three distinct water masses: Interglacial or recent meteoric water $(\delta^{18}\text{O} \approx -10.4\unicode{x2030})$ with a poorly evolved chemical and noble gas signature, glacial meltwater $(\delta^{18}\text{O} \leq -18\unicode{x2030})$ with elevated noble gas concentrations, and an old, high-salinity brine component $(\delta^{18}\text{O} \geq -4.5\unicode{x2030}, \geq 90 \text{g …

Human Impact Effects on Târnava River Basin Aquatic Biodiversity (Transylvania, Romania)

2020

Today the following categories of human impact are present in the Tarnava Watershed: hydrotechnical works, insufficiently treated/cleaned sewage, river substratum mineral exploitation/over-exploitation, manure leakage, artificial standing water, industry, river embankment, deforestation, pouching, etc., the first three of these inducing the highest impact on the lotic systems habitats and biodiversity.