3/7/2019 OUTLINE PREDICTING THE MOST SUITABLE MANGROVE SPECIES AS - - PDF document

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PREDICTING THE MOST SUITABLE MANGROVE SPECIES AS A NATURAL DEFENSE FOR FIJIAN COASTAL COMMUNITIES

SC356 2018 (Group GS 4) Elizabeth Ravonu Jason Tigarea Kolora Qativi

OUTLINE

• Introduction
• Project Aims and Objectives
• Research Question and Hypothesis
• Methodology
• Data Collection and Analysis
• Results and Discussion
• Conclusion

INTRODUCTION

• Mangroves provide the best form of defense for coastal communities

(Alongi, D. M., 2008; Rogers et al., 2016).

• This research identifies the mangrove species most suitable for coastal

protection in Fiji.

• Negative impact of seawalls on coastal environments and livelihoods of

coastal communities in Fiji. According to Betzord and Mohamed (2017): “… seawalls and other coastal defense structure are controversial, especially in a SIDS context, where they typically are poorly designed and constructed thus tend to increase rather than decrease erosion and are

• ften unable to prevent flooding.”
• Conversely, mangroves provide natural protection where processes of

ecological succession mean more the resilient species adapt to local conditions.

AIM

• Identify mangrove species from the coastal shoreline to the inland using

GIS tools and field surveying at 3 sites: (1)Ellington wharf, (2) Naboutini village and (3) Nasese.

• Identify the location and growth characteristics of each species to

determine which are most suitable as a natural coastal defense

OBJECTIVES

• Identify mangrove species occurrence using transects
• Interpret the mangrove species tree by growth
• Identifying the most suitable mangrove species to be the natural

coastal defense using the results

RESEARCH QUESTION AND BACKGROUND

 Research Question Which Mangrove Species are most suitable for coastal defense for Fijian coastal communities?

• According to Tomlinson (2011) mangroves are highly adaptable plant

families that occur in the coastal environment, and act as a natural barrier providing protection for coastal communities.

• Species that are dominant throughout the coastal shoreline are the most

suitable species to act as a barrier for coastal communities.

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RESEARCH HYPOTHESIS

 Null Hypothesis All mangrove species can act as effectively as the other as a natural coastal defense for Fijian coastal communities and species are equally distributed in their spatial extent  Alternative Hypothesis Mangrove species Rhizophora stylosa (scientific name) is the most dominant and suitable for providing a natural coastal defense for Fijian coastal communities

METHODOLOGY

 Study Sites 3 selected sites:

• 1. Ellington Wharf 2. Naboutini
• 3. Nasese

METHODOLOGY

 Data collection

• Transect method

Purpose: record tree species occurrence along a path

• Diameter breast height (dbh)

Purpose: “sweet spot” on a tree to calculate growth and volume

DATA COLLECTION

 Transect Method

• Determine spatial extent of the mangrove

boundary

• Transect line with starting and ending point
• 30m between transects
• subplots of 10m x 10m per transect
• Identify mangrove species within the subplots

DATA COLLECTION

 Measuring dbh for each tree mangrove species

• Measure dbh for identified species (in

centimeter units)

• Measuring tape used to measure dbh

 Data for 3 sites

• Data for Ellington wharf and Naboutini

village as provided by Prof. Nicholas Rollings

• Group field work and survey data

collection at Nasese site

DATA COLLECTION

 All species identified at the 3 sites

• Rhizophora samoensis
• Rhizophora stylosa
• Rhizophora x selala
• Bruguirea gymnorhiza
• Excoecaria agallocha

* Mangrove ID Book → field guide book describing properties of mangrove species (Tuiwawa, S.H., Skelton, P. A., & Tuiwawa, M. V. )

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DATA INTERPRETATION

 Outcome of data collection

• data compiled and finalized to specific

species and measurements  Software

• excel file → species and dbh values (total

value)

• PSPP → ANOVA test for 5 species found
• relationship between the species (level of

significance) to determine

excel file w ith data ANOVA test output

RESULTS

 Mean and standard error

• relationship between species
• higher the population (N) smaller

the standard error

• Rhizophora stylosa, Rhizophora x

selala, Rhizophora samoensis and Bruguiera gymnorhiza can be related due to smaller standard error

• Excoecaria agallocha cannot be

related to other species due to higher standard error

RESULTS

 5 species → perform ANOVA test due to get significant differences between 2 species  Output significance for between group (species) is less than 0.05  Significance differences between the Bruguiera gymnorhiza, Rhizophora stylosa, Rhizophora x selala and Rhizophora samoensis  Excoecaria agallocha is not significant

DISCUSSION

 Level of significance is 0.05  Significance level of Bruguiera gymnorhiza, Rhizophora stylosa, Rhizophora x selala and Rhizophora samoensis are all equal to 0.000  Excoecaria agallocha has significance value of 0.382  4 species show siginificance whereas for 1 species shows non-significance  Accept the null hypothesis → All mangrove species can act as the natural coastal defense for Fijian coastal communities and species are equally distributed in their spatial extent

CONCLUSIONS

 Five Species were identified at the three sites  ANOVA test shows the significance level of each species  All species can act as the natural barrier  By providing a natural barrier mangroves benefit the local community (through coastal protection and livelihood opportunities) and also the marine ecosystem

RECOMMENDATION

 To encourage the Fiji Government and local communities to preserve and protect mangroves  By providing a natural barrier, mangroves benefit the local community (through coastal protection and livelihood

• pportunities) and also the marine ecosystem

 Extending this research to additional sites across Fiji will provide a more comprehensive baseline of data to compare with the results described here.

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REFERENCES

• Alongi, D. M. (2008). Mangrove forests: Resilience, protection from tsunamis, and responses

to global climate change. Estuarine, Coastal and Shelf Science, 76(1), 1–13. https://doi.org/10.1016/j.ecss.2007.08.024

• Rogers, K., Boon, P. I., Branigan, S., Duke, N. C., Field, C. D., Fitzsimons, J. A., … Saintilan, N.

(2016). The state of legislation and policy protecting Australia’s mangrove and salt marsh and their ecosystem services. Marine Policy, 72, 139–155. https://doi.org/10.1016/j.marpol.2016.06.025

• Mangrove and Seagrass Species of Fiji. Tuiwawa, S.H., Skelton, P. A., & Tuiwawa, M. V.

 Corral-Rivas, J., Barrio-Anta, M., Aguirre-Calderón, ,O.A., & Diéguez-Aranda, U. (2007). Use

• f stump diameter to estimate diameter at breast height and tree volume for major pine

species in el salto, durango (mexico). Forestry, 80 (1) Pp.29-40, 2007, Retrieved from http://ezproxy.usp.ac.fj/login?url=https://search.proquest.com/docview/925439441?acco untid=28103