Floristic constitution and certain ecological characters of two selected natural mangrove vegetation in Kollam district, Kerala

Article Citation: Sekaran S, Nisha Raj S, Arun S and Paulsamy S

Floristic constitution and certain ecological characters of two selected natural mangrove vegetation in Kollam district, Kerala.

Journal of Research in Biology (2015) 5(5): 1763-1768

Jou

rn

al of R

esearch

in

Biology

Floristic constitution and certain ecological characters of two selected

natural mangrove vegetation in Kollam district, Kerala.

Keywords: Mangrove vegetation, Kollam district, Kerala.

ABSTRACT:

Mangroves are the important salt tolerant vegetation having more ecological and economical significances. In comparison to that of eastern coastal part, the western coastal region of Peninsular India comprises less area of mangroves. Therefore, establishing new mangroves in suitable habitats in this region is more essential to maintain the ecological processes in coastal landscape. To select the suitable mangrove species for newer areas of Kerala coast, a preliminary study on ecology was carried out in two natural mangrove vegetation at Ayiramthengu and Mandrothruthu, Kollam district. The study revealed that out of 34 (Ayiramthengu) and 24 (Mandrothruthu) species present, a sizable number of eight and six species respectively were true mangroves and adapted more prominently in their respective site indicated by higher Importance Value Index (IVI) and Relative Value of Importance (RVI) obtained by them. Therefore, these species are suggested for new formations of mangrove vegetation in the coastal regions of Kerala.

1763-1768 | JRB | 2015 | Vol 5 | No 5

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Authors:

Sekaran S1,

Nisha Raj S2,

Arun S1 and

Paulsamy S3

Institution:

1.Department of Botany,

Sree Narayana College,

Kollam-691 001, Kerala,

India.

2. PG Department of

Biotechnology, SAS, SNDP

Yogam College,

Konni- 689691,

Kerala, India.

3. Department of Botany,

Kongunadu Arts and

Science College,

Coimbatore – 641 029,

Tamil Nadu, India.

Corresponding author:

Sekaran S

Email Id:

Web Address: http://jresearchbiology.com/

documents/RA0506.pdf

Dates: Received: 07 Jan. 2015 Accepted: 07 Feb. 2015 Published: 30 June 2015

Journal of Research in Biology

An International Scientific Research Journal

ORIGINAL RESEARCH

ISSN No: Print: 2231 –6280; Online: 2231- 6299

INTRODUCTION

Mangroves are the interesting and characteristic

community in the shallow waters of tropical and

subtropical sea. They are the rich of productive

community but extremely sensitive and fragile (Odum,

1959). They protect the coastal line from heavy cyclones,

tidal thrusts, tsunami etc. (Saini et al., 2012; Sandilyan,

2013). Therefore, establishing mangroves in suitable

places of coastal line for the countries like India is more

essential to protect the landscape. To achieve this goal,

the species richness along with their perpetuation level

by knowing their ecological attributes is the basic

requisite to select the species for introduction in coastal

area. Despite the taxonomical works, no major study on

ecology has been done in the western coastal part of

Kerala for mangroves. To address this lacuna, the present

study was carried out to select the well established

species on the basis of ecological characters.

MATERIALS AND METHODS

Study area

The mangrove vegetation in two areas viz.,

Ayiramthengu and Mandrothruthu located in Kollam

district of Kerala were selected for the present study. The

former vegetation is situated in the coastal area and

spreads over an area of about 2.5ha and the later one is in

the backwater area of Kollam district, which covers an

area of about 1.5ha.

Methods

A one hectare plot was established in each study

area and then it was divided into 100 equal subsets each

with the size of 100m2. The sampling was made during

the month of April 2015 in both vegetations for the

quantitative ecological characters, (frequency and

abundance) of constituent species as per the methods of

Cottom and Curtis (1956). Quantitative ecological

attributes viz., density, basal area and Importance Value

Index (IVI), Relative Value of Importance (RVI) were

determined using standard methodology (Cintron and

Schaeffer-Novelli, 1984).

RESULTS AND DISCUSSION

In the vegetation of Ayiramthengu, a total

number of 34 species were enlisted which includes eight

true mangrove species and 26 mangrove associate

species. The frequency percentage was widely varied

between 20 and 100 across the species encountered

(Table 1). The plant species like Acrostichum aureum,

Bruguiera cylindrica, Cleome viscosa, Clerodendrum

inerme, Cyperus distans, Excoecaria agallocha,

Lumnitzera racemosa and Rhizophora mucronata

showed higher frequency percentage of 100 in the

community at the time of sampling. On the other hand,

the three species viz., Avicennia officinalis, Eupatorium

odoratum and Sonneratia caseolaris were exhibited

lower frequency value of less than 20 only. Density was

much varied between the species. Some species of higher

densities in the community were Cyperus distans (9.2

individuals/m2), Rhizophora mucronata (8.2 individuals/

m2) and Desmodium triflorum (7.0 indivuals/ m2). On the

other hand, the species, Sonneratia caseolaris showed

lower density of less than 0.50 individuals/m2 in this

vegetation.

The mangrove species, Rhizophora mucronata

registered higher basal cover (5875796mm2/100m2)

followed by the other species Avicennia officinalis

(3313376mm2/100m2) Excoecaria agallocha

(3312102mm2/100m2) and Bruguiera cylindrica

(2384713mm2/100m2) in the community of

Ayiramthengu. The associated species, Desmodium

triflorum recorded lowest basal area of less than

223mm2/100m2. The relative values of frequency,

density and dominance were also varied widely among

the species. Based on the importance value index, the

species like Avicennia officinalis, Rhizophora

mucronata, Bruguiera cylindrica and Excoecaria

agallocha were regarded as species of more ecological

Sekaran et al., 2015

1764 Journal of Research in Biology (2015) 5(5): 1763-1768

importance. On the other hand, the spices viz.,

Eupatorium odoratum, Andrographis echioides,

Desmodium triflorum, Eclipta alba, Euphorbia

geniculata, Hyptis capitata and Ipomoea biloba were

considered as species of poor ecological importance as

they secured lower IVI value.

In Mundrothuruth vegetation, altogether 24

species (6 true mangroves and 18 mangrove associates)

were enlisted. Among them, the two species, Acanthus

ilicifolius and Acrostichum aureum were recorded higher

frequency percentage (100%) followed by another

mangrove species, Excoecaria agallocha and two

associated non-mangrove species viz., Euphorbia hirta

and Hyptis suaveolens exhibited 80% frequency (Table

Journal of Research in Biology (2015) 5(5): 1763-1768 1765


Sl.

No.

Species

Fre-

quency

(%)

Density

(individu

als /m2)

Abun-

dance

Basal

cover

(mm2 /10

0m2 )

Relative

frequency

(%)

Relative

density

(%)

Relative

domi-

nance

(%)

IVI

1 Acalypha indica 60 2.6 4.33 2070 2.78 2.25 0.01 5.04

2 Acanthus ilicifolius 40 5.6 14.00 71337.6 1.85 4.84 0.41 7.10

3 Acrostichum aureum 100 3.4 3.40 389809 4.63 2.94 2.26 9.82

4 Aegiceras corniculata 80 4.8 6.00 749044.6 3.70 4.15 4.34 12.19

5 Aerva lanata 60 3.0 5.00 597.2 2.78 2.59 0.00 5.37

6 Andrographi sechioides 40 1.0 2.50 796.2 1.85 0.86 0.00 2.72

7 Avicennia officinalis 20 3.6 18.00 3313376 0.93 3.11 19.18 23.22

8 Boerhavia diffusa 80 5.2 6.50 37261.2 3.70 4.49 0.22 8.41

9 Bruguiera cylindrica 100 5.2 5.20 2384713 4.63 4.49 13.81 22.93

10 Cleome viscosa 100 5.2 5.20 16560.6 4.63 4.49 0.10 9.22

11 Clerodendrum inerme 100 2.8 2.80 222930 4.63 2.42 1.29 8.34

12 Crotalaria striata 40 3.2 8.00 10191 1.85 2.76 0.06 4.67

13 Crotalaria verrucosa 60 2.0 3.33 6369.4 2.78 1.73 0.04 4.54

14 Croton hirtus 60 1.8 3.00 1433.2 2.78 1.55 0.01 4.34

15 Cyperus distans 100 9.2 9.20 1831.2 4.63 7.94 0.01 12.58

16 Desmodium triflorum 60 7.0 11.67 223 2.78 6.04 0.00 8.82

17 Eclipta alba 80 4.8 6.00 15286.6 3.70 4.15 0.09 7.94

18 Eupatorium odoratum 20 0.8 4.00 10191 0.93 0.69 0.06 1.68

19 Euphorbia geniculata 40 1.2 3.00 5971.4 1.85 1.04 0.03 2.92

Table 1. Frequency, density, abundance and basal cover with their relative values and importance value

index (IVI) of species in the mangrove forest of Ayiramthengu during the month of August, 2014

20 Euphorbia hirta 60 2.2 3.67 437.8 2.78 1.90 0.00 4.68

21 Excoecaria agallocha 100 2.6 2.60 3312102 4.63 2.25 19.18 26.05

22 Hyptis capitata 40 0.8 2.00 5732.4 1.85 0.69 0.03 2.58

23 Hyptis suaveolens 40 1.8 4.50 5732.4 1.85 1.55 0.03 3.44

24 Ipomoea biloba 40 1.0 2.50 4976.2 1.85 0.86 0.03 2.74

25 Leucas diffusa 80 3.8 4.75 6807.4 3.70 3.28 0.04 7.02

26 Lippia nodiflora 80 4.6 5.75 3662.4 3.70 3.97 0.02 7.70

27 Lumnitzera racemosa 100 5.4 5.40 429936.4 4.63 4.66 2.49 11.78

28 Mimosa pudica 40 1.4 3.50 2508 1.85 1.21 0.01 3.08

29 Passiflora foetida 40 0.6 1.50 1910.8 1.85 0.52 0.01 2.38

30 Rhizophora mucronata 100 8.2 8.20 5875796 4.63 7.08 34.02 45.73

31 Scoparia dulcis 80 4.8 6.00 8598.8 3.70 4.15 0.05 7.90

32 Sida alnifolia 60 2.0 3.33 3582.8 2.78 1.73 0.02 4.53

33 Sonneratia caseolaris 20 0.4 2.00 368152.8 0.93 0.35 2.13 3.40

34 Tridax procumbens 40 3.8 9.50 1936.4 1.85 3.28 0.01 5.14

2). The species like Aristolochia indica, Bruguiera

cylindrica, Crotalaria striata and Lumnitzera racemosa

were showed restricted distribution due to their lower

frequency values.

The species, Acanthus ilicifolius registered

highest density of 56 individuals/m2 followed by

Excoecaria agallocha with 9.8 individuals/m2. On the

other hand, some species like Bruguiera cylindrica,

Crotalaria striata, Ipomoea biloba and Passiflora

foetida were present with lower density of less than 1

individuals/m2. In general, true mangrove speices

contributed higher density in the community than the

other non- mangrove plants. The species, Excoecaria

agallocha (12484074mm2/100m2), Rhizophora

mucronata (1003185mm2/100m2), and Acanthus

ilicifolius (35669.2mm2/100m2) have contributed higher

basal cover to the community (12484074, 1003185 and

713384mm2/100m2 respectively) than that of other

associated species in this study on mangrove formation.

The relative value of frequency, density and

dominance were also varied widely between the species.

On ecological point of view, the secured value of IVI and

hence the total ecological importance of the species like

Acanthus ilicifolius, Excoecaria agallocha, Acrostichum

aureum, Avicennia officinalis and Rhizophora mucronata



Table 2. Frequency, density, abundance and basal cover with their relative values and importance value

index (IVI) of species in the mangrove forest of Mundrothuruth during the month of August, 2014.

Sl.

No.

Species

Fre-

quency

(%)

Density

(individ

uals /m2)

Abun-

dance

Basal cover

(mm2 /100m2 )

Relative

fre-

quency

(%)

Relative

density

(%)

Relative

domi-

nance (%)

IVI

1. Acanthus ilicifolius 100 56.0 56.00 713384 8.20 53.74 4.04 65.98

2. Acrostichum aureum 100 7.6 7.60 871340 8.20 7.29 4.94 20.43

3. Andrographis

echioides

40 1.6 4.00 1273.6 3.28 1.54 0.01 4.82

4. Aristolochia indica 20 1.0 5.00 1791 1.64 0.96 0.01 2.61

5. Avicennia officinalis 60 2.2 3.67 2024840 4.92 2.11 11.48 18.51

6. Boerhavia diffusa 60 1.6 2.67 11465.6 4.92 1.54 0.06 6.52

7. Bruguiera cylindrica 20 0.4 2.00 183439.6 1.64 0.38 1.04 3.06

8. Cleome viscosa 40 1.8 4.50 5733 3.28 1.73 0.03 5.04

9. Clerodendrum inerme 40 1.4 3.50 111465.2 3.28 1.34 0.63 5.25

10. Crotalaria striata 20 0.6 3.00 1911 1.64 0.58 0.01 2.23

11. Desmodiumtriflorum 40 3.4 8.50 108.8 3.28 3.26 0.00 6.54

12. Eclipta alba 60 1.8 3.00 5733 4.92 1.73 0.03 6.68

13. Eupatoriu modoratum 60 1.6 2.67 20382.4 4.92 1.54 0.12 6.57

14. Euphorbia hirta 80 2.0 2.50 398 6.56 1.92 0.00 8.48

15. Excoecaria agallocha 80 9.8 12.25 12484074 6.56 9.40 70.76 86.73

16. Hyptis suaveolens 80 2.0 2.50 6370 6.56 1.92 0.04 8.51

17. Ipomoea biloba 40 0.8 2.00 3980.8 3.28 0.77 0.02 4.07

18. Lentana camera 60 1.2 2.00 54025.2 4.92 1.15 0.31 6.38

19. Lumnitzera racemosa 20 1.0 5.00 79618 1.64 0.96 0.45 3.05

20 Mimosa pudica 40 1.6 4.00 2865.6 3.28 1.54 0.02 4.83

21. Passiflora foetida 40 0.6 1.50 1911 3.28 0.58 0.01 3.87

22. Rhizophora mucronata 40 1.4 3.50 1003185 3.28 1.34 5.69 10.31

23. Scoparia dulcis 40 1.4 3.50 2507.4 3.28 1.34 0.01 4.64

24. Wattakaka bolubilis 40 1.4 3.50 50036 3.28 1.34 0.28 4.91

were significant as their IVI value are greater than the

other species.

In Ayiramthengu mangrove vegetations, four

true mangrove species viz., Rhizophora mucronata,

Excoecaria agallocha, Avicennia officinalis and

Bruguiera cylindrical were determined to have major

functional role as they secured higher value of relative

importance (RVI) (15.24, 8.66, 7.74 and 7.64%

respectively) (Figure 1). Similarly, in Mundrothuruth the

four true mangrove species viz., Excoecaria agallocha,

Acanthus ilicifolius, Acrostichum aureum and Avicennia

officinalis obtained higher RVI value of 28.91, 21.99,

6.81 and 6.17% respectively (Figure 2) and hence played

major role in community metabolism than the remaining

species. It may indicate that these site-specific species

were occupying higher ecological niches according to

their adaptability in the respective community.

Therefore, to establish new formations of mangrove

vegetation in coastal areas of Kollam district of Kerala

state, the above mentioned species of higher RVI values

may be considered. The other associates can be expected

to invade in such formations in course of time during

community development.

CONCLUSION

The establishment of mangrove vegetation by

constituting the important true mangrove species namely,

Rhizophora mucronata, Excoecaria agallocha,

Avicennia officinalis, Bruguiera cylindrical and

Journal of Research in Biology (2015) 5(5): 1763-1768 1767


Figure 1. Pie chart showing the contribution of

relative value of importance (RVI) by the

predominant species in the Ayiramthengu

mangrove vegetation.

Figure 2. Pie chart showing the contribution of

relative value of importance (RVI) the predominant

species in the Mandrothruthu mangrove vegetation.

Site 1. Ayiramthengu Site 2. Mandrothruth

Acrostichum aureum in all possible places of the coastal

part of Kollam district of Kerala is suggested to protect

this landscape very effectively.

ACKNOWLEDGEMENT

The Authors are thankful to the UGC Bangalore

for funding the Minor Research Project on “ Diversity

and Conservation Strategies on Mangrove Ecosystem

with special reference to Marshy Back waters of

Southern Kerala, Western Ghats” Vide ref No. No.F.

MRP/12th plan/14-15/KLKE057,dated 10th December

2014.

REFERENCES

Banerjee LK, Sastry ARK, Nayar MP. 1989.

Mangroves in India, Identification Manual. Botanical

Survey of India, Kolkata. 113pp.

Cintron G, Schaeffer-Novelli Y. 1984. Methods of

studying mangrove structure. pp. 91-113. In: S.C.

Snedaker and J.G. Snedaker (eds.). The Mangrove

Ecosystem: Research Methods. UNESCO, Paris.

Cottom G, Curtis JT. 1956. The use of distance

measures in phytosociological sampling. Ecology, 37(3):

451-460.

Joshi HG, Ghose M. 2014. Community structure,

species diversity, and aboveground biomass of the

Sundarbans mangrove swamps. Tropical Ecology, 55(3):

283-303.

Nameer PO, Mohan Kumar B, Minood CR. 1992.

Floristics, zonation and aboveground biomass production

in mangroves of Puduvyppu, Kerala. Indian J Forestry,

15(4): 317-325.

Odum EP. 1959. Fundamentals of Ecology. 2nd ed.

Sanders, Philadelphia, PA.

Ramachandran KK, Balasubramaniam G, Johnson

K, Jessy T. 1986. The Mangrove Ecosystem for Kerala:

its Mapping, Inventory and Some Environmental

Aspects. Centre for Earth Science Studies. Trivandrum,

India. 38pp.

Saini DC, Kulshrestha K, Kumar S, Gond DK,

Mishra GK. 2012. Studies on floristic diversity and its

importance of Pichavaram Mangrove reserve forest,

Tamil Nadu. Uttar Pradesh State Biodiversity Board, pp.

149-151.

Sandilyan S. 2013. The aftermath of Thane cyclone in

Pichavaram Mangrove East coast of Southern India.

Science India, 16(2): 35-38.

Tomlinson PB. 1986. Botany of Mangroves. Cambridge

University Press, Cambridge. 413pp.



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Floristic constitution and certain ecological characters of two selected natural mangrove vegetation in Kollam district, Kerala