Implications of crude oil pollution on natural regeneration of plant species in an oil-producing community in the Niger Delta Region of Nigeria

Abstract

The study evaluated the impact of crude oil pollution on natural regeneration of plant species in a major oil-producing community in the Niger Delta region of Nigeria. Three sites-unpolluted site (US), polluted and untreated site (PUS), and polluted and treated site (PTS)-were purposively chosen for the study. The seedling emergence method was used to evaluate soil seed banks in the various sites at two depths, 0 to 10 cm and 10 to 20 cm. Woody-plant species richness, abundance, and diversity were higher in the US seed bank than in the PUS and PTS seed banks. The highest number of non-woody plants was observed in the US, followed by the PTS, and then the PUS. Both species richness and diversity of non-woody plants were highest at the US, followed by the PUS, and lowest in the PTS. Woody species in the US seed bank were 87.5% and 80% dissimilar with those of the PUS and PTS at 0-10 cm and 10-20 cm respectively. No variation was observed between woody species in the PUS and PTS seed banks. Non-woody species at 0−10 cm US seed bank were 73.08% dissimilar with those of PUS at the two soil depths and 81.48/88.46% dissimilar with those of the 0-10/10-20 cm of the PTS respectively. At 10-20 cm, non-woody species of the US were 69.66% dissimilar with those from each of the two soil depths in PUS; and 73.91/81.82% dissimilar with those of 0-10/10-20 cm of the PTS respectively. Non-woody species variation between the PUS and PTS was higher at 10-20 cm than 0-10 cm. The poor seed bank attributes at the polluted sites demonstrates that crude oil pollution negatively affected the natural regeneration potential of the native flora because soil seed banks serve as the building blocks for plant succession. Thorough remediation and enrichment planting are recommended to support the recovery process of vegetation in the polluted areas.

Desert Vegetation Forty Years after an Oil Spill

“…Gazelle activity and feces have been observed in the contaminated area during the field work, even in the area affected by the recent oil spill in 2014 (personal observation); thus, enough fertile Acacia seeds should have been available throughout. Inhibition of germination by crude oil or its compounds has been reported before (Adam and Duncan, 2002;Besalatpour et al, 2008;Chima and Vure, 2014), and, like in Evrona, some species showed higher vulnerability than others (Chaîneau et al, 1997). A third scenario-which fits the pattern observed with S. cyclophylla-is that seeds germinate but that seedling growth is inhibited, as was shown for Brassica napus L. and Trifolium repens L. (Besalatpour et al, 2008) and Hordeum vulgare L. (Li et al, 1997).…”

“…The similarity in composition of perennial plants between the oil-contaminated area and the reference areas suggests that the plant community has either not been affected by the oil spill or has managed to recover within the 40 yr subsequent to it. In contrast to this result, other scholars documented persistent (after 1 to 20 yr) changes in plant community composition as a consequence of contamination with petroleum hydrocarbons (Cowell, 1969;Hussein and Terry, 2002;Chima and Vure, 2014). The different result obtained from Evrona may be due to different site conditions or the long time period that has passed since the 1975 oil spill, which may have allowed plants to recover.…”

“…Petroleum hydrocarbons have been found to have a particularly high negative impact on recruitment (Besalatpour et al, 2008; Chima and Vure, 2014), understood as the process by which new individuals are added to a population, including seed germination, seedling survivorship, and seedling growth (Eriksson and Ehrlén 2008). Greenhouse experiments on eight different species of desert plants on oil‐contaminated soil showed no effects of soil contamination on germination; however, seedling mortality was higher while seedling growth was reduced (Zhang et al, 2013).…”

An Exploratory Study on the Effect of Petroleum Hydrocarbon on Soils Using Hyperspectral Longwave Infrared Imagery

“…It mainly occurs through oil spills, leaks, and accidents due to system failures, human errors, or negligence. The presence of crude oil in the environment can be hazardous to humans and has negative effects on the natural environment [1][2][3][4]. Petroleum hydrocarbons (PHCs) are compounds found in crude oil comprised of carbon and hydrogen bonds.…”

Normalized Difference Vegetation Vigour Index: A New Remote Sensing Approach to Biodiversity Monitoring in Oil Polluted Regions

“…High NDVVI values extracted from predsites following implementation of the best performing model contrasted with the very low NDVI values and suggest that the new index is more capable of detecting vegetation presence than the NDVI in oil polluted regions. Due to the adverse effect of oil pollution on vegetation (reduced growth [165][166][167] and increased mortality [168][169][170], the NDVVI designed to have maximum sensitivity to soil TPH, appears to be a more suitable index to measure vegetation characteristics because of its ability to detect even sparse areas of vegetative growth/presence. Furthermore, the NDVVI variants successfully predicted the diversity indices for the randomly selected sites from the satellite image of the study area.…”