Phytoextraction of nickel and rhizosphere microbial communities under mono- or multispecies hyperaccumulator plant cover in a serpentine soil

2015 ◽  
Vol 63 (2) ◽  
pp. 92 ◽  
Author(s):  
Marie Rue ◽  
Jessica Vallance ◽  
Guillaume Echevarria ◽  
Patrice Rey ◽  
Emile Benizri
Keyword(s):  
Bacterial Community ◽  
Mixed Culture ◽  
Plant Biomass ◽  
Microbial Biomass Carbon ◽  
Plant Cover ◽  
Translocation Factor ◽  
Ultramafic Soil ◽  
Unplanted Soil ◽  
Phenotypic Structure ◽  
Fungal Genetic

The efficiency of nickel (Ni) phytoextraction by hyperaccumulating Brassicaceae was compared in two types of covers, namely, monoculture or mixed culture. The selected species were from the Pindus Mountains (Greece), including Alyssum murale, Noccaea tymphaea, Leptoplax emarginata and Bornmuellera tymphaea. After 4 months of culture in mesocosms using ultramafic soil (Ni = 1480 mg kg–1), plant biomass yield and Ni concentrations in shoots and roots were recorded for each of six treatments (mixed-culture cover, four monoculture covers and unplanted soil). Microbial biomass carbon, the size of the cultivable rhizosphere bacterial community and its phenotypic structure (Biolog EcoPlates™), bacterial and fungal genetic structure (SSCP), as well as the potential production of auxin compounds, were also evaluated. Moreover, measurements of various microbial enzymes were performed. The biomass and shoot Ni concentration (albeit not significant) of B. tymphaea increased in co-cropping system. A slight acidification of the soil occurred and a strong correlation between pH and the size of the bacterial community was also observed. No significant change in enzyme activity was observed among the cover types, except in the case of arylsulfatase. The phenotypic structure of the bacterial communities and the bacterial and fungal genetic structures appeared to be specific to the type of cover, although the size of the culturable bacterial community did not show variation among treatments. Therefore, on the basis of the bioaccumulation coefficient and the translocation factor, our results showed that B. tympheae, and to a lesser extent N. tympheae, were the two species with the greatest Ni phytoextraction potential in co-culture systems.

scholarly journals Relationships of NDVI, Biomass, and Leaf Area Index (LAI) for six key plant species in Barrow, Alaska

2015 ◽  
Author(s):  
Santonu Goswami ◽  
John Gamon ◽  
Sergio Vargas ◽  
Craig Tweedie
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Species ◽  
Vegetation Index ◽  
Plant Biomass ◽  
Plant Cover ◽  
Strongly Correlated ◽  
Area Index ◽  
Spectral Bands ◽  
Biomass Plant

Here we investigate relationships between NDVI, Biomass, and Leaf Area Index (LAI) for six key plant species near Barrow, Alaska. We explore how key plant species differ in biomass, leaf area index (LAI) and how can vegetation spectral indices be used to estimate biomass and LAI for key plant species. A vegetation index (VI) or a spectral vegetation index (SVI) is a quantitative predictor of plant biomass or vegetative vigor, usually formed from combinations of several spectral bands, whose values are added, divided, or multiplied in order to yield a single value that indicates the amount or vigor of vegetation. For six key plant species, NDVI was strongly correlated with biomass (R2 = 0.83) and LAI (R2 = 0.70) but showed evidence of saturation above a biomass of 100 g/m2 and an LAI of 2 m2/m2. Extrapolation of a biomass-plant cover model to a multi-decadal time series of plant cover observations suggested that Carex aquatilis and Eriophorum angustifolium decreased in biomass while Arctophila fulva and Dupontia fisheri increased 1972-2008.

scholarly journals Plant colonization, succession and ecosystem development on Surtsey with reference to neighbouring islands

2014 ◽  
Vol 11 (19) ◽  
pp. 5521-5537 ◽  
Author(s):  
B. Magnússon ◽  
S. H. Magnússon ◽  
E. Ólafsson ◽  
B. D. Sigurdsson
Keyword(s):  
Species Richness ◽  
Plant Biomass ◽  
Vascular Plant ◽  
Plant Cover ◽  
Soil Formation ◽  
Plant Succession ◽  
Permanent Plots ◽  
Plant Colonization ◽  
Nutrient Input ◽  
Species Richness And Diversity

Abstract. Plant colonization and succession on the volcanic island of Surtsey, formed in 1963, have been closely followed. In 2013, a total of 69 vascular plant species had been discovered on the island; of these, 59 were present and 39 had established viable populations. Surtsey had more than twice the species of any of the comparable neighbouring islands, and all of their common species had established on Surtsey. The first colonizers were dispersed by sea, but, after 1985, bird dispersal became the principal pathway with the formation of a seagull colony on the island and consequent site amelioration. This allowed wind-dispersed species to establish after 1990. Since 2007, there has been a net loss of species on the island. A study of plant succession, soil formation and invertebrate communities in permanent plots on Surtsey and on two older neighbouring islands (plants and soil) has revealed that seabirds, through their transfer of nutrients from sea to land, are major drivers of development of these ecosystems. In the area impacted by seagulls, dense grassland swards have developed and plant cover, species richness, diversity, plant biomass and soil carbon become significantly higher than in low-impact areas, which remained relatively barren. A similar difference was found for the invertebrate fauna. After 2000, the vegetation of the oldest part of the seagull colony became increasingly dominated by long-lived, rhizomatous grasses (Festuca, Poa, Leymus) with a decline in species richness and diversity. Old grasslands of the neighbouring islands Elliđaey (puffin colony, high nutrient input) and Heimaey (no seabirds, low nutrient input) contrasted sharply. The puffin grassland of Elliđaey was very dense and species-poor. It was dominated by Festuca and Poa, and very similar to the seagull grassland developing on Surtsey. The Heimaey grassland was significantly higher in species richness and diversity, and had a more even cover of dominants (Festuca/Agrostis/Ranunculus). We forecast that, with continued erosion of Surtsey, loss of habitats and increasing impact from seabirds a lush, species-poor grassland will develop and persist, as on the old neighbouring islands.

Effects of Different Treatments of Pasture Restoration on Soil Trace Gas Emissions in the Cerrados of Central Brazil

2006 ◽  
Vol 10 (1) ◽  
pp. 1-26 ◽  
Author(s):  
Alexandrede S. Pinto ◽  
Mercedes M. C. Bustamante ◽  
Maria Regina S. S. da Silva ◽  
Keith W. Kisselle ◽  
Michel Brossard ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Microbial Biomass Carbon ◽  
Soil Bacterial Community ◽  
Trace Gas ◽  
Soil N ◽  
Water Addition ◽  
Wet Season ◽  
Gas Emissions ◽  
Trace Gas Emissions ◽  
Soil Bacterial

Abstract Planted pastures (mainly Brachiaria spp) are the most extensive land use in the cerrado (savannas of central Brazil) with an area of approximately 50 × 106 ha. The objective of the study was to assess the effects of pasture restoration on the N dynamics (net N mineralization/nitrification, available inorganic N and soil N oxide gas fluxes—NO and N2O), C dynamics (CO2 fluxes and microbial biomass carbon), and diversity of the soil bacterial community using denaturing gradient gel electrophoresis (DGGE) profiles. Sampling was done monthly on a farm in Planaltina, Goiás, Brazil (15°13′S, 47°42′W) from November 2001 to April 2002. Three areas of cerradão (dense cerrado) were converted to pasture (Brachiaria brizantha) in 1991, and after 8 years degradation was evident with the decreasing plant biomass production. Methods to restore these pastures were investigated for their sustainability, principally their effects on trace gas emissions. The pastures have been managed since 1999 as follows: 1) fertilized plot (N = 60 kg ha−1 yr−1, P = 12 kg ha−1 yr−1); 2) grass–legume plot, Brachiaria associated with a legume (Stylosanthes guianensis) with addition of P (12 kg ha−1 yr−1); and 3) a traditional plot without management. A fourth area of cerradão was converted to pasture in 1999 and was not managed (young pasture). Ammonium was the predominant inorganic N form in the soils (∼76 mg N kg−1) for all treatments throughout the study. In December 2001 a reduction in average soil N-NH4+ was observed (∼30 mg N kg−1) compared to November 2001, probably related to plant demand. All plots had high variability of soil N gases emissions, but during the wet season, the NO and N2O soil fluxes were near zero. The results of the water addition experiment made during the dry season (September 2002) indicated that the transition of dry to wet season is an important period for the production of N gases in the fertilized pasture and in the young pasture. Soil CO2 fluxes also increased after the water addition and the grass–legume plot had the highest increase in soil respiration (from ∼2 to 8.3 μmol m−2 s−1). The lowest values of soil respiration and microbial biomass carbon (∼320 mg C kg−1 soil) tended to be observed in the young pasture, because the superficial layer of the soil (0–10 cm) was removed during the conversion to pasture. Trace gas emissions measured after the water addition experiment corresponded to rapid changes in the soil bacterial community. The young pasture sample showed the lowest level of similarity in relation to the others, indicating that the bacterial community is also influenced by the time since conversion. This study indicates that the restoration technique of including Stylosanthes guianensis with B. brizantha increases plant productivity without the peaks of N oxide gas emissions that are often associated with the use of N fertilizers. Additionally, the soil bacterial community structure may be restored to one similar to that of native cerrado grasslands, suggesting that this restoration method may beneficially affect bacterially mediated processes.

The effects of living roots and arbuscular mycorrhiza fungi (AMF) on soil N2O emissions

2020 ◽  
Author(s):  
Yawen Shen ◽  
Tianle Xu ◽  
Biao Zhu
Keyword(s):  
Arbuscular Mycorrhiza ◽  
Phosphorus Content ◽  
Plant Biomass ◽  
Terrestrial Ecosystems ◽  
N2o Emissions ◽  
Net N Mineralization ◽  
N Addition ◽  
Unplanted Soil ◽  
Arbuscular Mycorrhiza Fungi ◽  
P Addition

<p>Living roots and arbuscular mycorrhiza fungi (AMF) are widespread in most terrestrial ecosystems and play an important role in ecosystem nitrogen (N) cycling. However, the influence of living roots and AMF on soil N<sub>2</sub>O emissions remains poorly understood. In this study, we conducted a pot experiment with ryegrass (Lolium perenne) growing in a greenhouse for three months with three factors: root and AMF presence (None or unplanted, Root or with roots, and Root+AMF or with roots colonized by AMF), two N addition levels (N0 and N1 with 0 and 50 mg N kg<sup>-1</sup> soil) and two P addition levels (P0 and P1, with 0 and 20 mg P kg<sup>-1</sup> soil).</p><p> </p><p>Our results showed that N addition didn’t have significant effect on N<sub>2</sub>O emission, however, we detected significant effects of Root and Root+AMF, particularly under P addition. Though the colonization of AMF didn’t significantly influence N<sub>2</sub>O emission, the presence of roots (Root and AMF+Root treatments) deceased N<sub>2</sub>O emission by 58%-67% compared with the None treatment. P addition increased (+134%) N<sub>2</sub>O emission from unplanted soil but decreased (74%-98%) N<sub>2</sub>O emission under planted soil regardless of AMF colonization. Moreover, there were no significant relationship between N<sub>2</sub>O emission and soil pH, NH<sub>4</sub><sup>+</sup>-N and net N mineralization. The lower N<sub>2</sub>O emission from rooted treatments were mainly due to the lower soil NO<sub>3</sub><sup>-</sup>-N (and MBN) content which might be immobilized by plant biomass, while the higher N<sub>2</sub>O emission from unplanted soil under P addition was attributed to increased soil available (r=0.760, P<0.01) and total (r=0.654, P<0.01) phosphorus content. We conclude that root presence and P addition played an important role in regulating N<sub>2</sub>O emission from P-limited soils.</p><p></p>

scholarly journals Inorganic carbon fluxes across the vadose zone of planted and unplanted soil mesocosms

2014 ◽  
Vol 11 (3) ◽  
pp. 4251-4299 ◽  
Author(s):  
E. M. Thaysen ◽  
D. Jacques ◽  
S. Jessen ◽  
C. E. Andersen ◽  
E. Laloy ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Vadose Zone ◽  
Inorganic Carbon ◽  
Plant Biomass ◽  
Dissolved Inorganic Carbon ◽  
Carbon Fluxes ◽  
Atmospheric Co2 ◽  
Carbon Dioxide Partial Pressure ◽  
Post Harvest ◽  
Unplanted Soil

Abstract. The efflux of carbon dioxide (CO2) from soils influences atmospheric CO2 concentrations and thereby climate change. The partitioning of inorganic carbon fluxes in the vadose zone between emission to the atmosphere and to the groundwater was investigated. Carbon dioxide partial pressure in the soil gas (pCO2), alkalinity, soil moisture and temperature were measured over depth and time in unplanted and planted (barley) mesocosms. The dissolved inorganic carbon (DIC) percolation flux was calculated from the pCO2, alkalinity and the water flux at the mesocosm bottom. Carbon dioxide exchange between the soil surface and the atmosphere was measured at regular intervals. The soil diffusivity was determined from soil radon-222 (222Rn) emanation rates and soil air Rn concentration profiles, and was used in conjunction with measured pCO2 gradients to calculate the soil CO2 production. Carbon dioxide fluxes were modelled using the HP1 module of the Hydrus 1-D software. The average CO2 effluxes to the atmosphere from unplanted and planted mesocosm ecosystems during 78 days of experiment were 0.1 ± 0.07 and 4.9 ± 0.07 μmol carbon (C) m−2 s−1, respectively, and largely exceeded the corresponding DIC percolation fluxes of 0.01 ± 0.004 and 0.06 ± 0.03 μmol C m−2 s−1. Post-harvest soil respiration (Rs) was only 10% of the Rs during plant growth, while the post-harvest DIC percolation flux was more than one third of the flux during growth. The Rs was controlled by production and diffusivity of CO2 in the soil. The DIC percolation flux was largely controlled by the pCO2 and the drainage flux due to low solution pH. Plant biomass and soil pCO2 were high in the mesocosms as compared to a standard field situation. Our results indicate no change of the cropland C balance under elevated atmospheric CO2 in a warmer future climate, in which plant biomass and soil pCO2 are expected to increase.

Fluoride Contaminated Groundwater

2020 ◽  
pp. 31-54
Keyword(s):  
Groundwater Quality ◽  
Plant Biomass ◽  
Block Design ◽  
Translocation Factor ◽  
Principal Component ◽  
Quality Parameters ◽  
High Accumulation ◽  
Randomized Block Design ◽  
Highly Correlated ◽  
Component Map

In this chapter, the authors explore Fluoride (F) in groundwater as a major issue of water pollution. Geo-statistical analysis of groundwater quality in Newai Tehsil (India) has been done in order to identify the possible spatial distribution of water quality parameters and to assess the spatial dependence of water properties with the help of principal component analysis (PCA) structure. Two types of maps (spatial map and principal component map) of groundwater quality have been developed. A field experiment was conducted to investigate the effect of different Fluoride (F) concentration combined with Pseudomonas fluorescens (P.F) on Prosopis juliflora plant. The field design was used as completely randomized block design with three replicates. The study revealed that parameters were found to be positively and highly correlated with principal component. Low and high values (with their acceptable limit) have also been displayed over each spatial map. Plants treated with P. fluorescens showed the highest F uptake in root, shoot, and leaves tissues were 33.14, 19.41, and 15.15 mg kg-1 after 120 days, respectively. Both total bioaccumulation factor (BF) and translocation factor (TF) were obtained above one (i.e., 1.06 and 1.04). This confirmed the high accumulation and translocation of F in plant tissues. The F uptake efficiency of plant was enhanced to 67.7%, and plant biomass was increased to 57.03%. The present study will be beneficial for researchers working towards further improvement of F phytoremediation technology.

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