Answer the following two questions – briefly explain and justify your answers.

1:Phytoextraction of potentially toxic elements from soils has been suggested as a possible means of cleaning up contaminated land. You have calculated the fractions of As, Zn and K contained in ‘grass’ (Fplant) at both grassland and woodland sites. If all the ‘grass’ were cut and completely removed from grassland and woodland once each year this fraction would be removed from the soil. How many years would it take to remove 50% of the original As, Zn and K concentrations (as measured in 2018) from the soils? (25%)

275 words

2:Currently the standing biomass of trees at Bagworth Heath is rather low. If the trees grow vigorously and standing biomass of 40 kg m-2 is achieved by 2100, what will be the average C sequestration rate in the Bagworth Heath woodlands (in kg C m-2 y-1) between now and 2100, assuming present day carbon concentrations in the soil remain the same? Given that the average UK citizen emits approximately 11 tonnes CO2 per year, approximately how many people’s CO2 emissions could be offset by tree growth at Bagworth Heath (area = 13 hectares)? (25%)

275 words

Concentrations of arsenic, zinc and potassium in soil and vegetation samples

Your soil and plant samples have been analysed for arsenic, zinc and potassium. You will find the data obtained on the worksheet ‘Elemental Analysis’ with the following numbering system.
Group / sample identification Sample No. Group / sample identification Sample No.
Group1 Grassland Veg 1.1 Group4 Grassland Veg 4.1
Group1 Woodland Veg 1.2 Group4 Woodland Veg 4.2
Group1 Woodland Tree Tissue 1.3 Group4 Woodland Tree Tissue 4.3
Group1 Grassland Topsoil 1.4 Group4 Grassland Topsoil 4.4
Group1 Grassland Subsoil 1.5 Group4 Grassland Subsoil 4.5
Group1 Woodland Topsoil 1.6 Group4 Woodland Topsoil 4.6
Group1 Woodland Subsoil 1.7 Group4 Woodland Subsoil 4.7

Group2 Grassland Veg 2.1 Group5 Grassland Veg 5.1
Group2 Woodland Veg 2.2 Group5 Woodland Veg 5.2
Group2 Woodland Tree Tissue 2.3 Group5 Woodland Tree Tissue 5.3
Group2 Grassland Topsoil 2.4 Group5 Grassland Topsoil 5.4
Group2 Grassland Subsoil 2.5 Group5 Grassland Subsoil 5.5
Group2 Woodland Topsoil 2.6 Group5 Woodland Topsoil 5.6
Group2 Woodland Subsoil 2.7 Group5 Woodland Subsoil 5.7

Group3 Grassland Veg 3.1 Group6 Grassland Veg 6.1
Group3 Woodland Veg 3.2 Group6 Woodland Veg 6.2
Group3 Woodland Tree Tissue 3.3 Group6 Woodland Tree Tissue 6.3
Group3 Grassland Topsoil 3.4 Group6 Grassland Topsoil 6.4
Group3 Grassland Subsoil 3.5 Group6 Grassland Subsoil 6.5
Group3 Woodland Topsoil 3.6 Group6 Woodland Topsoil 6.6
Group3 Woodland Subsoil 3.7 Group6 Woodland Subsoil 6.7

Elemental concentrations obtained for As, Zn and K in soil and plant samples are reported in mg kg-1 on a dry weight basis.

Using the concentrations of As, Zn and K in soil and plant samples you can calculate the corresponding soil-plant concentration ratios (CRs).

It is reasonable to assume that herbs and trees absorb most of the elements found in their tissues from the upper part of the soil profile. Therefore, when calculating CRs use the topsoil concentrations only.



CRplant = the soil-plant concentration ratio (dimensionless)
CRtree = the soil-tree concentration ratio (dimensionless)
Cplant = the concentration of an element within the plant tissues (mg kg-1)
Ctree = the concentration of an element within the tree tissues (mg kg-1)
Csoil = the concentration of the same element within the topsoil (mg kg-1)

Organic carbon content of soil and vegetation samples

The organic carbon content of the soil samples (not vegetation) has been estimated based on the mass lost after combustion overnight at 500?C. This ‘Loss on Ignition’ value has been used to calculate the organic carbon content, CORG, in g kg-1.

Conveniently, approximately 50% of the dry mass of wood consists of carbon so the concentration of carbon within a tree’s wood (dry) is assumed to be 500 g kg-1 DW. For the ‘grass’ the concentration of carbon can be assumed to be 450 g kg-1 DW.

Though the carbon content of vegetation is not derived from the soil (actually by photosynthetic fixation of atmospheric C) it is still convenient for our purposes to calculate a soil-plant concentration ratio for C, in the same way as we did for As, Zn and K.

In situ bulk density and depth of topsoil

The in situ bulk densities of topsoil in grassland and woodland areas which have been calculated using your samples are presented in kg m-3 (on a dry weight basis) in the worksheet ‘Soil Data’ (NB. bulk densities only presented for topsoils).

In the same worksheet you will find the depth of topsoil (down to the topsoil-colliery spoil boundary) in m.

Standing Biomass

The dry standing biomass of grassland and woodland vegetation is provided on the ‘Vegetation Data’ worksheet in kg m-2.

The dry standing biomass of trees, which is calculated using the Forestry Commission Mensuration Tables, is also presented on the ‘Vegetation Data’ worksheet, in kg m-2.

Data Presentation

Using the data provided in Bagworth Heath Student Data 15Feb18.xlsx you should calculate and tabulate median values for the following data for presentation in your report.

Concentrations (dry weight basis) of arsenic, zinc, potassium and carbon in soil and vegetation samples.
Concentration ratios for each element for ‘grass’ and tree tissues (calculate individual CRs using each group’s data, then calculate median CRs from these 6 replicate values).
In situ bulk densities of topsoils (subsoil bulk density was not measured).
Standing biomass of ‘grass’ and trees.

Look at your tabulated data critically and ask yourself if the values look reasonable. If any data appear odd (eg. very high or very low values, one element very different to the others), check through the raw data in the spreadsheet and re-check your calculations.

Mass Balance Calculations

When you are satisfied that you have calculated everything correctly use the median values you tabulated previously to calculate the total mass of As, Zn, K and C in the soil-vegetation system at both the grassland and woodland sites, as follows.


Mtot = total mass of element in the soil plus vegetation expressed on a spatial
(ground area) basis (mg m-2)
Csoil = the measured concentration of element in the top soil (mg kg-1 DW)
? = the depth of topsoil (m)
?soil = the dry bulk density of the topsoil (kg m-3)
CRtree = the concentration ratio for the element in tree tissue
CRplant = the concentration ratio for the element in ‘grass’ tissue
Mtree = the standing biomass of tree tissue (kg m-2)
Mplant = the standing biomass of ‘grass’ tissue (kg m-2)

As a check on your arithmetic, calculate the concentration of element in the top soil as follows, using the Mtot value you obtained in the previous calculation.

If the Csoil value you calculate is not the same as the Csoil value that was measured then check your calculations.

Tabulate the calculated elemental masses (in mg m-2¬¬, g m-2¬¬ or kg m-2¬¬, as appropriate).

Next, calculate the fraction of the total elemental mass which is present in the soil, ‘grass’ and tree compartments, respectively, using the following three equations.

As a final check on your calculations the sum of Fsoil, Ftree and Fplant should be 1.0, exactly.

present the results of your mass balance calculations graphically so that the reader (me!) can see immediately and clearly the relative distributions of As, Zn, K and C in the three component (soil, ‘grass’, tree) system at Bagworth Heath.

Sample Solution

Sample solution

Dante Alighieri played a critical role in the literature world through his poem Divine Comedy that was written in the 14th century. The poem contains Inferno, Purgatorio, and Paradiso. The Inferno is a description of the nine circles of torment that are found on the earth. It depicts the realms of the people that have gone against the spiritual values and who, instead, have chosen bestial appetite, violence, or fraud and malice. The nine circles of hell are limbo, lust, gluttony, greed and wrath. Others are heresy, violence, fraud, and treachery. The purpose of this paper is to examine the Dante’s Inferno in the perspective of its portrayal of God’s image and the justification of hell. 

In this epic poem, God is portrayed as a super being guilty of multiple weaknesses including being egotistic, unjust, and hypocritical. Dante, in this poem, depicts God as being more human than divine by challenging God’s omnipotence. Additionally, the manner in which Dante describes Hell is in full contradiction to the morals of God as written in the Bible. When god arranges Hell to flatter Himself, He commits egotism, a sin that is common among human beings (Cheney, 2016). The weakness is depicted in Limbo and on the Gate of Hell where, for instance, God sends those who do not worship Him to Hell. This implies that failure to worship Him is a sin.

God is also depicted as lacking justice in His actions thus removing the godly image. The injustice is portrayed by the manner in which the sodomites and opportunists are treated. The opportunists are subjected to banner chasing in their lives after death followed by being stung by insects and maggots. They are known to having done neither good nor bad during their lifetimes and, therefore, justice could have demanded that they be granted a neutral punishment having lived a neutral life. The sodomites are also punished unfairly by God when Brunetto Lattini is condemned to hell despite being a good leader (Babor, T. F., McGovern, T., & Robaina, K. (2017). While he commited sodomy, God chooses to ignore all the other good deeds that Brunetto did.

Finally, God is also portrayed as being hypocritical in His actions, a sin that further diminishes His godliness and makes Him more human. A case in point is when God condemns the sin of egotism and goes ahead to commit it repeatedly. Proverbs 29:23 states that “arrogance will bring your downfall, but if you are humble, you will be respected.” When Slattery condemns Dante’s human state as being weak, doubtful, and limited, he is proving God’s hypocrisy because He is also human (Verdicchio, 2015). The actions of God in Hell as portrayed by Dante are inconsistent with the Biblical literature. Both Dante and God are prone to making mistakes, something common among human beings thus making God more human.

To wrap it up, Dante portrays God is more human since He commits the same sins that humans commit: egotism, hypocrisy, and injustice. Hell is justified as being a destination for victims of the mistakes committed by God. The Hell is presented as being a totally different place as compared to what is written about it in the Bible. As a result, reading through the text gives an image of God who is prone to the very mistakes common to humans thus ripping Him off His lofty status of divine and, instead, making Him a mere human. Whether or not Dante did it intentionally is subject to debate but one thing is clear in the poem: the misconstrued notion of God is revealed to future generations.



Babor, T. F., McGovern, T., & Robaina, K. (2017). Dante’s inferno: Seven deadly sins in scientific publishing and how to avoid them. Addiction Science: A Guide for the Perplexed, 267.

Cheney, L. D. G. (2016). Illustrations for Dante’s Inferno: A Comparative Study of Sandro Botticelli, Giovanni Stradano, and Federico Zuccaro. Cultural and Religious Studies4(8), 487.

Verdicchio, M. (2015). Irony and Desire in Dante’s” Inferno” 27. Italica, 285-297.