细化搜索
结果 1-10 的 99
Management of forests under nutrient and water stress.
1990
Sadanandan Nambiar E.K.
Forest decline and soil nutritional problems in Pacific areas.
1990
Mueller Dombois D.
The influence of air pollution on contents of pollutant in some components of nature environment in the protected landscape area Ponitrie
2002
Dureckova, E. (State Nature Protection of Slovak Republic, Nitra (Slovak Republic). Protected Landscape Area Ponitrie)
Since 1990 the investigations of quality of some components of nature environment were carried out on selected permanent plots in Protected Landscape Area Ponitrie focused on pollutant contents. The increased concentration of pollutants in precipitation from the top of the Vtacnik Mts. indicates firstly the effect of the nearby thermal power station, secondly documents an increased immission load on forest ecosystems in ridge positions of these mountains
显示更多 [+] 显示较少 [-]The response of the forest ecosystem to the reduction of TPP SO2 emissions with emphasis on the nutrient cycling
2002
Simoncic, P. | Kalan, P. | Kraigher, H.: Levanic, T. | Urbancic, M. | Vilhar, U. (Slovenian Forestry Institute, Ljubljana (Slovenia))
Selected parameters of the nutrients cycling process for forest ecosystem were investigated in period 1989-2000 at Prednji Vrh in the area affected by the Sostanj thermal power station. In the year 1995 desulphurization of exhaust gases from the TPP Sostanj caused considerable reduction of SO2 emission. We could not find serious tree-ring width decline in spruce. In the year 1956 and 1978 tree-ring widths rapidly declined. In the year 1995 slight icrement recovery could be observed. One probably climatically (drought) induced pointer year (1992) occurred
显示更多 [+] 显示较少 [-]Harnessing plant microbiome for mitigating arsenic toxicity in sustainable agriculture 全文
2022
Ali, Sajad | Tyagi, Anshika | Mushtaq, Muntazir | Al-Mahmoudi, Henda | Bae, Hanhong
Heavy metal toxicity has become an impediment to agricultural productivity, which presents major human health concerns in terms of food safety. Among them, arsenic (As) a non-essential heavy metal has gained worldwide attention because of its noxious effects on agriculture and public health. The increasing rate of global warming and anthropogenic activities have promptly exacerbated As levels in the agricultural soil, thereby causing adverse effects to crop genetic and phenotypic traits and rendering them vulnerable to other stresses. Conventional breeding and transgenic approaches have been widely adapted for producing heavy metal resilient crops; however, they are time-consuming and labor-intensive. Hence, finding new mitigation strategies for As toxicity would be a game-changer for sustainable agriculture. One such promising approach is harnessing plant microbiome in the era of ‘omics’ which is gaining prominence in recent years. The use of plant microbiome and their cocktails to combat As metal toxicity has gained widespread attention, because of their ability to metabolize toxic elements and offer an array of perquisites to host plants such as increased nutrient availability, stress resilience, soil fertility, and yield. A comprehensive understanding of below-ground plant-microbiome interactions and their underlying molecular mechanisms in exhibiting resilience towards As toxicity will help in identifying elite microbial communities for As mitigation. In this review, we have discussed the effect of As, their accumulation, transportation, signaling, and detoxification in plants. We have also discussed the role of the plant microbiome in mitigating As toxicity which has become an intriguing research frontier in phytoremediation. This review also provides insights on the advancements in constructing the beneficial synthetic microbial communities (SynComs) using microbiome engineering that will facilitate the development of the most advanced As remedial tool kit in sustainable agriculture.
显示更多 [+] 显示较少 [-]Biofiltration of methane using hybrid mixtures of biochar, lava rock and compost 全文
2018
La, Helen | Hettiaratchi, J. Patrick A. | Achari, Gopal | Verbeke, Tobin J. | Dunfield, Peter F.
Using hybrid packing materials in biofiltration systems takes advantage of both the inorganic and organic properties offered by the medium including structural stability and a source of available nutrients, respectively. In this study, hybrid mixtures of compost with either lava rock or biochar in four different mixture ratios were compared against 100% compost in a methane biofilter with active aeration at two ports along the height of the biofilter. Biochar outperformed lava rock as a packing material by providing the added benefit of participating in sorption reactions with CH4. This study provides evidence that a 7:1 volumetric mixture of biochar and compost can successfully remove up to 877 g CH4/m3·d with empty-bed residence times of 82.8 min. Low-affinity methanotrophs were responsible for the CH4 removal in these systems (KM(app) ranging from 5.7 to 42.7 µM CH4). Sequencing of 16S rRNA gene amplicons indicated that Gammaproteobacteria methanotrophs, especially members of the genus Methylobacter, were responsible for most of the CH4 removal. However, as the compost medium was replaced with more inert medium, there was a decline in CH4 removal efficiency coinciding with an increased dominance of Alphaproteobacteria methanotrophs like Methylocystis and Methylocella. As a biologically-active material, compost served as the sole source of nutrients and inoculum for the biofilters which greatly simplified the operation of the system. Higher elimination capacities may be possible with higher compost content such as a 1:1 ratio of either biochar or lava rock, while maintaining the empty-bed residence time at 82.8 min.
显示更多 [+] 显示较少 [-]Long-term microplastic retention causes reduced body condition in the langoustine, Nephrops norvegicus 全文
2016
Welden, Natalie A.C. | Cowie, Phillip R.
Microplastic represents a rising proportion of marine litter and is widely distributed throughout a range of marine habitats. Correspondingly, the number of reports of species containing microplastics increases annually. Nephrops norvegicus in the Firth of Clyde have previously been shown to retain large aggregations of microplastic fibres. The potential for N. norvegicus to retain plastic over an extended time period increases the likelihood of any associated negative impacts to the individual. This study represents the longest observation of the impacts of microplastic retention in invertebrates. We exposed N. norvegicus to plastic over eight months to determine the impacts of extended exposure. Over this period we compared the feeding rate, body mass, and nutritional state of plastic-fed N. norvegicus to that of fed and starved control groups. Following the experimental period, the plastic-fed langoustine contained microplastic aggregations comparable to those of small individuals from the Clyde Sea Area. Comparisons between fed, unfed and plastic-fed individuals indicated a reduction in feeding rate, body mass, and metabolic rate as well as catabolism of stored lipids in plastic contaminated animals. We conclude that N. norvegicus exposed to high levels of environmental microplastic pollution may experience reduced nutrient availability. This can result in reduced population stability and may affect the viability of local fisheries.
显示更多 [+] 显示较少 [-]Foliar application of lambda-cyhalothrin modulates root exudate profile and the rhizosphere bacteria community of dioecious Populus cathayana 全文
2022
He, Yue | Zhu, Zuodong | Zhou, Zhenghu | Lu, Tao | Kumar, Amit | Xia, Zhichao
Dioecious plants show sexual differences in resistance traits to abiotic stresses. However, the effects of exogenous pesticide application on female and male plant growth and their associated adaptation mechanisms are unclear. Our study investigated the effects of the broad-spectrum pesticide lambda-cyhalothrin (λ-CY) on dioecious Populus cathayana growth and explored the factors through which λ-CY changed the rhizosphere bacterial community and physicochemical soil properties via sex-specific metabolomics. The sequential application of λ-CY significantly suppressed male shoot- and root biomass, with little effect on the growth of females. Females possessed a higher intrinsic chemo-diversity within their root exudates, and their levels of various metabolites (sugars, fatty acids, and small organic acids) increased after exposure to λ-CY with consequences on bacterial community composition. Maintaining high bacterial alpha diversity and recruiting specific bacterial groups slowed down the loss of rhizosphere nutrients in females. In contrast, the reduction in bacterial alpha diversity and network structure stability in males was associated with lower rhizosphere nutrient availability. Spearman's correlation analysis revealed that several bacterial groups were positively correlated with the root secretion of lipids and organic acids, suggesting that these metabolites can affect the soil bacterial groups actively involved in the nutrient pool. This study provided novel insights that root exudates and soil microbial interactions may mediate sex-specific differences in response to pesticide application.
显示更多 [+] 显示较少 [-]Denitrification and anammox: Understanding nitrogen loss from Yangtze Estuary to the east China sea (ECS) 全文
2019
Wang, Jing | Kan, Jinjun | Qian, Gang | Chen, Jianfang | Xia, Zhiqiang | Zhang, Xiaodong | Liu, Haijiao | Sun, Jun
The Yangtze River, which is the largest in Euro-Asian, receives tremendous anthropogenic nitrogen input and is typically characterized by severe eutrophication and hypoxia. Two major processes, denitrification and anaerobic ammonium oxidation (anammox), play vital roles for removing nitrogen global in nitrogen cycling. In the current study, sediment samples were collected from both latitudinal and longitudinal transects along the coastal Yangtze River and the East China Sea (ECS). We investigated community composition and distributions of nosZ gene-encoded denitrifiers by high throughput sequencing, and also quantified the relative abundances of both denitrifying and anammox bacteria by q-PCR analysis. Denitrifying communities showed distinct spatial distribution patterns that were impacted by physical (water current and river runoffs) and chemical (nutrient availability and organic content) processes. Both denitrifying and anammox bacteria contributed to the nitrogen removal in Yangtze Estuary and the adjacent ECS, and these two processes shifted from coastal to open ocean with reverse trends: the abundance of nosZ gene decreased from coastal to open ocean while anammox exhibited an increasing trend based on quantifications of hzsB and 16S rRNA genes. Further correspondence correlation analysis revealed that salinity and nutrients were the main factors in structuring composition and distribution of denitrifying and anammox bacteria. This study improved our understanding of dynamic processes in nitrogen removal from estuarine to open ocean. We hypothesize that denitrification is the major nitrogen removal pathway in estuaries, but in open oceans, low nutrient and organic matter concentrations restrict denitrification, thus increasing the importance of anammox as a nitrogen removal process.
显示更多 [+] 显示较少 [-]Influence of activated charcoal amendment to contaminated soil on dieldrin and nutrient uptake by cucumbers 全文
2009
Hilber, Isabel | Wyss, Gabriela S. | Mäder, Paul | Bucheli, Thomas D. | Meier, Isabel | Vogt, Lea | Schulin, R (Rainer)
Influence of activated charcoal amendment to contaminated soil on dieldrin and nutrient uptake by cucumbers 全文
2009
Hilber, Isabel | Wyss, Gabriela S. | Mäder, Paul | Bucheli, Thomas D. | Meier, Isabel | Vogt, Lea | Schulin, R (Rainer)
Activated charcoal (AC) amendments have been suggested as a promising, cost-effective method to immobilize organic contaminants in soil. We performed pot experiments over two years with cucumber (Cucumis sativusL.) grown in agricultural soil with 0.07 mg kg⁻¹ of weathered dieldrin and 0, 200, 400, and 800 mg AC per kg soil. Dieldrin fresh weight concentrations in cucumber fruits were significantly reduced from 0.012 to an average of 0.004 mg kg⁻¹, and total uptake from 2 to 1 μg in the 800 mg kg⁻¹ AC treatment compared to the untreated soil. The treatment effects differed considerably between the two years, due to different meteorological conditions. AC soil treatments did neither affect the availability of nutrients to the cucumber plants nor their yield (total fruit wet weight per pot). Thus, some important prerequisites for the successful application of AC amendments to immobilize organic pollutants in agricultural soils can be considered fulfilled. The addition of activated charcoal to soil reduced dieldrin residues in cucumbers and did not affect nutrients availability.
显示更多 [+] 显示较少 [-]Influence of activated charcoal amendment to contaminated soil on dieldrin and nutrient uptake by cucumbers 全文
2009
Hilber, Isabel | Wyss, Gabriela S. | Mäder, Paul | Bucheli, Thomas D. | Meier, Isabel | Vogt, Lea | Schulin, Rainer
Activated charcoal (AC) amendments have been suggested as a promising, cost-effective method to immobilize organic contaminants in soil. We performed pot experiments over two years with cucumber (Cucumis sativus L.) grown in agricultural soil with 0.07 mg kg_1 of weathered dieldrin and 0, 200, 400, and 800 mg AC per kg soil. Dieldrin fresh weight concentrations in cucumber fruits were significantly reduced from 0.012 to an average of 0.004 mg kg_1, and total uptake from 2 to 1 mg in the 800 mg kg_1 AC treatment compared to the untreated soil. The treatment effects differed considerably between the two years, due to different meteorological conditions. AC soil treatments did neither affect the availability of nutrients to the cucumber plants nor their yield (total fruit wet weight per pot). Thus, some important prerequisites for the successful application of AC amendments to immobilize organic pollutants in agricultural soils can be considered fulfilled.
显示更多 [+] 显示较少 [-]