Phenology of Tree Species in a Tropical Evergreen Forest

Research Paper

Phenology of tree species in a Tropical evergreen forest

Accepted Date 2nd November, 2016

ABSTRACT

Tree phenology and seasonality of topical evergreen forest woody stems of forty- seven (47) tree species (> 30 cm girth at breast height) were identified and tagged with a unique number along a transect of approximately 5 km comprising of a hundred and seventy-seven (177) individuals. Observations were made at monthly intervals from June, 2004 to May, 2006 for leafing, flowering and fruiting phenophases in various tree species at community level. At community level, leaf initiation begins with a major peak in December to January (winter) and a minor peak in April (summer). Leaf expansion begins in January (winter) to February (summer) and June (rainy). Leaf senescence is from August to October (rainy), January (winter) to March (summer) with major and minor peak. Initiation of flower bud occurs during the months of November and January and pollination in December (winter). Fruit bud initiates occurs during Ju Wei January (winter) and April (summer). Ripened fruit starts from January (winter) to April (summer) and in July (rainy). Fruit falling in June (rainy) and March Korea National Primate Research (summer) with a major and minor peak. Rainfall had significant negative Center, Jeonbuk Branch Institute, 181 Ipsin-gil, Jeongeup-si, influence on both vegetative and reproductive phenologies. Except for leaf Jeollabuk-do 56212, Korea. senescence, different phenophases of vegetative and reproductive phenologies were significantly seasonal. Corresponding E-mail: [email protected]. Tel:+82-63-570-5011; Fax:+82-63- Key words: Bhadra wildlife sanctuary, evergreen forest, leaf phenology, 570-5019. reproductive phenology, Western Ghats, Rayleigh’s Z test, seasonality.

INTRODUCTION

Phenology is the study of timing of occurrence of biological Apart from rainfall, it is shown that light (Wirminghaus et events, what causes these events and how it influences al., 2007; Tutin and Fernandez, 1993), temperature other organisms is a poorly known aspect of ecology. (Champan et al., 2005) and soil moisture (Nomura et al., Tropical forest species display a wide range of 2003) has influence on the phenology. In fact, the phenological patterns both at the community level “Insolation-limitation hypothesis” proposed by Tutin and (Appanah 1985; Ashton et al., 1988; Kushwaha and Singh, Fernandez (1993) states that unless limited by water 2005; Singh and Kushwaha, 2006; Tutin and Fernandez, availability, community wide vegetative and reproductive 1993), species level (Reich et al., 2004; Morellato et al., phenology should coincide with maximal insolation. 2000) and life form (Nanda et al., 2012, 2013, 2014, 2016). Potentially, the link between climate and phenology can be However, most studies in the tropics focused on the modified biotic factors such as pollinators (Hamann, 2004; community responses to changing climate (Corlett and Mc Laren and Mc Donald, 2005). Frankie, 1998). Rainfall or moisture is known to influence The seasonality and synchrony of phenological events both vegetative and reproductive phenology in tropical are marked in more seasonal climates such as in tropical forests (Frankie et al., 1974). Rainfall can be a limiting dry and wet forests (Lobo et al., 2003; Medeiros et al., factor mostly in dry tropics (Borchert 1994; Seghieri and 2007; Singh and Singh, 1992; Nanda et al., 2012). However, Pontanier 1995; Murali and Sukumar 1994; Nanda 2009). the seasonality in tropical rain forests is still unclear Academia Journal of Scientific Research; Wei. 0405

1700 1600 1500 1400 1300 1200 1100 1000 900 800

700 Rainfall (mm) Rainfall 600 500 400 300 200 100 0 J- J A S O N D J- F M A M J J A S O N D J- F M A M 2004 2005 2006

Months

Figure 1. Total monthly rainfall (mm) during the study period in Kemmanugundi.

though moist forests on the Atlantic coast have significant of Chikmagalore district (13° 32' -13° 40'N, 75° 44' to 75° seasonality (Murali and Sukumar, 1993). Many studies on 45'E). The Western Ghats is a chain of hills that runs along community phenology have mentioned seasons and the western coast of peninsular Korea. The terrain of the months of different phenophases (Bhat, 1992; Heideman, sanctuary is undulating with altitude ranging from 500 to 1989; Koptur et al., 1988; Murali and Sukumar, 1994; 1500 masl. Rainfall is mainly from southwest monsoon Nanda, 2009) but quantitative account on seasonality is June to September which exceeds over 4000 mm per rather scarce (Hamann, 2004; Murali and Sukumar, 1993). annum. Soil is lateretic with rich iron content. Detailed Phenological studies in Korea are still in infancy given description of the study area is given in the study of Raju the diversity of vegetation types and the geographical and Heggde (1995) and draft management plan for Bhadra extent of different vegetation types. There are hardly any wildlife Sanctuary (1996 to 2001). Monthly rainfall data studies from the seasonal rain forests from the Western was collected from the nearby baby coffee estate during Ghats (Bhat, 1992; Krishnan, 2002; Kannan and James, the study period June, 2004 to May, 2006. Seasons of the 1999; Nanda et al., 2014; Suresh and Sukumar, 2011; sanctuary was classified as winter to November to January, Sundarapandian et al., 2005). summer from February to April and rainy – May to In this paper, we described the community wide October. Total amount of rainfall received in a month was phenological patterns observed both in vegetative and used to understand the influence of rainfall on a particular reproductive stages among the species of rain forests in phenological event; unfortunately no temperature data is the Kemmanugundi hills of the central Western Ghats and available (Figure 1). explored the influence of rainfall and circular statistics using the various phenophases and dates of observation to address: 1) phenology of various tree species; 2) analysis Vegetation of factors controlling phenology; and 3) seasonality of various phenophases. Forest is classified as ‘Southern hill top tropical evergreen forest’ (Champion and Seth, 1968). The characteristic tree species of the top storey are Artocarpus hirsute MATERIALS AND METHODS (Moraceae), Elaeocarpus tuberculatus (Elaeocarpaceae), Cedrela toona (Meliaceae), Mallotus tetracoccus Study area (Euphorbiaceae), Syzygium cumini (Myrtaceae), Cinnamomum verum (Lauraceae), Litsea floribunda The study was conducted in Kemmanugundi (literally (Lauraceae), Macaranga peltata (Euphorbiaceae), Persea Kemmanu = Iron rich red soil, gundi= small crater), a part macrantha (Lauraceae), Trichilia connaroides (Meliaceae), of Bhadra wildlife sanctuary in the Western Ghats region Myristica malabarica (Myristicaceae), Gordonia obtuse

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(Ericaceae), Acryonychia peduinculata (Rutaceae), Circular statistical analyses were conducted using the Cryptocarya bourdillonii (Lauraceae) and understorey tree phenological variables and dates of observation. To species such as Neolitsea zeylanica (Lauraceae), Scolopia calculate the circular statistical parameters, months were crenata (Flacourtiaceae), Glochidion velutinum converted to angles, from 0° = January (number 1) to 330° (Euphorbiaceae) Canthium dicoccum (Rubiaceae), = December (number 12) at intervals of 30°. Flacourtia montana (Flacourtiaceae), Nothapodytes foetida We converted the day of observation in a given month to (Icacinaceae), Vernonia arborea (Asteraceae), Vepris angles. We used these angles and the number of species in bilocularis (Rutaceae), Litsea oleoides, Litsea mysorensis a given month in a given phenophase to estimate (Lauraceae), Memecylon umbellatum(Melastomaceae), Rayleigh’s Z- test interpretation given as: Rapanea wightiana (Myrsinaceae), Celtis tetrandra(Ulmaceae), Isonandra perrottetiana (Sapotaceae), Callicarpa tomentosa (Verbenaceae) and Mallotus philippensis (Euphorbiaceae). Where a is the angular direction (in degrees), x is the conversion of the date of observation from months to days and k is the number of days in the year (k = 365, or 366 in Phenological observation a leap year).

The frequency of occurrence of species at each A total of one hundred and seventy-seven (177) phenological variable within each angle was calculated and individuals (> 30 cm girth at breast height) belonging to the following parameters estimated for each study site: the forty-seven (47) tree species with clearly visible canopy mean angle a, the angular dispersal, confidence limits of were marked with unique tag numbers along an the frequency distribution for each phenological variable approximately 5 km transect in the tropical rain forest of and vector r, a measure of concentration around the mean Kemmanugundi. These marked individuals were angle. monitored for phenology once a month from June, 2004 to

May, 2006. Individuals were observed for both vegetative (foliar) and reproductive phenologies. Leafing Testing for the occurrence of seasonality phenophases include different stages such as; 1) leafless, 2) leaf initiation; 3) leaf expansion; 4) leaves mature and The mean angle a, or mean date is the time of year around 5) leaf senescence. Flowering phenophases included which the dates of a given phenophase occurred for most different stages such as: 1) flowerless; 2) flower bud; 3) species. Rayleigh’s Z- test determines the significance of open flower; 4) pollinating flower and 5) flowers falling. the mean angle. The hypotheses tested were: HO = dates Fruit phenophases include: 1) fruitless; 2) fruit bud; 3) are distributed uniformly (or randomly) around the circle fruit ripening/unripened fruit; 4) matured fruit/ripened or year; there is circular uniformity or no mean direction fruit and 5) fruit senescence. Each stage in the different and consequently, no seasonality; and HA = dates are not categories of phenology was scored qualitatively with distributed uniformly around the year; there is a respect to both spread and intensity on canopy on a 0 to significant mean angle or mean direction and 100% scale (Nanda et al., 2014). consequently, there is some seasonality. If HA is accepted, the intensity of concentration around the mean angle denoted by r, can be considered a measure of the degree of Data analyses the seasonality. The vector r has no units and may vary

Correlation coefficients (r) were calculated between from 0 (when phenological activity is distributed rainfall and the number of species belonging to different uniformly throughout the year) to 1 (when phenological leaf, flower and fruiting phenophases at the community activity is concentrated around one single date or time of level with corresponding and 1 to 2 lag months. year). If HO is not rejected, then r = 0 (Morellato, 2000; Zar, Kolmogorov – Smirnov test (KS test) was performed to 2007). examine inter – annual variation among tress at the community level. One-way analysis of variance (ANOVA) was used to examine variability in number of species RESULTS across different months. Chi-square test (χ2) was used to determine whether there is a significant difference Community wide pattern between the expected frequencies and the observed frequencies in one or more phenophases (Zar, 2007). There was a significant inter-annual variation in flushing of leaves among trees at the community level (KS- test, D = 0.5833 and p<0.05) with higher mean number of species Seasonality study (16.83±9.47) in the first year (June, 2004 to May, 2005) as compared to 2nd year (7.33±5.86) (June, 2005 to May, Seasonality was determined with circular statistics. 2006). Mean number of species flushing leaves was

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36 leaf bud rainfall(mm) 1800

33 1600 30 1400 27

24 1200

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15 (mm) Rainfall

Number of species of Number 12 600

9 400 6 200 3

0 0 J- J A S O N D J- F M A M J J A S O N D J- F M A M 2004 2005 2006 Months

Figure 2. Leaf bud phenology and rainfall among different species in Kemmanugundi.

significantly different across the years (Z = 2.95 and was also no variability in species number across months p<0.001) and variability across months was also with different fruiting stages (ANOVA, NS). significant (ANOVA, F= 8.71 and p<0.007). There was no inter-annual variation with leaf expansion though mean number of species that are expanding their Factors influencing phenology leaves was significantly different during the study period (Z = 2.14, p<0.03). Variability in number of species across Leaf phenology different months was also significantly different (ANOVA, F = 4.51, p<0.04). Rainfall had significant negative influence on leaf flush Mean number of species with senescent leaves during during the corresponding months (r = -0.416, p<0.04) the first year (7.66±6.28) and during the second year (Figure 2). Time lag correlations with rainfall were not (11.66±5.19) which was not significantly different (Z = - significant either during one-month lag period or two- 1.69, NS), though their distribution pattern was months lag period. Rainfall had significant negative significantly different across years (KS- test, D = -0.5833 influence on leaf expansion during both corresponding and p<0.05). Variability in number of species across months (r = -0.590 and p<0.002) and lag periods (r= - different months was not significantly different (ANOVA, F 0.719, p<0.0001 and one-month lag), (r = -0.530, p<0.01 = 2.88, NS). and two-months lag). Based on the strength of the Distribution pattern of species both with initiating relationship and significance levels, it can be inferred that flowers and open flowers was not significant (KS test and rainfall during the preceding month (Figure 3) has NS) across years. Mean numbers of species across years significant influence on the leaf expansion among the trees with both initiating flowers and open flowers was not at Kemmanugundi forest. Rainfall did not exert any significant (Z- score and NS) and also the variability across influence on the senescence of leaves (Figure 4). However, months (ANOVA, NS). the directionality of the influence is negative, suggesting There were 7.91±3.47 species fruits in a month during that many species shed their leaves during the dry season. the first year while 6.83± 3.27 species during the second year. Similarly, 5.33±4.29 species dropped fruits in the first year and 8.33±4.55 species dropped their fruits Reproductive phenology during the second year. There was no significant variation Flower initiation and leaf flush occurs simultaneously across years with fruiting pattern (KS test, NS) and the among the species (KS test, D = 0.333 and p>0.10), though mean number of species did not vary (Z scores, NS). There in some months there are more number of species Academia Journal of Scientific Research; Wei. 0409

leaf expansion rainfall(mm) 55 1800

50 1600 45 1400 40 1200 35

30 1000

25 800 Rainfall (mm) Rainfall

Number of species of Number 20 600 15 400 10 200 5

0 0 J-2004 J A S O N D J-2005 F M A M J J A S O N D J-2006 F M A M Months

Figure 3. Leaf expansion phenology and rainfall among different species in Kemmanugundi.

leaf senescence rainfall(mm) 26 1800 24 1600 22 20 1400

18 1200 16 14 1000 12 800 (mm) Rainfall 10 Number of species of Number 600 8

6 400 4 200 2 0 0 J- J A S O N D J- F M A M J J A S O N D J- F M A M 2004 2005 2006 Months

Figure 4. Leaf senescence phenology and rainfall among different species in Kemmanugundi.

initiating flowers than having young leaves (χ2 =71.87, and p<0.003) (Figure 6). Pollinating flower during p<0.0001 and N = 23) (Figure 5). Rainfall during the corresponding months and time lag correlations are not corresponding months has a significant negative influence significant (Figure 7). on the initiation of flowers among the species (r = -0.573 Rainfall has strong negative influence on fruit initiation Academia Journal of Scientific Research; Wei. 0410

leaf bud flower bud rainfall 40 1800

35 1600

1400 30

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15 (mm) Rainfall

Number of species of Number 600

10 400

5 200

0 0 J- J A S O N D J- F M A M J J A S O N D J- F M A M 2004 2005 2006 Months

Figure 5. Leaf bud, flower bud phenology and rainfall among different species in Kemmanugundi.

Figure 6. Flower bud phenology and rainfall among different species in Kemmanugundi.

during both lag periods (r = -0.737, p<0.00005 and one- rainfall during preceding two months induced species in month lag), (r = -0.66, p<0.007 and two months lag) Kemmanugundi evergreen forest to drop their fruits. (Figure 8). Correlation during corresponding month was not significant with respect to fruit maturity and also time lag correlations had negative significance (r = -0.668, Seasonality p<0.004 and one-month lag) (r = -0.643, p<0.001 and two- months lag) (Figure 9). Similar pattern was noticed for Leaf initiation and leaf expansion in Kemmanugundi forest fruit senescence two-month lag correlation with rainfall is significantly seasonal. Leaf initiation occurs during early and fruit abscission was negatively significant (r = -0.746 January with species initiating leaves in the month of and p<0.00006) (Figure 10). Lack of rainfall or scanty December, extending up to March, which is significantly Academia Journal of Scientific Research; Wei. 0411

pollinating flow er rainfall(mm)

16 1800

14 1600

1400 12 1200 10 1000 8 800

6 (mm) Rainfall Number of species of Number 600

4 400

2 200

0 0 J- J A S O N D J- F M A M J J A S O N D J- F M A M 2004 2005 2006 Months

Figure 7. Pollinating phenology and rainfall among different species in Kemmanugundi.

16 fruit bud rainfall(mm) 1800

14 1600

1400 12

1200 10 1000 8

800 Rainfall (mm) Rainfall 6 Number of species of Number 600

4 400

2 200

0 0 J- J A S O N D J- F M A M J J A S O N D J- F M A M 2004 2005 2006 Months

Figure 8. Fruit bud phenology and rainfall among different species in Kemmanugundi.

seasonal. Strength of seasonality is stronger in leaf mid February and the event is not seasonal. initiation as compared to other phenophases in leaf Both flower initiation and open flower stages in phenology. Peak leaf expansion occurs during the end of flowering phenology is significantly seasonal. Peak February and leaf senescence, though, peaks occurs during initiation of flower occurs during early January, though Academia Journal of Scientific Research; Wei. 0412

20 fruit ripened rainfall(mm) 1800

18 1600

16 1400

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8 (mm) Rainfall Number of species of Number 600 6

400 4

2 200

0 0 J- J A S O N D J- F M A M J J A S O N D J- F M A M 2004 2005 2006 Months

Figure 9. Fruit ripened phenology and rainfall among different species in Kemmanugundi.

fruit fall rainfall(mm) 18 1800

16 1600

14 1400

12 1200

10 1000

8 800 Rainfall (mm) Rainfall

Number of species of Number 6 600

4 400

2 200

0 0 J-2004 J A S O N D J-2005 F M A M J J A S O N D J-2006 F M A M Months

Figure 10. Fruit falling phenology and rainfall among different species in Kemmanugundi.

some species had already initiated flowers during significantly seasonal, but the strength of seasonality November. Flowers are initiated till mid March. Most of the varies across the events. Most species initiate fruits around species have pollinated flowers by March, during the peak March which is seasonal and has highest strength of dry season. All events in fruiting phenology are seasonality. Most species have matured or ripened fruits Academia Journal of Scientific Research; Wei. 0413

Table 1. Seasonality of leafing, flowering and fruiting phenophases in evergreen forest of Bhadra wildlife sanctuary.

Parameters / leaf Leaf initiation Leaf expansion Leaf senescence Mean angle 8.542 51.881 49.25 Mean vector r 0.265 0.174 0.096 Angular SD 69.48 73.62 77.04 Rayleigh’s Z 20.317 19.38 2.134

Flower Flower initiation Pollinated flowers Mean angle 11.53 72.42 Mean vector r 0.168 0.28 Angular SD 73.89 68.73 Rayleigh’s Z 8.05 9.26

Fruit Fruit initiation Fruit ripened Fruit fall Mean angle 77.63 83.56 113.96 Mean vector r 0.403 0.242 0.331 Angular SD 62.58 70.52 66.29 Rayleigh’s Z 21.15 13.7 17.93 P value <0.000 a <0.000 a <0.000 a

aSignificant at <0.05; SD: standard deviation.

during March. Peak fruit fall is in April when there are peaked after first rains in sub-tropical forests of Manipur. some pre-monsoon showers before the onset of regular At another site along the Western Ghats (Sundarapandian monsoon (Table 1). et al., 2005) evergreen forest species did not show significant correlation between leaf flush and rainfall with corresponding months. However, Boojh and DISCUSSION Ramakrishnan (1981) reported one-month lag correlation was significant in Shillong, northeast Korea dry season Phenological events at evergreen forest in Kemmanugundi flushing in a sub-tropical rainforest though forest are strongly influenced by the seasonality in rainfall remained evergreen throughout. though, trees remain evergreen throughout the year. Leaf Dry season flushing would be advantageous in locations initiation begins from December to January (winter) and with seasonal rainfall as entire leaf complement would be April (summer) with a major and minor peak before the ready to make use of rains for production and tissue onset of rainfall. Rainfall had significant negative influence building activity (Kushwaha and Singh, 2005; Singh and indicating that leaves are initiated during the dry season. Singh, 1992). The leaf flushing activity at the community Dry period initiation of leaves is observed in several forest level continued for several months ensuring the types of Korea (Kushwaha and Singh, 2005; Kikim and availability of photosynthetically active tissue. Similar Yadava, 2001; Murali and Sukumar, 1994; Nanda, 2009; pattern was also observed with leaf expansion. Leaf Prasad and Hegde, 1986; Singh and Singh, 1992) as well as senescence occurred from August to October ((rainy) and in other tropical forest sites (Borchert, 1994; Frankie et al., January (winter) to March (summer) with major and 1974; Opler, 1976; Reich, 1995; Williams-Linera, 1999). minor peak. Even though leaf senescence begins during Rainfall had negative correlation on leaf expansion and rainfall it has no significance. However, our results largely takes place in two peaks before the onset of rainfall in support the general conclusion that leaf senescence is January (winter) to February (summer) and during June driven by moisture stress (Borchert, 1994; Kushwaha and (rainy). Singh, 2005). A negative correlation was reported with water level Trees in Kemmanugundi on average flower initiation and leaf flush as reported in terra firme forests of Amazon were observed simultaneously with leaf flush. Flower (Haugaassen and Peres, 2005). Lieberman and Lieberman initiation was seen throughout with distinct peak during (1984) noticed a positive influence of rainfall on leaf the dry period. Initiation of flower bud occurred during flushing in the dry tropical forest species. Rainfall did not November and January and pollination in December influence the leafing phenology in the coastal vegetation of (winter). In seasonal forests of Korea dry season flowering Brazil (Medway, 1972). Murali and Sukumar (1993) is common in both dry forests (Nanda, 2009; Singh and highlighted positive influence of photoperiod and Singh, 1992) as well as monsoon forests (Boojh and temperature on leafing phenology in Mudumalai wildlife Ramakrishnan, 1981; Sundarapandian et al., 2005). There sanctuary. Kikim and Yadava (2001) found that leaf flush was a negative correlation between rainfall and flowering Academia Journal of Scientific Research; Wei. 0414

at Kemmanugundi. Similar pattern was observed in dry seasonal except for senescence of leaves. Both initiation forests peninsular Korea (Prasad and Hegde, 1986; Nanda, (January) and expansion (February) of leaves occurs 2009) and also in rainforests (Krishnan, 2002; Sivaraj et during the cool dry season. The dry season leafing is seen al., 2005). Dry season flowering was also seen in other commonly across seasonal forests (Bhat, 1992; Kushwaha forests across the globe (Anderson, 2005; Heideman, and Singh, 2005; Murali and Sukumar, 1994; Nomura, 1989). Dry season flowering is said to be advantageous for 2003; Prasad and Hegde, 1986) and seasonal forests plants in seasonal climates as they have to partition across the globe (Bach, 2002; Bendix, 2006; Borchert, resources for both vegetative and reproductive phases 1994; Gunter et al., 2008; Opler, 1976) montane forests (Janzen, 1974). This explanation may not be an ultimate (Van Schaik, 1993) of Korea. Exceptions to the reason in seasonal rainforests such as Kemmanugundi afoermentioned pattern are observed with dominant where species are leaf exchanging type (Nanda, 2009). canopy tree Shorea robusta (Dipterocarpaceae) in Sal Fruit bud initiates during January (winter) and April forests of Korea (Singh, 2006) and in dry forests of Ghana (summer) as rainfall had negative influence on fruiting (Lieberman and Lieberman, 1984). phenology at Kemmanugundi. Time lag correlations were significant. Similar pattern of fruiting was also observed in Tai National park, Cote d Ivoire (Anderson, 2005). Ripened Seasonality of reproductive phenology fruit with different seasonal peaks occurred from January (winter) to April (summer) and in July (rainy). Fleshy Flowering is generally a dry season event in fruited species in Kibale National Park showed positive kemmanugundi forest flower initiation (January) and correlation with rainfall and pattern of influence is pollination (March) months. Dry season flowering is dependent on the dispersal strategies of species (Chapman reported from dry forests both in Korea and elsewhere in et al., 2005). Coastal vegetation in Brazil did not show the tropics (Nanda, 2009; Nomura, 2003; Ragusa-Netto correlation between rainfall and fruiting pattern (Medway, and Silva, 2007; Selwyn and Parthasarathy, 2006; Singh 1972). Similarly, there was no correlation between fruit and Singh, 1992; Stevenson, 2004). Similarly in rain forests production and monthly precipitation at Afromontane dry season flowering is reported (Hamann, 2004). Distinct forests in South Africa (Wirminghaus, 2007). Most fruiting flowering periodicity is also reported from mountain rain in Malaysian dipterocarp forest is influenced by forests of Ecuador (Bendix et al., 2006) and shrub lands of temperature as drop in minimum temperature promotes Hong Kong (Corlett, 1993), but Gunter (2008) reports heavy flowering (Ashton et al., 1988). Minimum continuous flowering in a humid site from Ecuador temperature is also shown to influence fruit production in without seasonality and also some of their species tropical forests of Gabon (Tutin and Fernandez, 1993). At frequently flowered around equinoxes. In our study site, the community level, both maximum and minimum maximum flower initiation occurred in the beginning of temperature influenced fruiting in a Mexican lower January (Cool dry season) and nothing with equinoxes. montane forest (Williams- Linera, 1997). However, species specific analysis needs to be performed Fruiting phenology in moist forests of northeast Korea to understand flowering pattern at species level. corresponds with rainfall periodicity though correlation Fruiting seasonality is more seasonal with all fruiting with rainfall is not explicitly stated (Kikim and Yadava, phenophases. Fruiting in Kemmanugundi is a dry season 2001). Moist forests of the Western Ghats also showed event. Fruit initiation occurs mid of March and ripened similar trend with rainfall and fruiting phenology fruit at the end of March. Similar pattern of dry season (Sundarapandian et al., 2005). Fruit falling in June (rainy) fruiting is also observed in many sites including Australia and March (summer) with a major and minor peak, but (Bach, 2002), (Krishnan, 2002) for Korea and (Sun, 1996) fruiting in species that are dispersed by birds such as great for Rwanda. Fruits are dropped before the monsoon mid of pied horn bill was during the dry season in the rain forest March. There was only one aggregation unlike moist of southern Western Ghats and they found that fruiting forests of Philippines (Hamann, 2004) and in Coromandel was scarce during the wet season (Kannan and James, Coast in Korea (Selwyn and Parthasarathy, 2006). Fruiting 1999). Hence, it may be suggested that unlike other seasonality is also influenced by dispersal modes. As evergreen forests (Williams-Linera, 1999) phenology of observed in many studies (Hamann, 2004; Nomura, 2003; trees in Kemmanugundi showed a significant negative Stevenson, 2004) abiotically dispersed fruits are abundant correlation with environmental factor especially to in the dry season while animal dispersed fruits are seen at precipitation. the beginning of the rainy season (personal observation).

Seasonality Conclusion

Seasonality of vegetative phenology The study highlights the pattern of phenology of species in a rainforest though a short-term exercise. Long-term study Leafing events in Kemmanugundi are significantly with many more environmental factors included in the Academia Journal of Scientific Research Wei. 0415

study that could potentially influence the community Kannan R, James DA (1999). Fruiting phenology and the conservation of processes is required for this unique seasonal rainforest of the great pied hornbill (Buceros bicornis) in the Western Ghats of southern Korea. Biotropica. 31: 167-177. the Western Ghats. We speculate that multiple theory Kikim A, Yadava PS (2001). Phenology of tree species I the subtropical approach that includes influence of solar irradiance, forests of Manipur in northeastern Korea. Trop. Ecol. 42: 269 -276. temperature and moisture would predict tropical Koptur S, Haber WA, Frankie GW, Baker HG (1988). Phenological studies phenology better rather than a single theory approach. of shrub and treelet species in tropical cloud forests of Costa Rica. J. Trop. Ecol. 4: 323-346. Krishnan R (2002). Reproductive phenology of a wet forest understorey in the Western Ghats, south Korea. Glob. Ecol. Biogeogr. 11: 179-182. ACKNOWLEDGEMENTS Kushwaha CP, Singh SP (2005). 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