Geographical comparison of soil and vegetation variables between
sampling areas
Vegetation variables (vegetation height; quadrat-scale plant
alpha-diversity, SQ; abundance of three dominant
species: Table.1) showed significant differences between the seven
sampling areas, though no consistent pattern between oil-contaminated
areas and unaffected areas was apparent. Our survey results suggested
that Haloxylon salicornicum tended to be abundant at sampling
areas located in northern Kuwait, and was absent from southern sampling
areas. The other two species occurred in both northern and southern
areas and showed high frequency values at individual areas in both
regions of Kuwait.
A similar pattern of significant differences in soil moisture (though
all values were very low in absolute terms), Table 1, was seen between
the sampling areas, again apparently unrelated to the presence or
absence of oilfield installations.
In contrast, the TPH and individual PAHs in soil samples from the seven
areas showed a significant correlation to the presence of oilfield
installations within or close to the sampling areas (Table 1). The
semi-quantitative Oil Damage Score (ODS) indicates the severity of
oil-pollution in soils of impacted areas (Um Al-Aish, Sabriya, Burgan,
and Um Ghadair Oilfields), with greater ODS indicating more severe
contamination and lower ODS for the less impacted areas (Bahra, Sabah
Al-Ahmad Protected Area) and Um Al-Rros Military Base).