Reproductive phenology of a wet forest understorey in the Western Ghats, South India

Abstract

The reproductive phenology of 60 understorey species was monitored at monthly intervals for 20 months in a medium elevation wet evergreen forest in the Southern Western Ghats. The life forms monitored were herbs (including terrestrial orchids), shrubs and small trees. Flowering and fruiting were non‐uniform with a dry season flowering peak and wet season fruiting peak. Flowering in the understorey correlated negatively with rainfall. No significant correlation was detected for fruiting. Life forms had flowering and fruiting peaks at different times of the year.

Flowering and Fruiting Patterns of Woody Species in the Tropical Montane Evergreen Forest of Southern India

“…Supra-annual flowering events (mass flowering once every two years) have been recorded in tropical rainforests of Costa Rica 20,21 and subtropical forests of Taiwan 5 . However, previous studies did not find supraannual flowering patterns in the forests of North East and South India 12,13,18 . Global climate change causes variation in the timing, duration and synchronization of phenological events in tropical forests 22,23 .…”

“…For instance, studies have shown that flowering and fruiting seasonality influences species demography, biotic interactions and other ecosystem processes [7][8][9][10][11] . Asia has a variety of forest types, including temperate forests, subtropical forests, montane evergreen rainforests and lowland tropical rainforests with varying degrees of seasonality [12][13][14][15][16] . The reproductive phenology of some of these forests has been extensively studied at the individual, population and community level 6,14,15,17 .…”

“…The reproductive phenology of some of these forests has been extensively studied at the individual, population and community level 6,14,15,17 . However, in the southern parts of Asia, especially India, relatively few phenology studies have been conducted in tropical wet evergreen and dry deciduous rainforests 13,18 . At present and to the best of our knowledge, there is no reliable and long-term information on community-level reproductive phenology of tropical montane evergreen rainforests.…”

“…Knowledge of how climate change and evolutionary constraints affect flowering and fruiting patterns is critical because it provides useful insight and in-depth understanding for monitoring plant responses to environmental change and for predicting its consequences on ecosystem functioning 19 . In South India, a majority of tropical wet evergreen and dry deciduous rainforest species exhibit annual flowering patterns due to regular reproductive cycles 13,18 . However, studies predict that climate seasonality might shape community-level flowering frequency within this region.…”

“…Temperature and/or precipitation seasonality may also influence regular flowering, while solar-related factors could influence flower synchrony 4 . In tropical wet and dry deciduous forests, reproductive phenology negatively correlates with monthly rainfall 13,18 . Fruiting patterns in tropical montane rainforests showed significant positive correlations with the number of rainy days but not with temperature 26 , whereas leaf initiation showed positive correlation with temperature 27 .…”