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991.

Purpose

Copper (Cu) contamination has been increasing in land ecosystems due to economic development activities. Excessive amount of Cu in soils is toxic to both plants and microorganisms. Biochar (BC) is known to immobilize soil Cu. The objectives of this research were to investigate the effects of chicken-manure-derived BC (CMB) on Cu immobilization, and growth of native metallophyte Oenothera picensis in a Cu-contaminated soil.

Materials and methods

A Cu-contaminated sandy soil (338 mg Cu kg?1) was spiked and equilibrated with additional Cu (0, 100, and 500 mg Cu kg?1). The spiked soil was then amended with CMB (0, 5, and 10 % w/w) and incubated for 2 weeks. The metallophyte was grown on these treatments under greenhouse conditions for 3 months. Pore water solutions were collected from the plant pots every 30 days. After the harvest, soil and pore water pH, soil Cu fractions, pore water Cu concentration, soil microbial activity, plant biomass weight, and Cu concentration in plant parts were determined.

Results and discussion

The CMB increased the pH of soils and soil pore water, and probably also soil major nutrients. It reduced the exchangeable fraction of Cu but increased its organic matter and residual fractions. At the same time, it decreased the Cu concentration in the soil pore water. The CMB increased basal respiration and dehydrogenase activity. The CMB application produced up to three and seven times more root and shoot biomass, respectively. In addition, shoots accumulated lesser Cu than control but roots did more. Plants survived in soil that was spiked with 500 mg Cu kg?1, only when CMB dose was 10 %.

Conclusions

The CMB affected the Cu uptake in plant by altering the mobility, bioavailability, and spatial distribution of Cu in soils. The increase in available nutrients and decrease in Cu toxicity facilitated plant growth. The increased microbial activity probably also promoted the plant growth and reduced the Cu bioavailability. Therefore, CMB can be used to remediate Cu-contaminated soils.
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992.

Purpose

This study was undertaken to determine the feasibility of using three aquatic macrophytes, Phragmites australis, Juncus effusus and Iris pseudacorus, to phytoextract potentially toxic elements (PTEs) from a contaminated area by mining activities.

Materials and methods

An artificial pond was constructed with two topsoils (yellow and black samples) collected from Portman Bay. In order to simulate the mixing with carbonate materials, which naturally occurs in this area, a stabilisation approach was applied by mixing with 30 % of limestone filler. Three replicates of each type of soil have been prepared in pots for the selected species. The total PTEs content (arsenic, cadmium, copper, iron, lead and zinc) was determined and the bioconcentration factor (BCF) and transfer factor (TF) calculated.

Results and discussion

Soil samples showed high PTEs content as a result of mining activities. As regards the root contents, the PTEs is higher in yellow samples (YS) than in black ones, because in these samples the PTEs content that could be mobilised is higher. The BCF results were higher than unity for arsenic, copper, lead and cadmium for I. pseudacorus and P. australis growing on YS soil. Overall, copper and manganese showed a larger number of plants with BCF higher than unity. The PTEs content in leaves is low, and the TF results are lower than unity in almost all samples.

Conclusions

The results indicate that it is possible to use the selected species for phytostabilisation of soils contaminated with PTEs. J. effusus, P. australis and I. pseudacorus could be considered as tolerant, and natural or artificial wetlands containing these species could be used for remediation purposes.
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993.

Purpose

Mercury pollution in agricultural soils associated to the use of fertilizers and its influence on crops is a cause of major concern. The purpose of this work was to investigate the impact of the application of different organic and mineral fertilizers on the Hg concentration in the agricultural soils and its uptake by barley.

Materials and methods

Hg concentration was studied through a field test in an agricultural land located in the province of Palencia (Spain) over a 5-year period. The impact of irrigation and of four different fertilizers (a mineral one and three different organic waste materials, namely municipal solid waste compost, sewage sludge, and dehydrated sewage sludge) was assessed. The amounts of the mineral and organic fertilizers added to the soil were determined according to agricultural fertilization needs. The experimental crop was barley (Hordeum vulgare L.), planted as an annual crop. Mercury analyses were conducted using a direct mercury analyzer and validated according to EPA Method 7473. BCR-141R was used as a certified reference material.

Results and discussion

After 5 years, whereas the application of the mineral fertilizer did not increase the mercury content in the agricultural soils, the application of the organic residues led to Hg contents 1.7–7.6 times higher than that of the control soil. The treatment with solid municipal waste compost (MSWC) led to the largest increase in Hg content in the soil, followed by composted sewage sludge (CSS) and by dehydrated sewage sludge (DSS). No significant differences were observed in the Hg content in the barley grains, although the highest values were associated to the sludge-treated plots.

Conclusions

The application of organic fertilizers such as sewage sludges and municipal solid wastes led to an increase in the mercury concentration in the agricultural soils, noticeable for soils with low initial Hg concentrations (similar to background levels). This increase differed depending on the type of waste and on the intra-organic matter diffusion mechanisms, as well as on the type of irrigation of the agricultural land. Conversely, no significant differences in the Hg content in grains were found among the soils with the different fertilization treatments, although the highest values were observed for those treated with sewage sludge. The resulting Hg levels in both soils and grains were within legal limits, posing no danger to the environment or to human health.
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994.
? Key message The above- and belowground impacts due to Acacia invasions have been described in detail over the last 25 years. Future research should focus on the early detection and prevention of new Acacia introductions and on a cost-effective and sustainable management of the novel ecosystems resulting from invasions. ? Context Invasive alien plants (IAPs) strongly alter ecosystems reducing biodiversity, modifying ecosystem services and increasing negative impacts at social and economic level. Among invasive taxa, Acacia is a highly problematic genus worldwide. In fact, almost 500 papers have been published on several aspects of Acacia invasions for the last 25 years.? Aims We aim at reviewing the current knowledge on the consequences of the invasion by Acacia genus in Mediterranean ecosystems. We also collect and propose different approaches for the management and recovery of invaded areas and suggest future perspectives on Acacia research.? Methods We compile, summarise and discuss recent findings on physicochemical, ecological, microbiological and socioeconomic aspects of invasion related to Australian acacias (Acacia dealbata, Acacia longifolia, Acacia mearnsii, Acacia saligna and Acacia melanoxylon) focusing on Mediterranean areas.? Results Acacia invasion generally entails soil physicochemical alterations and changes in microbial function and structure. Consequences such as the decreased biodiversity, altered ecosystem structure, larger seed banks dominated by invasive species, new biotrophic relationships or alterations in water availability and fire regimes suggest that acacias are locally creating novel ecosystems.? Conclusions Forecasting invasions, modelling and managing ecosystems dominated by acacias are challenging tasks that should be addressed in the future, since climatic conditions and intensification in land uses are increasing the likelihood of Acacia invasions in Mediterranean areas. Unsuccessful management actions suggest that restoration should be meticulously monitored, but the magnitude of invasion or the inconsistency of economic investment indicate that eradication is often unfeasible. Alternatively, novel integrative and cost-effective solutions including the collaboration of society, politicians and stakeholders are necessary to prevent new introductions and achieve sustainable control of acacias. There is a growing interest in applied research on the valorisation or novel uses for acacias and their residues that result in economic benefits.  相似文献   
995.
Microbiological activities are essential in the bioremediation of polluted soils. The enzymatic activities of microorganisms are usually used as a biological indicator of soil health. The aim of this work was to observe the catalase, acid phosphatase (AcP), and alkaline phosphatase (AlP) activities in soil that was amended with agro-industrial by-products and macronutrients during the process of total petroleum hydrocarbon (TPH) removal. To this end, microcosm tests were performed with soil and agro-industrial by-products ratios of 100:2:2, for soil:sugarcane bagasse pith:filter cake mud (SSF); 100:2, for both soil:sugarcane bagasse pith (SS); and for soil filter cake mud (SF). The macronutrients—carbon, nitrogen, and phosphorus—in the experimental treatments were adjusted to 100:10:1 with a solution of NH4NO3 and K2HPO4. The best TPH removal (51.4%) was obtained with SSF at 15 days. In addition, a significant correlation was observed between TPH removal and AlP as well as AcP (r = 0.74, p < 0.0001; r = 0.70, p < 0.0107, respectively). Fungi growth was also correlated with both AlP (r = 0.97, p < 0.0001) and AcP (r = 0.95, p < 0.0001) activities. Besides, bacterial and fungi growth showed a correlation with TPH (r = 0.86, p < 0.001; r = 0.77, p < 0.0034, respectively). It could be said that the agro-industrial by-products and macronutrients contributed to pollutant removal from the oil-polluted soil at relatively short amount of time. In addition, the enzymatic activities were increased after the treatment; in this study, the high sensitivity enzyme was AlP, and it could be used as an indirect indicator of oil pollutant removal.  相似文献   
996.
Genetic erosion has been variously defined as the loss of particular alleles, the reduction in richness of the total number of alleles, and the reduction in evenness of the frequencies of alleles in a given place within populations or across species. Picea chihuahuana Martínez is an endangered endemic species known to occur in at least 40 locations along the Sierra Madre Occidental, in the states of Durango and Chihuahua (Mexico), but covering a total area of no more than 300 ha. The total number of individuals has been estimated to be around 42,600, and the number of mature individuals may be <2500. The populations (including mature trees, saplings and seedlings) vary in size from 21 to 5546 individuals. It has been suggested that small populations may be more susceptible to loss of genetic variability via genetic erosion caused by genetic drift, endogamy depression and strong unidirectional selection. The predicted reduction and eventual disappearance of a suitable habitat for P. chihuahuana due to climatic change imposes an additional risk of extinction. The principal aim of this study was therefore to estimate genetic erosion in 14 populations of P. chihuahuana Martínez by comparing genetic diversity across diameter at breast height classes (as a proxy for age classes) by using AFLP markers and four indices of genetic diversity that are commonly applied in combination with dominant genetic markers. No evidence of genetic erosion was found in the 14 P. chihuahuana populations analyzed.  相似文献   
997.
Six native plants of South America traditionally consumed in the Patagonian region (southern Argentina and Chile), namely: Adesmia boronioides Hook. f., Apium australe Thouars, Buddleja globosa Hope, Drimys andina (Reiche) R. Rodr. & Quezada, Dysphania multifida L. and Solidago chilensis Meyen were investigated to determine the nutraceutical properties of infusions of their aerial parts. The infusions were characterized in terms of their antioxidant activity, phenolic and flavonoid content, profile of phenolic compounds, general toxicity and cytotoxicity on two different human cell lines: T84 (derived from colon cancer) and HTR8/SVneo (not derived from cancer). Twenty-nine compounds, mainly phenolic acids and flavonoids, were identified. This is the first analysis of phenolic compounds in infusions from native plants of Patagonia. D. andina, B. globosa and S. chilensis showed high levels of antioxidants, even higher than those of Green Tea. The content of phenolic compounds correlated significantly with the antioxidant activity of the samples analyzed. The toxicity test indicated that the use of A. australe, B. globosa and D. multifida seems safe, but a moderate consumption is suggested for A. boronioides, D. andina and S. chilensis until more exhaustive and long-term results are available. Moreover, A. boronioides and S. chilensis showed anticancer potential due to their antiproliferative activity on human cancer cell lines.  相似文献   
998.
Potatoes are one of the main foods throughout the world contributing to the daily intake of nutrients. This work studies the relationship among some physical characteristics of tubers from 35 potato varieties, the total phenol and flavonoid content and their antioxidant potential. Some significant differences were found depending on the potato variety. Thus, Fleur Bleue, Violetta, Yona, Stronga and Flamenco tubers had the highest antioxidant capacity. This is apparently a consequence of the presence of purple and red pigments in skin and flesh. A regression model for radical scavenging activity, total phenol content and the value of coordinate a* (CIElab scale) for tuber flesh was obtained.  相似文献   
999.
Senegalese sole has been shown to be highly susceptible to betanodavirus infection, although virulence differences were observed between strains. To study the mechanisms involved in these differences, we have analysed the replication in brain tissue of three strains with different genotypes during 15 days after bath infection. In addition, possible portals of entry for betanodavirus into sole were investigated. The reassortant RGNNV/SJNNV and the SJNNV strain reached the brain after 1 and 2 days postinfection, respectively. Although no RGNNV replication was detected until day 3–4 postinfection, at the end of the experiment this strain yielded the highest viral load; this is in accordance with previous studies in which sole infected with the reassortant showed more acute signs and earlier mortality than the RGNNV and SJNNV strains. Differences between strains were also observed in the possible portals of entry. Thus, whereas the reassortant strain could infect sole mainly through the skin or the oral route, and, to a minor extent, through the gills, the SJNNV strain seems to enter fish only through the gills and the RGNNV strain could use all tissues indistinctly. Taken together, all these results support the hypothesis that reassortment has improved betanodavirus infectivity for sole.  相似文献   
1000.
In the case of grapevine (Vitis vinifera L.), leaf blade and petioles at different sampling times are used for nutritional diagnosis and planning fertilization practices. However, reference values for each nutrient depend on the scion‐rootstock combination. In this sense, the current study aimed at determining the reliability of leaf blade and petiole for diagnosis at different phenological stages and, also, of the period of validity, around flowering and veraison, in which the nutrient concentrations obtained could be compared with reference values. The study was carried out in three vineyards (two planted with cv. Mencía and one with cv. Sousón) within the Ribeira Sacra Designation of Origin (NW Spain). Blades and petioles were collected throughout a growth season (2014) and total concentrations of ten essential elements were determined in both tissues. In general, petioles showed greater variability between replicates for P, K, Ca, Mg, and Zn, while N, Fe, Mn, Cu, and B presented greater variability in blades. Differences between consecutive sampling dates suggest that references for flowering were valid until fruit‐set. Furthermore, blade and petiole references at the beginning of veraison were valid until the advanced ripening stage for most nutrients, with the exception of N, P, and Zn. The seasonal variation of the concentrations in both tissues confirmed the need for reference values for each phenological stage and tissue.  相似文献   
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