Plants of the Amazon Rainforest. Hence, a traveller should be a botanist, for in all views plants form the chief embellishment. C. Darwin, HMS Beagle

Transcription

1 Plants of the Amazon Rainforest Hence, a traveller should be a botanist, for in all views plants form the chief embellishment. C. Darwin, HMS Beagle

2 The Amazon Rainforest biome 2,100,000 sq mi an estimated 390 billion individual trees divided into 16,000 species

3 The Amazon is one of the true Tropical Rainforests on earth

4 The climate maintains a dense and diverse plant cover red and purple colors: rainforest cover green: (savannas) shades of green

5 Geologic forces during the Cenozoic (65.5MY to present) created the forest Andean uplift created the environmental conditions that promoted plant and animal diversity

6 The forest has been in existence for at least 55 million years

7 The Amazon Rainforest contains c80,000 species of flowering plants out of 422,000 world-wide

8 and roughly 30 Million species of Insects Titanus giganteus 700 species of beetle discovered on just one tree.

9 The flora is extremely diverse, with up to 300 species/acre Socratea exorrhiza Bertholletia excelsa Brazil Nut

10 But very few individuals per species This is in contrast to what is found in Northern forests

11 Zones, or layers of the tropical rainforest

12 Top layer: Emergent trees Ceiba pentandra Kapoc

13 The tallest trees are the emergents, towering as much as 200 feet above the forest floor with trunks that measure up to 16 feet around. Wimba: Ceiba samauma 55m Brazilian mahogany Swietenia macrophylla, 70m Brazil nut, 50m Lupuna (Kapoc): Ceiba pentandra 55m

14 Many emergents have Buttress Roots Ceiba pentandra

15 Closed layer: the Canopy

16 The canopy contains most of the life of the forest Epiphytes insects (25% of all species) lianas and vines canopy trees

17 Epiphytes: Plants that grow on plants

18 Orchids

19 Bromeilads

20 Ferns Staghorn fern Bird s nest fern

21 Lianas (woody vines) Bauhinia (pea family)

22 Understory

23 Plants need to be shade tolerant as only 5% of the available sunlight reaches this layer

24 Palms are well represented 34 genera (24% endemic), 189 species Desmoncus mitis The Amazon contains about 50% of the New World species

25 Aroids Caladium bicolor Alocasia amazonica

26 Ferns Hymenophyllum sp Filmy fern Microgramma lycopodioides Adiantum macrophyllum

27 The forest floor Plants adapted to low light fungi bacteria

28 The soil depth is often <2

29 Roots for an intertwined mat on top of the soil

30 Saprophytes: Fungi and Bacteria Termite bacteria

31 Roots (probably) always are associated with fungi Mycorrhiza

32 Nutrients are recycled almost immediately and absorbed by the biomass above

33 Due to this symbiotic relationship, nutrients are almost 100% recycled Nutrients (C and N) Biomass (plants & animals) = 50% Forest floor and the first 50cm of soil = 40% Microbial and Fungal activity in Rivers and the Forest floor convert biomass back into CO2 45% from soil 55% from rivers 5% of the Carbon reaches the ocean.

34 Adaptations of plants to the Rainforest

35 Roots Plants modify their three organs Stem Leaves

36 Roots Plants of the rainforest have adapted to their epiphytic habit prop palms buttress Ceiba clasping Philodendron aerial/contractile figs absorptive orchids

37 Prop Roots

38 Buttress Roots

39 Clasping Roots Phyllodendron

40 Aerial Roots, strangler figs

41 Absorptive Roots Orchids

42 Adaptations of leaves

43 Leaf shape Entire margin, thick and tough, often waxy Young leaves reflexed and red pigmented

44 Large leaves capture light Victoria amazonica Manicaria saccifera Leaves up to 30 ft long Alocasia

45 Leaves form a tank The leaves overlap to form a tank that catches water and detritus. Hairs at the base of the leaves absorb nutrients. Also, this genus can transform it s photosynthetic mechanism to a more drought-tolerant pathway (C3 -> CAM) during water stress.

46 Leaf Drip-Tip

47 Modifications of the Stem

48 Prickly Stems Ceiba pentandra kapoc Desmoncus orthacanthos Palm

49 Climbing stems Ribbon vine of Bauhinia guianensis

50 Stolons for vegetative reproduction Salvinia

51 Fruit dispersal

52 Hard Palm fruits are dispersed by large animals Attalea palm Agouti New World monkeys Astrocaryum palm

53 Smaller fruits are dispersed by smaller animals Three-toed sloth Fig tree

54 Really large fruits may have evolved when South America had Megafauna Glyptodon Megatherum Couroupita guianensis Cannonball tree Theobroma cacao cacao Cuvieronius

55 Some fruits have been especially taken care of by humans! Next Time!