Reproductive phenology over a 10‐year period in a lowland evergreen rain forest of central Borneo

Abstract

Summary 1The aim of this study was to document patterns in tree reproductive phenology in a rain forest of central Borneo and examine relationships between phenology and climatic patterns. 2 A 10-year data set (1990)(1991)(1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000) of monthly observations of flowering and fruit production of 171 trees (including 39 members of the Dipterocarpaceae) at Barito Ulu, Central Kalimantan, Indonesia, showed that most trees (73%) underwent reproductive activity on a supra-annual timescale. 3 There were three general flowering (GF) events, in 1991, 1994 and 1997, which were preceded by major drought periods (30-day sliding total rainfall of less than 100 mm for more than 10 days) in which at least 40% of dipterocarps and at least 18% of all other trees underwent synchronized reproductive activity; there was also a minor event in 1990. Around 1.3% of trees flowered and 3.8% produced fruit in months outside of these four events. 4 At the community level, the strongest negative correlation was found between the percentage of flowering individuals and total rainfall in the preceding 150 days. 5 Within three genera of dipterocarps examined in more detail ( Dipterocarpus , Shorea and Vatica ) there were clear and consistent patterns of sequential flowering with certain species flowering early in the GF events and others towards the end of these events. 6 Our results confirm the importance of large-scale climatic fluctuations (El Niño-Southern Oscillation) on plant reproductive phenology in South-east Asian tropical forests and indicate that drought may be a more important cue than low night-time temperatures.

Flowering and fruiting phenology in maquis of New Caledonia

“…Fructification peaks mainly occurred at the beginning of the wet season. Such associations have been commonly observed in the tropics, particularly where there is climatic seasonality (Janzen, 1967;Daubenmire, 1972;Frankie et al, 1974;Lescure et al, 1990;Borchert, 1996;McLaren & McDonald, 2005;Brearley et al, 2007). A similar pattern has been observed within rain-forest communities from ultramafic regions of New Caledonia, where the greatest number of flowering species occurred in October (i.e.…”

Toward a synthetic understanding of the role of phenology in ecology and evolution

“…The phenology of flowering and fruiting in southeast Asian rain forests, in which community-wide mass-flowering events take place at irregular intervals of more than 1 year (Medway 1972;Brearley et al 2007), has little to do with the life history of individual trees and much to do with the factors favouring population-and communitylevel synchrony among individuals. In short-lived taxa with several generations per year, the link between life history and phenology may likewise not be immediately apparent.…”

“…In different types of tropical forests, either rain or drought can induce flowering (Medway 1972;van Schaik et al 1993;Brearley et al 2007); often, this does not occur on an annual cycle. Many desert plants germinate (annuals) or resume growth (perennials) in response to rainfall (Beatley 1974;Zhang et al 2006;Kimball et al 2010).…”

Phenology of tropical understory trees: patterns and correlates

“…Community-level surveys of plant phenology in the wet tropics have mainly focused on canopy trees (Newstrom et al 1991, Bhat 1992, Berlin et al 2000, Sakai 2002, Anderson et al 2005, Haugaasen & Peres 2005, Brearley et al 2007, Cannon et al 2007, with little attention paid to woody plants of the forest understory. However, the phenology of understory trees is of great relevance to understanding tropical plant-animal interactions, especially mutualisms between pollinating and seed-dispersing vertebrates and the plants they feed on.…”

“…If attack rates vary in seasonally predictable ways, pathogens could also contribute to shaping temporal patterns of fruiting. Finally, because rainfall is a major axis of seasonality in these forests, influencing plant growth (Brearley et al 2007), seed disperser behavior (Boyle et al 2010), and likely pathogen populations, we related precipitation to community-level phenological patterns.…”