Potential use of lichens as an indicator of air polution in urban airshed

It was hypothesized that large regions of urban vegetation would improveair quality and therefore the presence and abundance of lichen species.Environmental variables such as road densit

THAI NGUYEN UNIVERSITY

UNIVERSITY OF AGRICULTURE AND FORESTRY

NGO DUC GIANG

Potential use of Lichens as an indicator of air polution in urban airshed

BACHELOR THESIS

Study Mode: Full-time Major : Environmental science and management Facully : International Training and Developing centre Batch : 43 Advance Education Program

Thai Nguyen, 21/09/2015

Thai Nguyen University of Agriculture and Forestry

Degree Program Bachelor of Environment science and Management

Abstract:

The aim of this study was to assess the effectiveness lichens as an indicator of airpollution in the Perth Metropolitan Region (PMR) urban airshed Sample siteswere selected by identifying regions of high, medium and low NOx concentrationsbased on interpolation models using data from a previous study In each of theseregions 40 rooves were sampled for the presence and abundance of lichen species.Additionally sites within Kings Park and within 1km and 5km of the park wereselected It was hypothesized that large regions of urban vegetation would improveair quality and therefore the presence and abundance of lichen species.Environmental variables such as road density and vegetation density within aspecified distance of the sample location were collected for each of the samplesites using GIS Two way analysis of variance (ANOVA) was used to evaluate the

relationship between lichen abundance at each site of sample and eachenvironmental variable Correlations between lichen abundance and eachenvironmental variable at each site were also undertaken Vegetation cover wassignificantly associated with lichen abundance Generalized linear model toexamine those environment variables which best predicted a response in lichenabundance Results show that urban bushland has significantly associated withlichen abundance Other final conclusions were contrary to what have expectedthat areas containing greater NOxconcentration had higher lichen abundance, morelichen abundance with an increasing of road density.

The results of this investigation suggest that lichens have the potential to evaluatethe air quality in urban bushland but some others factors were influencing theresult

Keywords: Lichens, air quality, Perth Metropolitan Region, NOx

concentration, environment variables, vegetation cover

Date of submission: September 30, 2015

Supervisor’s signature

I would like to express my sincere thanks and appreciations to mysupervisor David Blake for his continuous support throughout the project, frominitial advice and every step of the way Furthermore, I am also my immenselygrateful to Prof Andrea Hinwood, Dr Duong Van Thao and Prof Will Stock forcomments that greatly improved the manuscript and for guiding me from veryfirst steps of this project

Many thanks and appreciations go to Emily Allen, Jonathon Boeyen fortheir contributions and supports throughout the process of this project

TABLE OF CONTENT

LIST OF FIGURES 1

LIST OF TABLES 3

LIST OF ABBREVIATIONS 4

PART I INTRODUCTION 5

1.1 Research rationale 5

1.2 Research’s objectives 8

1.3 Research questions and hypotheses 8

1.4 Limitations 8

1.5 Definitions 9

PART II: LITERATURE REVIEW 11

PART III: METHODS 13

3.1 Material 13

3.2 Methods 14

3.2.1 Study area 14

3.2.2 Sites selection 16

3.2.3 Sampling 18

PART IV: RESULT 24

4.1 Air quality categories 24

4.2 Environmental variables 27

4.3 Generalized linear model (GLZ) 33

PART V: DISCUSSION AND CONCLUSION 35

5.1.1 Air quality categories 35

5.1.2 Environmental variables 36

5.1.3 Generalized linear model 38

5.2 Conclusion 38

REFERENCES 41

LIST OF FIGURES

Figure 2.1: Lichens (light grey) living on rooves top of house……….…11

Figure 3.1: Perth metropolitan region……… ………16

Figure 3.2: NO x interpolations model at PMR using DER AQMS and HIMAQs study sites Interpolations were modeled using data collected in autumn………18

Figure 3.3: 300m Buffer vegetation regions……….20

Figure 3.4: 300m buffer road density regions……… 22

Figure 3.5: Distances from each house to Industrial facility………23

Figure 4.1: Mean and standard error bars of lichen abundance at High, Medium and Low concentration zones……… 27

Figure 4.2: Distribution of lichens in correlation with 300m road density in each house at Kings Park sites……… …30

Figure 4.3: Distribution of lichens in correlation with 300m road density at 1km buffer to Kings Park……… ……31

Figure 4.4: Distribution of lichens in correlation with proximity to industry at 1km buffer to Kings Park……….31

Figure 4.5: Distribution of lichens in correlation with vegetation cover at Low

Figure 4.6: Distribution of lichens in correlation with 500m road density at Medium

Figure 4.7: Distribution of lichens in correlation with proximity to industry at high

LIST OF ABBREVIATIONS

Regulation Air Quality MonitoringSites

PART I INTRODUCTION

1.1 Research rationale

Urbanization and industrial development impact significantly on air qualityglobally In urban areas that are surrounded by industry and that have high trafficuse; emissions to the atmosphere can be high The World Health Organizationindicates that air pollution is a major environment-related health threat to childrenand a risk factor for both acute and chronic respiratory disease (WHO 2015) Poorair quality can also impact the respiratory system, circulation and other organs of thebody (Kampa & Castanas, 2008) Health effects range from minor upper respiratoryirritation, chronic respiratory and heart disease, lung cancer and acute respiratoryinfections in children chronic bronchitis in adults and aggravating pre-existing heartand lung disease, or asthmatic attacks (Kampa & Castanas, 2008)

There are specific pollutants which are emitted to the atmosphere in highconcentrations They are: carbon monoxide, nitrogen dioxide, ozone and particles(PM10 PM2.5) (NEPM 1998) Most of the research on assessing the impacts of airpollution has been focused on human health However air pollutants also impactupon plants resulting in foliage disease or mortality of weak plants (Vike, 1999).The uptakes of phytotoxic amounts of metals have also been shown to affect enzymeinhibition (Assche & Clijsters, 1990) Plants can be injured when SO2 damages the

Conversely, vegetation may improve air quality Where large areas of naturalvegetation exist, air quality is likely to be better than in less vegetated areas (Nowak,

et al, 2006) This may be because if vegetation is present then it is less likely thatheavier polluting activities such as vehicles or industry are also present Vegetationhas also been shown to improve air quality by interrupting air flow and causing thedeposition of particulate matter (Vos, et al, 2013) In the United States, the studied

of Nowak, et al, (2006) showed that urban trees remove large amounts of airpollution such as O3, PM10, NO2, SO2, CO Moreover, grass on rooves (extensivegreen roof) can enhance the effectiveness of trees and shrubs in air pollution (Currie

& Bass, 2008)

Traditional methods to measure air quality are expensive because of the timeand effort involved in collecting and analyzing samples This often means that thethoroughness of air quality monitoring or sampling is compromised due to a lack ofavailable resources Hoek, et al, (2008) showed that passive sampling for NOx with

40 sites with 4 weekly survey cost 10000-12000 Euros or the same survey for active

PM sampling costs up to 30000 Euros Measurements of VOCs for example can cost

in the order of $600 per sample Or particle material equipment consisting of pumpand injectors used in the TRAPCA study was estimated to cost 5000 Euros (Brauer,

et al, 2002) However plants, especially lichens can be used as indicators of airpollutions in local areas

An alternative to expensive, traditional monitoring methods is the use of indicators As mentioned previously vegetation in particular, can be sensitive to poorair quality (Nowak, et al, 2006) Bioindicators are organisms that can be used foridentification, qualitative determination of human-generated environmental factors

bio-or evaluating the quality of the air cbio-orresponding with Environmental ImpactAssessment (EIA) (Conti & Cecchetti, 2001) “Lichens are the result of a symbioticassociation of a fungus or algae and are very sensitive to air quality” (Ahmadjian, V,1993) and have been used to monitor air pollution in many research fields such asmetal (Assche & Clijsters, 1990); ammonia emissions and nitrogen (Frati, et al,2007); organic air pollution (Van der Wat & Forbes, 2015); air pollution of lichensnear the Strathcona Industrial area Alberta (Elsinger, et al, 2007) For comparingthe air quality in the differences areas, we might see the quantity of lichens maychange and have abnormal symptoms

From the above mentioned studies, it is clear that lichens are sensitive tochanges in air quality and are commonly found in urban areas, but lichens are notcommonly applied in air quality assessments in Australia, particularly in urbanenvironments Lichens provide a cost-effective method of determining air quality asthey are easy to find out in bark of trees, clay rooves of house, but further research isrequired into their accuracy This study will determine the effectiveness of usinglichens as a bioindicator for air quality in an urban airshed

1.2 Research’s objectives

The objective of this research was to investigate the relationship betweenlichens presence on the roof tops of houses in residential areas in a gradient of airquality Specially, study aimed to investigate the relationship between lichenpresence and air quality levels across the PMR as well as from proximity to KingsPark Botanic Garden in central Perth

1.3 Research questions and hypotheses

The aim of this study is to investigate whether lichens are useful bio-indicators

of air pollution in an urban airshed? In order to achieve this aim, this study willinvestigate the following hypotheses:

Areas of poor air quality will result in lower lichen abundance

Areas containing large areas of vegetation will have higher lichen abundancecompared with areas containing less vegetation

Which environmental/land-use variables influence lichen abundance

1.4 Limitations

In an urban airshed, the presence and abundance of lichens may be affected by

a number of factors besides air quality These include the type of roof substrate, theage of the building/roof and whether the roof had been cleaned recently (surveyasked) The roof substrate will have an effect on the presence of lichens, asmentioned above the lichens could survive on the rooves with types of materialssuch as: clay (red color), asbestos-cement (gray color)

The modeling was based on road density over the study sites due to the factthat road density is a proxy measure for vehicle density over a given area; roaddensity however, may not be an accurate reflection of the traffic and emission in thatarea.

The data of this study was calculated based on 2 week sampling period forautumn, which may not be a true reflection of the annual air quality in that regiondue to seasonal variations

Several studies were state that good air quality will have higher lichensabundance but some lichens species need some chemicals to grow, but in certainamount Białońska and Dayan, 2005, has shown that the added of physodic acid isdefensing against stressed caused by pollution It means some type of lichens will bestronger with the existence of chemical substances

1.5 Definitions

measured in units of distance or time Abuffer is useful for proximity analysis

Regulation Air Quality Monitoring Sites

GIS Geographic information system.

An integrated collection ofcomputer software and data used to viewand manage information aboutgeographic places, analyze spatialrelationships, and model spatialprocesses A GIS provides a frameworkfor gathering and organizing spatial dataand related information so that it can bedisplayed and analyzed

PART II: LITERATURE REVIEW

“Lichens are the result of a symbiotic association of a fungus or algae and arevery sensitive to air quality” (Ahmadjian, V, 1993) Lichens absorb atmosphericmoisture gases and other components directly through thalli (Ahmadijian, V, 2012).Thallus are single cell or mass of cell not distinguish as stems, root or leaves(Ahmadijian, V, 2012) Most lichens are gray or brown when they dry but with wetthalli the color will be more or less green Lichens can live on trunk, bark of trees,rock or on the rooves of houses and they never stop growing in any condition, theyjust grow faster or slower during the time (Ahmadijian,V, 2012)

Figure 2.2: Lichens (light grey) living on rooves top of house

Unlike higher plants, lichens absorb water and nutrients through their surface

Ivanov & Boccardi, 2002) Correlations between high concentrations of emissions inair quality and decreased lichen presence/abundance is well documented (Elsinger,

et al, 2007) An investigation of lichens in the USA noted that lichen communitieswere strongly associated with vegetation cover (Root & McCune, 2012) Anotherinvestigation showed that lichens were sensitive to pollution caused by traffic andabundance declined significantly when close to roads (Llop, et al, 2012)

Furthermore, lichens can be accumulative bioindicators; accumulativebioindicators means that they have the ability to store contaminants in their tissuesand the host remains unharmed (Conti & Cecchetti, 2001)

Lichens have been used to monitor air pollution in many research fields inrural areas or highly focus on industrial zones such as: lichens can be used toidentify the type and possible sources of pollution (Jeran, et al, 2002) Frati, et al,.(2007) showed the diversity of nitrophytic lichens species was highly correlatedwith the concentration of NH3 and bark pH Moreover, essential informationrequired for ecological impact assessment, and waste management may be provided

by lichens (Paoli, et al, 2012)

The above studies have shown that lichens were successfully used to monitorair quality or assess the ecological impacts in rural or industrial zones but very fewstudies have focused on urban areas Urban airsheds are affected by road density andother environmental variable such as industrial emission, fire emission etc…

PART III: METHODS 3.1 Material

This study was designed to investigate the relationship between the presenceand abundance of lichens and different levels of air quality in PMR Perth peoplerequire and depend heavily on their vehicles for business or other demands This canrelease high amounts of air pollutants to urban airshed (Newman & Kenworthy,2006)

This study made use of visual inspection of roof tops using binoculars to countlichen presences/absences and GPS to record the location of each house This wasthe enable the use of GIS to investigate the relationship between lichen presence andenvironmental variables

This study was divided into three parts:

Using NOxinterpolations modeled for PMR: to categorize into regions of high,medium and low air pollution Additionally categorize into regions of 0km buffer,1km buffer and 5km buffer to Kings Park

Environmental variables: to examine the influence of road density, vegetationcover and proximity to industrial area, using GIS

Generalized linear model to examine the influence of environment variableswhich best predicted a response in lichen abundance

3.2 Methods

3.2.1 Study area

The study area was the metropolitan Perth area bounded by Joondalup in theNorth, Fremantle in the South and Midland in the East (Figure 3.1) Perth has a drysummer in the months of December, January and February with the weatherchanging in March, April and May to a cooler environment before winter in June,July and August, then the weather increases in temperature in September, Octoberand November (Rennie, et al, 2006).The PMR covers an area of 1,300 km2 and has

an estimated population of 1.6 million (Curtis 2006) PMR is reputation as one ofthe most car-dependent cities Car owner and use are the highest of all Australiancities with 723 vehicles per thousand people (Curtis 2006)

Figure 3.1: Perth metropolitan region

3.2.2 Sites selection

Sample sites were selected based on the interpolated model of air pollution(figure 3.2) Three major zones of air pollutions (high, medium, low) weredetermined by using GIS Zones of high, medium and low air quality exposurezones were determined based upon interpolated model levels of NOx using autumndata from the Department of Environment Regulation Air Quality Monitoring Sites(DER AQMS) and the Health in Men’s Air Quality (HIMAQs) study sites.Additionally, a proximity analysis study was performed in to the vicinity of KingsPark with sampling sites situated within the park as well as 1km and 5km’s from thepark perimeter Based on data from DER AQMS and HIMAQs sites, zones werecategorized as follows; the high exposure zones were arranged from 16.21 to 23.9

µg m-3NOxcontours, medium exposure zones falling between 8.51-16.2 µg m-3NOxcontours and low exposure zones for sites at < 8.5 µg m-3NOxcontours (Figure 3.2).Four sites per zone were selected for sampling at zones of high medium andlow NOx concentration (n=120), with ten control sites selected as in Kings ParkGarden (n=22) Four sites were selected within 1km of the perimeter of Kings Park(n=40) and three sites within 5km of Kings Park (n=30)

Figure 3.2: NOx interpolations model at PMR using DER AQMS and HIMAQs study

sites Interpolations were modeled using data collected in Autumn.

3.2.3 Sampling

Previous studies have shown that, lichens could live in materials with clay, oldconcrete tile (Garty & Delarea, 1988) or asbestos-cement (Favero-Longo, et al,2009) So at each site, ten residential houses with clay rooves or asbestos-cementrooves were selected randomly At each house, a count of the presence/absence oflichen by a cumulative area of 5x5 quarter roof tile will be taken The cumulativearea were measured from the bottom left of the roof starting at the 1sttile beneath theridge capping Those 5x5 roof tile were taken in the same position at each house toensure consistency between sample sites

* Environment variable by GIS

Vegetation (NDVI)

Surrounding greenness at each house of sample was determined using theNormalized Difference Vegetation Index (NDVI) derived fromfrom Landsat 7 ETMSCL-off data at a resolution of 30 m x 30 m The Landsat 7 ETM imagery obtainedwas cloud-free, captured during the daytime NDVI values fall within -1 to 1, wherevalues of ≤0 indicate areas with no green vegetation content and values approaching

1 indicate areas with high green vegetation density (Wade & Sommers, 2006) 300mand 500m buffer sizes were selected due to uncertainty in what the optimal buffersize is in identifying how vegetation may influence the presence/absence of lichens.This method was based on a study by Lalande, et al, (2012), using buffer from 30m,100m, 300m 500m up to maximum of 2400m were tested on land uses impacts on

water quality in Germany Due to limited time, and the quality of the PMR airshed,

it was assumed that small buffer would not have much pollution (Figure 3.3)

Figure 3.3: 300m Buffer vegetation regions