280 likes | 408 Views
Seasonal and annual variability in tropical ecosystems. Factors determining reproductive phenology of plants in rainforests. Supra-annual variability in flowering in tropical trees. Andira inermis. Fruiting seasonality: intra-population variability. Shrubs on Barro Colorado Island.
E N D
Seasonal and annual variability in tropical ecosystems
Factors determining reproductive phenology of plants in rainforests
Supra-annual variability in flowering in tropical trees Andira inermis
Fruiting seasonality: intra-population variability Shrubs on Barro Colorado Island
Fruiting seasonality in a seasonal forest (Barro Colorado Island) Dry season
Temporal correlation between leaf flush and fruiting Bimass of primates (kg/ha): America 5-7, Asia 8-28, Africa 7-23
Heliconia spp. in Costa Rica: staggered flowering to reduce competition for hummingbird pollinators
Dipterocarps: mass flowering at irregular intervals of 2-10 years [El Nino years]
Annual variability in dipterocarp seeds (“illipe nuts”) exports El Nino [marked from 1969]
Dipterocarp seeds: • large, energy rich (used as a source of cooking oil) • poorly protected chemically • wind dispersed
SE |Asian forests: many tree species join dipterocarps in their supra-annual mass flowering cycle
Temperature drops by >2oC for at least 3 nights identified as a cue for mass flowering of dipterocarps
Dipterocarps are pollinated by insects (thrips, beetles) Sakai et al. (1999)
Parashorea tomentella: seedling cohorts following mass fruiting
Length of active season of adult Homoptera on Barro Colorado Island
Cicada emergence in lowland rainforest, Costa Rica Diceroprocta sp.
Insect seasonality on Luehea seemannii, a lowland rainforest tree
Seasonal patterns of leaf production and herbivory in a lowland seasonal forest (Barro Colorado island)
Dry forest during dry season, Queensland Tropical extreme seasonal, i.e. monsoonal, forest during dry season. Cape York Peninsula, Queensland. Lyn Webb image.
Dry x humid forests: leaf fall seasonality
Dry x humid forests: leaf life span
A deciduous emergent tree in lowland forest, Queensland Deciduos emergents. Queensland. Lyn Webb photo
Increased amount of leaf litter during dry season, Queensland Deep leaf litter on floor of tropical monsoon forest at end of dry winter season, Queensland. Lyn Webb photo
Sand dunes: an example of a strongly seasonal tropical environment Extensive horizontal roots and deep tap-root of Eucalyptus sp. in sand dunes, strongly seasonal in tropics. Queensland. Len Webb photo.
Acer sp. in montane rainforest in Vietnam: one of a few deciduous species there