Comparative study of Conocarpus erectus and Phoenix dactylifera as plant biomonitors of particulate matter pollution in Kuwait over three residential areas
This study evaluated two widely distributed ornamental species, buttonwood and palm for their effectiveness as biomagnetic monitors over three different land use classes (urban, suburban and industrial land classes).Three experimental sites were classed based on functionalities, population numbers and vicinity to emission sources (Al-Mansouriya ‘urban’ residential area, Al-Shuwaikh Residential area ‘industrial' and Al-Rumaithya ‘suburban’ residential area. Date palm and buttonwood were selected as they are easily identifiable and widely distributed throughout Kuwait’s landscape. Sampling was conducted in September 2017 and continued for a month. At each selected study site, 100 samples of both species were randomly selected and collected. Sampling height was not specified for this experimental set up, as it was not the main goal of this research. Each sample consists of five leaves from the same randomly chosen tree. Leaves were selected on: size similarity, visual absence of abnormalities or signs of nutritional deficiencies, using a 3m telescopic pruning lopper. Leaves were selected at an azimuth angle of 70 degrees. Plants, coordinates, height, distance from the nearest road and distance from the closest plant were recorded. A variety of magnetic measurements were applied to the leaf samples to enable the quantification of magnetic concentration within selected sites and also identify grain size variations and magnetic mineralogy. Prior to magnetic analysis Image J software was used to determine total surface area (cm2) to attain NRM, SIRM, HIRM values normalized for leaf area. Samples were then air dried for 5 days, packed in A4 size cling film under went magnetic measurement using a using an AGICO magnetometer. Leaf abaxial and adaxial micro-morphological characteristics were analyzed using scanning electron microscopy (SEM) imaging using an environmental scanning electron microscope (FEG-ESEM) equipped with an energy dispersive X-Ray (EDX) detector. Descriptive statistics (SPSS, (21.0)). The rest of the Statistical analyses were conducted using (R 3.5.1) software. Kolmogorov-Smirnov normality test (K-S) was applied to determine the most suitable statistical test. A General Linear Model (GLM) analysis of variance (ANOVA) was employed to determine the interaction between the two subject factors: tree species and land class use assess main effects and interactions . For multiple comparisons, Bonferroni´s tests were applied. A Multivariable model was used adjust and obtain true effects of variables. An (ANCOVA) model was applied to determine significant difference between variables and assess their effects on parameters. Additionally, the effects of species and land class as well as interactions terms were adjusted and corrected. One-way Anova models assessed homogeneity of the land classes and species. Spatial variation of magnetic parameters was determind by Inverse Distance Weighted technique (IDW) using ArcGIS.