Presentation on theme: "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."— Presentation transcript:
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
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) –32/104/20313/32/45
Rainforest Diversity Ecuador –365 vascular plants on 0.1 ha –33% epiphytes, 13% herbs, 10% shrubs and 9% non-epiphytic lianes Costa Rica (100m 2 ) –233 vascular plants, 32 bryophytes (1/6 GB) Most of these small ( 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 Structure trunks 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 Structure leaves Vastly different? No…most are oval, unlobed, smooth edged, sharp points at end, thick and waxy, and generally palmate
Rainforest Structure flowers Flowers do come in many shapes, sizes, and colors
Rainforest Diversity flowers 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 Diversity fruits & seeds Many species produce small to medium- sized fruits, but a number a very large Palms, the monkey-pot tree, brazil nut
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 Diversity Palms 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 Diversity vines 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 Diversity lianas 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 Diversity lianas 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 Diversity lianas 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
Rainforest Diversity epiphytes 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
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 Diversity epiphytes 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 Diversity epiphytes Many species have mycorrhizae, which aids in the uptake of many nutrients and minerals
Rainforest Diversity epiphytes 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 Diversity epiphytes 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 Diversity orchids 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 Diversity orchids 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 Diversity species 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 Diversity species 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 Diversity species richness Other groups are equally rich Columbia birds: 1,695 sp Peruvian Amazon (50 mi 2 ) 550 sp La Selva (1,500 ha 2 ) 410 sp North America…700 sp
One night 56 sp collected Ecuadorian Amazon, one site 81 sp
Rainforest Diversity species richness Insects in Costa Rica 550 butterflies Peruvian Amazon (Explorers Inn) 1,234 sp
Rainforest Diversity species 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…