Rainforests

• “if the traveller notices a particular species and wishes to find more lite it, he may often turn his eyes in vain in every direction. Trees of varied forests dimensions and color ae around him, but he rarely sees any one of them repeated. Time after time he goes towards a tree which looks like the one he seeks, but a closer examination proves it to be distinct”. A.R. Wallace

Rainforests

• What is it?– Vines

Rainforests

• What is it?– Tall canopy

Rainforests

• What is it?– Buttressed trees

Rainforests

• What is it?– Rivers

Rainforest…critters

• What is it?

Rainforest…critters

• What is it?– frogs

Rainforest…critters

• What is it?– Macaws other

seed/fruit eaters

Rainforest…critters

• Monkeys

Rainforests…look alike

Rainforest rivers…look alike

Rainforests…smell alike

Inside a Rainforest

• Structurally very complex (physiognomy) with up to 5 layers present– Forest floor– Shrub– Mid-canopy– Canopy– Emergents

Rainforest Diversity

• Comparisons• Malay Peninsula vs. Britain (2x)

– S 8000 (1400G, 28 end vs 1430, 620G, 0e)

• Malay vs Denmark (mammals..FGS)– 32/104/203 13/32/45

Rainforest Diversity

• Ecuador– 365 vascular plants on 0.1 ha– 33% epiphytes, 13% herbs, 10% shrubs

and 9% non-epiphytic lianes

• Costa Rica (100m2)– 233 vascular plants, 32 bryophytes (1/6

GB)

• Most of these small (<1m)…but in Amazonia found 300/ha of dbh>10cm

Rainforest Diversity

• What about a typical tropical tree?

• Although can be tall and wide, most are medium and skinny (25-30m)

• Their structure tends to reinforce this misconception

Rainforest Structure

• Many species have buttresses and prop roots

Rainforest Structure

• Function not completely understood (perhaps support)

• Not all species have prop roots or buttresses (e.g. Brazilnut)

Rainforest Structuretrunks and crowns

• Many trees have long, slender boles• Bark comes in a variety of color and

textures (although some more common)

• Many trees have a flattened crown (think umbrella)

Rainforest Structure

• Cauliflory – flowers and fruits abruptly growing from the trunk (e.g. cocoa)

• Why? May be due to weight, could facilitate pollination by ___, facilitate dispersal by ____.

Rainforest Structureleaves

• Vastly different?• No…most are oval, unlobed, smooth

edged, sharp points at end, thick and waxy,

and generally palmate

Rainforest Structureflowers

• Flowers do come in many shapes, sizes, and colors

Rainforest Diversityflowers

• Color not random– Red, orange and yellow – birds– Lavender – insect– White – bats or moths

• Smell– Fragrant = moths, bees, beetles– Musty = bats

• Pollination – many nectar rich…why?– Some wind pollinated…who?

Rainforest Diversityfruits & seeds

• Many species produce small to medium-sized fruits, but a number a very large

• Palms, the monkey-pot tree, brazil nut

Rainforest Diversityfruits & seeds

Rainforest Diversity fruits & seeds

• Large seeds are a major source of food for the large mammals (e.g. monkeys, bats, peccaries, agoutis) and birds (e.g. tinamous, guans, curassows, trogans, and toucans) and in flooded forests, some fish are important fruit consumers and seed dispersers. Insects are frequent predators of small seeds

Rainforest DiversityPalms

• Palms are distinctively tropical• There are about 1,500 species (550)• All palms are members of the family

Palmae, are all monocots, sharing characteristics with lilies, orchids and grasses.

• Widely used by indigenous peoples for diverse purposes such as thatch, ropes, strings, weavings, hunting bows, various food and drink.

Rainforest Diversityvines

• Vines are conspicuous, abundant, and important in the rainforest

• In some forests they are a dominant form of biomass

• in Panama, 1ha contained 1,597 climbing lianas (in 43% of the canopy)

Rainforest Diversity

• In the Neotropics, there are > 133 families that have climbing members

• Some, lianas, entwine themselves and dangle from the canopy. Others climb.

Rainforest Diversitylianas

• Lianas get their start in gaps where they have been living as a harmless shrub

• Once in the canopy, they can spread from tree to tree

Rainforest Diversitylianas

• Lianas are a growth form, not a family of plants and as such, come from a variety of families (making the identification hard)

• In Panama, a single ha had 1,597 climbing lianas, 22% of the upright plants were lianas

Rainforest Diversitylianas

• Other vines start on the ground (e.g. many philodendrons). Once their seed germinates, it sends out its tendrils to the shade of a nearby tree.

• Many times as the vine extends into the canopy, it is no longer rooted (thus becoming an epiphyte)

Rainforest Diversity

• The most aggressive vines are stranglers (Ficus spp.)

• About 150 sp neotropics

• Many dispersed by monkeys or birds

• Consequently, send down tendrils to form root system

Strangler Fig Sequence

Rainforest Diversityepiphytes

• Epiphytes live on other plants• Although not directly parasitic, they do

compete for space, light, and water• Rainforests worldwide (both temperate

and tropic) abound with epiphytes of many different kinds (cloud forests)

• In many lowland forests, ¼ of all plants may be epiphytes. Less AB where drier

Rainforest Diversityepiphytes

Rainforest Diversityepiphytes

• Many different plants grow epiphytically (e.g. lichens, ferns, orchids, liverworts, cacti, mosses)

• In C and S Am, there are estimated to be 15,500 species

Rainforest Diversityepiphytes

• A single tree may house a great diversity of species or simply a great abundance of individuals

• Survive by trapping soil and nutrients from air

Rainforest Diversityepiphytes

• Many species have mycorrhizae, which aids in the uptake of many nutrients and minerals

Rainforest Diversityepiphytes

• Bromeliads are abundant epiphytes in almost all Neotropical moist forests

• Leaves of many species are arranged in an overlapping rosette to form a cistern that holds water and detrital material

• About 2,000 Neotropical bromeliads (pineapples)

Rainforest Diversityepiphytes

• Epiphytic bromeliads provide a source of moisture for many canopy creatures (e.g. tree frogs, mosquitos, flat-worms, snails, salamanders, and even crabs can complete their life cycle in the small flower arboreal cisterns.

• One study found 250 animal species occurring in bromeliads

Rainforest Diversityorchids

• Orchids are a global family (Orchidaceae) with 25-35k species

• In Costa Rica, 88% are epiphytes, others grow as vines

• Many have bulbous stems (called pseudobulbs) that store water

• Strong mutualistic relationship with mycorrhizae

Rainforest Diversityorchids

• Cross pollination is done by insects (primarily bees)

• Some orchid flowers mimic insects, facilitating visitation by insects thinking they are meeting a ‘special’ friend

• Obvious importance to collectors • 90 species in the genus Vanilla

Rainforest Diversityorchids

Rainforest Diversityspecies richness and

biodiversity• Appalachians 30 sp/ha• Tropics 40-100 sp/ha

– Peru 300 sp/ha• Brazil 85,000 sp (2x Af, 1.7x Asia, 5x

NAm, • How? Lots of rare species (BCI old

500 trees/151 sp; young 500/115)• Kapok tree, some legumes,

Carribbean pine

Rainforest Diversityspecies richness

• Costa Rica (La Selva) 1,668 sp• BCI 1,320 sp• Amazon Peru-good soils - 1,856 sp• Near Manaus – poor soil – 825 sp• Tree sp much greater in Amazon, but

epiphyte, herbs, and shrubs are greater in CAm.

Rainforest Diversityspecies richness

• Other groups are equally rich• Columbia birds: 1,695 sp• Peruvian Amazon (50 mi2) 550 sp• La Selva (1,500 ha2) 410 sp• North America…700 sp

Rainforest Diversityspecies richness

Rainforest Diversityspecies richness

• One night 56 sp collected• Ecuadorian Amazon, one site 81 sp

Rainforest Diversityspecies richness

• Insects in Costa Rica 550 butterflies• Peruvian Amazon (Explorers Inn)

1,234 sp

Rainforest Diversityspecies richness

• Ants – Peruvian Amazon 135 sp• 43 sp in one tree (Great Britain)• 163 beetles in one tree (8M)

– Beetles are 40% of arthropod diversity…20M..30M with ground & shrub

• Difficult to comprehend, most are in the canopy

• This applies to many groups…

Rainforest Diversityspecies richness

Rainforest Diversityspecies richness

Rainforest Diversityspecies richness

Rainforest Diversityspecies richness