The possibility of using mosses as environmental indicators of metal pollution has been investigated. Mosses of the species Bryum argenteum were collected from different parts of Piedmont (Italy), ranging from highly polluted areas to nearly uncontaminated mountain areas. Periodical samplings were planned in every site on a monthly base, in order to check variations of metal uptake throughout one year; correlations with pluviometric and thermal patterns were investigated for all sampling stations. On every moss sample 20 elements, ranging from major (K, P, Al, Ca, Fe and Mg) to minor (Mn, Na, Ti and Zn) and trace (As, Ba, Cd, Co, Cr, Cu, Li, Ni, Pb and Sr), were quantitatively determined by inductively coupled plasma-atomic emission spectrometry or graphite furnace-atomic absorption spectrometry, depending on the needed sensitivity. Statistical analyses, carried out with principal component analysis and cluster analysis methods, revealed that a good correlation exists between metal content in mosses and pollution degree in the areas sampled. 相似文献
We evaluated the distribution of 15 metal ions, namely Al, Cd, Cu, Cr, Fe, La, Mn, Ni, Pb, Sc, Ti, V, Y, Zn and Zr, in the soil of a contaminated site in Piedmont (Italy). This area was found to be heavily contaminated with Cu, Cr and Ni. The availability of these metal ions was studied using Tessier’s sequential extraction procedure: the fraction of mobile species, which potentially is the most harmful for the environment, was much higher than that normally present in unpolluted soils. This soil was hence used to evaluate the effectiveness of treatment with vermiculite to reduce the availability of the pollutants to two plants, Lactuca sativa and Spinacia oleracea, by pot experiments. The results indicated that the addition of vermiculite significantly reduces the uptake of metal pollutants by plants, confirming the possibility of using this clay in amendment treatments of metal-contaminated soils. The effect of plant growth on metal fractionation in soils was investigated. Finally, the sum of the metal percentages extracted into the first two fractions of Tessier’s protocol was found to be suitable in predicting the phytoavailability of most of the pollutants present in the investigated soil. 相似文献
Climate services entail providing timely and tailored climate information to end-users in order to facilitate and improve decision-making processes. Climate services are instrumental in socio-economic development and benefit substantially from interdisciplinary collaborations, particularly when including Early Career Researchers (ECRs). This commentary critically discusses deliberations from an interdisciplinary workshop involving ECRs from the United Kingdom and South Africa in 2017, to discuss issues in climate adaptation and climate services development in water resources, food security and agriculture. Outcomes from the discussions revolved around key issues somewhat marginalized within the broader climate service discourse. This commentary discusses what constitutes “effective” communication, framings (user framings, mental models, narratives, co-production) and ethical dimensions in developing climate services that can best serve end-users. It also reflects on how ECRs can help tackle these important thematic areas and advance the discourse on climate services. 相似文献
Phospholipid fatty acid (PLFA) analysis has gained great importance in the study of soil microbial community structure. This structure can give indication of the soil status. Purpose of the present paper is to analyse PLFA patterns in altered agricultural soils in order to develop a soil status alteration index. Soils subjected either to intensive agricultural exploitation, or to overflow by municipal and industrial wastes, or to irrigation with saline waters were analysed for PLFA content and compared to adjacent untreated soils by means of different statistical techniques.
Principal component analysis separated PLFAs in three groups: unsaturated PLFAs (first axis, 48% of total variance), monounsaturated and cyclopropane PLFAs (second axis, 28% of total variance) and polyunsaturated PLFAs (third axis, 24% of total variance).
By means of canonical discriminant analysis, a soil alteration index (SAI) was produced from 15 PLFAs using two data sets. A third data set was used to test the SAI general validity together with other data sets reported in literature. The index validity was confirmed in most cases: SAI gave higher scores for control soils and was generally able to classify soils according to their reported degree of alteration. 相似文献
The water exchange between a small (4.1 hectare) salt marsh adjoining the Great Bay Estuary system of New Hampshire, USA was sampled during 16 tidal cycles between July, 1976 and November, 1977. Tidal amplitude, temperature, salinity, nutrient concentrations (ammonia-N, nitrate-N, nitrite-N, orthophosphate-P, total-P, silicates) and suspended particulates were measured. Conspicuous tidal hydrographic patterns were observed. Mean concentrations of nitrate-N and silicates varied with season. The tidal information, combined with volume determinations, was extrapolated to determine the net flux of hydrographic parameters on monthly and yearly bases. Ammonia-N showed a pronounced seasonality of net exchange by regression analyses. Ammonia-N and suspended particulates had a statistically significant import into the marsh. However, the net fluxes of the other materials were not statistically different from O.Published with the approval of the Director of the New Hampshire Agricultural Experiment Station as Scientific Contribution No. 930Scientific Contribution No. 69 of the Jackson Estuarine Laboratory 相似文献