The Impact of Different Types of Hydrocarbon Disturbance on the Resiliency of Native Desert Vegetation in a War-Affected Area: A Case Study from the State of Kuwait.

Eman Kalander,Jawad Al-Bakri,Meshal M Abdullah

doi:10.3390/plants10091945

Abstract

This study assesses the impact of total petroleum hydrocarbon (TPH) concentration and soil parameters (heavy metals, chemical properties, and water-soluble boron) on the succession process of vegetation survival in the Al-Burgan oil field in Kuwait. A total of 145 soil samples were randomly collected from the three main types of hydrocarbon contamination, including dry oil lake (DOL), wet oil lake (WOL), and tarcrete. Sampling was also extended to noncontaminated bare soils that were considered reference sites. Remote-sensing data from Sentinel-2 were also processed to assess the level of contamination in relation to soil surface cover. The results showed that TPH concentration was significantly higher in WOL and DOL (87,961.4 and 35,740.6 mg/kg, respectively) compared with that in tarcrete (24,063.3 mg/kg), leading to a significant increase in soil minerals and heavy metals, greater than 50 mg/kg for Ba, and 10 mg/kg for V, Zn, Ni, and Cr. Such high concentrations of heavy metals massively affected the native vegetation’s resiliency at these sites (<5% vegetation cover). However, vegetation cover was significantly higher (60%) at tarcrete-contaminated sites, as TPH concentration was lower, almost similar to that in uncontaminated areas, especially at subsurface soil layers. The presence of vegetation at tarcrete locations was also associated with the lower concentration of Ba, V, Zn, Ni, and Cr. The growth of native vegetation was more likely related to the low concentration of TPH contamination at the subsurface layer of the soils in tarcrete sites, making them more suitable sites for restoration and revegetation planning. We concluded that further investigations are required to provide greater insight into the native plants’ phytoextraction potential and phytoremediation.

Highlights

Hydrocarbons and heavy metals are globally a common source of soil pollution. heavy metals are naturally present in the soil, geologic and anthropogenic activities increase the concentrations of these elements to amounts that are harmful to plants, animals, and human [1,2]
It covers all types of total petroleum hydrocarbon (TPH) contamination, including wet oil lake (WOL), dry oil lake (DOL), and tarcrete
The results showed that hydrocarbon contamination differed between bare soils and the three oil disturbance types, with TPH concentration being significantly higher at the TPH-contaminated sites than in the bare soil (Table 3)

Summary

Introduction

Heavy metals are naturally present in the soil, geologic and anthropogenic activities increase the concentrations of these elements to amounts that are harmful to plants, animals, and human [1,2]. Increasing the soil concentration of heavy metals can negatively impact physical, chemical, and geotechnical soil properties, leading to significant changes in physiological and biochemical processes of plant growth including the major soil elements and soil grain size [3,4]. Oil lakes are accumulations of spilled crude oil from damaged well-heads and pipelines in topographically low-lying sites within the oil fields. They are differentiated into WOL and DOL [7,8]. Soil contaminated by tarcrete is estimated to be in the order of 6% of Kuwait’s total area [7]

Methods

Results

Discussion

Conclusion