Class 8 - montane forest Flashcards
What is the range in vegetation type?
From dry woodland to extremely wet forest
Why are they one of the most threatened in the world?
Beacuse of humans
Why is the cloud forest the most diverse and important?
Filters global air so they seize and incorporate water and nutrients from mist and fog – more diverse than lowland forest
What lattitudes are montane forests at?
Found only between northern latitude 23 degrees in Mexico and 25 degree southern latitude in Argentine – and only in mointains
Which altitudes do they occur at?
Occur between 500 and 4000 m, majority between 1200 and 2800 m
Where do cloud forests occur?
Cloud forests occur in a narrow belt where there is persistent, frequent or seasonal cloud cover at vegetation level
What do cloud forests do to the atmosphere?
They cause a conciderable increase in atmospheric humidity = horizontal precipitation
What are the most important environmental factors determining TMF?
Horizontal presipitation, reduced photosynthesis due to solar radiation, periodic water shortage, temperate changes, reduction in evapotranspiration rate, exposure to strong winds, limited nutrient uptake
What are the main vegetation differences compared to lowland forest?
Reduced tree stature, increased stem density, gnarled trunks and branches, dense crowns
What covers trees in TMF?
A complex mosaic like assemblage of epiphytes – plants that obtain water directly from the atmosphere (orchids, ferns, mosses, algae, fungi) blankets the surface of trees and shrubs
What does the cover of epiphytes do for trees?
Contributes to an enormous extra above-ground biomass which can retain more water from clouds
Where do the most developed TMF occur?
Northern Andes
Why do TMF occur at higher elevations on taller mountains?
It is mainly associated with a lowering in the level at which clouds form, the greater the humidity at the mountains base, the lower the cloud level occurs
What are the temperature and rainfall ranges?
Annual temps between 8 and 20 degrees, rainfall between 500 and 10,000 mm, mostly between 1000 and 3000
What characterises the soil?
Acidic, peaty, yellowish, with organic upper layer – soil characteristics correlate strongly with plant distribution
Why do people deforest TMF?
Deforestation has happened for timber, fuelwood, charcoal, made into pastureland = severe land degradation
How much mountain landmass does TMF cover globally?
30%
What occurs above the treeline?
Above the tree-line occurs a treeless, alpine, cold, wet, misty biome, often dominated by giant stem rosette plants, shrubs, forbs, grasses, bamboo, mosses, lichens
Example of a tree in TMF?
There are small, flattened, bonsai-like trees which have curved trunks due to soil creep and slopes – very close together
What are the max canopy heights?
Max canopy height between 7 m and 20 m
Example of how temperate trees and tropical trees grow together?
In Costa Rica for example, oaks grow and below is a sub-canopy layer with many tree species of both tropical and temperate origin
At what elevation do temperate plants start growing?
2000 m
What happens in seasonally dry TMF?
There are some seasonally dry montane forests, where pine trees dominate and the forest experiences frequent drought and fire
Where is there the most species richness (latitude and altitude)
Species richness decreases with latitude, and is highest at mid-altitude elevations
Why high endemism?
Many species on mountaintops which became isolated during last ice age
What is a very important and diagnostic species in cloud forests?
Tree fern, diagnostic for cloud forests, occur in almost every cloud forest in the world
What plants are there almost an infinite number of species of?
An almost infinite number of orchids, bromeliads, ferns
Animals
Endangered spectacled bear, mountain gorilla, tapir, large cats, deer, monkeys, rodents, rabbits, mice, bats
What are the main disturbances?
Storms and hurricanes – causes landslides
Example of an invasive species in the Andes?
Invasive species from maize agriculture in the Andes 2500-3000 years ago
What animal has gone extinct in cloud forests due to climate change?
The golden toad
Why is the forest hard to sustainably manage?
Because of climate, slopes, fragile soils
What is one successful example of managing TMF?
Planting secondary forest
What do rural communities get from TMF?
Forest products, food, fodder, fiber, fuel, medicine, dyes, gums, oils, spices, poisons, plants and pets
How many percent of plants did a community in Costa Rica use?
25%
How much of cloud forest area is protected?
1/3
Do TMF differ globally?
Yes, but tropical mountain forests look very consistent globally
Examples of tropical mountains in Africa
Ras Dashen, Kilimanjaro, Ermin, Speke
Examples in South America
Simon Bolivar, Cotopaxi, Huascaran
Examples in Asia/Pacific
Anamudi, Hkakabo, Kinabalu, Puncak Jaya
Where do humans live on tropical mountains?
Human habitation is concentrated in the valleys, close to rivers, valleys are warmer, slope less steep (easier for infrastructure and agriculture), steeper it is, higher the risk of landslides
What are the Holdridge life zones?
Millimetres of rain determines the vegetation, the evapotranspiration determines the vegetation as well (or other way around), temperature and altitude as well, frost line determines vegetation as well
What is Orographic rain?
As wind goes up one side of the mountain, water rises, as it rises it gets colder and rains down
What is the rain shadow?
As air goes across the mountain to the other side, water has already rained down, and thus one side will be dry = two different ecosystems on the same mountain
Where are the cloud forests and what grows there?
Where the clouds form with the orographic rain: Tree ferns, snarled trees, epiphytes
Characterize montane ecosystems
Not much seasonality, but big difference between day and night (summer in the day, winter in the night), high levels of UV radiation, plants adapt to cold and warm shifts (compact growth forms, leaves thick and covered with hairs)
Characterize the giant rosette plant
Giant rosette plant has evolved all over the world at 3400-4500 meters, leafs develop from the top, water storage in the stem, anti-freeze chemicals in the leaves, leaves go close together when cold, looks like a giant leafy cactus/succulent but not ish, looks like a flower at the top
What does a cushion plant look like?
A big pile of moss
Mountain foods
Tea, fruits, root fruits, grains, llamas, cattle, potatoes, rye, wheat, corn, banana
Illegal mountain crops
Koka, Opium
What are the drivers of degradation in these systems?
Agriculture, climate change, deforestation, species invasion, fire, natural hazards, grazing, plantations, slash and burn (swidden agriculture)
How do we fight the drivers of degradation?
Agroforestry, direct seeding, exotic plantation, grazing exclusion (fencing), invasive plant management, native plantation, natural regeneration, seedling planting, soil amendments
What are the ES?
Pharmaceutical value, carbon storage, landslide and flood control, pollination, aesthetic value, tourism, existence value
What does deforestation do?
Tree cover loss means higher temperatures and higher cloud base height – affects fresh water supply, forest structures, canopy cover, canopy height. At lower heights, deforestation rises cloud cover significantly, at higher heights it raises them less
What does climate change do to cloud height?
At lower heights, climate change affects cloud height less, at higher heights climate change affects cloud height more
What are factors that limit the success of restoration?
Extreme weather and climate, land use legacy, negative biotic interactions (like grazing), dispersal limitations (animals too far from each other, cannot reproduce), abiotic habitat constraints (barriers like rivers, mountains, roads, towns)
What are the three levels of TMF?
Lower montane forest, upper montsne forest, sub-alpine vegetation
Can plants migrate on mountains?
Yes, there was a mountain where plants migrated upwards over 200 years
