Journal
of Threatened Taxa | www.threatenedtaxa.org | 26 May 2024 | 16(5): 25188–25197
ISSN 0974-7907 (Online) | ISSN
0974-7893 (Print)
https://doi.org/10.11609/jott.8456.16.5.25188-25197
#8456 | Received 29 March 2023
| Final received 10 April 2024 | Finally accepted 29 April 2024
Floristic diversity of mangroves
and mangrove associate species of Kali River Estuary, Karwar, Karnataka, India
Amruta G. Hondappanavar
1, Shivanand S. Bhat 2 &
Praveen Kumar Verma 3
1 Forest Research Institute,
Dehradun, (Residential Address: #F-103, Krishna Solitaire, Desai Colony,
Srinagar), Dharwad, Karnataka 580003, India.
2 Smt. Indira Gandhi Govt. First
Grade Women’s College, Sagar, Shivamogga District,
Karnataka 577401, India.
3 Forest Botany Division, Forest
Research Institute, Deemed to be University, Kaulagarh Road, PO. I.P.E. Dehradun, Uttarakhand 248195,
India.
1 amruta.1297@gmail.com, 2 shivanandbhatgfgc@gmail.com
(corresponding author), 3 vermapk@icfre.org
Editor: Kannan C.S. Warrier,
ICFRE - Institute of Forest Genetics and Tree Breeding, Coimbatore, India. Date of publication: 26 May 2024
(online & print)
Citation: Hondappanavar, A.G., S.S. Bhat & P.K. Verma
(2024). Floristic
diversity of mangroves and mangrove associate species of Kali River Estuary,
Karwar, Karnataka, India. Journal
of Threatened Taxa 16(5): 25188–25197. https://doi.org/10.11609/jott.8456.16.5.25188-25197
Copyright: © Hondappanavar et al. 2024. Creative Commons Attribution 4.0 International
License. JoTT
allows unrestricted use, reproduction, and distribution of this article in any
medium by providing adequate credit to the author(s) and the source of
publication.
Funding: None.
Competing interests: The authors declare no competing interests.
Author details: Dr. Amruta G. Hondappanavar, associate analyst (Research – Carbon Market) at SG Analytics, Pune. Dr. Shivanand S. Bhat, assistant professor and head of Botany, Smt. Indira Gandhi Govt. First Grade Women’s College, Sagar. Dr. Praveen Kumar Verma, scientist-D, Systematic Discipline, Forest Botany Division, Forest Research Institute, deemed to be University, Kaulagarh Road, PO. I.P.E. Dehradun.
Author contributions: AGH—conducted fieldwork, led primary research, drafted and revised the manuscript. DDB—conducted field work, supervision, identified the species, reviewed and edited original draft. PKV—conducted supervision, reviewed and edited tables.
Acknowledgements: The authors are grateful to Shri. K.V. Vasantha Reddy, IFS, conservator of forests, Kanara Circle,
Sirsi, for facilitating this work. We are thankful to
the team of Karnataka State Forest Department for support and guidance during
many field visits and data collection.
Abstract: This study
assessed the mangrove flora
of the Kali River estuary, Uttara
Kannada district, Karnataka. Fourteen true mangrove species belonging to eight families and 11 genera were documented from four locations: Devbagh, Mavinhole, Kalimatha Island, and Halgejoog.
The mangrove species show a discontinuous
distribution pattern in the Kali River estuary. The highest IVI in true mangroves
was recorded for Avicennia officinalis at
Devbagh, Acanthus ilicifolius
at Mavinhole, Sonneratia
caseolaris (after Oryza coarctata)
at Kalimatha Island, and S. caseolaris
(after Derris trifoliata) at Halgejoog.
Of the four sites, Devbagh has the highest
Shannon-Wiener diversity index, and with regard to species composition, Devbagh and Kalimatha Island are
the most similar sites. Kalimatha island has the most
well-preserved mangrove community.
Keywords: Floristic diversity, Kalimatha Island, Kali mangroves, phytosociology,
vegetation analysis.
Abbreviations: A/F Ratio—Abundance to Frequency
Ratio | GBH—Girth at Breast Height | IVI—Importance Value Index | L1—Location
1: Devbagh | L2—Location 2: Mavinhole
| L3—Location 3: Kalimatha Island | L4—Location 4: Halgejoog.
Introduction
Mangroves are unique plant
communities found in sheltered shores, estuarial inter-tidal zones, tidal
creeks, backwaters, lagoons, mudflats, and marshes of the tropical and
sub-tropical areas of the world. Mainly found in areas between latitude 24° N
and 38° S (India State of Forest Report 2019), evergreen trees and shrubs
chiefly make up the vegetational components of the mangrove ecosystem. They
have adapted to grow in hostile conditions such as high salinity, recurring
inundation by tidal saltwater, high temperature & wind speeds, and anaerobic
soils. Mangrove species can be obligate halophytes, euryhalines, or stenohalines.
Mangroves provide a broad range
of ecosystem services, including protecting coastline against erosion, storms
and cyclones, serving as a natural carbon sink, and providing breeding grounds
and nurseries for fish and prawns. This fragile ecosystem is in a seriously
threatened state due to natural and anthropogenic causes. Standing at the brink
of degradation, the mangroves are in need of urgent
protecting and safeguarding. It is of grave importance that all the components
of every ecosystem on earth, along with its interactions, are preserved. This
conservation of the health of the ecosystems is imperative, not only for the
sake of nature itself but also to ensure the survival of the present life and
of the generations to come. This is because the human race heavily depends on
the services (all the four types – provisioning, regulating, supporting, and
cultural services) that the ecosystem so freely provides.
A global plan has to be made and
executed in order to conserve not only a few species, but the whole mangrove
ecosystem. Global mangrove mappings and biodiversity documentations are crucial
for they define the mangrove limits, show an estimation of the carbon stores
(Ximenes 2015), serve as an essential source of information about the
biodiversity of the area and its biomass and describe the ecosystem as a whole.
These mappings can also sometimes be used to determine the extent of the
degradation or alteration of the mangrove communities. They serve as a guide
for conservation efforts and hence policymaking for the same.
Chandran et al. (2012) studied
the mangroves of Gangavali, Aghanashini
estuaries, and Sharavathi-Badgani estuarine complex.
Ramachandra et. al. (2013) estimated the total economic value of the ecosystem
benefits provided by the mangroves of Venktapur, Sharavathi, Aghanishini, Gangavali, and Kali River estuaries. The study shows how
the estuarine ecosystems contribute to the sustenance of the Uttara Kannada district’s
economy. The present study aims to understand the vegetation structure and
estimate the floral diversity of the mangrove forests of the Kali River estuary
at Karwar, Uttara Kannada district, Karnataka.
Materials and Methods
Study Area
The current study was undertaken
in the mangrove forests belonging to Karwar’s Kali River estuary (74.1876°N,
14.8836°E) in Uttara Kannada district, Karnataka. Four locations were chosen to
represent the floral diversity in the mangrove species varying with the salinity
of the Kalli River estuary: Devbagh,
Mavinhole, Kalimatha
Island, and Halgejoog (Image 1). Except for the Kalimatha Island, which belongs to the Karwar Range of the
Karwar Sub-Division, all the locations belong to the Gopshitta
Range of Karwar Sub-Division, Canara Circle of the Karnataka State Forest
Department.
Devbagh: located at the creek mouth (14.84760N and 74.12110E), at the junction of
the creek and the river Kali. This water is ‘euhaline’
(salinity levels > 30.0ppt). The mangrove cover in the area is 40.07 ha of
the total 102 ha belonging to the Devbagh region.
Mavinhole: located in a creek of the river
Kali (14.86770N and 74.12190E), at 2.5 km from the mouth
of the river. The water is ‘polyhaline’ (with
salinity levels in the range of 18.0–30.0 ppt). The mangroves occupy 23.8 ha of
the total 30 ha belonging to the Mavinhole region.
Kalimatha Island: located 3.2 km away from
the river-mouth (14.84200N and 74.14280E), the water around
the island is ‘polyhaline’ (with salinity levels in
the range of 18.0–30.0 ppt). There is a patch of coconut trees and other
cultivable plants at the center and at the periphery of this 8.5 ha island sits
a 7 ha mangrove belt.
Halgejoog: located 10.5 km away from the
mouth of the river (14.88180N and 74.19740E), the river water
here is ‘mesohaline’ (with salinity levels in the range of 5.0–18.0 ppt). The
mangroves here occupy an area of 91.13 ha.
Sampling and data collection
Nested quadrat method was used to
gather primary data from the chosen study area. The quadrats sizes for trees,
shrubs, and herbs were 31.62 × 31.62 m (approx. 0.1 ha), 3 × 3 m, and 1 × 1 m,
respectively. On the confirmation of the presence of the mangroves in the area
and their accessibility, random plots were selected for the study. Species accumulation
curves were plotted, and 5 quadrats were sampled at each of the four locations.
The true mangrove and the
mangrove associate species were identified and enumerated in all the chosen
plots. The girth of all trees (> 15 cm) was measured at a height of 1.37 m
above the ground level (GBH). The plots for shrubs and herbs were nested inside
the plot for trees.
The phytosociology and the
diversity indices for true mangroves and the associate mangroves were then
estimated using this data.
The field data was gathered in
various sessions in March 2021, during the low tides.
Species Identification
The plant specimens of true
mangroves and mangrove associates were collected for identification purposes.
Standard books and research papers on mangroves (Banerjee et al. 1989; Rao
& Suresh 2001; Chandran et al. 2012) were consulted for the verification of
the names of the species after their photographs were taken.
Species
Composition and Importance Value
The plant species at the study
plots of each location were identified and enumerated. The data collected from
the field was used to analyze the distribution pattern of mangroves and their
population structure by establishing a quantitative relationship among the
plant species.
Relative frequency, relative density,
relative dominance, abundance, abundance to frequency ratio, and Importance
Value Index (IVI) were calculated in the application ‘Microsoft Excel 2019’,
using the standard phytosociological methods (Curtis & McIntosh 1951). IVI
was calculated as the sum of relative frequency, relative dominance, and
relative density (Vijayan et al. 2015).̧
Number of quadrats in which a
species occurs
Frequency (%) =
––––––––––––––––––––––––––– x 100
(Eq.
1)
The total number of quadrats
sampled
Density = Number of individuals /
ha (Eq. 2)
GBH
Dominance = ––––– (Eq. 3)
4π
Total number of individuals of a species
Abundance =
––––––––––––––––––––––––––––––––
(Eq.
4)
Total number of
quadrats in which the species occurs
Abundance of a species
Abundance/ Frequency (A/F) Ratio
= –––––––––––––––––––––
(Eq. 5)
Frequency (in %) of
the species
Frequency of a species
Relative Frequency (%) =
––––––––––––––––––––––– x 100 (Eq. 6)
Frequency of all species
Total number of
individuals of a species
Relative Frequency (%) =
––––––––––––––––––––––––– x 100 (Eq. 7)
Total number of individuals of all species
The dominance of a species
Relative Dominance (%) =
––––––––––––––––––––––––– x 100 (Eq. 8)
The dominance of all species
IVI = Relative Frequency +
Relative Density + Relative Dominance (Eq. 9)
Species
Diversity
Two of the three main components
of diversity—α-diversity and β-diversity were calculated. For α-diversity,
three measures of diversity – evenness, richness, and heterogeneity were
calculated to analyse the diversity in the chosen
locations based on the data collected. Cluster analysis was carried out to
calculate β-diversity.
To determine the species
evenness, Pielou’s equitability index (J) and Buzas-Gibson’s evenness index (E) were calculated; for
species richness, Margalef’s index (d) was
calculated; for species diversity or heterogeneity, Shannon-Weiner index (H’)
and Simpson’s diversity index (1-D) were calculated. These were calculated
using the software ‘PAST (PAleontological STatistics) Version 4.03’ (Hammer et al. 2001). Further,
the similarity in the species composition among the four locations was compared
by the method of cluster analysis on the presence/absence transform data, using
the software ‘BioDiversity Professional Version 2.0’.
Results
Species
Composition
A total of 14 true mangrove species
from eight families and 11 genera, and nine mangrove associate species
belonging to six families and nine genera were found in the quadrats chosen for
the present study.
Other true mangrove (Bruguiera gymnorhiza (L.)
Lam. (Family: Rhizophoraceae)) and mangrove associate
species (Ixora concinna R.Br. ex Hook.f. (Family: Rubiaceae), Casuarina
equisetifolia L. (Family: Casuarinaceae),
Sesuvium portulacastrum
(L.) L. (Family: Aizoaceae), Salvadora
persica L. (Family: Salvadoraceae),
Pongamia pinnata (L.)
Pierre (Family: Fabaceae), Terminalia catappa L.
(Family: Combretaceae)) were also observed in the
vicinity, but outside of the study plots.
The highest number of species
(true mangroves and mangrove associates) of the four locations was observed at
the Kalimatha Island (Location 3), with 17 species—12
true mangroves and five mangrove associates, followed by Mavinhole
(Location 2), with 16 species—10 true mangroves and six mangrove associates. At
Devbagh (Location 1), 13 species—seven true mangroves
and six mangrove associates were observed, while at Halgejoog
(Location 4), it was 12 species—seven true mangroves and five mangrove
associates.
Acanthus ilicifolius
and Excoecaria agallocha
occurred at all the four locations, Avicennia
marina and Avicennia officinalis occurred
at locations 1, 2, and 3; Sonneratia caseolaris occurred at locations 1, 3, and 4; Kandelia candel and
Rhizophora apiculata
were found at locations 2, 3, and 4; Lumnitzera
racemosa was observed at locations 1 and 2; Sonneratia alba occurred at locations 1 and
3; Rhizophora mucronata
was found at locations 2 and 3, while Bruguiera
cylindrica was observed only at location 3. Caesalpinia crista, Cassytha
filiformis, and Derris trifoliata were the
most widespread mangrove associates. They were found distributed at all the
four locations (Table 1).
The floral composition that was
observed at the four locations is as follows:
Location 1 – Devbagh: A. officinalis and S. caseolaris were present in all the sample plots and
were observed to have good growth. A. ilicifolius,
A. marina, L. racemosa, and S.
alba were found only in two sample plots; S. alba was found in
plenty in the samples studied near the sea. The shrubby vegetation was sparse
at best. This could probably be due to the lack of huge areas of deposited
sediments that do not float away with the water because of the daily low- and
high-tide phenomena. Vast expanses of mangroves were destroyed due to
the inundation caused by heavy floods that occurred in 2019.
Location 2 – Mavinhole: R. mucronata
occurred in all the sample plots at the location. There was a good amount
of shrubby vegetation in some plots.
Location 3 – Kalimatha
Island: Oryza coarctata was observed in newly forming mudflats in
some plots (and in the adjacent areas) at the location. In some plots, a very
good growth of S. alba was observed, and so was the case of S. caseolaris in some other plots. A good amount of
species richness was observed at the location.
Location 4 – Halgejoog: K. candel
and S. caseolaris were found in all the
study stations of the location; but the plots were mostly dominated by shrubby
and ground vegetation. A large number of mangrove associates were also observed
adjacent to the study plots.
Vegetation Structure and Importance Value
Location 1 – Devbagh: Frequency (%) was the highest
for S. caseolaris and A. officinalis (100%);
density was the highest for S. caseolaris (a
total of 366 stems in the study plots, i.e., 732 stems/ha and a relative
density of 12.28%) and Volkameria inermis (1560 stems/ha and a relative density of
42.95%). Relative dominance was the highest for A. officinalis (31.82%).
Abundance and A/F ratio were the highest for S. alba (abundance—41.5 |
A/F ratio—1.05) and V. inermis (abundance—320
| A/F ratio 8). A. officinalis had the highest Importance Value
Index—58.19 (Table 2).
Location 2 – Mavinhole: Frequency (%) was the highest
for R. mucronata (100%); density was the
highest for A. ilicifolius (a total of 9746
stems in the study plots, i.e., 19492 stems/ha and a relative density of 74.37%),
Aegiceras corniculatum
(3764 stems/ha and a relative density of 13.98%), K. candel
(660 stems/ha and a relative density of 2.52%), and R. mucronata (636 stems/ha and a relative density of
2.43%). Relative dominance was the highest for K. candel
(45.82%) and A. corniculatum (34.52%).
Abundance was the highest for A. ilicifolius (abundance—1218.5)
and E. agallocha (abundance—39.67). A/F
ratio was the highest for A. ilicifolius
(15.93) and K. candel (0.92). A. ilicifolius had the highest Importance Value
Index—84.47 (Table 3).
Location 3 – Kalimatha
Island: Frequency (%)
was the highest for A. corniculatum, A.
officinalis, B. cylindrica, and R. apiculata (80%); density was the highest for S. caseolaris (a total of 454 stems in the study plots,
i.e., 908 stems/ha and a relative density of 9.33%) after O. coarctata (a grass species with a total of 5520
stems/ha and a relative density of 56.70%). Relative dominance was the highest
for S. caseolaris (41.38%). Abundance and A/F
ratio were the highest for O. coarctata (abundance—460,
A/F ratio—7.67) and S. caseolaris (abundance—75.67,
A/F ratio—1.26). S. caseolaris had the highest
Importance Value Index—56.96 at location 3 (Kalimatha
Island), after O. coarctata (63.79) (Table
4).
Location 4 – Halgejoog:
Frequency (%)
was the highest for A. ilicifolius, Acrostichum aureum, K. candel, and S. caseolaris
(100%); density was the highest for A. aureum (a
mangrove fern). Relative dominance was the highest for S. caseolaris (48.27%). Abundance was the highest for A.
aureum (506) and S. caseolaris
(9.6). A/F ratio was the highest for O. coarctata (11.62)
and R. apiculata (0.12). D. trifoliata had
the highest Importance Value Index—67.25, followed by S. caseolaris
(61.11) (Table 5).
Species Diversity
α-diversity
Species richness, species
evenness, and species heterogeneity were calculated for the four locations
using various diversity indices (Table 6).
According to Margalef’s
index (d), the Kalimatha Island (location 3) had the
highest species richness (with a Margalef’s index
value of 2.052) of the four locations. The Margalef’s
index values were 1.642, 1.706, 2.052, and 1.233 for locations 1, 2, 3, and 4,
respectively.
Both the indices to calculate
species evenness—Pielou’s evenness index (J) and Buzas-Gibson’s evenness (E) measure indicate to Devbagh (location 1) having the highest species evenness
(with Pielou’s index value of 0.7282 and Buzas-Gibson’s index value of 0.498) of all the four
locations. Pielou’s index of species richness gives a
measure of the degree of community structuring, and ranges from 0–1. A higher
value indicates a lesser variation of the species abundance within a community,
and this means that all the species occur in relatively similar proportions.
Pielou’s index values were 0.7282,
0.3609, 0.602, and 0.6525 for the locations 1, 2, 3, and 4, respectively. Buzas-Gibson’s index values were 0.498, 0.17, 0.3238, and
0.4217 for the locations 1, 2, 3, and 4, respectively.
For the calculation of species
heterogeneity of the study sites, Shannon-Wiener’s diversity index (H’) and
Simpson’s diversity index (1 - D) were calculated. Shannon-Wiener’s diversity
index values were 1.868, 1.001, 1.706, and 1.621 for location 1, 2, 3, and 4,
respectively. Simpson’s diversity index values were 0.7654, 0.428, 0.6561, and
0.7688 for locations 1, 2, 3, and 4, respectively. According to
Shannon-Wiener’s diversity index, Devbagh (location
1) had the highest species heterogeneity or diversity (with the index value of
1.868) of the four locations. But the Simpson’s diversity index values of the
four locations showed that location 4 (Halgejoog) was
the most diverse one, with an index value of 0.7688, while Devbagh
had the index value of 0.7654.
Shannon-Wiener’s diversity index
is a Type I index, i.e., it is most sensitive to the changes in the rare
species of the community sample, while Simpson’s diversity index is a Type II
index, which means that it is most sensitive to the changes in the more
abundant species of the community sample (Peet 1974).
The calculated diversity indices
indicate to Devbagh having the highest diversity of
the four locations with the diversity being sensitive to the less-abundant
species of the community sample, and Halgejoog having
the highest diversity with the diversity being sensitive to the common or more
abundant species at the location. This would imply that Devbagh
was more diverse due to the presence of less-abundant species, while Halgejoog was more diverse due to the dominance of the
common species at the location. This can be supported by the fact that the
index values of both measures – species richness and species evenness, of Devbagh are higher as compared to those of Halgejoog. The index value for Margalef’s
species richness of Halgejoog (1.233) is much lesser
than that of Devbagh (1.642), while there is a lesser
difference between the index values of the measure of species evenness of the
two locations – the Pielou’s species evenness index
value of Devbagh is 0.7282, and that of Halgejoog is 0.6525. Similarly, the Buzas-Gibson’s
species evenness index value of Devbagh is 0.498,
while that of Halgejoog is 0.4217. This means that
the species abundance at both Devbagh and Halgejoog was almost similar, but Devbagh
was more species-rich, i.e., there were more less-abundant species at Devbagh than there were at Halgejoog.
β-diversity
Based on the presence/absence
transform data of the species, the similarity index was calculated, and the
dendrogram (Figure 1) briefs it based on the Bray-Curtis Cluster Analysis
(Single-Link).
Locations 1 (Devbagh)
and 3 (Kalimatha Island) were most similar to each
other (73.33% similarity), while location 2 (Mavinhole)
is 72.73% similar to this cluster. Location 4 (Halgejoog)
matched the least with the rest of the locations, with a similarity of 62.07%.
Discussions
Of the four locations studied, Kalimatha Island had the highest number of species (17)—12
true mangroves and five mangrove associates. Devbagh
had the highest species evenness of the four locations and is also the most
diverse concerning the less-abundant species, and second-most diverse when
common species are emphasized. Halgejoog had the
highest species diversity from Simpson’s diversity indices (0.7688), i.e.,
diversity with respect to common species. Kalimatha
Island and Devbagh are the most similar locations
regarding the species composition. Tree density was the highest at Mavinhole (2,505 trees/ha).
Although plantation activities
have been taken up at all the four locations, the study shows that, out of Devbagh, Mavinhole, Kalimatha Island, and Halgejoog, Kalimatha Island has the best-preserved mangrove community
as it has the highest number of true mangroves (12) and the least number of
mangrove associates (five). Halgejoog is located well
inland compared to the other three sites and shows mostly shrubby vegetation,
despite having seven true mangrove and five mangrove associate species. Devbagh, located at the mouth of the river, has the maximum
number of mangrove associate (six) and the least number of true mangroves
species (seven), which seems to be so because of frequent floods and long-term
inundations. Non-native species like Acacia auriculiformis
was observed in the study plots at Mavinhole,
which could hamper the growth of native biodiversity of the area. Anthropogenic
interference – both positive (like plantation activities, and other measures
for conservation) and negative (pollution, and fishing), was observed at all
the sites.
The Karwar mangrove forests can
be classified as scattered patches since the mangrove species, at all the sites,
showed a discontinuous distribution pattern.
The studied mangrove forests
create a very fragile ecosystem as they depend on unique ecological conditions
like salinity, depth of water, specific substrate, and any alteration triggers
to these conditions may lead to invasion of other associate species resulting
in risks to the true mangrove species in the future.
Table 1. Occurrence of true
mangroves and mangrove associates at the four locations.
|
Mangroves |
Locations |
|||||
|
Family |
Species |
Life form |
L – I |
L – II |
L – III |
L – IV |
|
True Mangroves |
||||||
|
Acanthaceae |
Acanthus ilicifolius
L. |
S |
+ |
+ |
+ |
+ |
|
Avicennia marina (Forssk.) Vierh. |
T |
+ |
+ |
+ |
- |
|
|
Avicennia officinalis L. |
T |
+ |
+ |
+ |
- |
|
|
Combretaceae |
Lumnitzera racemosa Willd. |
T |
+ |
+ |
- |
- |
|
Euphorbiaceae |
Excoecaria agallocha L. |
T |
+ |
+ |
+ |
+ |
|
Lythraceae |
Sonneratia alba Sm. |
T |
+ |
- |
+ |
- |
|
Sonneratia caseolaris Engl. |
T |
+ |
- |
+ |
+ |
|
|
Poaceae |
Oryza coarctata
Roxb. |
H |
- |
- |
+ |
+ |
|
Primulaceae |
Aegiceras corniculatum (L.) Blanco |
S |
- |
+ |
+ |
- |
|
Pteridaceae |
Acrostichum aureum L. |
H |
- |
+ |
- |
+ |
|
Rhizophoraceae |
Bruguiera cylindrica Blume |
T |
- |
- |
+ |
- |
|
Kandelia candel Druce |
T |
- |
+ |
+ |
+ |
|
|
Rhizophora apiculata Blume |
T |
- |
+ |
+ |
+ |
|
|
Rhizophoraceae |
Rhizophora mucronata Poir. |
T |
- |
+ |
+ |
- |
|
Mangrove Associates |
||||||
|
Bignoniaceae |
Dolichandrone spathacea
(L.f.)
Baillon ex Schumann |
T |
- |
- |
- |
+ |
|
Convolvulaceae |
Ipomoea pes-caprae
(L.) R.Br. |
C |
+ |
- |
- |
+ |
|
Fabaceae |
Acacia auriculiformis
A.Cunn. ex Benth. |
T |
- |
+ |
- |
- |
|
Caesalpinia crista L. |
C |
+ |
+ |
+ |
+ |
|
|
Derris trifoliata Lour. |
C |
+ |
+ |
+ |
+ |
|
|
Lamiaceae |
Premna corymbosa Rottler & Willd. |
S |
- |
+ |
- |
- |
|
Volkameria inermis L. |
S |
+ |
+ |
+ |
- |
|
|
Lauraceae |
Cassytha filiformis L. |
C |
+ |
+ |
+ |
+ |
|
Malvaceae |
Thespesia populnea
Sol. ex Corrêa |
T |
+ |
- |
+ |
- |
+—Presence
| -—Absence | S—Shrub | T—Tree | H—Herb | C—Creeper/Climber
Table 2. Phytosociological
characters of mangroves at Devbagh.
|
Species |
Frequency (%) |
Relative frequency (%) |
Density |
Relative density (%) |
Dominance |
Relative dominance (%) |
Abundance |
A/F ratio |
IVI |
|
Acanthus ilicifolius |
40 |
5.71 |
40 |
1.34 |
5.74 |
0.007 |
10 |
0.25 |
7.06 |
|
Acrostichum aureum |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Aegiceras corniculatum |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Avicennia marina |
40 |
5.71 |
84 |
2.82 |
6781.19 |
8.26 |
21 |
0.52 |
16.80 |
|
Avicennia officinalis |
100 |
14.29 |
360 |
12.08 |
26126.16 |
31.82 |
36 |
0.36 |
58.19 |
|
Bruguiera cylindrica |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Excoecaria agallocha |
80 |
11.43 |
112 |
3.76 |
3657.38 |
4.46 |
14 |
0.18 |
19.64 |
|
Kandelia candel |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Lumnitzera racemosa |
40 |
5.71 |
6 |
0.20 |
206.90 |
0.25 |
1.5 |
0.04 |
6.17 |
|
Oryza coarctata |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Rhizophora apiculata |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Rhizophora mucronata |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Sonneratia alba |
40 |
5.71 |
166 |
5.57 |
17330.78 |
21.11 |
41.5 |
1.04 |
32.40 |
|
Sonneratia caseolaris |
100 |
14.29 |
366 |
12.28 |
24677.61 |
30.06 |
36.6 |
0.37 |
56.63 |
|
Acacia auriculiformis |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Caesalpinia crista |
40 |
5.71 |
340 |
11.41 |
646.23 |
0.79 |
85 |
2.12 |
17.91 |
|
Cassytha filiformis |
40 |
5.71 |
24 |
0.81 |
1.51 |
0.002 |
6 |
0.15 |
6.52 |
|
Derris trifoliata |
40 |
5.71 |
52 |
1.74 |
264.65 |
0.32 |
13 |
0.32 |
7.78 |
|
Dolichandrone spathacea |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Ipomoea pes-caprae |
40 |
5.71 |
110 |
3.69 |
43.20 |
0.05 |
27.5 |
0.69 |
9.46 |
|
Premna corymbosa |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Thespesia populnea |
60 |
8.57 |
40 |
1.34 |
1536.00 |
1.87 |
6.67 |
0.11 |
11.78 |
|
Volkameria inermis |
40 |
5.71 |
1280 |
42.95 |
814.87 |
0.99 |
320 |
8 |
49.66 |
|
Total |
700 |
100 |
2980 |
100 |
82092.23 |
100 |
618.77 |
|
300 |
Table 3. Phytosociological
characters of mangroves at Mavinhole.
|
Species |
Frequency (%) |
Relative frequency (%) |
Density |
Relative density (%) |
Dominance |
Relative dominance (%) |
Abundance |
A/F ratio |
IVI |
|
Acanthus ilicifolius |
80 |
9.30 |
9746 |
74.37 |
1256.41 |
0.80 |
1218.5 |
15.23 |
84.47 |
|
Acrostichum aureum |
40 |
4.65 |
44 |
0.34 |
6.22 |
0.004 |
11 |
0.28 |
4.99 |
|
Aegiceras corniculatum |
60 |
6.98 |
1832 |
13.98 |
54331.54 |
34.52 |
305.33 |
5.09 |
55.48 |
|
Avicennia marina |
40 |
4.65 |
62 |
0.47 |
4600.45 |
2.92 |
15.5 |
0.39 |
8.05 |
|
Avicennia officinalis |
40 |
4.65 |
6 |
0.05 |
820.28 |
0.52 |
1.5 |
0.04 |
5.22 |
|
Bruguiera cylindrica |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Excoecaria agallocha |
60 |
6.98 |
238 |
1.82 |
7620.12 |
4.84 |
39.67 |
0.66 |
13.63 |
|
Kandelia candel |
60 |
6.98 |
330 |
2.52 |
72111.05 |
45.82 |
55 |
0.92 |
55.31 |
|
Lumnitzera racemosa |
40 |
4.65 |
10 |
0.08 |
602.88 |
0.38 |
2.5 |
0.06 |
5.11 |
|
Oryza coarctata |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Rhizophora apiculata |
40 |
4.65 |
126 |
0.96 |
3193.13 |
2.03 |
31.5 |
0.79 |
7.64 |
|
Rhizophora mucronata |
100 |
11.63 |
318 |
2.43 |
10860.88 |
6.90 |
31.8 |
0.32 |
20.96 |
|
Sonneratia alba |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Sonneratia caseolaris |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Acacia auriculiformis |
40 |
4.65 |
24 |
0.18 |
1294.01 |
0.82 |
6 |
0.15 |
5.66 |
|
Caesalpinia crista |
60 |
6.98 |
76 |
0.58 |
171.91 |
0.11 |
12.67 |
0.21 |
7.67 |
|
Cassytha filiformis |
40 |
4.65 |
28 |
0.21 |
2.75 |
0.002 |
7 |
0.18 |
4.87 |
|
Derris trifoliata |
60 |
6.98 |
62 |
0.47 |
298.26 |
0.19 |
10.33 |
0.17 |
7.64 |
|
Dolichandrone spathacea |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Ipomoea pes-caprae |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Premna corymbosa |
40 |
4.65 |
16 |
0.12 |
99.47 |
0.06 |
4 |
0.1 |
4.84 |
|
Thespesia populnea |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Volkameria inermis |
60 |
6.98 |
186 |
1.42 |
118.41 |
0.08 |
31 |
0.52 |
8.47 |
|
Total |
860 |
100 |
13104 |
100 |
157387.77 |
100 |
1783.05 |
|
300 |
Table 4. Phytosociological
characters of mangroves at Kalimatha Island.
|
Species |
Frequency (%) |
Relative frequency (%) |
Density |
Relative density (%) |
Dominance |
Relative dominance (%) |
Abundance |
A/F ratio |
IVI |
|
Acanthus ilicifolius |
60 |
6.25 |
260 |
5.34 |
41.38 |
0.03 |
43.33 |
0.72 |
11.62 |
|
Acrostichum aureum |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Aegiceras corniculatum |
80 |
8.33 |
172 |
3.53 |
4613.58 |
3.59 |
21.5 |
0.27 |
15.46 |
|
Avicennia marina |
40 |
4.17 |
12 |
0.25 |
2429.26 |
1.89 |
3 |
0.08 |
6.31 |
|
Avicennia officinalis |
80 |
8.33 |
188 |
3.86 |
42784.91 |
33.32 |
23.5 |
0.29 |
45.52 |
|
Bruguiera cylindrica |
80 |
8.33 |
136 |
2.79 |
4645.89 |
3.62 |
17 |
0.21 |
14.75 |
|
Excoecaria agallocha |
60 |
6.25 |
54 |
1.11 |
1612.88 |
1.26 |
9 |
0.15 |
8.62 |
|
Kandelia candel |
40 |
4.17 |
70 |
1.44 |
2195.54 |
1.71 |
17.5 |
0.44 |
7.32 |
|
Lumnitzera racemosa |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Oryza coarctata |
60 |
6.25 |
2760 |
56.70 |
1083.85 |
0.844 |
460 |
7.67 |
63.79 |
|
Rhizophora apiculata |
80 |
8.33 |
38 |
0.78 |
915.38 |
0.71 |
4.75 |
0.06 |
9.83 |
|
Rhizophora mucronata |
60 |
6.25 |
96 |
1.97 |
2652.00 |
2.07 |
16 |
0.27 |
10.29 |
|
Sonneratia alba |
40 |
4.17 |
148 |
3.04 |
10811.63 |
8.42 |
37 |
0.92 |
15.66 |
|
Sonneratia caseolaris |
60 |
6.25 |
454 |
9.33 |
53129.58 |
41.38 |
75.67 |
1.26 |
56.96 |
|
Acacia auriculiformis |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Caesalpinia crista |
40 |
4.17 |
46 |
0.94 |
122.11 |
0.095 |
11.5 |
0.29 |
5.20 |
|
Cassytha filiformis |
40 |
4.17 |
16 |
0.33 |
1.01 |
0.001 |
4 |
0.1 |
4.50 |
|
Derris trifoliata |
60 |
6.25 |
42 |
0.86 |
225.79 |
0.18 |
7 |
0.12 |
7.29 |
|
Dolichandrone spathacea |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Ipomoea pes-caprae |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Premna corymbosa |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Thespesia populnea |
40 |
4.17 |
16 |
0.33 |
900.18 |
0.70 |
4 |
0.1 |
5.20 |
|
Volkameria inermis |
40 |
4.17 |
360 |
7.36 |
229.18 |
0.18 |
90 |
2.25 |
11.74 |
|
Total |
960 |
100 |
4868 |
100 |
128394.16 |
100 |
844.75 |
|
300 |
Table 5. Phytosociological
characters of mangroves at Halgejoog.
|
Species |
Frequency (in) |
Relative frequency (%) |
Density |
Relative density (%) |
Dominance |
Relative dominance (%) |
Abundance |
A/F ratio |
IVI |
|
Acanthus ilicifolius |
100 |
12.20 |
3240 |
21.57 |
623.95 |
1.51 |
324 |
3.24 |
35.27 |
|
Acrostichum aureum |
100 |
12.20 |
5060 |
33.68 |
715.34 |
1.73 |
506 |
5.06 |
47.61 |
|
Aegiceras corniculatum |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Avicennia marina |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Avicennia officinalis |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Bruguiera cylindrica |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Excoecaria agallocha |
60 |
7.32 |
12 |
0.08 |
467.36 |
1.13 |
2 |
0.03 |
8.53 |
|
Kandelia candel |
100 |
12.20 |
24 |
0.16 |
954.85 |
2.31 |
2.4 |
0.02 |
14.67 |
|
Lumnitzera racemosa |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Oryza coarctata |
40 |
4.88 |
1860 |
12.38 |
730.42 |
1.77 |
465 |
11.62 |
19.03 |
|
Rhizophora apiculata |
40 |
4.88 |
20 |
0.13 |
454.78 |
1.10 |
5 |
0.12 |
6.11 |
|
Rhizophora mucronata |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Sonneratia alba |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Sonneratia caseolaris |
100 |
12.20 |
96 |
0.64 |
19937.82 |
48.27 |
9.6 |
0.1 |
61.11 |
|
Acacia auriculiformis |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Caesalpinia crista |
80 |
9.76 |
1060 |
7.06 |
1665.04 |
4.03 |
132.5 |
1.66 |
20.84 |
|
Cassytha filiformis |
40 |
4.88 |
46 |
0.31 |
2.89 |
0.007 |
11.5 |
0.29 |
5.19 |
|
Derris trifoliata |
80 |
9.76 |
3380 |
22.50 |
14454.55 |
35.00 |
422.5 |
5.28 |
67.25 |
|
Dolichandrone spathacea |
40 |
4.88 |
24 |
0.16 |
1218.73 |
2.95 |
6 |
0.15 |
7.99 |
|
Ipomoea pes-caprae |
40 |
4.88 |
200 |
1.33 |
78.54 |
0.19 |
50 |
1.25 |
6.40 |
|
Premna corymbosa |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Thespesia populnea |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Volkameria inermis |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Total |
820 |
100 |
15022 |
100 |
41304.27 |
100 |
1936.5 |
|
300 |
Table 6. Diversity indices of the
four locations.
|
Diversity indices |
Location 1 |
Location 2 |
Location 3 |
Location 4 |
|
Species richness |
||||
|
Margalef’s index (d) |
1.642 |
1.706 |
2.052 |
1.233 |
|
Species evenness |
||||
|
Pielou’s index (J) |
0.7282 |
0.3609 |
0.602 |
0.6525 |
|
Buzas-Gibson’s index (E) |
0.498 |
0.17 |
0.3238 |
0.4217 |
|
Species diversity |
||||
|
Shannon-Wiener’s index (H’) |
1.868 |
1.001 |
1.706 |
1.621 |
|
Simpson’s index (1-D) |
0.7654 |
0.428 |
0.6561 |
0.7688 |
For
figure & image - - click here for full PDF
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