scholarly journals Long-term dynamics of plant communities after biological remediation of oil-contaminated soils in far north

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. B. Novakovskiy ◽  
V. A. Kanev ◽  
M. Y. Markarova
Keyword(s):  
Plant Communities ◽  
Contaminated Soils ◽  
Poa Pratensis ◽  
Control Plot ◽  
Vegetation Recovery ◽  
Oil Degradation ◽  
Polluted Soils ◽  
Biological Remediation ◽  
Clear Shift

AbstractWe studied the long-term dynamics of plant communities after bio and phytoremediation of oil-polluted soils. Nine plots located in European Northeast and treated using various bioremediation methods were monitored from 2002 to 2014. Geobotanical descriptions (relevés) of each plot were performed in 2006 and 2014, and Grime’s theoretical CSR (competition–stress–ruderality) framework was used to assess the vegetation state and dynamics. We observed a clear shift of communities from pioneer (where ruderal species were prevalent) to stable (where competitor species were dominant) states. However, the remediation type did not significantly impact the vegetation recovery rate. After 12 years, all methods led to a 55–90% decrease in the oil content of the soil and a recovery of the vegetation cover. The plant communities contained mainly cereals and sedges which significantly differed from the original tundra communities before the oil spill. The control plot, treated only by mechanical cleaning, had minimum oil degradation rate (50%) and vegetation recovery rates, although, in CSR terms, its vegetation assemblage resembled the background community. Cereals (Agrostis gigantea, Deschampsia cespitosa, Phalaris arundinacea, and Poa pratensis), sedges (Carex canescens, Carex limosa, and Eriophorum vaginatum), and shrubs (Salix) were found to be the most effective species for phytoremediation, exhibiting high community productivity under the harsh northern conditions.

scholarly journals Phytoremediation and Microorganisms-Assisted Phytoremediation of Mercury-Contaminated Soils: Challenges and Perspectives

2021 ◽  
Vol 18 (5) ◽  
pp. 2435
Author(s):  
Emanuela D. Tiodar ◽  
Cristina L. Văcar ◽  
Dorina Podar
Keyword(s):  
Contaminated Soils ◽  
Polluted Soils ◽  
Plant Growth Promoting ◽  
Bacteria And Fungi ◽  
Global Threat ◽  
Effective Use ◽  
Assisted Phytoremediation ◽  
Potential Use

Mercury (Hg) pollution is a global threat to human and environmental health because of its toxicity, mobility and long-term persistence. Although costly engineering-based technologies can be used to treat heavily Hg-contaminated areas, they are not suitable for decontaminating agricultural or extensively-polluted soils. Emerging phyto- and bioremediation strategies for decontaminating Hg-polluted soils generally involve low investment, simple operation, and in situ application, and they are less destructive for the ecosystem. Current understanding of the uptake, translocation and sequestration of Hg in plants is reviewed to highlight new avenues for exploration in phytoremediation research, and different phytoremediation strategies (phytostabilization, phytoextraction and phytovolatilization) are discussed. Research aimed at identifying suitable plant species and associated-microorganisms for use in phytoremediation of Hg-contaminated soils is also surveyed. Investigation into the potential use of transgenic plants in Hg-phytoremediation is described. Recent research on exploiting the beneficial interactions between plants and microorganisms (bacteria and fungi) that are Hg-resistant and secrete plant growth promoting compounds is reviewed. We highlight areas where more research is required into the effective use of phytoremediation on Hg-contaminated sites, and conclude that the approaches it offers provide considerable potential for the future.

Long-term fertilization experiments on a natural grassland on calcareous meadow soil

2010 ◽  
Vol 59 (2) ◽  
pp. 255-268
Author(s):  
István Harmati
Keyword(s):  
Trifolium Pratense ◽  
Poa Pratensis ◽  
Festuca Pratensis ◽  
Meadow Soil ◽  
Medicago Lupulina ◽  
Arrhenatherum Elatius ◽  
Natural Grassland ◽  
Fertilization Experiments ◽  
Agropyron Repens

Sekély humuszos szintű, erősen karbonátos réti talajon kialakult természetes (Achilleo-Festucetum pseudovinae) gyepen beállított tartamkísérletekben vizsgáltuk a műtrágyázás kérdéseit a gyep növényi összetételének megjavítása, termésének növelése és minősége javítása céljából. A kísérlet humuszban gazdag, nitrogénnel és káliummal igen jól ellátott, de foszforban szegény talaján az N- és P-műtrágya 2-2 adagját szólóban és kombinációikban alkalmaztuk. Az öntözetlen kísérletet 28, az öntözöttet 14 éven át folyamatosan, széleskörűen vizsgáltuk. Megállapításainkat a következőkben foglaljuk össze. – A gyep növényi összetételét a N- és a P-műtrágyák adagjaiktól és kombinációiktól függően megváltoztatták. A nitrogén a füvek, a foszfor a pillangósok versenyképességét fokozta és segítette elő növekedését. Az önmagában alkalmazott N-műtrágya a talaj nagyfokú P-szegénysége miatt nem gyakorolt pozitív hatást a gyepre. A P-műtrágya viszont kedvező változásokat okozott: a füvek fejlődésének elősegítése mellett nagymértékben növelte a pillangósok borítási értékét és tömegarányát, különösen az öntözött parcellákon. Öntözetlen viszonyok között a réti perje (Poa pratensis), a sovány csenkesz (Festuca pseudovina) és a komlós lucerna (Medicago lupulina) alkotta a gyep termésének túlnyomó részét, néhány egyéb fű- és pillangósvirágú komponens társaságában. Az öntözött kísérletben a pillangósok abszolút uralma mellett gyakran a réti perje jutott vezető szerephez. A pillangósok közül az eperhere (Trifolium fragiferum), a komlós lucerna (Medicago lupulina) és a vörös here (Trifolium pratense) váltakozva jutott uralomra. Az időjárás nagyban befolyásolta a gyep pillangós komponenseinek tömegarányát. Az NP kombinációkban a pillangósok tömegaránya erősen lecsökkent, különösen a nagyobb N-adag használata esetén. Öntözetlen területen a sovány csenkesz és a réti perje változó arányban alkotta a gyep termésének túlnyomó részét. Az öntözött parcellákon azonban a réti perje abszolút uralkodóvá vált és az egyre jobban előretörő tarackbúza (Agropyron repens) is jelentősen részt vett a termés kialakításában, elsősorban a nagyobb N-dózisú kombinációkban. A kísérlet 3. évtizedében a csapadékos években megjelent a francia perje (Arrhenatherum elatius) és a réti csenkesz (Festuca pratensis) is. – A gyep termését az önmagában alkalmazott N-műtrágya nem növelte jelentősen. Ezzel szemben a P-műtrágya nagy hatékonysággal 2–4-szeresére (3–5 t·ha–1-ra) növelte a gyep szénatermését, elsősorban a pillangósok nagyarányú térhódítása révén. 1 kg P2O5 öntözetlen körülmények között 43, míg öntözöttben 68 kg szénaterméstöbbletet eredményezett, sokévi átlagban. A 90 kg P2O5·ha–1 adag néhány év után soknak bizonyult. A legjobb eredményt a 200 kg N·ha–1 + 60 kg P2O5·ha–1 adaggal értük el, amellyel az öntözetlen területen – 28 év átlagában – 7,87, öntözötten – 14 év átlagában – 7,12 t·ha–1 szénatermést kaptunk. Az időjárás nagymértékben befolyásolta a termés mennyiségét és minőségét, legfőképpen a pillangósok tömegarányának változása révén, különösen az öntözetlen kísérletben. A három növedék tömegének aránya 7 évi átlagban, az öntözetlen kísérletben a szóló foszforkezeléseknél 48:37:15%, míg az NP kombinációknál 56:35:9% volt. Az öntözött területen ezek az arányok az előbbi sorrendben: 39:49:12, illetve 43:41:16%. A nitrogénből számított nyersfehérjehozam sokévi átlagban az öntözetlen kísérletben 428–550, míg az öntözöttben 560–760 kg·ha–1 volt. – A talaj felvehető tápanyagtartalma az évek során jelentősen megváltozott, különösen a talaj 0–10 cm-es rétegében. A P-trágyázás önmagában, de az NP kombinációiban is az adagoktól, illetve az ezek hatására kialakult termések mennyiségétől függő mértékben növelte a talaj P-tartalmát. A legjobbnak a 200 kg N·ha–1 + 60 kg P2O5·ha–1 kezelésű parcellákban bizonyult: a kísérlet 22. évében a talaj 0–10 cm-es rétegében a P-tartalom 260 mg P2O5·kg–1 lett, ami az erősen karbonátos talajok esetében igen jó P-ellátottságnak mondható. A K-ellátottság azonban az NP-kezeléseknél az optimális szint alá csökkent (172 mg K2O·kg–1) a termések nagyarányú K-kivonása következtében. Ezért néhány évi NP-trágyázás után K-pótlásra is szükség van.

Long-term dynamics and destruction of marsh vegetation in the Kolokolkova Bay of the Barents Sea

2012 ◽  
pp. 66-77 ◽  
Author(s):  
I. A. Lavrinenko ◽  
O. V. Lavrinenko ◽  
D. V. Dobrynin
Keyword(s):  
Species Composition ◽  
Plant Communities ◽  
Barents Sea ◽  
Mean Value ◽  
Marsh Vegetation ◽  
Composition And Structure ◽  
The Mean ◽  
Species Composition And Structure

The satellite images show that the area of marshes in the Kolokolkova bay was notstable during the period from 1973 up to 2011. Until 2010 it varied from 357 to 636 ha. After a severe storm happened on July 24–25, 2010 the total area of marshes was reduced up to 43–50 ha. The mean value of NDVI for studied marshes, reflecting the green biomass, varied from 0.13 to 0.32 before the storm in 2010, after the storm the NDVI decreased to 0.10, in 2011 — 0.03. A comparative analysis of species composition and structure of plant communities described in 2002 and 2011, allowed to evaluate the vegetation changes of marshes of the different topographic levels. They are fol­lowing: a total destruction of plant communities of the ass. Puccinellietum phryganodis and ass. Caricetum subspathaceae on low and middle marches; increasing role of halophytic species in plant communities of the ass. Caricetum glareosae vic. Calamagrostis deschampsioides subass. typicum on middle marches; some changes in species composition and structure of plant communities of the ass. Caricetum glareosae vic. Calamagrostis deschampsioides subass. festucetosum rubrae on high marches and ass. Parnassio palustris–Salicetum reptantis in transition zone between marches and tundra without changes of their syntaxonomy; a death of moss cover in plant communities of the ass. Caricetum mackenziei var. Warnstorfia exannulata on brackish coastal bogs. The possible reasons of dramatic vegetation dynamics are discussed. The dating of the storm makes it possible to observe the directions and rates of the succession of marches vegetation.

scholarly journals Remediation of mercury-contaminated soils and sediments using biochar: a critical review

Biochar ◽  
2021 ◽  
Author(s):  
Qian Yang ◽  
Yongjie Wang ◽  
Huan Zhong
Keyword(s):  
Health Risks ◽  
Contaminated Soils ◽  
Functional Materials ◽  
Redox Conditions ◽  
Existing Problems ◽  
Soils And Sediments ◽  
Underlying Mechanisms ◽  
Biochar Amendment

AbstractThe transformation of mercury (Hg) into the more toxic and bioaccumulative form methylmercury (MeHg) in soils and sediments can lead to the biomagnification of MeHg through the food chain, which poses ecological and health risks. In the last decade, biochar application, an in situ remediation technique, has been shown to be effective in mitigating the risks from Hg in soils and sediments. However, uncertainties associated with biochar use and its underlying mechanisms remain. Here, we summarize recent studies on the effects and advantages of biochar amendment related to Hg biogeochemistry and its bioavailability in soils and sediments and systematically analyze the progress made in understanding the underlying mechanisms responsible for reductions in Hg bioaccumulation. The existing literature indicates (1) that biochar application decreases the mobility of inorganic Hg in soils and sediments and (2) that biochar can reduce the bioavailability of MeHg and its accumulation in crops but has a complex effect on net MeHg production. In this review, two main mechanisms, a direct mechanism (e.g., Hg-biochar binding) and an indirect mechanism (e.g., biochar-impacted sulfur cycling and thus Hg-soil binding), that explain the reduction in Hg bioavailability by biochar amendment based on the interactions among biochar, soil and Hg under redox conditions are highlighted. Furthermore, the existing problems with the use of biochar to treat Hg-contaminated soils and sediments, such as the appropriate dose and the long-term effectiveness of biochar, are discussed. Further research involving laboratory tests and field applications is necessary to obtain a mechanistic understanding of the role of biochar in reducing Hg bioavailability in diverse soil types under varying redox conditions and to develop completely green and sustainable biochar-based functional materials for mitigating Hg-related health risks.

scholarly journals Changes in surface characteristics and adsorption properties of 2,4,6-trichlorophenol following Fenton-like aging of biochar

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Liqiang Cui ◽  
Qinya Fan ◽  
Jianxiong Sun ◽  
Guixiang Quan ◽  
Jinlong Yan ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Surface Properties ◽  
Aging Process ◽  
Surface Characteristics ◽  
Natural Soil ◽  
Peanut Shell ◽  
Soil Environment ◽  
Polluted Soils ◽  
Physico Chemical

AbstractFenton-like system formed in a natural soil environment deemed to be significant in the aging process of biochar. Aged biochars have distinct physico-chemical and surface properties compared to non-aged biochar. The aged biochar proved to be useful soil amendment due to its improved elements contents and surface properties. The biochar aging process resulted in increased surface area and pore volume, as well as carbon and oxygen-containing functional groups (such as C=O, –COOH, O–C=O etc.) on its surface, which were also associated with the adsorption behavior of 2,4,6-trichlorophenol (2,4,6-TCP). The biochar aging increased the adsorption capacity of 2,4,6-TCP, which was maximum at pH 3.0. The 2,4,6-TCP adsorption capacity of aged-bush biochar (ABB) and aged-peanut shell biochar (APB) was increased by 1.0–11.0% and 7.4–38.8%, respectively compared with bush biochar (BB) and peanut shell biochar (PB) at the same initial concentration of 2,4,6-TCP. All biochars had similar 2,4,6-TCP desorption rates ranging from 33.2 to 73.3% at different sorption temperatures and times. The desorbed components were mainly 2,4,6-TCP and other degraded components, which were low in concentration with small molecule substance. The results indicated that the aged-biochar could be effective for the long-term remediation of naturally organic polluted soils.

scholarly journals A floristic description of the Afromontane fynbos communities on Platberg, Eastern Free State, South Africa

Koedoe ◽  
2008 ◽  
Vol 50 (1) ◽  
Author(s):  
Robert F. Brand ◽  
Pieter J. Du Preez ◽  
Leslie R. Brown
Keyword(s):  
Natural Resources ◽  
Plant Communities ◽  
Conservation Management ◽  
Alien Invasive Species ◽  
Ecological Processes ◽  
The North ◽  
Shrub Community ◽  
Management Plans ◽  
Twinspan Classification

Within the Platberg area and the wider Drakensberg region, the shrinking natural resources and the threat posed to biodiversity are of concern to conservation management and require an understanding of long-term ecological processes. The vegetation of Platberg was investigated as part of an ecological survey to establish Afromontane floristic links to the Drakensberg as well as for the management of natural resources. From a TWINSPAN classification, refined by the Braun-Blanquet method, four main plant communities were identified, which were subdivided into fynbos, wetland, a woody/shrub community and grassland. A classification and description of the fynbos are presented in this article.The analysis showed the fynbos divided into two communities comprising four sub-communities and seven variants. The fynbos community had an average of 28.34 species per relevé, ranging from 14 to 54 species per sample plot. Twenty-four endemic or near-endemic Drakensberg Alpine Centre (DAC) species and 22 exotic (alien-invasive) species were recorded. Numerous floristic links with the DAC, Cape flora fynbos and grassland bioregions to the north and west were also found. The description of the fynbos plant communities can serve as a basis for the formulation of management plans for the area.

Effects of long-term protection from grazing on phenotypic expression in geographically separated mountain rough fescue populations

2014 ◽  
Vol 94 (1) ◽  
pp. 33-39 ◽  
Author(s):  
D. J. Thompson ◽  
W. D. Willms
Keyword(s):  
Plant Communities ◽  
Phenotypic Expression ◽  
Highly Sensitive ◽  
History Of ◽  
Genetic Makeup ◽  
Rough Fescue ◽  
Geographic Sources ◽  
Lake Site ◽  
Summer Grazing

Thompson, D. J. and Willms, W. D. 2014. Effects of long-term protection from grazing on phenotypic expression in geographically separated mountain rough fescue populations. Can. J. Plant Sci. 94: 33–39. Whether or not long-term grazing or protection from grazing alters the genetic makeup of grass populations has been debated. Mountain rough fescue [(Festuca campestris (Rydb.)], which is highly sensitive to summer grazing, and becomes dominant in plant communities with long-term protection, was chosen to address this question. Plants from three geographic sites (Stavely in AB, Milroy in the Kootenay trench, BC and Goose Lake on the BC interior plateau) with divergent grazing histories were vegetatively propagated from tillers. Daughter plants were planted into two field nurseries (at Kamloops, BC, and Stavely, AB) and morphological measurements were taken in two field seasons post-establishment. Plants from all three populations were taller, flowered earlier, and were more productive at the Kamloops nursery site. Of the three geographic sources, plants from the Goose Lake site were most distinct with narrower leaves, later flowering, and greater yield. Plants with a long history of grazing had slightly shorter fertile tillers and leaves than plants with a history of long-term protection.

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