Class 7 - tropical rainforest Flashcards
What biomes are present in the Amazon?
Forests, savannas, swamps, aquatic ecosystems
How big is the lowland amazon forest?
Covers 5.79 million km2 over 9 countries and is the largest continuous cover of tropical moist forest
How many tree species, plant species and trees are there in the amazon forest?
16,000 tree species, 50,000 plant species, 400 billion trees - 13% of all trees globally
What characterises the Western Amazon?
Most diverse forest, fertile soil, species rich, high stem turnover, lower above-ground biomass
What characterises central and eastern Amazon?
Poor soils, less dynamic, high biomass
Where is the largest tropical wetland on earth?
In the Amazon river basin
What characterises the Amazon river basin?
World’s largest store of freshwater, 15% of all fish species
What are contact areas between terrestrial and aquatic systems called and what characterises them?
Ecotones (contact areas) are important, they contribute to movement of animals, nutrients, promote habitat heterogeneity
What does the Amazon do with carbon?
A huge carbon store
What drives the spatial variation in carbon stock and biomass?
Driven more by soil condition than climate and more by spatial variation in tree mortality than productivity
What do the major river classes strongly determine?
Floodplain forest ecology and species
What has climate change done to the forest?
Some forests are already close to their thermal and hydrological limits of sustaining productive ecosystems – tree mortality rates are increasing
How much do freshwater ecosystems cover?
1 million km2
Mean annual rainfall?
Varies between 3000 and 1500 mm
How do the rainfall and soil gradients go?
Rainfall goes from most wet (northwest) to least wet (southeast), soil goes from most fertile (southwest) to least fertile (northeast)
What determines the composition of forest?
Soil fertility and annual rainfall
What is the total flora?
Between 15,000 and 50,000 species estimated
How many percent of vascular plants, birds, mammals and ambhibians in the tropics live in the Amazon?
18% of vascular plant species, 14% of birds, 9% of mammals, 8% of amphibians
What families contribute to most trees in the Amazon?
Fabaceae, Arecaceae (palms), Lecythidaceae are most abundant
Where is species richness highest and lowest?
Highest = Dryland forest, lowest = flooded forest, swamp forest, white sands
What is the white sand forest and what characterises it?
Found on pockets of highly leached deposits of podzolized white sand.
Ocupy 3-5% of the Amazon, species poor, high level of endemism
How much does savanna occupy in the Amazon and what annimals live there?
14%, white tailed dear, banded armadillo, maned wolf
What is unique about fish in the freshwater systems?
Sustain the greatest diversity of freshwater fish on earth
What characterises white-water systems?
Originate in the Andes or hilly rugged moderate elevations. Turbid, transparency between 20 and 60 cm, high sediment loads, near neutral pH
What characterises clear-water systems?
Start in cerrado region of central Brazil, draining the ancient Brazilian shield. Acidic to neutral pH
What charactises the black-water systems?
Origins in lowlands. Translucent, high in dissolved organic carbon, low in nutrients, transparency between 60-400 cm, low quantities of suspended matter, high amounts of acids
What is a wetland?
Ecosystems at the interface between aquatic and terrestrial environments, biota adapted to life in water or water-saturated soils
How much of the Amazon basin is covered by wetland?
30%
Define the two types of wetlands
Those with relatively stable water levels and those with changing water levels (10% of the basin)
How long does flooding last and how much does water levels fluctuate in seasonally flooded wetlands?
Flooding lasts up to 6 months, and water levels fluctuate up to 10 meters
What characterises seasonally flooded forest?
Contains 1,000 species of trees. Highly productive but less flora and fauna diverse than lowland forest
How much does flooded savanna cover?
200,000 km2 (fragile ecosystem)
What affects gross production the most?
Climate
The role of animals in the forest?
They increase nutrient cycling and the productivity of the forest
What controlls primate abundance?
Fruit production
What controls production of flowers and fruits?
Soil nutrient status
Why are aqautic ecosystems highly dynamic?
Flow of energy and nutrient recycling. Nutrients travel downstream and as the channel gets wider, algae can grow
What happens to algae in turbid white-water?
Algae growth is limited because of less light penetration
Why do wetlands contribute to carbon storage?
PEAT bitch
What is peat?
Type of soil with a top layer composed of at least 50% decomposed to semi-decomposed organic material
When is the maximum flow of flooding in the basin?
Varies between feb and jul
What is the role of the massive fish migrations in terms of nutrients?
Massive fish migrations transfer a small amount of nutrients from white-water to clear and black-water
Explain the co-evolution between trees and fish
Tree species produce fruit during the high-water season when fish invade the flooded forest – hundreds of fish have evolved to eat fruit, spread the seeds of trees over long distances. They also eat leaf-eating insects and carnivorous invertebrates – indirect feeding link between fish and trees. This brings monkeys and kingfishers to the forest, because the trees grow fruit and the fish are there
What does tropical forest affect more than any other biome?
Weather, freshwater, natural disasters, biodiversity, food, and health
How much land cover is covered by forest now compared to before?
From 12 to less than 5%
Why does it rain so much in tropical forests?
Tropical forests return up to 90% of the rainfall they receive to the atmosphere and winds in tropical forests produce twice the rain as winds elsewhere
How does deforestation affect the weather long distance?
Deforestation reduces the moisture and rainfall crossing oceans, making temperatures hotter and storms more intense
How does deforestation affect the dry season?
Declines in forest cover causes declines in freshwater supply and makes dry seasons last about a month longer
What kind of natural disasters do TF mitigate?
Tropical forests mitigate natural disasters like erosion, landslides, and floods, torrential rainfall, fires
What natural disasters can coastal forests mitigate?
Coastal forests reduce effects from storms, peak tides and small tsunamis
Why is high biodiversity a biological insurance?
Provides ecosystem stability and resilience, and ES
How do TF provide food security?
They provide food, pollitnation and pest control, people living near forests have better diets and nutrition
How much of global food supply depends on wild pollinators?
1/3, 70% of leading global crops benefit from pollination by wild insects and bees
What animals provide free pest control?
Bats and birds
How do mangroves provide food security?
They serve as hatcheries, breeding grounds, and nurseries for offshore fish. They also provide nutrients and food for fish living in them
What diseases are deforestation related to?
Malaria, ebola, yellow fever, avian influenza
How many of the drugs approved to treat cancer come from natural products?
Half
How does deforestation affect effect from storms?
Storms hit harder, mudslides occur, fields flood, rivers carry debris, silt damages offshore reefs and fishing ground. Soil erosion – rivers fill with silt which reduces water quality, diminishes hydropower, damages infrastructure
What types of forests have the lowest variety and quality of ES?
Degraded forest, secondary and plantation forest
What do tropical forests do with rain and fog?
Slow, capture and recycle fog and rain and pumps humidity back into the air