3.Reproductive phenology.full

REPRODUCTIVE PHENOLOGY OF AEGICERAS CORNICULATUM (L) BLANCO- A

MANGROVE SPECIES IN THE GULF OF KACHCHH, GUJARAT, INDIA

PANDEY R1

& PANDEY C. N2

1Project Coordinator-Climate Change Studies, GIPL, Gujarat Forest Department, Aranya Bhavan,

Gandhinagar, Gujarat, India

2Principal Chief Conservator of Forest, (Wildlife), Aranya Bhavan, Gandhinagar, Gujarat, India

ABSTRACT

The reproductive phenology of A. corniculatum (L) Blanco has not been examined comprehensively in the Gulf of

Kachchh, Gujarat, India. The present work has examined the temporal and spatial variations in the reproductive phenology

of this species in this area. Besides, the study also reports the reproductive vigour (inflorescence production per tree) and

reproductive success of this species. The species remains in the reproductive phase throughout the year. The reproductive

cycle initiates during September- October and terminates during September of the next calendar year. The reproductive

phenology and reproductive vigour have shown temporal as well as spatial variations. The reproductive success has been

found to be different at different locations.

KEYWORDS: Mangrove, A. Corniculatum, Reproductive Phenology, Vigour

INTRODUCTION

The phenological studies have been carried out in various ecosystems throughout the world. These studies largely

tend to find relation in the phenological processes with biotic and abiotic factors (Frankie et al., 1974; Wielgolaski, 1974;

French & Sauer, 1974; Malaisse, 1974; Monasterio & Sarmiento, 1976; Tomlinson, 1986; Boinski & Fowler, 1989;

Seghieri et al., 1995; Morellato & Leitão-Filho, 1996; Brooke et al., 1996).

The phenology of mangrove forests has also been studied in various regions of the world (Gill & Tomlinson,

1971; Wium-Andersen and Christensen, 1978; Duke et al., 1984, Primack, 1985; Tomlinson, 1986; Duke, 1990; Marcus,

1999; Tyagi, 2003).

These studies largely pertain to the productivity of mangrove forests and its seasonal variations with reference to

the environmental conditions. Clarke (1995) has examined the growth and reproduction of A. corniculatum and A. marina

in the mangrove forests of New South Wales. Clarke, (1995) has also examined the population dynamics of this species in

the same mangrove forests.

The environmental conditions of a place are known to influence the phenological patterns (Liebermann, 1982).

Therefore, the phenological cycle tends to vary and, in turn, the reproductive cycle proceeds in accordance with the local or

regional environmental conditions. In spite of the relevance of the phenological events in the mangrove system, very few

authors have dealt with the phenological aspects of mangroves. As far as mangrove forests of Gulf of Kachchh, Gujarat,

India are concerned, no previous studies have been carried out about the reproductive phenology.

The present study aims at examining the temporal and spatial variation in reproductive phenology, reproductive

success and the spatial variations in the reproductive vigour of A. corniculatum in the Gulf of Kachchh, Gujarat.

International Journal of Botany and

Research (IJBR)

ISSN 2277-4815

Vol. 3, Issue 1, Mar 2013, 19-28

© TJPRC Pvt. Ltd.

20 Pandey R & Pandey C. N

MATERIALS AND METHODS

Study Area

The present work has been carried out at three islands viz. Pirotan -22°35'849'' North and 69°57'486" East-

(Population I), Sanada -22o34' 084'' North and 69

o57' 374'' East -(Population II) and Patthapir -22

o31'838'' North and

69o56'187'' East -(Population I) (Figure1.1) in the Gulf of Kachchh which falls under semi arid condition with average

annual rainfall of about 400 mm (Pandey, et. al., 2005). The average tidal amplitude is 5 m that may go even up to 8-10 m.

Most of the mangrove areas, therefore, get regular inundation.

Figure 1: Location of the Study Area in the Gulf of Kachchh, Gujarat

Reproductive Phenology- Crop Level

Ten matured trees were selected from each of the three research sites (30 trees from the three sites). These trees

were allotted specific Plant Index Numbers (PIN) and the range and the mean values of the heights and canopy perimeters

of these trees are indicated in Table 1.

Table 1: Range and Mean Height and Canopy Cover of Selected Trees

Site Height (m) Canopy Perimeter (m)

Range Mean±SD Range Mean±SD

Patthapir 0.6 to 2.1 1.5±0.3 0.5 to 4.3 2.3±1.1

Pirotan 0.7 to 2.0 1.4±0.3 0.6 to 4.7 2.0±1.0

Sanada 0.8 to 2.0 1.3±0.9 0.2 to 2.8 0.9±0.5

SD: Standard Deviation

The inflorescences were categorized into four developmental stages viz. A-1, A-2, A-3 and A-4 (Table 2).

Reproductive Phenology of Aegiceras corniculatum (L) Blanco- A Mangrove Species in the Gulf of Kachchh, Gujarat, India 21

Table 2: Description of the Four Developmental Stage of A. Corniculatum

Developmental

Stage Photograph

Characters Adopted for

Identifying Different Stages

Duration of the

Developmental Stage

Represents

A-1 Inflorescences with buds only Maturation of buds

A-2 Inflorescences with flowers, bud

and developing fruit (s) Flowering

A-3 Inflorescences with only

developing fruits Maturation of fruit

A-4 Inflorescences with matured

propagules Dispersal of fruits

The occurrence of these inflorescences was examined throughout the year for each population. For this, all the

inflorescences of the four developmental stages of selected trees were recorded fortnightly from April 2007 to May 2009.

Thus the observations pertains to 52 fortnights.

Reproductive Phenology-Inflorescence Level

For inflorescence level examination, 200 inflorescences of A-1 developmental stage were selected at each site

(600 inflorescences considering all the three sites) in October 2007. These inflorescences were observed fortnightly till the

surviving ones transformed into A-4 developmental stage. Hence, for each month two observations, corresponding to two

fortnights, were made. For instance, the two observations of January represented by Jan.1 and Jan.2 corresponding to the

periods of 1st to 15

th January and 16

th to 31

st January respectively.

The A-4 developmental stage represents the inflorescence with all matured propagules only. During field

observations it was found that the flowering is asynchronous at inflorescence level. Therefore, within an inflorescence, the

individuals attain maturity at different time and as one individual attains the maturity, it gets dispersed. Since the

observations were made fortnightly, it was not possible to accurately note when all individuals of an inflorescence attained

maturity. Hence, the life of the inflorescence during A-4 developmental stage could not be estimated.

Reproductive Vigour

The inflorescence production per tree has been taken to represent the reproductive vigour of the three populations.

This information was deduced from the data collected to examine reproductive phenology at crop level.

Reproductive Success

This information was deduced from the data collected for inflorescence level examination of reproductive

phenology.

OBSERVATIONS

Reproductive Phenology-Crop Level

The reproductive phenology of A. corniculatum at the three locations i.e. occurrence of the four developmental

stages over the 52 fortnights are shown in Figure 2, 3, 4 respectively. The initiation of reproductive penology i.e. beginning

of the occurrence of A-1 developmental stages i.e. has been reported during September-October for all the three

populations. Further, the peak of A-1 stage was reported during December-January in all the three populations.


Figure 2: Reproductive Phenology of A. Corniculatum at Patthapir (Population I)

Figure 3: Reproductive Phenology of A. Corniculatum at Pirotan (Population II)

Figure 4: Reproductive Phenology of A. Corniculatum at Sanada (Population III)

The A-1 stage terminated during March in all the three populations during the reference years except at Pirotan

during 2009 when it terminated in April. Hence, the inflorescence with developing buds may be seen during September to

March in the Gulf of Kachchh. Further, the flowering which is represented by A-2 developmental stages have been

reported to initiate during October-November in all the three population during reference years except at Patthapir where it


initiated during December in the year 2008 (Figure 2). The flowering attained its peak during February-March in all the

populations. The flowering was reported to terminate during March- April in all the three populations. The developmental

stage A-3 (fruit development) representing the fruit development initiated December onwards and terminated during July

(except at Sanada in 2007). The peak of A-3 was attained -considering all the 52 fortnights of observation- during April-

May at Pirotan, April at Patthapir and May at Sanada. The developmental stage A-4 representing propagule maturation has

shown variation in its initiation for all the three populations. In the case of Patthapir (Population I), A-4 initiated during

Jun.1 (2007), May 2 (2008) and Apr.1 (2009). At Pirotan (Population II), the stage A-4 commenced in Jul.1 (2007), Jun.1

(2008) and Mar.1 (2009). At Pirotan, some A-4 developmental stages were also seen in Feb.1 during 2008. However at

Sanada, it initiated during Apr.2 (2007), May2 (2008) and Mar.2 (2009). The A-4 developmental stage was reported to

terminate by September in all the three populations, irrespective of their initiation periods (Figure 2, 3 and 4). Hence,

dispersal of matured propagules (A-4 developmental stage) complete by the end of monsoon season of the study area.

Reproductive Phenology - Inflorescence Level

The inflorescence life of the three developmental stages (A-1, A-2 and A-3) is summarized in Table 3. The

inflorescence life of the developmental stage A-1 and A-3 were similar and were significantly large that that at A-2 stage.

Among the three populations, the inflorescence life of all the three developmental stages was found to be longest at Pirotan

followed by Patthapir and Sanada.

Table 3: Inflorescence Life at Different Developmental Stages

Developmental

Stage

Inflorescence Life (Mean ± s.e.) (Days)

Pirotan Patthapir Sanada All Populations

A-1 117.9±3.82 110.6±1.60 106.3±2.10 110.4±1.31

A-2 19.6±1.18 15.4±0.73 14.0±0.51 15.6±0.43

A-3 117.4±2.94 106.8±1.70 104.6±1.85 108.9±1.34

Reproductive Vigour

The reproductive vigour has shown spatial and temporal variations. Among the three populations, the

reproductive vigour (inflorescence production per tree) was found to be the maximum at Pirotan followed by Patthapir and

Sanada (Figure 5).

Figure 5: Reproductive Vigour (Inflorescence Production Per Tree) of the Three Populations During 2007 to 2009


Further, it was reported to be higher during 2008 and relatively lower during 2007 and 2009. Hence, the

inflorescence production per tree has been found to show noticeable variation over time and space. However, the trends

were found to be similar.

Reproductive Success

Out of the 200 inflorescences, at each research site, 131 inflorescences at Pirotan island, 141 inflorescences at

Patthapir island and 78 inflorescences at Sanada island were found to have detached before attaining maturity of A-4 stage

as shown in Table 3.

Table 3: Reproductive Success of A. Corniculatum in three Populations

Population

No. of

Selected

Inflorescence

No. of

Inflorescences Detached Prior

to Attaining Maturity of A-4

No. of Inflorescences

that Attained the

Maturity of A-4

(Reproductive Success)

%

Reproductive

Success

Pirotan 200 131 69 34.5

Patthapir 200 141 59 29.5

Sanada 200 78 122 61

The reproductive success was found to be 34.5%, 29.5% and 61% in the populations of Pirotan, Patthapir and

Sanada. Considering all the three populations, the reproductive success comes out to be 41.66%.

DISCUSSIONS

The phenology of A. corniculatum has been studied by various scientists for different mangrove forests of the

world (Carey & Fraser, 1932; Duck et. al., 1984; Hutchings & Saenger, 1987) and for India (Singh, 1994; Kothari &

Singh, 1998; Naskar & Mandal, 1999; Banerjee et. al., 2002; Debnath, 2004). The flowering season of A. corniculatum

reported from various mangrove forests of India and that of Australia show noticeable variations as indicated in Table 4.

The flowering season of A. corniculatum has been reported to be different at east and west coasts of India. In fact,

flowering seasons were reported to vary even at single coast. In the case of Gujarat, Singh (1994) has reported the

flowering season of this species from January to February (2 months). However, the present work has reported the

flowering period from October to April (considering all the three populations together) with its peak during February-

March. It appears that Singh (1994) has reported the peak flowering period. It may be mentioned that the reproductive

phenology has shown temporal as well as spatial variations even in areas closely located (viz. the three populations of the

present study). Hence, the temporal and spatial variations in reproductive phenology is expected among locations separated

by larger distances.

Table 4: Flowering Season of A. Corniculatum Reported by Various Scientists

Researcher Study Area Flowering Season

Duck, 2006 Queensland, Australia January to September

Banerjee, 1989 India April to September

Banerjee ,2002 India February to April

East Coast of India

Debnath, 2004 India-Andaman & Nicobar March to September

Kumudranjan Naskar, 1999 West Bengal. Orissa January to September

West Coast of India

Kothari & Singh, 1998 Goa, Maharashtra, Gujarat February to October

Singh, 1994 Gujarat January to February

Present work Gujarat October to April


Clarke (1994, 1995) has given detailed information about the reproductive phenology of Aegiceras corniculatum

of Queensland forests, Australia. The reproductive phenology of A. corniculatum reported by Clarke (1994) for Australian

mangrove forests and that reported for mangroves of the Gulf of Kachchh, Gujarat, India during the present study are

summarized in Table 5. Clarke (1994) reported that the commencement of the bud formation occurs during May and

continues up to November. In the present study, this (stage A-1) was reported during September to April with peak in

December-January.

The flowering was reported during July to November in the Queensland mangroves (Clarke, 1994). However, in

the case of Sydney mangrove forests (Carey & Fraser, 1932) earlier flowering was reported. In the present work, flowering

has been reported from October (beginning to winter) to April (beginning of summer) with peak during February-March.

Further, Clarke (1994) reported commencement of flowering during the winters (July) with a peak during the summer

(December). Clarke (1994) has reported immature fruits (A-3) during December to March. In the case of the present work,

it was found to be during December to July. Further, the present work has reported matured fruits (A-4) during March to

September and Clarke (1994) reported the same during March-April for the Australian mangrove forests.

Table 5: Reproductive Phenology of A. Corniculatum in Indian and Australian Mangrove Forests

Reproductive

Phenology

Australia (Clark 1994) India, Gujarat (Present Work)

Period Duration

(Months) Period

*Duration of

Occurrence

(Months)

**Life Span of that

Developmental

Stage (Months)

Initiation and

continuation of bud

formation (A-1)

May to

November 7

September to

April 8 About 4.0

Flowering (A-2) July to

November 5

October to

April 7 About 0.5

Fruit formation December to

March 4

December to

July 5 About 4.0

(A-3)

Fruit maturation (A-4) March-April 2 March to

September 7 About 0.5

Total Duration of

Reproductive Cycle About 12-14 Months About 12 Months About 9 Months

* Occurrence of a Particular Developmental Stage Over the Period of 12 Months and ** Inflorescence Life of a

Particular Developmental Stage

It has been reported that the reproductive phenology of A. corniculatum is influenced by the distance from the

tropical latitude (Duke, 1990). Duck (2006) has reported that the period between flowering and fruiting increased from 2-3

months in northern tropical areas to 10 months in southern temperate areas. This is because the growth rate of reproductive

development increases two to three times with the increase in temperature of 100C each (Duke, 1990). Though Clarke

(1994) has not mentioned whether the duration of various phenophase (developmental stages) represents the inflorescence

level occurrence or crop level occurrence, it appears that it represents crop level occurrence (probably peak occurrences at

crop level).

The present study has also reported that the period between peaks of flowering and fruiting is 2 to 3 months in the

study area which falls close to the Tropic of Capricorn. Thus, the observations of the current study are in agreement with

Duck (2006) for areas close to tropics. Further, the overall duration of the reproductive phenology is similar in the

mangrove forests of Queensland (12 to 14 months) and Gulf of Kachchh (12 months). However, the occurrence of each

developmental stage is spread over larger period in the Gulf of Kachchh, Gujarat. Though the inflorescence life is only

about 9 months, the reproductive phenology is spread over 12 months in Gulf of Kachchh. The reproductive vigour of a


different mangrove species-Rhizophora stylosa, Rhizophora mangle (synonym R. samoensis) and Bruguiera gymnorhiza

has been reported to be higher in wet areas than those of dry areas (Tyagi, 2003). However, the reproductive vigour of A.

corniculatum has not been examined. The reproductive vigour of the three populations of A. corniculatum have shown

noticiable varations during the current study. In the case of A. corniculatum, a significant number of inflorescences get

detached prior to attaining maturity as well developed propagules. Considering all the three populations, only about

41.66% of the total inflorescences were found to achieve reproductive success and the remaining 58.34% samples were

observed to have detached prior to achieving maturity of fruiting (A-4). High pre-dispersal mortality (up to 95%) in A.

corniculatum has been reported from other mangrove areas of the world (Clarke, 1995).

ACKNOWLEDGEMENTS

We acknowledge GEER Foundation, Gandhinagar for providing necessary support for implementing the project.

We also acknowledge the Ministry of Environment and Forest (MoEF), Gov. of India for sponsoring the project and to

Gujarat Forest department for providing the local help and the permissions for field works. The thanks are also due to Dr.

Harshad Salvi (Research associate, GEER Foundation), Mrs. Urvi Bhatt (Senior Research Fellow, GEER Foundation), Ms.

Anjali Sharma (Senior Research Fellow, GEER Foundation), Mr. Shailesh Dodiya (Senior Research Fellow, GEER

Foundation), Mr. Nilesh Vaghela (Senior Research Fellow, GEER Foundation), Mr. Sandeep Patel (Junior Research

Fellow, GEER Foundation), Mr. Irshad Theba (Research assistant, GEER Foundation) for helping field observations. We

are also thankful to the boatman Mr. Junusbhai and his team.

REFERENCES

1. Banerjee, L. K.; Shashtri A. R. K. & Nayar, M. P. (1989). Mangrove in India- Identification Manual. Pub.

Calcutta: Botanical Survey of India.

2. Banerjee, L. K.; T. A. Rao, A. R. K. Sastry & D. Ghosh. (2002). Diversity of Coastal plant Communities in India.

Pub. Kolkata: Botanical Survey of India.

3. Boinski, S. & N. L. Fowler, (1989). Seasonal patterns in a tropical lowland forest. Biotropica, 21: 223–233.

4. Brooke, L. M., J. P. Jones, J. A. Vickery & S. Waldren, (1996). Seasonal patterns of leaf growth and loss,

flowering and fruiting on a subtropical central pacific island. Biotropica, 28: 164–179.

5. Carey, G., and Fraser, L., (1932). The embryology and seedling development of Aegiceras majus Gaertn. Proc.

Linn. Soc. N.S. W. 57: 341-360.

6. Clarke, P. J. (1994). Baseline Studies of Temperate Mangrove Growth and Reproduction; Demographic and

Litterfall Measures of Leafing and Flowering. Australian Journal of Botany, 42: 37-48.

7. Clarke, P. J. (1995). The population Dynamics of the mangrove Shrub Aegiceras corniculatum (Myrsinaceae):

Fecundity, Dispersal, Establishment and Population Structure. Proc. Linn. Soc. N. S. W., 115: 35-44.

8. Debnath, H. S. (2004). Mangroves of Andaman and Nicobar Islands: Taxonomy and Ecology (A community

Profile). Pub. Bhisan Singh and Mahendra Pal Singh, New Delhi.

9. Duke, N. C. (1990). Phenological trends with latitude in the mangrove tree Avicennia marina. Journal of Ecology,

78, 113-33.


10. Duke, N. C., J. S. Bunt & W. T. Williams, (1984). Observations on the floral and vegetative phenologies of

North-eastern Australian mangroves. Australian. Journal of Boany. 32: 87–99.

11. Duck, N. C. (2006). Australia's Mangroves. The Authoritative Guide to Australia's Mangrove Plants. Pub.

University of Queensland, Brisbane. pp.200.

12. Frankie, G. W., H. G. Baker & P. A. Opler, (1974). Comparative phenological studies of trees in tropical wet and

dry forests in the lowlands of Costa Rica. Journal of Ecology, 62: 881–913.

13. French, N. & R. H. Sauer, (1974). Phenological studies and modeling in grasslands. In Lieth, H. (ed.), Phenology

and Seasonality Modeling. Chapman & Hall, London: 227–236.

14. Gill, A. M., and Tomlinson, P. B. (1971). Studies on the growth of red mangroves (Rhizophora mangle L.). 3.

Phenology of the shoot. Biotropica 3, 109-124.

15. Kothari, M. J. & Singh, N. P. (1998). Mangrove Diversity along the North-West Coast of India. J. Econ. Tax.

Bot., 22:571-585.

16. Liebermann, D., (1982). Seasonality and phenology in a dry tropical forest in Ghana. Journal of Ecology, 70:

791–806.

17. Malaisse, F. P., (1974). Phenology of the Zambezian woodland area with emphasis on the miombo ecosystem. In

Lieth, H. (ed.), Phenology and Seasonality Modeling. Chapman & Hall, London: 269–286.

18. Marcus, E. B. Fernandes (1999). Phenological Patterns of Rhizophora L., Avicennia L., Laguncularia Gaertn. f. in

Amazon mangrove swamp. Hydrobiologia, 413: 53-62.

19. Monasterio, M. & G. Sarmiento, (1976). Phenological strategies of plant species in the tropical savanna and the

semi-deciduous forest of the Venezuelan llanos. J. Biogeogr 3: 325–356.

20. Morellato, P. C. & H. F. Leitão-Filho, (1996). Reproductive phenology of climbers in a southeastern Brazilian

forest. Biotropica 28: 180–191.

21. Naskar, K. R. & R. N. Mandal. (1999). Ecology and biodiversity of Indian Mangroves-Global Status. Daya

Publishing House, Delhi, (2 vol.), pp.1-754.

22. Pandey, C. N; Rawal, B. R.; Mali, S. and Salvi, H.; (2003), Medicinal Plants of Gujarat, Pub. Gujarat Ecological

Education and Research (GEER) Foundation, Gandhinagar. pp. 410.

23. Primack, R. B. (1985). Patterns of Flowering Phenology in Communities, Populations, Individuals and Single

Flowers. In: White J. (ed.) The population structure of vegetation, Dordrecht: Junk, 571-593.

24. Seghieri, J. Ch. Floret & R. Pontanier, (1995). Plant phenology in relation to water availability: herbaceous and

woody species in the savannas of northern Cameroon. J. Trop. Ecol. 11: 237–254.

25. Singh. H. S. (1994). Status report on Mangrove in Gujarat State. Pub. Gujarat Forest Department, Gandhinagar,

pp. 100.

26. Tomlinson, P. B., (1986). The botany of mangroves. Cambridge University Press. 413 pp.

27. Tyagi, A. P. (2003). Location and Interseasonal Variation in Flowering, Propagule Setting and Propagule Size in

Mangroves Species of the Family Rhizophoraceae. Wetland ecology and management, 11:167-174.


28. Wielgolaski, F. E., (1974). Phenological studies in tundra. In Lieth, H. (ed.), Phenology and Seasonality

Modeling. Chapman & Hall, London: 209–214. pp.

29. Wium-Andersen, S., and Christensen, B. (1978). Seasonal growth of mangrove trees in southern Thailand. II.

Phenology of Bruguiera cylendrica, Ceriops tagal, Lumnitzera littorea and Avicennia marina. Aquatic Botany 5,

383-390.