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Species richness, diversity and phytosociology along the elevation gradient Chapter 5

TAXONOMY, DISTRIBUTION AND ECOLOGY OF THE RIPARIAN FLORA OF PAMBA RIVER, KERALA /Ph.D Thesis /99

Chapter

SPECIES RICHNESS, DIVERSITY AND PHYTOSOCIOLOGYALONG THE ELEVATION GRADIENT

Objectives

1. To analyse the species richness and diversity of riparian forests of Pamba river

basin, Kerala based on quadrat method along the elevation gradient.

2. To analyse the phytosociology of riparian forests of Pamba river basin, Kerala

based on Braun-Blanquet method along the elevation gradient.

3. To analyse the phenology regeneration status of major riparian trees in the Pamba

river basin, Kerala based on vegetation survey and quadrat methods.

5.1 Introduction

Riparian plant communities along the rivers are dynamic, species rich (Salo et al., 1986; Kalliola

& Phuhakka, 1988; Nilsson, 1991) and sensitive to anthropogenic interference (Malanson, 1993)

resulting disturbance adapted communities. Plant communities in these systems are likely to be

affected by both longitudinal [i.e. upstream-downstream (Vannotte et al., 1980; Noss, 1983)] and

transversal [i.e. stream-floodplain or floodplain-basin (Newbold et al., 198l)] linkages for species

recruitment and diversity. The spatial heterogeneity resulting from geomorphological processes

is viewed as one of the major causes of high species richness (Hupp, 1988; Gould & Walker, 1997;

Ferreira & Stohlgren, 1999). As a consequence of the shifting mosaic of landforms and communities

resulting from natural disturbance (Whittaker, 1977), high levels of species richness are usually

found along rivers.

Studies on species richness patterns in river corridors indicated that total species richness

in a river is maximum in the middle reaches (Vannotte et al., 1980). According to intermediate

disturbance hypothesis (IDH), intermediate intensity and frequency of disturbance would create

the highest diversity (Connell, 1978). IDH has been supported by Huston (1979), Sousa (1979), Pollock

et al. (1998) Chapin et al. (2002) even though both negative (Englund, 1991; Wilson & Tilman,

1991) and positive (Tilman, 1983; Philips et al., 1994) linear relationships between diversity and

disturbance existed. Nilsson et al. (1989) found such a pattern of species richness for riparian

plants in northern Swedish rivers. Planty-Tabacchi et al. (1996) have subsequently described a

similar pattern in French and North American rivers, suggesting similarities in underlying

processes. Mechanisms proposed to explain this pattern include: (1) intermediate disturbance,

or (2) maximum heterogeneity in the most species-rich, middle reaches, and (3) downstream

5

Species richness, diversity and phytosociology along the elevation gradientChapter 5

200 Page /Ph.D Thesis /TAXONOMY, DISTRIBUTION AND ECOLOGY OF THE RIPARIAN FLORA OF PAMBA RIVER, KERALA

dispersal of plants (hydrochory) successively building up species richness downstream to the

middle reaches, where after riparian substrates become too homogeneous and erosive to allow

realization of the potential species richness (Nilsson & Jansson, 1995). In addition, the invasibility

of the river corridor has been suggested as a potential pattern-forming mechanism (Renofalt et

al., 2005b). Species richness patterns in the riparian corridor change in response to the dynamics

of flood disturbance (Renofalt et al., 2005a) but regular moderate flooding is required to sustain

high levels of diversity in riparian ecosystems (Naiman & Decamps, 1997).

The local species richness has been considered a product of competition, disturbance and

niche diversification (Pianka, 1966) which are greatly manifested in the tropics due to high

humidity and temperature (Ojo & Ola-Adams, 1996). The relationship between local and regional

richness has been analyzed by Caley & Schluter (1997), Cornell & Karlson, (1997) and Karlson

et al. (2004). The understanding of internal (river-related) and external control in riparian

communities provide the basis for efficient management strategies for biodiversity conservation

(Naiman et al., 1993) at the local scale (riparian reaches) or at the regional scale (catchment area

and hydrological network).

Human activities have been drastically transformed the major rivers of Asia such as Indus,

Ganges and Yangtze (Dudgeon, 2000) and are now categorized as threatened ecosystems (Dudgeon,

1992; Johnsingh & Joshua, 1989) due to the loss of species richness. In India, the phytodiversity

riparian forests are under threat due to anthropogenic disturbances such as deforestation, overgrazing

and land reclamation (Gopal, 1988). The Ganga river has lost 80% of its original forest cover in

its basin (Smakhtin et al., 2007). Riparian forests adjoining stream and river banks have been

almost entirely eliminated outside the protected areas (Gadgil, 2004). Moreover, there has been

no quantitative estimation of riparian diversity in Indian rivers. In Peninsular India, although

a few quantitative plant biodiversity inventories are available from the forests of the Western

Ghats (Sukumar et al., 1992; Ganesh et al., 1996; Pascal & Pelissier, 1996; Ayyappan & Parthasarathy, 1999;

Parthasarathy, 1999, 2001; Muthuramkumar et al., 2006; Davidar et al., 2007) but none of them

were in riparian forests except Chalakkudy river (Bachan, 2003), Valapattanam river (Sreedharan,

2005) of Kerala and Cauvery river of Tamil Nadu (Sunil et al., 2010).


TAXONOMY, DISTRIBUTION AND ECOLOGY OF THE RIPARIAN FLORA OF PAMBA RIVER, KERALA /Ph.D Thesis /Page 201

The Southern Western Ghats (SWG) region is an important centre for plant diversity and

endemism (Ramesh et al., 1997) where the Pamba river basin located. Even though Pamba River

has been undergone great materialistic and cultural changes, so far there is no riparian vegetation

assessment. The present chapter aims: (1) to analyze the species diversity along the general

elevation gradient in the tropical riparian forest of Pamba river basin, Southern Western Ghats,

India, (2) to analysis the density, distribution and abundance of riparian trees along the elevation

gradient of Pamba river, (3) to determine community structure, stand type, dispersion pattern of

riparian trees in the river basin along the elevation gradient and (4) to study the regeneration

status of major riparian trees in the Pamba river basin.

5.2 Review of Literature

Species richness, diversity and phytosociology of riparian vegetation have been studied in

many rivers of America, Europe, Africa and Australia. Significant research on riparian diversity

has been conducted by Thompson (1961) in Sacramento River, Tabacchi et al. (1990) in Adour

River, Roberts & Ludwig (1991) in Murray River, Baker (1990) and Tiegs et al. (2005) in Colorado

River, Nilssion et al. (1994) in Vindel River, Metzger et al. (1997) in Jacare-Pepira river, Salinas et al.

(2000) in Andarax River, Rosales et al. (2001) in Caura River, Boutin et al. (2002) in Boyer river,

Wassen et al. (2002) in Biebrza River, Johnson (2002) in Missouri River, Heartsill-Scalley & Aide

(2003) in La Plata River, Fierke & Kauffman (2005) in Willamette River, Balian & Naiman (2005)

in Queets River, Urban et al. (2006) in Macal River, Wittmann et al. (2008) in Miranda River and

Molder & Schneider (2011) in Danube River.

In Asian rivers, limited riparian diversity studies have been conducted. Sugimoto et al.

(1997) studied riparian vegetation of Toikanbetsu River and Nakamura et al. (1997) studied riparian

vegetation of Tokachi River. In Indian scenario, riparian vegetation diversity research has been

conducted in Tambiraparani River (Johnsingh & Joshua, 1989), Chalakkudy river (Bachan, 2003),

Valapattanam river (Sreedharan, 2005) of Kerala, Yamuna river (Chauhan & Gopal, 2005) of

Delhi and Cauvery river (Sunil et al., 2010) of Tamil Nadu. None of them discussed the regeneration

and phenology of riparian trees.



5.3 Materials and methods

The study area and physiography of has discussed in Chapter 2; Section 2.3.1 (Page no.: 25)

and Figs. 2.1 & 2.2. The study was conducted during 2007–2012. The voucher specimens of

riparian species were collected and identified with standard floras (Hooker, 1872–1897; Gamble

& Fischer, 1915–1936; Anilkumar & Sivadasan, 2005) and nomenclature validation with IPNI

(2011) and The PlantList (2011). The herbarium specimens were deposited in the School of

Environmental Sciences Herbarium, Mahatma Gandhi University, Kottayam, Kerala, India.

5.3.1 Field methods

Variation of elevation in meters above sea level (m asl) was considered as an indicator of

topographic species diversity and compared between the four stretches. The entire river stretch

was divided in to four fragments such as Lowland (abbreviated as LL, 1–7m asl, 10km), Midland

(abbreviated as ML, 8–70m asl, 90km), Highland (abbreviated as HL, 71–700m asl, 35km) and

Highrange (abbreviated as HR, ≥701m asl, 41km) as equivalent to the general elevation ranges

of the Kerala state. The elevation of each stretch and location of quadrat sites were obtained with

GPS 72 (Table 5.1). The quantitative data were gathered by nested quadrat method along the

elevation gradient, standardized to the length of stretch and natural vegetation in both banks

of the river (54 quadrats) (Fig. 5.1). Quadrats of 10×10m for trees, 5×5m for shrubs, climbers

and epiphytes and 1×1m for herbs were employed. The sizes of the quadrats for diversity

and phytosociology were determined by species-area curve method (Braun-Blanquet, 1932).

Species–area curve was plotted for all species, as the sequence of enumeration proceeded i.e.,

by sequential arrangement of fifty-four 1×1m, 5×5m and 10×10m quadrats. A total of 0.54ha was

sampled from the study area. The girth at breast height (GBH) of all trees (≥15 cm) was measured

with a measuring tape. The GBH classes of trees were analyzed for vegetation profile and

community structure.

The arrangement of quadrats for phytosociology has been modified (Fig. 5.3) due to

specific topography, linear shape of the ecosystem and floodplain width (ranges from 10–



30m) in the entire stretches of the river. Community or

stand types were analyzed by the Braun-Blanquet

table analysis approach (Braun-Blanquet, 1964). Relative

frequency classes of trees were noted from the 54 releves

(quadrats) in the entire study area along the elevation

gradient and constancy table prepared. Total number of

individuals, occurrence and relative frequency were

considered for analyzing stand type. We excluded

herbs, shrubs, climbers, epiphytes and parasites from

the phytosociological analysis due to their low relative

density in the quadrats studied. Moreover the frequent flood disturbance modifies herbaceous

vegetation and woody tree species were persisted to form the dominant component in community.

The Braun-Blanquet table analysis approach was also validated with TWINSPAN (Hill, 1979).

Regeneration status was analyzed for saplings from the 5×5m quadrats of 54 releves. Tree species

with a diameter of <15cm and height of <1.5m were considered as saplings.

Fig. 5.2 Nested quadrat used for the diversity and phytosociology analysis

Fig. 5.1 Study area and quadrat locations of the riparian diversity and phytosociology analysis



Altitude range Quadrat locations GPS locations Number of quadrats Total quadrats1-7m asl Pavukara N 9.322000, E 76.502000 6 6

8-70m asl

Aranmula N 9.329822, E 76.689797 6

26Melukara N 9.351467, E 76.711349 6Kezhukara N 9.347280, E 76.728230 4Edappavoor N 9.356720, E 76.784500 4Perunthenaruvi N 9.398000, E 76.863000 6

71-700m asl

Edakadathi N 9.415960, E 76.894480 2

16

Azhutha N 9.418160, E 76.941050 2Kisimim N 9.420520, E 76.989390 4Attathode N 9.413500, E 77.010556 2Kakkad Ar N 9.303450, E 77.053810 2Pamba Ar N 9.427500, E 77.095560 2Kakki Ar N 9.393230, E 77.115910 2

701-1962m aslKochupamba N 9.409940, E 77.148390 4

6Pancharamanal N 9.286300, E 77.118890 2

Table 5.1 Altitude ranges, locations and GPS points of the quadrats studied

Table 5.2 Phytosociological and statistical formulas used for the study



5.3.2 Phytodiversity analysis

The quantitative parameters such as frequency, density and abundance for trees, shrubs and

herbs and importance value index (IVI) of trees were calculated for plant diversity and floristic

structure (Simpson, 1949; Curtis & McIntosh, 1950; Shannon & Weiner, 1963; Pascal, 1988) (Table

5.2). The data were analyzed for species composition, structure, profile as per Curtis & McIntosh

(1951). A five-letter code was assigned to all the species for floristic structure with the first 2

letters denoting the generic epithet and the next 3 letters, the specific epithet. For taxa having

same codes, the last letter should be capitalized / extra letter added. Family importance value

(FIV) was calculated after Mori et al., (1983). GBH size class were analyzed by classification

and grouping of four stretches of river. The five degree scale of abundance (Braun-Blanquet &

Pavillard, 1928) was used for community analysis. The phenologies of major riparian trees were

analyzed seasonally along different stretches of the river. The flowering and fruiting months of

the year are noted and corroborated with available literature.

5.3.3 Statistical analysis

One-way analysis of variance (ANOVA) was used to analyze significant differences in the

species richness across the four stretches. Shannon-Weiner's diversity index (H’), Simpson’s

index (D), Margalef’s index of richness (Dmg), Pielou’s evenness index (J’) were calculated as

per Magurran (1988) with Microsoft Excel 2007. Tree dispersion pattern was determined by

standardized Morista’s index (Krebs, 1989). Species similarity between stretches was determined

by the multiple site similarity index (Diserud & Odegaard, 2007) (Table 5.2).

Reciprocal averaging (RA) was performed in order to examine the relationship between

the four riparian forest stretches of the Pamba river basin. Hierarchical cluster analysis for

54 quadrats were done with flexible beta (-0.250) linkage method and Sorensen (Bray-Curtis)

distance measure. Tree species data of 52 quadrats were used to classify both species and

quadrats by Two-Way Indicator Species Analysis (TWINSPAN) of Hill (1979), Gauch (1982),

Kent & Coker (1992) to determine the indicator species in riparian vegetation types. TWINSPAN

produces a tabular matrix arrangement that approximates a Braun-Blanquet phytosociological

analysis table. RA, Hierarchical clustering and TWINSPAN were done using PC-ORD version

4.14 (McCune & Mefford, 1999).



5.4 Results

The field inventory from 54 x 3 quadrates yielded a total of 2,468 individuals of plants

belonging pteridophytes, gymnosperms and angiosperms. This includes 230 species of plants,

of which 159 (69.13%) are woody in nature (Appendix 5.1–5.4). The tree species count obtained

from the total study area 79/0.54ha is comparable with tropical humid forest Silent Valley

(84/0.4ha) (Singh et al., 1981) and wet evergreen mixed forest of Nelliyampathy Hills (30/1ha)

(Chandrashekara & Ramakrishnan, 1994). In tropical rainforests, the range of tree species count

per ha is from about 20 to a maximum of 223 (Proctor et al., 1983; Whitmore, 1984). Excluding the

herbs, shrubs, climbers, epiphytes and parasites, there are 79 tree species belongs to 39 families,

of which Myrtaceae was the richest family with 8 species, followed by Euphorbiaceae, Moraceae

and Fabaceae with 5 species. However, based on the total number of individuals in all quadrats,

the family Rubiaceae (64 individuals) dominated, followed by Euphorbiaceae and Moraceae (49

individuals each), Fabaceae (44 individuals) and Dipterocarpaceae (43 individuals) (Fig. 5.3). A

similar trend of dominance by Euphoribaceae, Myrtaceae and Rubiaceae was reported in the

riparian forests of Chalakkudy river basin (Bachan, 2003).

5.4.1 Species–area curve and species richness

The species–area curves for the four stretches, increased up to 40 quadrats and there after

the species increment was gradual (Fig. 5.4). One-way ANOVA for the species richens among

the four riparian stretches showed significant variation (p>0.05, f = 1.1611). Species richness (SR)

in the riparian forests of Pamba river basin has resulted a ranking ML (151) >HL (103) >HR (45)

>LL (42) (Table 5.1). Similar trend (129 species from five 10×10m plots) was observed in the middle

stretches (Vazhachal region) of Chalakkudy river basin in Kerala (Bachan, 2002). The Margalef’s

richness index D(mg) indicated similar trend of SR from ML (20.56762) >HL (16.00336) >HR

(8.385706) >LL (7.607989) (Table 5.3).

5.4.2 Frequency and abundance of shrubs, climbers, epiphytes and herbs

The relative frequency of shrub, climber and epiphyte group (Appendix 5.1–5.4) indicated

that Clidemia hirta has highest value in HL and HR stretches, Piper longum in ML and Mikania micrantha in

LL stretches. The relative density also indicated that, C.hirta has highest value in ML, HL and HR



Fig. 5.4 Species-area curve of 54 quadrats from riparian forests of Pamba river basin

0

10

20

30

40

50

60

70

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Num

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Individuals

Species

Fig. 5.3 Dominant tree families with their species count and total individuals from the 54 quadrats of Pamba river basin

stretches but Leea guineense in LL stretch. The abundance indicated that L.guineense has highest in LL

and ML stretches, Clerodendrum infortunatum in HL and Sarcrandra chloranthoides in HR stretches.

Among this C.infortunatum, Clidemia hirta and M.micrantha are invasive weeds while L.guineense

is a pioneer floodplain shrub and S.chloranthoides is a natural evergreen undergrowth.



Indices Lowland Midland Highland HighrangeSpecies richness 42 151 103 45Shannon-Weiner Index H’ 1.46877 1.84841 1.71745 1.43689Simpsons dominance index D 1.00000 0.974481 0.966819 0.945374Simpsons reciprocal index 1/D 1.00000 1.026184 1.03432 1.057782Margalef’s richness index D(mg) 7.607989 20.56762 16.00336 8.385706Pielou’s evenness index J’ 0.392964 0.368409 0.370561 0.379709Multiple site similarity index 0.825396825

Table 5.3 Species richness, diversity indices, richness indices and multiple site similarity indices of riparian forests of Pamba river basin

The relative frequency of herbs indicated that Ageratum conyzoides in LL, Colocasia esculenta

in ML, Dictyospermum montanum and Globba sessiliflora in HL and G.sessiliflora in HR stretches

has highest values. The herbs showed highest relative density are C.esculenta in the LL and ML

stretches, G.sessiliflora in HL and Lagenandra meeboldii in HR stretches. The highest abundance showed

by Scoparia dulcis (LL), C.esculenta (ML), G.sessiliflora (HL) and Sonerilla versicolor (HR).

5.4.3 Phytodiversity

The diversity indices are enumerated in Table 5.3. Shannon-Weiner Index (H’) varies from

1.43689 to 1.84841 in four stretches of the river which indicated that all the stretches have

uniform diversity. The Simpsons dominance index (D) of four stretches varies from 0.945374

to 1.0 which indicated that the LL stretch was less diverse than the HR stretch, where

the dominance of single species minimized. Simpson’s reciprocal index (1/D) also ranges from

1.00000 to 1.057782 which was similar to the general trend. The Pielou’s evenness index (J’) of

the four stretches ranges from 0.368409 to 0.392964 which indicated that the communities of each

stretches were relatively varied in their species composition. The multiple site similarity index of

four stretches (0.825396825) which was near to 1, indicated greater homogeneity between the LL,

ML, HL and HR by having identical lists of species.

5.4.4 Important value index (IVI) and Family importance value (FIV)

Humboldtia vahliana showed the highest IVI (59.86) among dominant trees in the riparian

forests followed by Neolamarckia cadamba (50.05), Vateria indica (47.75) and Syzygium hemisphericum

(44.38) (Fig. 5.5, Appendix 5.1–5.4). All these species are natural riparian evergreen components,

essentially protects the river. The family Fabaceae has the highest importance value (34.82)



followed by Moraceae (28.08) Rubiaceae (26.57), Euphorbiaceae (25.42) and Dipterocarpaceae

(20.42) (Table 5.4). This FIV profile has the dominance of semi-evergreen (Fabaceae, Moraceae,

Euphorbiaceae etc) and evergreen (Rubiaceae, Dipterocarpaceae, Sapotaceae, Myrtaceae etc)

families. Probably this is due to the succession pattern in the floodplain forests, where frequent

terrain modification of riparian floodplain supports semi-evergreen species.

5.4.5 Forest types

The riparian plant communities of tropical rivers are composed of a diverse matrix of

evergreen, semi evergreen, deciduous, riverine, wetland and mangrove components and its sub

divisions (Fig. 5.6). The major forest types found in the Western Ghats mergers with the riparian

habitats to form a matrix of complex riparian communities and cannot be distinguish between

each forest types. However, the Pamba riparian forest composition showed affinity towards

West Coast Evergreen forests (Champion & Seth, 1968), Southern Moist Mixed Deciduous forests

which are usually found <700m asl., ie. in HL and ML regions of the river. Besides, in the uppers

stretches of the river (HR), components of Southern Montane Wet Temperate forests, Southern

Montane Wet Grasslands and Southern Hilltop Tropical Evergreen forests were found. In the

lower stretches (LL) components of Mangrove and Tidal forests, Wetland and Aquatic vegetation

and Coastal vegetation found. However, there is no clear cut distinction between forest types

and upper, middle and lower forest strata in the entire riparian stretches of the river basin.

5.4.6 Stand type

Unlike the surrounding Cullenia-Mesua-Palaquium and Dipterocarpus-Mesua-Palaquium stand

types recognized from the Western Ghats forests by Meher-Homji (1984), the riparian forests of

Pamba river basin has particular indicator species and stand types dominated in the four stretches

based on their density, relative frequency, total number and occurrence in the same quadrat.

Ochreinauclea missionis-Ficus hispida-Neolamarckia cadamba type

This stand type dominated in the LL stretch (Sediment deposition zone, 1–7m asl) of

riparian forests which were found limited patches along the cultivated surrounding landscape.

O.missionis (Endemic to Southern Western Ghats; Vulnerable B1+2c; IUCN, 2011) and N.cadamba

are true riparian tree species whose distribution solely protects the LL floodplain. Both trees



LL 1

1.17

LL 1

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LL 1

9.93

LL 5

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8.84

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81

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9.86

HL 1

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HL 2

4.81

HR 1

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25.

24

HR 4

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HR 4

7.75

0.00

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Fig. 5.5 IVI of major trees in the riparian forests of Pamba river basin. LL = Lowland, ML = Midland, HL = Highland and HR = Highrange

have long and deep tap root system which can withstand intense flood regime. These are relics of

evergreen riparian forests that once existed along the entire stretches of Pamba river. However,

F.hispida is a light demanding secondary species whose presence indicates disturbance in the

stand type and recent establishment within the stand.

Mallotus philippensis-Macaranga peltata-Ficus hispida type

In disturbed ML (Sediment deposition zone, 8–70m asl) stretch of the Pamba riparian forests

dominated disturbance adapted secondary species Mallotus philippensis, Macaranga peltata and

F.hispida. Natural riparian forest in this region has been destroyed by anthropogenic pressure

and dominated disturbance indicators in the floodplain.

Ochreinauclea missionis-Lagerstroemia speciosa-Hydnocarpus pentandra type

Besides the disturbance indicator secondary stand type, a natural riparian stand composed

of pioneer riparian tree O.missionis along with H.pentandra and L. speciosa was also found in

the ML (Sediment deposition zone, 8–70m asl) riparian forests of Pamba river basin. This stand

functions as protecting belt for the alluvial floodplains in the ML where agriculture and

anthropogenic activities evident.



Family SR RDi RD RBA FIVFabaceae 5 6.49 7.63 20.70 34.82Moraceae 5 6.49 8.49 13.09 28.08Rubiaceae 2 2.60 11.09 12.88 26.57Euphorbiaceae 5 6.49 8.49 10.43 25.42Dipterocarpaceae 2 2.60 7.45 10.37 20.42Sapotaceae 4 5.19 6.07 5.33 16.59Myrtaceae 6 7.79 4.85 3.34 15.98Lythraceae 2 2.60 5.37 5.81 13.78Achariaceae 2 2.60 5.89 4.38 12.87Lauraceae 3 3.90 3.81 0.74 8.45Anacardiaceae 2 2.60 1.73 4.05 8.38Malvaceae 3 3.90 2.60 1.53 8.02Phyllanthaceae 3 3.90 1.56 0.21 5.67Symplocaceae 1 1.30 3.99 0.38 5.67Ebanaceae 3 3.90 1.39 0.24 5.52Calophyllaceae 2 2.60 1.56 1.07 5.23Apocynaceae 2 2.60 1.91 0.66 5.16Clusiaceae 2 2.60 1.39 0.77 4.75Combretaceae 2 2.60 1.56 0.36 4.51Arecaceae 1 1.30 2.08 0.17 3.54Myristicaceae 1 1.30 1.21 0.93 3.45Verbenaceae 1 1.30 1.56 0.30 3.16Lamiaceae 1 1.30 0.87 0.39 2.56Tetramelaceae 1 1.30 1.04 0.18 2.51Lecythidaceae 1 1.30 1.04 0.15 2.49Staphyleaceae 1 1.30 0.87 0.16 2.33Celastraceae 1 1.30 0.35 0.57 2.21Salicaceae 1 1.30 0.69 0.12 2.12Sapindaceae 1 1.30 0.69 0.11 2.11Dilleniaceae 1 1.30 0.52 0.23 2.05Elaeocarpaceae 1 1.30 0.35 0.15 1.80Cycadaceae 1 1.30 0.35 0.06 1.70Oleaceae 1 1.30 0.35 0.00 1.65Podocarpaceae 1 1.30 0.17 0.07 1.54Meliaceae 1 1.30 0.17 0.02 1.49Bignoniaceae 1 1.30 0.17 0.02 1.49Rhizophoraceae 1 1.30 0.17 0.01 1.48Pentaphylacaceae 1 1.30 0.17 0.00 1.48Annonaceae 1 1.30 0.17 0.00 1.48Polygalaceae 1 1.30 0.17 0.00 1.47

Table 5.4 The contribution of tree families to species richness (SR), Relative diversity (RDi) Relative density (RD), Relative basal area (RBA) and family importance value (FIV), arranged in decreasing FIV in the 54 plots of riparian forest in Pamba river basin.



131

86

66

64

61

52

44

44

31

0 20 40 60 80 100 120 140

Evergreen forests

Semi evergreen forests

Wetland & Marshes & Mangrove associates

Riparian forests

Moist deciduous forests

Cultivated

Deciduous forests

Degraded forests & Wastelands & Weeds

Grassland & Shola forests

Number of species

Madhuca neriifolia-Hydnocarpus alpina-Humboldtia vahliana type

This natural stand of riparian forests composed of evergreen riparian pioneer floodplain

species H.alpina, M.neriifolia and H.vahliana in the HL (Sediment transport zone, 71–700m asl)

stretches. In this stretch, the channel has ‘V’ shaped with rocky substratum and formation of

floodplain has been minimum. Hydnocarpus alpina belongs to the West Coast Tropical Evergreen

forests while M.neriifolia and Humboldtia vahliana belongs to typical riparian trees

Hopea ponga -Vitex leucoxylon -Vateria indica type

This natural stand has the critically endangered (A1cd; IUCN, 2011) Southern Western Ghats

endemic tree V.indica and Western Ghats endemic endangered (A1cd+2cd, B1+2c; IUCN, 2011)

H.ponga which forms dominant riparian trees in the HL (Sediment transport zone, 71–700m asl)

riparian stretches. The ‘V’ shaped channel and limited floodplain of this region has supported

evergreen Vitex leucoxylon and Vateria indica.

Symplocos cochinchinensis var. laurina-Syzygium hemisphericum-Cullenia exarillata type

The highrange (Sediment erosion zone, ≥701m asl) stretch riparian forests has composed of

evergreen species. The Southern Western Ghats endemic C.exarillata is a typical dominant tree in

the Southern hilltop tropical evergreen forests, associated with Palaquium ellipticum and Mesua

ferrea (Pascal, 1988). But in the riparian forests, it found associated with Symplocos cochinchinensis

var. laurina and Syzygium hemisphericum.

Fig. 5.6 Major forest/habitat components of riparian vegetation in Pamba river basin



5.4.7 Community structure

The riparian forest stands showed vertical distribution of trees with the predominance of

medium-sized individuals; followed by a decreased proportion of small and emergent trees.

The tree density of the four stretches indicated an increasing trend from LL (4.00m2/0.06ha)

<ML (10.56m2/0.26ha) <HL (11.07m2/0.16ha) and <HR (16.50m2/0.06ha). Similarly total basal

area also showed an increasing drift from LL (8569.7m2/0.06ha) <ML (146276.8m2/0.26ha),

<HL(157914.1m2/0.16ha) and <HR (20033.8m2/0.06ha) (Table 5.5) even though sampling area

for both measurements are according to the length of stretches.

5.4.8 GBH and Abundance class

The GBH size class of the riparian trees ranges from 15 to >331 where most of the trees having

low GBH class (Fig. 5.7). The ML, HL and HR regions have the dominance of 15–30cm, 31–60cm

and 61–90cm GBH class. The general trend in the GBH size class distribution was a reverse ‘J’

shaped curve suggesting relatively young riparian forest stand and continuous recruitment of

pioneer tree species along the stretches. This is probably due to the proximity and frequency

of minor floods in which vegetation on surfaces close to an active river channel are likely to be

characterized by younger stands of shrubs and trees, whereas floodplains further from the

active channel may contain older, less species rich plant communities (Kovalchik & Chitwood,

1990; Gregory et al., 1991; Goodwin et al., 1997). The local abundance along the river stretches

include abundant (Abundance class = 10–14) Leea guineense and Colocasia esculenta from LL and

ML stretches respectively. For the not very abundant (Abundance class = 5–9) group, a total of

28 species and rare (Abundance class = 1–4) 140 species were found in all stretches. However, the

local abundance is not significant when intermittent flooding regime prevalent.

5.4.9 Spatial dispersion pattern

From the Morisita index of dispersion (Table 5.6), the dominant Ochreinauclea missionis,

Neolamarckia cadamba and Ficus hispida in the LL stretch, showed clumped dispersion pattern. In

ML stretch, O.missionis, F.hispida, Macaranga peltata, Lagerstroemia speciosa and Mallotus philippensis

also showed clumped dispersion pattern. However, 48.14% of trees showed random dispersion

pattern in ML stretch due to anthropogenic interference. In the HL stretch, Humboldtia vahliana,

Madhuca neriifolia, Hopea ponga and Hydnocarpus alpina showed clumped dispersion pattern.



River stretches Releves (n)* Species richness Tree density Basal area

Lowland 6 42 4.00 m2/0.06ha 8569.7 m2/0.06haMidland 26 151 10.56 m2/0.26ha 146276.8 m2/0.26haHighland 16 103 11.07 m2/0.16ha 157914.1 m2/0.16haHighrange 6 45 16.50 m2/0.06ha 20033.8 m2/0.06haTotal 54 42–103 4.00 –16.50 8569.7–157914.1

57.14% tree species randomly dispersed in this stretch. In Hr stretch, Symplocos cochinchinensis

var. laurina and Vateria indica were dispersed in clumped pattern. Here also 57.14% tree species

were randomly dispersed. The random dispersed trees were rare in the corresponding stretches

as per their abundance class. The predominant clumped dispersion of dominant trees was consistent

with the results of various other tropical forest studies (Ashton, 1969; Whitmore, 1975; Hubbell,

1979; Thorington et al., 1982; Parthasarathy & Karthikeyan, 1997a,b).

5.4.10 Succession types

The floristic composition of the 4 stretches indicated that, natural riparian forests in LL and

ML were damaged by anthropogenic activities and flood disturbance. However, the remaining

limited patches of riparian forests in Pavukara, Aranmula, Kezhukara and Melukara have the

relict pioneer species. Even though Ochrenauclea missionis showed high regeneration status of in

Aranmula region, the remaining areas of LL and ML have secondary species like Macaranga peltata,

Ficus hispida and Mallotus philippensis. Regeneration of pioneer riparian trees was minimum in

these stretches. In the Hl stretches, the natural primary riparian forest trees dominated with

good regeneration percentage and the secondary tree species constitute 11.11% of total stand

composition. In the Hr stretch, pioneer evergreen trees were dominated in the stand and secondary

light demanding trees constitute 4.76%.

5.4.11 Phenological spectra

The phonological spectrum of the major trees in the riparian forests (Table 5.7) showed

peak and lean seasons. Observation on 40 trees from the riparian forests of Pamba river basin

indicated that, a general trend of peak flowering during December–January months (winter

season) and the fruiting peak during the months of March–May (hot summer season) (Fig. 5.8).

However intermittent flowering and fruiting also observed. The flowering and fruiting of these

riparian trees generally related to the tropical monsoon with seasonally excessive rainfall and

hot summer climate.

Table 5.5 Stand characteristics of riparian forest stretches of Pamba river basin. * Each releve consists of 1×1m, 5×5m and 10×10m quadrats



Botanical name LL ML HL HRAlstonia scholaris - 0.010248 (r) - -Aporosa acuminata 0.096774 (r) - - -Aporosa cardiosperma - 0.102544 (c) - -Artocarpus hirsutus - 0.061514 (r) 0.031444 (r) -Baccaurea courtallensis - - 0.010478 (r) -Barringtonia acutangula - 0.061514 (r) 0.010478 (r) -Bombax ceiba - 0.030751 (r) - -Calophyllum calaba - - 0.06291(r) -Caryota urens - 0.677725 (c) - -Cinnamomum keralaense - - - 0.033645 (r)Cinnamomum malabatrum - 0.677725 (c) 0.010478 (r) -Cullenia exarillata - - - 0.406015 (c)Cycas circinalis - 0.010248 (r) - -Dillenia pentagyna - 0.030751 (r) - -Dimocarpus longan - - 0.031444 (r) -Diospyros malabarica - 0.010248 (r) - 0.011204 (r)Diospyros paniculata - - - 0.033645 (r)Ficus hispida 1.5 (c) 3.088497 (c) 0.031444 (r) -Ficus racemosa - 0.153846 (c) - -Garcinia wightii - - 0.104884 (c) -

Fig. 5.7 GBH size class in the riparian forests stretches of Pamba river, Kerala. LL= lowland, ML = Midland, HL = Highland and HR = Highrange

Table 5.6 Morisita index and dispersion pattern of trees in the different stretches Pamba river. LL = Lowland, ML = Midland, HL = Highland and HR = Highrange; r = random, c = clumped

LL 7

LL 6

LL 4

LL 1 LL

3

LL 2

LL 1

ML 8

0

ML 7

7

ML 5

1

ML 2

2

ML 1

4

ML 1

6

ML 8

ML 5

ML 1 M

L 2

HL 4

4

HL 4

1

HL 4

0

HL 1

6

HL 1

3

HL 9

HL 4

HL 4

HL 2

HL 2

HL 2

HL 1

HR 37

HR 22

HR 13

HR 9

HR 7

HR 4

HR 2

HR 2

HR 1

HR 1

0

10

20

30

40

50

60

70

80

15 -

30

31 -

60

61 -

90

91 -

120

121

-150

151

-180

181

-210

211

-240

241

-270

271

-300

301

-330

> 33

1

Num

ber o

f ind

ivid

uals

GBH Size class



Holigarna arnottiana - 0.030751 (r) - -Hopea ponga - - 2.436388 (c) -Humboldtia vahliana - - 5.248677 (c) -Hydnocarpus alpina - 0.010248 (r) 1.43205 (c) -Hydnocarpus pentandra - 0.934808 (c) - -Lagerstroemia microcarpa - - 0.104884 (c) -Lagerstroemia speciosa - 1.954114 (c) 0.157377 (c) -Lophopetalum wightianum - - 0.010478 (r) -Macaranga peltata - 2.603602 (c) - -Madhuca neriifolia - - 4.919008 (c) -Mallotus philippensis - 1.397905 (c) 0.010478 (r) -Mallotus tetracoccus - - 0.031444 (r) -Mesua ferrea - - - 0.067353 (r)Myristica fragrans - 0.215427 (c) - -Neolamarckia cadamba 0.590164 (c) 0.030751 (r) - -Ochreinauclea missionis 2.847458 (c) 11.17757 (c) 0.010478 (r) -Palaquium ellipticum - - - 0.011204 (r)Persea macrantha - 0.030751(r) - 0.011204 (r)Pongamia pinnata - 0.061514 (r) - -Salix tetrasperma - - - 0.067353 (r)Symplocos cochinchinensis var. laurina - - - 2.637488 (c)Syzygium gardneri - - - 0.033645 (r)Syzygium hemisphericum - - - 0.746466 (c)Syzygium munronii - - - 0.168697 (c)Syzygium occidentale - 0.030751 (r) 0.010478 (r) -Tabernaemontana alternifolia - 0.287293 (c) - -Terminalia paniculata - 0.287293 (c) - -Tetrameles nudiflora - 0.102544 (c) - -Turpinia malabarica - - - 0.11236 (c)Vateria indica - - 0.157377 (c) 1.190926 (c)Vitex leucoxylon - - 0.378077 (c) -

5.4.12 Regeneration status

The regeneration status of trees in the riparian forests of Pamba river basin indicated that

Madhuca neriifolia (Sapotaceae) showing highest sapling frequency, density and abundance

followed by Hopea ponga and Humboldtia vahliana (Table 5.8). All these trees are typical riparian

floodplain / slope species which forms the dominant canopy and stand in the HL region of the

river. Moreover riparian trees in the ML and LL region showed low percentage of regeneration

except Ochreinauclea missionis, which has a sapling abundance of 10.00.



5.4.13 Reciprocal averaging (RA)

The Reciprocal Averaging (Fig. 5.9) of total species counts (Trees, shrubs, climbers,

epiphytes and herbs) clearly separates along the first axis by the 6 releves of HR stretch (Cluster

III) from the 12 releves of HL stretch (Cluster II). The second axis separates Cluster I to Cluster

II and III, where Cluster I consists of LL and ML releves. The rest of the releves can be seen in

varied in between locations, at the central point of this axis which belongs to the ML stretches.

The assimilation of LL and ML releves are largely due to the similar species composition.

However, the species composition of HR stretch clearly separates from the other stretches which

are also evident from the cluster analysis.

5.4.14 Hierarchical clustering

A similar trend of RA was observed in the cluster analysis and unequivocally define two

major groups: HR (6 quadrat sites) and Ll (6–1quadrat sites) stretches, which is in accordance

with the elevation river profile, where ±700m asl is a critical delimiting factor the type of vegetation

in the Western Ghats mountain ranges. The vegetation type of Kerala State largely depends this

elevation gradient and 1m asl up to 700m asl, more or less anthropogenic disturbances modifies

vegetation and forest type. From the cluster dendrogram (Fig. 5.10), many of the LL (1–7m asl)

and ML (8–70m asl) quadrats sites intergrading due to similar species composition. However,

the HL stretch (71–700m asl) show relatively stable species composition due to less anthropogenic

disturbances.

5.4.15 TWINSPAN

The diversity of trees is fundamental to total rainforest biodiversity, because trees provide

resources and habitat structure for almost all other rainforest species (Cannon et al., 1998). The

TWINSPAN analysis for the tree species indicated that there was a distinct assemblage of indicator

species in the four stretches (Fig. 5.11). Like Braun-Blanquet phytosociological analysis table, the

two-way ordered table clearly separates 4 clusters of trees with their corresponding elevation

stretches. The classification of species at the first level (Eigenvalue: 0.8842) clearly separated 20

Hr tree species from the rest. Among this cluster Symplocos cochinchinensis var. laurina-Syzygium

hemisphericum-Cullenia exarillata type dominated. In the second level (Eigenvalue: 0.3275), 19



Botanical nameMonths

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecAporosa cardiosperma ❀ ❀ ◉ ◉Barringtonia acutangula ❀ ◉ ◉ ❀

Barringtonia racemosa ❀ ❀◉ ◉Calophyllum calaba ❀ ❀◉ ◉Calophyllum inophyllum ❀ ❀ ◉Carallia brachiata ❀ ❀◉ ◉Cerbera odollam ❀ ❀◉ ◉Chionanthus mala-elengi ❀ ◉ ◉ ◉ ❀

Cinnamomum malabatrum ❀ ◉ ◉ ❀

Crataeva magna ❀ ◉ ◉ ◉ ❀ ❀

Diospyros sulcata ◉ ◉ ❀ ❀Elaeocarpus tuberculatus ❀ ❀ ◉ ◉Garcinia gummi-gutta ❀ ❀ ◉ ◉Garcinia wightii ❀◉ ◉ ◉ ❀Glochidion zeylanicum ❀ ❀◉ ◉Hibiscus tiliaceus ◉ ❀ ❀ ◉Holigarna arnottiana ❀ ❀ ◉ ◉Hopea ponga ❀ ❀◉ ◉Humboldtia vahliana ❀ ❀ ◉ ◉Hydnocarpus alpina ❀ ❀

Hydnocarpus pentandra ❀ ❀ ◉ ◉Ixora brachiata ❀ ❀ ❀ ◉ ◉ ❀

Lagerstroemia speciosa ❀ ❀ ◉ ◉Lophopetalum wightianum ❀ ❀ ◉ ◉Madhuca neriifolia ❀ ◉ ◉ ❀

Mallotus nudiflorus ◉ ◉ ❀ ❀ ❀

Mallotus tetracoccus ◉ ❀ ❀ ❀ ◉Morinda citrifolia ◉ ◉ ❀ ❀

Neolamarckia cadamba ❀ ❀ ◉ ◉Ochreinauclea missionis ❀ ❀ ❀ ❀ ◉ ◉Pongamia pinnata ❀ ❀◉ ◉Salix tetrasperma ❀ ❀ ◉ ◉Syzygium occidentale ❀ ◉ ◉ ❀

Syzygium salicifolium ❀ ❀ ◉ ◉Tetrameles nudiflora ◉ ◉ ◉ ❀ ❀

Thespesia populnea ◉ ❀ ❀ ◉Vateria indica ❀ ❀◉ ◉Vitex altissima ❀ ❀◉ ◉ ◉Vitex leucoxylon ❀ ◉ ◉ ❀

Xanthophyllum arnottianum ◉ ◉ ❀ ❀

Table 5.7 Flowering and fruiting phenology of major riparian trees in the Pamba river basin.❀ = Flowering and ◉ = Fruiting


TAXONOMY, DISTRIBUTION AND ECOLOGY OF THE RIPARIAN FLORA OF PAMBA RIVER, KERALA /Ph.D Thesis /9

HL tree species separated from the rest. In this cluster, Hopea ponga-Vitex leucoxylon-Vateria indica type

and Madhuca neriifolia-Hydnocarpus alpina-Humboldtia vahliana type dominated. In the third level

clustering (Eigenvalue: 0.0729), ML trees are separated where Ochreinauclea missionis-Lagerstroemia

speciosa-H.pentandra type and Mallotus philippensis-Macaranga peltata-Ficus hispida type dominated.

In the fourth level (Eigenvalue: 0.0606) LL trees are separated where O.missionis-F.hispida-

Neolamarckia cadamba type dominated.

0

5

10

15

20

25

30

35

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Num

ber o

f tre

e sp

ecie

s

Fruiting

Flowering

Fig. 5.8 Flowering and fruiting phenology of major riparian trees in the Pamba river basin

5.5 Discussion

The riparian forests of Pamba river basin harbors diverse flora with high species richness.

Species composition and richness varies relatively homogenous along the elevation gradient but

high species richness observed in the ML stretch. Similar trend (129 species from five 10×10m

plots) was observed in the middle stretches (Vazhachal region) of Chalakkudy river basin of Kerala

(Bachan, 2003). The high species richness in the midland region of the Pamba river probably

explained by intermediate disturbance hypothesis (Connell, 1978; Huston, 1979; Renofalt et

al., 2005) where intermittent small scale floods prevalent. After the 1986 major flood event in the



Botanical name Total individuals Qn Frequency Density AbundanceMadhuca neriifolia 174 13 23.21429 3.107143 13.38462Hopea ponga 74 12 21.42857 1.321429 6.166667Barringtonia acutangula 56 5 8.928571 1.000000 11.2Humboldtia vahliana 36 9 16.07143 0.642857 4Xanthophyllum arnottianum 34 6 10.71429 0.607143 5.66667Artocarpus hirsutus 31 9 16.07143 0.553571 3.444444Mallotus philippensis 31 8 14.28571 0.553571 3.875Garcinia wightii 31 3 5.357243 0.553571 10.3333Ochreinauclea missionis 30 3 5.357243 0.535714 10Cinnamomum malabatrum 27 9 16.07143 0.482143 3Barringtonia racemosa 27 8 14.28571 0.482143 3.375Dimocarpus longan 27 2 3.571429 0.482143 13.5Ficus hispida 25 9 16.07143 0.446429 2.777778Caryota urens 24 12 21.42857 0.428571 2Symplocos cochinchinensis var. laurina 24 6 10.71429 0.428571 4

Table 5.8 Regeneration of major riparian trees along the entire stretches of Pamba river. Qn = Number of quadrat in which the species occurred

Fig. 5.9 RA diagram of different riparian forest stretches of Pamba river basin. ▲= quadrat sites. Cluster I is a combination of Lowland and Midland regions of the river stretch, Cluster II represents the Highland and Cluster III represents Highrange. An outlier group which belongs to Midland region is represented in red circular line.



Fig. 5.10 Hierarchical clustering diagram of 54 quadrat sites in 4 stretches of Pamba river

river basin, there was no major flood event occurred. The alluvial flood plain formation in the

river started from an elevation of 22m asl near Vadasserikkara. This local geology and topogra-

phy of the river in the midland region influence the recruitment of upland species by hydrochory.

Species composition varies widely according to the frequency of river disturbances (Oliveira-

Filho et al., 1994; Metzger et al., 1997). This spatial heterogeneity resulting from geomorphological

processes is viewed as one of the major causes of species richness (Hupp, 1988; Gould & Walker,

1997; Ferreira & Stohlgren, 1999). Even though the degree of disturbance in the riparian forests

of Pamba river has not been analyzed, the anthropogenic stress like cultivation, sand mining and

the intermittent small scale floods prevalent in LL and ML stretches. However, the disturbance

is not among the most important factors that affect species diversity (Mackey & Currie, 2001) but

variation in species richness and composition also related to natural site variations like elevation,

slope and mean annual precipitation (Wyant & Ellis, 1990). It was recorded that the maximum

environmental heterogeneity occurs in midcourse resulting highest species richness and habitat

diversity (Huston, 1979; Vannotte et al., 1980; Tabacchi et al., 1990).



Fig. 5.11 Two-Way ordered table of TWINSPAN of 52 quadrats in 4 stretches of Pamba river (TWINSPAN calculation excluded insufficient data from 2 quadrats)



The dominance of tree families Rubiaceae, Euphorbiaceae Moraceae, Fabaceae and

Dipterocarpaceae in the riparian forests of Pamba river basin indicated rather a mixture of

forest types of the tropical climate. There has no riparian tree data for comparison from India

except Chalakkudy river basin where a similar trend was noticed (Bachan, 2003). However in

Malaysian tropical forests (Ho et al., 1987; Manokaran et al., 1991) and tropical evergreen forest at

Varagalaiar, Western Ghats (Ayyappan & Parthasarathy, 1999), the family Euphorbiaceae dominated.

In broad-leaved forest of Taiwan, the family Lauraceae and Rubiaceae were dominated (Hara et

al., 1997). The wet evergreen forest of Kalakad-Mundanthurai Tiger Reserve was dominated by

Lauraceae, Euphorbiaceae, Myrtaceae and Rubiaceae families (Parthasarathy, 2001).

Riparian forest structure and composition affected by the surrounding forest type but an

unambiguous dominance of relatively young riparian stand and indicator species along the four

stretches of the Pamba river. The composition of riparian forests includes components of west

coast tropical evergreen, southern moist mixed deciduous, southern montane wet temperate,

southern montane wet grassland, southern hilltop tropical evergreen, mangrove and wetland

forests in mixed matrix. However, the close similarity was with west coast tropical evergreen

type as observed in Chalakkudy river (Bachan, 2003). The riparian vegetation also showed similarity

with tree species composition along the Valapattanam river where a significant dominance of

mangroves in the lowland region reported (Sreedharan, 2005). Unlike the surrounding landscapes,

the riparian forest stand type consists of both pioneer and secondary tree species in the lowland

and midland stretches, where anthropogenic and flood disturbance regime predominant. In

highland and highrange stretches, the river flows through the protected area Periyar Tiger Reserve

(PTR) so that the anthropogenic pressure has been minimized where natural pioneer riparian

stand type dominated. Conversely, in the headwater stretch of the river (Kochupamba, Gavi,

Anathode, Kullar and Meenar) was fragmented due to dam operations. Even though this river

regulation affected the diversity pattern in the highrange stretches to large extent, the natural

recovery of this evergreen riparian zone has been endure well due to conservation of the area

as tiger reserve. This field observation was supported by floodplain wetland study in the River

Yamuna, near Delhi (Chauhan & Gopal, 2005) which reported that hydrological regime play the

dominant role in developing and maintaining plant community structure.



It was reported that clumping of individuals of the same species may be due to inefficient

mode of seed dispersal (Richards, 1996) or opportunity or chance as when numerous saplings

are able to grow up where a large tree has died or in a large gap due to wind fall (Armesto et al.,

1986; Richards, 1996). But as in the case of riparian floodplains, it was observed that the clumping

of stands probably due to the sapling density and limitation of floodplain area along the linear

stretches. It was also found that the floodplain of the ML found be 2-5 meters lower from the highest

terrace, where cultivation was evident. This constraint of seed recruitment and sapling density of

riparian trees in the floodplain due to physiographical restriction resulted clumped dispersion.

Uniform dispersion patterns of species in tropical forests largely enable the maintenance of high

levels of diversity (Connell, 1971) and this pattern may be the consequence of direct competition

for water or allelopathy (MacMohan & Schimpf, 1981). In the riparian forests of Pamba river

basin, this uniform dispersion pattern also restricted due to physiographical limitation. Random

pattern was relatively higher in the ML stretch probably due to the intermittent flood disturbance.

According to Armesto et al. (1986), random patterns are exhibited by species that are subjected to

frequent large-scale disturbance. The dispersion pattern and density of riparian trees along the

ML stretch indicated that, disturbance regime played significant role in the community structure.

The effects of flooding on growth of the seedlings differed with the tree species because of

differences in leaf-emergence pattern and physiological flood tolerance. The responses of tree

seedlings to flooding reflected species habitats and growth patterns (Sakio, 2005).

In South India, no data unavailable for riparian forest trees for direct comparison and

difficult to compare with other tree diversity records due to variation in the methods, plot area,

dimension and size threshold considered. However, comparison with the diversity inventories

from Malaysia (Poore, 1968; Ho et al., 1987; Manokaran and LaFrankie, 1990), Peninsular India

(Parthasarathy & Karthikeyan, 1997a; Parthasarathy, 1999; Pascal & Pelissier, 1996; Sukumar et

al., 1992), French Guiana (Riera, 1995), Costa Rica (Lieberman et al., 1983; Nadkarni et al., 1995)

and Brazilian Amazon (Campbell et al., 1986; Swaine et al., 1987) indicated that the GBH size

class distribution in the riparian stretches of Pamba river basin was immature. The LL stretch,

the GBH size class distribution has irregular due to the anthropogenic activities like clearing of

riparian trees for cultivation and timber. While in ML, HL and HR stretches relative young GBH

class (15–30cm, 31–60cm and 61–90cm) dominated probably due to the intermittent distur-

bances which modifies the stand age and structure.



The stand type along the riparian stretches revealed that there has been an elevation gradient

for distinct assemblages of disturbance adapted indicator species. These stand types are significantly

different from Cullenia-Mesua-Palaquium and Dipterocarpus-Mesua-Palaquium types recognized by

Meher-Homji (1984) in the evergreen Western Ghats forests, rather a mixture of surrounding

landscape elements like west coast tropical evergreen, southern moist mixed deciduous and

southern montane wet temperate forests as per Champion & Seth (1968). However, the elements of

these evergreen stands such as Cullenia exarillata, Mesua ferrea and Palaquium ellipticum have been

reported from the HR stretch of the river similar to Nelliyampathy Hills (Chandrashekara &

Ramakrishnan, 1994). The strata differentiation of the riparian forests indicated that there has

been no precise differentiation between upper and middle strata due to relatively young stand.

The phenological spectrum of the major trees in the riparian forests showed peak and lean

seasons. A general trend of flowering peak during December–January (winter season) and the

fruiting peak during the months of March–May (hot summer season) is corroborated with the

general observation in the Western Ghats forests (Joshi & Janarthanam, 2010). Similar peak and

lean seasons were observed with regard to tree species in the Neotropics (Smythe, 1970; Frankie

et al., 1974; Milton et al., 1982). The flowering and fruiting of these riparian trees generally related to

the tropical monsoon with seasonally excessive rainfall and hot summer climate. The dry season

peak flowering and fruiting is similar to the patterns reported in the tropical seasonal dry forests

of India (Shukla & Ramakrishnan, 1982; Singh & Singh, 1992; Murali & Sukumar, 1994; Selwyn

& Parthasarathy, 2006), Costa Rica (Opler et al., 1980) Africa (Burger, 1974; Boaler, 1966) and that

of trees in the tropical moist deciduous forests (Rawitscher, 1948; Webb, 1959; Daubenmire, 1972;

Longman & Jenik, 1974; Borchert, 1980; Reich & Borchert, 1982). Trees in the semi-evergreen and

the evergreen forests flower in the months of March and May, respectively. These habitats are

characterized by an absence of lateritic substrate and are at higher altitude. As a result of the

higher elevations they also receive mist, which provides additional moisture (Ramesh & Pascal,

1997). It appears that the moisture content of the soil is the main determinant of phenological

patterns (Prins, 1988; Joshi & Janarthanam, 2004). Therefore, it can be expected that phenological

patterns shown by the riparian trees may vary along the altitudinal gradients, variation in the

length of the dry season and the amount of rainfall.



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Botanical name HabitLOWLAND

RF RD A RBA IVITreesAporosa acuminata T 1.28 0.91 2.00 1.28 3.47Ficus hispida T 2.56 2.74 3.00 5.86 11.17Garcinia gummi-gutta T 1.28 0.46 1.00 9.38 11.12Mangifera indica T 1.28 0.91 2.00 17.73 19.93Neolamarckia cadamba T 2.56 1.83 2.00 45.66 50.05Ochreinauclea missionis T 5.13 3.65 2.00 20.06 28.84Pongamia pinnata T 1.28 0.46 1.00 0.03 1.77Shrubs, Climbers & EpiphytesCentrosema pubescens C 5.13 6.39 3.50Chassalia curviflora var. ophioxyloides S 1.28 0.91 2.00Chromolaena odorata S 1.28 0.46 1.00Dioscorea bulbifera C 1.28 2.28 5.00Flueggea leucopyrus S 1.28 0.46 1.00Glycosmis pentaphylla S 5.13 3.20 1.75Ichnocarpus frutescens C 1.28 0.46 1.00Ixora coccinea S 1.28 2.74 6.00Leea guineense S 2.56 11.87 13.00Mikania micrantha C 6.41 7.31 3.20Mukia maderaspatana C 1.28 0.46 1.00Mussaenda frondosa S 1.28 0.91 2.00Pothos scandens C 1.28 2.74 6.00Solanum rudepannum S 1.28 0.46 1.00Tiliacora acuminata C 5.13 5.02 2.75Triumfetta rhomboidea S 2.56 1.83 2.00Urena lobata S 1.28 0.46 1.00Ziziphus oenopolia S 1.28 0.91 2.00HerbsAgeratum conyzoides H 3.85 3.20 2.33Alternanthera sessilis H 2.56 2.28 2.50Amaranthus spinosus H 2.56 2.28 2.50Cleome rutidosperma H 2.56 5.02 5.50Colocasia esculenta H 2.56 4.57 5.00Commelina diffusa H 3.85 2.74 2.00Eclipta prostrata H 2.56 1.83 2.00Grangea maderaspatana H 1.28 0.46 1.00Leucas zeylanica H 2.56 2.74 3.00

Appendix 5.1 Relative frequency, relative density, abundance, relative basal area and IVI of riparian vegetation in lowland stretch of Pamba river basin. RF = Relative Frequency, RD = Relative Density, A = Abundance, RBA = Relative Basal Area, IVI = Importance Value Index, T = Tree, C = Climber, S = Shrub, E = Epiphyte and H = Herb.



Botanical name HabitMIDLAND

RF RD A RBA IVITreesAdenanthera pavonina T 0.47 0.27 2.00 3.67 4.48Alstonia scholaris T 0.47 0.14 1.00 0.49 1.16Annona squamosa T 0.23 0.07 1.00 0.02 0.32Aporosa cardiosperma T 0.47 0.34 2.50 0.49 1.46Areca catechu T 0.47 0.14 1.00Artocarpus heterophyllus T 0.23 0.07 1.00 0.14 0.44Artocarpus hirsutus T 0.70 0.27 1.33 4.76 5.63Bambusa bambos B 0.23 0.07 1.00Bambusa vulgaris B 0.23 0.07 1.00Barringtonia acutangula T 0.47 0.27 2.00 0.14 1.04Bombax ceiba T 0.47 0.20 1.50 0.69 1.59Calophyllum calaba T 0.23 0.07 1.00 0.01 0.31Carallia brachiata T 0.23 0.07 1.00 0.05 0.35Caryota urens T 1.40 0.82 2.00 0.84 3.15Chrysophyllum cainito T 0.23 0.07 1.00 0.01 0.31Cinnamomum malabatrum T 1.16 0.82 2.40 1.10 3.41Cocos nucifera T 1.16 0.54 1.60Cycas circinalis T 0.47 0.14 1.00 0.29 0.73Dillenia pentagyna T 0.70 0.20 1.00 1.19 1.69Diospyros malabarica T 0.23 0.14 2.00 0.08 0.38Ficus hispida T 2.09 1.70 2.78 6.88 11.20Ficus racemosa T 0.47 0.41 3.00 0.47 1.44Garcinia gummi-gutta T 0.23 0.07 1.00 0.17 0.47Hevea brasiliensis T 0.23 0.14 2.00 0.21 0.58Holigarna arnottiana T 0.70 0.20 1.00 1.40 1.91Hydnocarpus alpina T 0.47 0.14 1.00 0.04 0.64

Appendix 5.2. Relative frequency, relative density, abundance, relative basal area and IVI of riparian vegetation in midland stretch of Pamba river basin. RF = Relative Frequency, RD = Relative Density, A = Abundance, RBA = Relative Basal Area, IVI = Importance Value Index, T = Tree, B = Bamboo, C = Climber, S = Shrub, E = Epiphyte and H = Herb.

Lindernia antipoda H 2.56 2.28 2.50Ludwigia perennis H 2.56 3.65 4.00Oldenlandia corymbosa H 2.56 2.28 2.50Panicum auritum H 2.56 1.37 1.50Persicaria barbata H 2.56 0.91 1.00Physalis angulata H 1.28 0.46 1.00Scoparia dulcis H 1.28 3.20 7.00Spermacoce latifolia H 2.56 0.91 1.00



Hydnocarpus pentandra T 1.40 0.95 2.33 3.33 5.38Lagerstroemia speciosa T 1.40 1.36 3.33 9.62 12.42Macaranga peltata T 2.56 1.56 2.09 14.33 11.54Mallotus philippensis T 2.33 1.16 1.70 6.06 10.18Mangifera indica T 0.70 0.34 1.67 5.57 6.98Mimusops elengi T 0.23 0.07 1.00 0.17 0.47Myristica fragrans T 0.70 0.48 2.33 4.74 5.75Neolamarckia cadamba T 0.23 0.20 3.00 0.74 1.41Ochreinauclea missionis T 1.40 3.20 7.83 20.33 25.13Persea macrantha T 0.70 0.20 1.00 0.04 0.71Pongamia pinnata T 0.70 0.27 1.33 0.21 0.71Psidium guajava T 0.23 0.07 1.00 0.01 0.31Sterculia guttata T 0.70 0.20 1.00 0.04 0.71Syzygium occidentale T 0.23 0.20 3.00 0.03 0.40Tabernaemontana alternifolia T 1.16 0.54 1.60 1.14 2.15Tamarindus indica T 0.23 0.07 1.00 0.15 0.45Tectona grandis T 0.70 0.34 1.67 1.98 2.85Terminalia catappa T 0.23 0.07 1.00 0.03 0.33Terminalia paniculata T 0.70 0.54 2.67 1.37 2.62Tetrameles nudiflora T 0.70 0.34 1.67 0.59 1.39Shrubs, Climbers & EpiphytesAbrus precatorius C 1.16 0.82 2.40Acacia pennata C 1.40 1.02 2.50Acampe praemorsa E 0.23 0.07 1.00Anamirta cocculus C 0.23 0.14 2.00Bulbophyllum sterile E 0.23 0.07 1.00Calamus hookerianus C 0.70 0.41 2.00Canthium angustifolium S 0.23 0.07 1.00Centrosema pubescens C 1.16 0.75 2.20Chassalia curviflora var. ophioxyloides S 1.40 1.16 2.83Chromolaena odorata S 1.86 2.45 4.50Clerodendrum infortunatum S 0.93 2.38 8.75Clidemia hirta S 1.40 3.40 8.33Cyclea peltata C 0.70 0.20 1.00Dendrobium ovatum E 0.23 0.07 1.00Derris trifoliata C 0.23 0.07 1.00Dioscorea bulbifera C 0.70 0.48 2.33Ficus heterophylla S 0.93 1.70 6.25Flueggea leucopyrus S 0.23 0.07 1.00Glycosmis pentaphylla S 1.16 1.63 4.80Goniothalamus cardiopetalus S 0.23 0.07 1.00Goniothalamus thwaitesii S 0.23 0.27 4.00Helicteres isora S 0.70 0.54 2.67



Hemidesmus indicus C 0.47 0.61 4.50Hibiscus hispidissimus C 0.23 0.07 1.00Ichnocarpus frutescens C 1.16 1.36 4.00Ixora coccinea S 0.23 0.14 2.00Ixora johnsonii S 0.47 0.20 1.50Jasminum multiflorum C 0.23 0.07 1.00Leea guineense S 0.47 1.29 9.50Lygodium flexuosum C 0.23 0.07 1.00Memecylon angustifolium S 0.23 0.07 1.00Merremia vitifolia C 0.93 1.02 3.75Mikania micrantha C 2.56 1.50 2.00Mimosa diplotricha C 0.23 0.07 1.00Mukia maderaspatana C 0.23 0.07 1.00Myxopyrum smilacifolium C 0.23 0.07 1.00Naravelia zeylanica C 0.23 0.34 5.00Ochlandra travancorica S 0.23 0.27 4.00Pholidota imbricata E 0.23 0.07 1.00Piper longum C 2.33 3.06 4.50Pothos scandens C 0.93 1.09 4.00Pueraria phaseoloids C 0.23 0.07 1.00Rhynchostylis retusa E 0.23 0.07 1.00Salacia fruticosa S 0.23 0.14 2.00Sarcostigma kleinii C 0.23 0.07 1.00Sida acuta S 0.23 0.07 1.00Sida rhombifolia S 0.47 0.88 6.50Smilax zeylanica C 0.70 0.27 1.33Solanum rudepannum S 0.23 0.27 4.00Stenochlaena palustris C 1.16 0.82 2.40Strobilanthes ciliata S 0.70 0.95 4.67Strychnos potatorum C 0.47 0.20 1.50Thottea siliquosa S 0.47 0.68 5.00Tiliacora acuminata C 0.23 0.20 3.00Tinospora cordifolia C 0.47 0.34 2.50Urena lobata S 0.70 1.02 5.00Ziziphus oenopolia S 0.70 0.75 3.67Ziziphus rugosa S 0.93 0.61 2.25HerbsAcalypha indica H 0.23 0.07 1.00Achyranthes aspera H 0.47 0.27 2.00Acmella paniculata H 0.47 0.48 3.50Adiantum latifolium H 0.23 0.27 4.00Ageratum conyzoides H 1.40 3.33 8.17Alternanthera sessilis H 1.16 2.99 8.80



Amaranthus spinosus H 0.23 0.07 1.00Andrographis paniculata H 0.23 0.34 5.00Arcytophyllum nitidum H 0.47 0.20 1.50Axonopus compressus H 1.16 1.09 3.20Biophytum sensitivum H 1.16 1.97 5.80Blepharis maderaspatensis H 0.23 0.61 9.00Colocasia esculenta H 2.79 8.91 10.92Commelina diffusa H 0.23 0.20 3.00Cyanthillium cinereum H 0.23 0.07 1.00Dactyloctenium aegyptium H 0.23 0.07 1.00Desmodium gangeticum H 0.23 0.14 2.00Dictyospermum montanum H 0.70 0.95 4.67Eragrostis unioloides H 0.47 0.20 1.50Euphorbia thymifolia H 0.47 0.41 3.00Fimbristylis quinquangularis H 1.63 0.68 1.43Geophila repens H 0.47 0.20 1.50Globba sessiliflora H 0.47 0.88 6.50Hymenachne amplexicaulis H 0.47 0.20 1.50Hyptis capitata H 0.47 0.54 4.00Justicia japonica H 0.70 1.02 5.00Kyllinga brevifolia H 0.23 0.07 1.00Lindernia antipoda H 1.16 1.16 3.40Ludwigia perennis H 1.40 2.93 7.17Mimosa pudica H 0.93 1.02 3.75Mollugo pentaphylla H 1.16 0.88 2.60Panicum paludosum H 0.23 0.07 1.00Paspalum conjugatum H 0.93 0.48 1.75Peperomia pellucida H 0.23 0.34 5.00Persicaria glabra H 0.47 0.20 1.50Phyllanthus amarus H 1.40 1.70 4.17Physalis angulata H 0.47 0.61 4.50Pityrogramma calomelanos H 0.70 1.56 7.67Pteris quadriaurita H 0.70 1.09 5.33Saccharum spontaneum H 0.23 0.27 4.00Scoparia dulcis H 1.86 2.65 4.88Selaginella tenera H 0.47 0.34 2.50Spermacoce latifolia H 0.47 0.20 1.50Sphaeranthus africanus H 0.70 0.88 4.33Synedrella nodiflora H 0.47 0.82 6.00Wedelia chinensis H 0.47 0.20 1.50Xanthium indicum H 0.23 0.07 1.00



Appendix 5.3 Relative frequency, relative density, abundance, relative basal area and IVI of riparian vegetation in highland stretch of Pamba river basin. RF = Relative Frequency, RD = Relative Density, A = Abundance, RBA = Relative Basal Area, IVI = Importance Value Index, T = Tree, C = Climber, S = Shrub, E = Epiphyte and H = Herb.

Botanical name HabitHIGHLAND

RF RD A RBA IVITreesArtocarpus hirsutus T 0.88 0.48 1.50 0.51 1.86Baccaurea courtallensis T 0.44 0.32 2.00 0.01 0.76Barringtonia acutangula T 0.44 0.32 2.00 0.26 1.02Calophyllum calaba T 1.32 0.64 1.33 3.11 5.07Cinnamomum malabatrum T 0.44 0.32 2.00 0.02 0.78Dimocarpus longan T 0.88 0.48 1.50 0.57 1.93Diospyros buxifolia T 0.44 0.16 1.00 0.00 0.60Elaeocarpus tuberculatus T 0.44 0.16 1.00 0.45 1.05Erythrina variegata T 0.44 0.16 1.00 0.02 0.62Ficus hispida T 0.88 0.48 1.50 0.08 1.44Ficus tsjakela T 0.44 0.16 1.00 0.51 1.11Garcinia gummi-gutta T 0.44 0.16 1.00 0.23 0.83Garcinia wightii T 1.75 0.80 1.25 0.13 2.68Glochidion zeylanicum T 0.44 0.16 1.00 0.01 0.61Hopea ponga T 2.63 3.53 3.67 13.00 19.15Humboldtia vahliana T 3.51 5.13 4.00 51.22 59.86Hydnocarpus alpina T 2.63 2.72 2.83 6.18 11.54Hydnocarpus pentandra T 0.44 0.16 1.00 0.04 0.64Lagerstroemia microcarpa T 0.88 0.80 2.50 1.66 3.33Lagerstroemia speciosa T 1.32 0.96 2.00 1.06 3.33Lophopetalum wightianum T 0.44 0.32 2.00 2.85 3.61Madhuca neriifolia T 3.95 4.97 3.44 15.89 24.81Mallotus philippensis T 0.88 0.32 1.00 0.06 1.26Mallotus tetracoccus T 0.44 0.48 3.00 0.01 0.93Ochreinauclea missionis T 0.44 0.32 2.00 0.01 0.77Olea dioica T 0.44 0.16 1.00 0.00 0.60Pongamia pinnata T 0.44 0.16 1.00 0.00 0.60Spathodea campanulata T 0.44 0.16 1.00 0.09 0.69Sterculia guttata T 0.44 0.16 1.00 0.02 0.62Symplocos cochinchinensis var. laurina T 0.44 0.16 1.00 0.00 0.60Syzygium occidentale T 0.88 0.32 1.00 0.05 1.25Syzygium salicifolium T 0.44 0.16 1.00 0.03 0.63Tabernaemontana alternifolia T 0.44 0.16 1.00 0.00 0.60Tetrameles nudiflora T 0.44 0.16 1.00 0.03 0.63Vateria indica T 1.75 0.96 1.50 0.36 3.08Vitex leucoxylon T 2.19 1.44 1.80 1.51 5.14



Shrubs, Climbers & EpiphytesAbrus precatorius C 0.44 0.16 1.00Acacia pennata C 1.75 1.28 2.00Aeschynanthus perrottetii E 0.44 0.16 1.00Bauhinia phoenicea C 2.19 2.24 2.80Canthium angustifolium S 0.44 0.16 1.00Centrosema pubescens C 1.75 0.80 1.25Chassalia curviflora var. ophioxyloides S 2.19 2.24 2.80Chromolaena odorata S 0.44 0.16 1.00Clerodendrum infortunatum S 0.88 2.72 8.50Clidemia hirta S 4.82 11.70 6.64Derris trifoliata C 0.44 0.16 1.00Dioscorea bulbifera C 0.44 0.64 4.00Drynaria quercifolia E 0.88 0.32 1.00Flueggea leucopyrus S 0.44 0.16 1.00Getonia floribunda C 0.44 0.96 6.00Glycosmis pentaphylla S 1.32 1.92 4.00Gomphandra tetrandra S 1.32 3.04 6.33Goniothalamus thwaitesii S 0.44 0.16 1.00Helicteres isora S 1.75 1.92 3.00Hibiscus hispidissimus C 0.44 0.80 5.00Homonoea riparia S 0.44 0.48 3.00Ipomoea obscura C 0.44 0.16 1.00Ixora coccinea S 1.32 1.12 2.33Jasminum azoricum C 0.44 0.48 3.00Jasminum multiflorum C 0.44 0.48 3.00Leea guineense S 0.44 0.16 1.00Memecylon angustifolium S 0.44 0.32 2.00Merremia vitifolia C 0.88 0.64 2.00Mikania micrantha C 3.07 2.24 2.00Mussaenda frondosa S 0.88 0.32 1.00Myxopyrum smilacifolium C 0.44 0.16 1.00Naravelia zeylanica C 0.44 0.48 3.00Nothopegia travancorica S 0.88 0.32 1.00Ochlandra scriptoria S 1.32 1.12 2.33Ochlandra travancorica S 0.88 0.48 1.50Pavetta hispidula S 0.44 0.32 2.00Pholidota imbricata E 0.44 0.16 1.00Piper longum C 2.19 1.28 1.60Pothos scandens C 3.07 3.69 3.29Psychotria flavida S 2.63 5.13 5.33Smilax zeylanica C 1.32 0.96 2.00Strychnos potatorum C 0.44 0.64 4.00



Thottea siliquosa S 1.32 1.92 4.00Ziziphus oenopolia S 1.32 1.92 4.00Ziziphus rugosa S 0.88 0.64 2.00HerbsAgeratum conyzoides H 0.88 0.80 2.50Andrographis paniculata H 0.44 0.64 4.00Arcytophyllum nitidum H 0.88 1.28 4.00Blepharis maderaspatensis H 0.88 0.64 2.00Cheilocostus speciosus H 0.44 0.16 1.00Colocasia esculenta H 0.88 0.32 1.00Cyperus haspan H 0.44 0.48 3.00Desmodium triflorum H 0.44 0.16 1.00Dictyospermum montanum H 1.32 2.08 4.33Diplazium esculentum H 0.44 0.16 1.00Floscopa scandens H 0.44 0.48 3.00Globba sessiliflora H 1.32 2.56 5.33Hyptis capitata H 0.44 0.80 5.00Ophiorrhiza pectinata H 0.44 0.80 5.00Oplismenus compositus H 0.88 0.80 2.50Peperomia pellucida H 0.44 0.16 1.00Pteris quadriaurita H 0.88 0.80 2.50Saccharum spontaneum H 0.44 0.16 1.00Selaginella delicatula H 0.88 0.32 1.00Spermacoce latifolia H 0.44 0.16 1.00Synedrella nodiflora H 0.44 0.16 1.00Wedelia chinensis H 0.44 0.16 1.00

Appendix 5.4 Relative frequency, relative density, abundance, relative basal area and IVI of riparian vegetation in Highrange stretch of Pamba river basin. RF = Relative Frequency, RD = Relative Density, A = Abundance, RBA = Relative Basal Area, IVI = Importance Value Index, T = Tree, C = Climber, S = Shrub, E = Epiphyte and H = Herb.

Botanical name HabitHIGHRANGE

RF RD A RBA IVITreesCinnamomum keralaense T 2.56 1.59 1.50 0.14 4.30Cullenia exarillata T 3.85 4.76 3.00 10.57 19.18Diospyros malabarica T 2.56 1.06 1.00 0.85 4.48Diospyros paniculata T 2.56 1.59 1.50 0.47 4.62Dysoxylum malabaricum T 1.28 0.53 1.00 0.46 2.27Elaeocarpus tuberculatus T 1.28 0.53 1.00 0.18 1.99Eurya nitida T 1.28 0.53 1.00 0.08 1.90Mallotus philippensis T 1.28 0.53 1.00 0.04 1.85Mesua ferrea T 2.56 2.12 2.00 0.89 5.57



Nageia wallichiana T 1.28 0.53 1.00 1.41 3.22Olea dioica T 1.28 0.53 1.00 0.01 1.82Palaquium ellipticum T 2.56 1.06 1.00 1.98 5.61Persea macrantha T 1.28 1.06 2.00 0.11 2.45Salix tetrasperma T 2.56 2.12 2.00 2.58 7.26Symplocos cochinchinensis var. laurina T 6.41 11.64 4.40 7.18 25.24Syzygium gardneri T 1.28 1.59 3.00 0.35 3.22Syzygium hemisphericum T 6.41 6.35 2.40 31.62 44.38Syzygium munronii T 2.56 3.17 3.00 0.49 6.23Turpinia malabarica T 2.56 2.65 2.50 3.31 8.52Vateria indica T 2.56 7.94 7.50 37.25 47.75Xanthophyllum arnottianum T 1.28 0.53 1.00 0.02 1.83Shrubs, Climbers & EpiphytesCalamus travancoricus C 1.28 0.53 1.00Chromolaena odorata S 2.56 2.12 2.00Clematis gouriana C 1.28 0.53 1.00Clerodendrum infortunatum S 1.28 0.53 1.00Clidemia hirta S 6.41 12.17 4.60Derris benthamii C 1.28 2.12 4.00Erythropalum scandens C 2.56 2.12 2.00Lantana camara S 1.28 0.53 1.00Mikania micrantha C 3.85 2.12 1.33Ochlandra travancorica S 1.28 2.12 4.00Osbeckia virgata S 2.56 1.06 1.00Piper trichostachyon C 1.28 0.53 1.00Psychotria nigra S 1.28 0.53 1.00Rubus ellipticus S 2.56 1.06 1.00Sarcandra chloranthoides S 3.85 7.41 4.67Tabernaemontana gamblei S 1.28 0.53 1.00Thottea siliquosa S 1.28 1.06 2.00Toddalia asiatica C 1.28 0.53 1.00HerbsCurculigo orchioides H 1.28 1.06 2.00Floscopa scandens H 1.28 1.59 3.00Globba sessiliflora H 3.85 2.12 1.33Lagenandra meeboldii H 2.56 2.65 2.50Pteris quadriaurita H 1.28 1.06 2.00Sonerilla versicolor H 1.28 2.12 4.00

5 species richness, diversity and ...shodhganga.inflibnet.ac.in/bitstream/10603/19622/15/15...river,...

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