Global Forest Biomes Flashcards
major forest biomes globally
distinguishing features of biomes
latitudinal gradients
biome composition and diversity
seasonality
How many global terrestrial biomes are there?
14
How many of the terrestrial biomes are forested?
8
What defines a biome?
geography and biota
What shapes a terrestrial biome?
climate and conditions (temperature, moisture, nutrients, nutrient cycling)
How many ecoregions are the biomes subdivided into?
867
T or F: biomes and ecoregions have distinct and clear boundaries
false! it’s usually more of a continuum/gradient
What are 3 examples of non-forested biomes?
grassland
tundra
deserts
What 3 biome types can forests be found in?
boreal
temperate
tropical
What are the 2 major factors that influence and shape major vegetation communities and forest types globally?
mean annual temperature and precipitation
What 4 factors influence the climate in a region?
latitude
elevation
continentality (coastal v interior)
ocean currents (moderate rainfall)
On a local scale, what influences biomes?
geography
geology (parent rock)
soils
location (continentality, elevation, aspect)
historical disturbances (ex. glaciation, volcanoes, floods, fire, disease, forestry, urban development, climate change)
Describe the global distribution of the MAT
a gradient from the equator, the warmest being at and around the equator and cools with increasing latitude toward the poles
Describe the global distribution of the MAP
generally more near the equator but seasonality exists and
generally more along coast lines
What are Whittaker’s 8 biomes?
TR = tropical rain forests
TD = tropical dry forests
AR = arid lands
ME = Mediterranean type
TG = temperate grasslands
TB = temperate broadleaf forests
CF = coniferous forests
AA = Arctic and Alpine (includes TU tundra and AL alpine)
When looking at Whittaker’s biome diagram, which biome has highest MAT + MAP?
Tropical rainforests
How does latitude influence climate?
the distance from the equator creates gradients of abiotic and biotic conditions (temp + ppt) and creates seasonality
How does elevation influence climate?
increasing altitude from sea level creates changes in growing conditions and what biota can grow
temperature and seasonality can differ greatly at different altitudes
How does continentality influence climate?
coastal vs inland temperatures and precipitation levels can vary greatly
ex. wet, moderate (little variation) in BC coastal forests vs. dry hot and very cold seasonality in south Okanagan
mountain rainshadows play a large role in this
generally, inland regions have more variability and coasts are more moderate
How does ocean currents and temperature influence climate?
ocean currents moderate global weather patterns including ppt and temperature (Gulf Stream)
and can have a variable effect on weather depending on the El Nino or La Nina cycle
What major components of a biome do precipitation and temperature act on?
composition
productivity
biodiversity
What determines a forest type and extent of the forest?
seasonality of temperature and precipitation
generally, how is species richness distributed globally?
a higher richness at equator with a decreasing gradients towards the poles
Which biome is the most variable in terms of climate?
alpine
where does the Tundra biome exist? what type of vegetation is here?
above 70d N
very limited vegetation due to very short growing season and poor soils and slow decomposition rates = low productivity
What type of plant families are found in the Tundra?
Ericaceae, Vacciniaceae, Cyperaceae, some trees
What 2 distinct regions are included in coniferous forests?
Temperate coniferous and Boreal
Where do coniferous forests exist?
50-70d N
Which ecosystem types do coniferous forests border on?
tundrat at northern edge
temperate grasslands at southern edge
how much seasonality do coniferous forests experience?
temperate = moderate
Boreal = lots of seasonality in temperature
Why does the Boreal forest have lower biodiversity than the temperate coniferous?
Boreal forests may have peat formations (saturated soils) with low decomposition rates or frozen soils (permafrost)
Which major factor is limiting in coniferous forests?
temperature
What tree species are found in temperate broadleaf forests?
deciduous and some coniferous
Which major factor is limiting in T broadleaf forests?
temperature
Where do TBLFs exist?
40-50 d N and S
How is plant biodiversity related to latitude? explain why
plant biodiversity decreases with increasing latitude
latitudes away from the equator experience more seasonality and lower MAT and variations in precipitation = all these contribute to lower productivity
How does animal biodiversity change with latitude? explain
richness and endemism decreases with increasing latitude
for the same reason as plants, if there’s lower PP then the region can’t support as much diversity in higher trophic levels
How does fungal biodiversity vary with latitude? explain
less studied, but appears to be influenced by ecological function and host species and different roles have different patterns of diversity
Temperate vs tropical biomes: where would you expect to find more ectomycorrhizal fungi? why?
temperate because ectomycorrhizal fungi have associations with tree roots, and most commonly, conifers and temperate forests have higher diversity of conifers than tropical
Temperate vs tropical biomes: where would you expect to find more endophytic fungi? why?
tropical because endophytic fungi have associations WITHIN plant tissues and tropical biomes have higher density and diversity of plants
Temperate vs tropical biomes: where would you expect to find more saprophytic/decomposer fungi? why?
tropical because decomposition rates in tropical»_space;> temperate = for climatic reasons (warm, wet)
Temperate vs tropical biomes: where would you expect to find more fungi from indoor air environments? why?
temperate = less clear why - maybe we spend more time inside because of colder climate?
Define NPP
net primary productivity is the amount of carbon fixed from atmospheric CO2 (via photosynthesis) by plants minus the amount of carbon released by plants through respiration
NPP = photosynthesis - plant respiration
Describe the global trends of NPP
Higher rates of NPP around the equator and decreasing gradient with latitude
Which biome has the highest estimated NPP? lowest?
highest = tropical evergreen forests
lowest = desert/shrublands
How does the seasonal variation in NPP in north temperate and boreal forests compare to that of tropical evergreen forests?
Temperate and boreal forests have peaks of NPP in northern hemisphere summers (April-August)
tropical evergreen forests are relatively stable and then have dips in southern winters (April-August)
What two major factors have an effect on the NPP of a system?
latitude and seasonality
