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41.
42.
Little is known about seasonal changes in burrowing activity and burrow architecture in subterranean African mole-rats (Bathyergidae, Rodentia). The solitary genus Heliophobius is the least known genus of this family. We examined burrow systems of the silvery mole-rat ( Heliophobius argenteocinereus) in Malawi in two periods of the dry season. Burrow pattern was influenced by the time of the year, becoming more reticulated at the peak of the dry season when soil was dry and hard. Overall digging activity did not cease during the dry season; yet burrowing strategy changed and the soil was deposited in tunnels rather than transported to mounds. The length of burrow systems was correlated with the body mass of the respective occupants. In spite of their solitary habits – and contrary to the prediction of the aridity food-distribution hypothesis – silvery mole-rats are able to occupy poor habitats with low food supply. 相似文献
43.
Background Worldwide, large amounts of sediments have to be dredged annually from waterways and harbours. These sediments are sometimes
polluted with a variety of toxic compounds. In some countries, including Belgium, the load with the biocide tributyltin (TBT)
from ship coatings prohibits the dumping of harbour sludge into the sea. Land-based dumping is a commonly used alternative.
Objective This research investigated the feasibility to use land-deposited harbour sludge for plant production. In a field trial, the
growth of 38 more or less salt-tolerant plant species on low and high TBT-contaminated sediments was studied. The elimination
of TBT from sludge with and without vegetation was compared. The uptake of TBT and its degradation products di- and monobutyltin
(DBT and MBT) into harvest products under field conditions was determined.
- Experimental Set-up. Sediments dredged in May 2003 from the brackish waters of the port of Antwerp were analysed in the laboratory
for soil texture, pH, electroconductivity, sodium, magnesium, potassium, calcium, ammonium, nitrate, total nitrogen, chloride,
sulphur and the organotins TBT, DBT and MBT. The sediments were lagooned for one year to dewater, desalinate and improve their
structure. Salt-tolerant domestic and wild plants were selected and sown in May 2004. In August 2004, plants were harvested
and the produced biomass was determined. Samples were taken from vegetated and non-vegetated top and bottom sediments and
from plants growing above soil and analysed for TBT, DBT and MBT.
Results The fresh sediments showed a good supply with nutrients and a neutral pH, but were rather saline (EC 14 mS cm-1 of the saturated
paste extract). The salinity decreased to 3.7 mS cm-1 during lagoonation. The high and the low contaminated sediment had initially
43 and 1.6 mg TBT kg-1 dry weight, respectively. Besides TBT, several other contaminants were present in the sediments at
critical levels. The biomass production of the plant species from the field trial ranged from 0.2 to 13 tons dry mass per
hectare. Plants performing excellently were barley, sorghum, rape seed, a clover/grass mix and reed. If at all, a positive
influence of TBT on plant growth was seen. TBT was degraded significantly faster (>40%) below barley. The uptake of TBT, DBT
and MBT into stem and leaves of reed, grass and clover was very low, but measurable and not related to concentrations in soil.
No uptake of TBT or its metabolites into corn of barley was found.
Discussion This study confirmed former results: the toxicity of TBT to higher plants is low, and even high levels in soils would not
be a hindrance for crop production. The removal of TBT seemed to be increased by both lagooning and plant growth, although
the target values for sea dumping in use in certain European countries were not reached. A plausible explanation for the faster
degradation of TBT under vegetation is that oxygen is a limiting factor, and plants dewater the soil, thus aerating it. The
uptake of the organotins TBT, DBT and MBT into harvest products is probably due to attached soil particles.
Conclusions To summarize, barley was the optimal species: it grew very well despite the salinity of the dredged sediments, it had a significantly
positive effect on TBT removal; it showed no measurable uptake of TBT or the other butyltins into the harvested product; and
it is a cash crop well established in European agriculture.
Outlook The amounts of dredged sediments are high, and good soils are becoming increasingly rare. The feasibility of using dredged
sediments for non-food production, such as energy crops, should be investigated by a critical risk assessment. 相似文献
44.
Thomas Fellmann Peter Witzke Franz Weiss Benjamin Van Doorslaer Dusan Drabik Ingo Huck Guna Salputra Torbjörn Jansson Adrian Leip 《Mitigation and Adaptation Strategies for Global Change》2018,23(3):451-468
Taking the European Union (EU) as a case study, we simulate the application of non-uniform national mitigation targets to achieve a sectoral reduction in agricultural non-carbon dioxide (CO2) greenhouse gas (GHG) emissions. Scenario results show substantial impacts on EU agricultural production, in particular, the livestock sector. Significant increases in imports and decreases in exports result in rather moderate domestic consumption impacts but induce production increases in non-EU countries that are associated with considerable emission leakage effects. The results underline four major challenges for the general integration of agriculture into national and global climate change mitigation policy frameworks and strategies, as they strengthen requests for (1) a targeted but flexible implementation of mitigation obligations at national and global level and (2) the need for a wider consideration of technological mitigation options. The results also indicate that a globally effective reduction in agricultural emissions requires (3) multilateral commitments for agriculture to limit emission leakage and may have to (4) consider options that tackle the reduction in GHG emissions from the consumption side. 相似文献
45.
46.
47.
Albrecht Hase R. Hesse Adolf Mayer Paul Weiss Karl Bělař 《Die Naturwissenschaften》1929,17(44):863-866
48.
Růžičková Jana Raclavská Helena Juchelková Dagmar Šafář Michal Kucbel Marek Švédová Barbora Slamová Karolina Grobelak Anna 《Environmental science and pollution research international》2023,30(4):8582-8600
Environmental Science and Pollution Research - The utilisation of waste wood from furniture production brings new problems connected with an incomplete thermochemical decomposition of additives... 相似文献
49.
Samson G. Mengistu Heather E. Golden Charles R. Lane Jay R. Christensen Michael L. Wine Ellen D’Amico Amy Prues Scott G. Leibowitz Jana E. Compton Marc H. Weber Ryan A. Hill 《Journal of the American Water Resources Association》2023,59(5):1162-1179
Eutrophication, harmful algal blooms, and human health impacts are critical environmental challenges resulting from excess nitrogen and phosphorus in surface waters. Yet we have limited information regarding how wetland characteristics mediate water quality across watershed scales. We developed a large, novel set of spatial variables characterizing hydrological flowpaths from wetlands to streams, that is, “wetland hydrological transport variables,” to explore how wetlands statistically explain the variability in total nitrogen (TN) and total phosphorus (TP) concentrations across the Upper Mississippi River Basin (UMRB) in the United States. We found that wetland flowpath variables improved landscape-to-aquatic nutrient multilinear regression models (from R2 = 0.89 to 0.91 for TN; R2 = 0.53 to 0.84 for TP) and provided insights into potential processes governing how wetlands influence watershed-scale TN and TP concentrations. Specifically, flowpath variables describing flow-attenuating environments, for example, subsurface transport compared to overland flowpaths, were related to lower TN and TP concentrations. Frequent hydrological connections from wetlands to streams were also linked to low TP concentrations, which likely suggests a nutrient source limitation in some areas of the UMRB. Consideration of wetland flowpaths could inform management and conservation activities designed to reduce nutrient export to downstream waters. 相似文献
50.
Andráš Peter Dadová Jana Romančík Roman Borošová Daniela Midula Pavol Dirner Vojtech 《Environmental geochemistry and health》2021,43(9):3675-3681
Environmental Geochemistry and Health - The abandoned Malachov deposit belongs among the most important historic Hg deposits in the world. The soil, groundwater, surface water, plants, and animals... 相似文献