Paper · 2026 · Nigerian Journal of Soil Science

Comparative Assessment of Indigenous and Exotic Tree Species for Phytoremediation of Heavy Metal-Contaminated Soils in Southwest Nigeria.

Olayiwola Victor

4
claims
4
verbatim quotes
0
citations
2
research areas
—
Not open access

Abstract

The growth and overall health of a tree can be negatively impacted by various contaminants, and the specific concentration at which these effects occur can differ from one tree species to another, as well as between different contaminants. This study aimed to explore the phytoremediation potential of Tectona grandis, Gmelina arborea, Shorea roxburghii, Terminalia ivorensis, and Terminalia superba in soils contaminated with heavy metals from the Forestry Research Institute of Nigeria (FRIN) in Ibadan, Oyo State, and Ijebu-Igbese in Ogun State. The heavy metals analyzed included copper, zinc, manganese, lead, and cadmium. The soil was contaminated at three different levels: double the permissible level (twice the tolerable limit in soil) with cadmium at 0.006 g/kg, copper at 0.2 g/kg, lead at 0.4 g/kg, zinc at 0.6 g/kg, and manganese at 6 g/kg, triple the permissible level (three times the tolerable limit) with cadmium at 0.009 g/kg, copper at 0.3 g/kg, lead at 0.6 g/kg, zinc at 0.9 g/kg, and manganese at 9 g/kg, and a control group with no contamination. Particle size analysis revealed that the soil was loamy sand with a pH range of 5.69 to 6.44. Gmelina arborea exhibited significantly greater height (176.00 cm) and collar diameter (29.78 mm) compared to the other species, while Terminalia ivorensis produced a higher number of leaves. In conclusion, Gmelina arborea seems to demonstrate a greater tolerance to higher levels of contamination than the other species studied, indicating that it may have a natural ability to adapt to adverse conditions.

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Claims 4

Observationobservedoriginal resultpositivesignificant (as stated)measured

Claim · model-written summary

Gmelina arborea had significantly greater height than the other studied species.

Taxon
Gmelina arboreaGmelina arboreae0
Outcome
heighte0
Direction
greatere0
Value
176.00 cme0
Comparator
other speciese0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Gmelina arborea
Gmelina arborea · Taxon · picture from its Wikimedia Commons categoryObsidian Soul · CC BY-SA 3.0 · Wikimedia Commons ↗

Verbatim

e0

“Gmelina arborea exhibited significantly greater height (176.00 cm) and collar diameter (29.78 mm) compared to the other species, while Terminalia ivorensis produced a higher number of leaves.”

✓ located verbatim in the source · abstract, characters 1164–1355 · show in text ↑
Observationobservedoriginal resultpositivesignificant (as stated)measured

Claim · model-written summary

Gmelina arborea had significantly greater collar diameter than the other studied species.

Taxon
Gmelina arboreaGmelina arboreae0
Outcome
collar diametere0
Direction
greatere0
Value
29.78 mme0
Comparator
other speciese0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Gmelina arborea
Gmelina arborea · Taxon · picture from its Wikimedia Commons categoryObsidian Soul · CC BY-SA 3.0 · Wikimedia Commons ↗

Verbatim

e0

“Gmelina arborea exhibited significantly greater height (176.00 cm) and collar diameter (29.78 mm) compared to the other species, while Terminalia ivorensis produced a higher number of leaves.”

✓ located verbatim in the source · abstract, characters 1164–1355 · show in text ↑
Observationobservedoriginal resultpositivemeasured

Claim · model-written summary

Terminalia ivorensis produced a higher number of leaves.

Taxon
Terminalia ivorensisTerminalia ivorensise0
Outcome
number of leavese0
Direction
highere0

Verbatim

e0

“Gmelina arborea exhibited significantly greater height (176.00 cm) and collar diameter (29.78 mm) compared to the other species, while Terminalia ivorensis produced a higher number of leaves.”

✓ located verbatim in the source · abstract, characters 1164–1355 · show in text ↑
Observationauthor interpretationoriginal resultpositivemeasured

Claim · model-written summary

The authors interpret Gmelina arborea as more tolerant of higher contamination levels than the other species.

Taxon
Gmelina arboreaGmelina arboreae0
Outcome
tolerancee0
Direction
greatere0
Qualifier
higher levels of contaminatione0
Comparator
other species studiede0

Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Gmelina arborea
Gmelina arborea · Taxon · picture from its Wikimedia Commons categoryObsidian Soul · CC BY-SA 3.0 · Wikimedia Commons ↗

Verbatim

e0

“In conclusion, Gmelina arborea seems to demonstrate a greater tolerance to higher levels of contamination than the other species studied, indicating that it may have a natural ability to adapt to adverse conditions.”

✓ located verbatim in the source · abstract, characters 1356–1571 · show in text ↑