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Biomes 1. Biomes. The objective of this set of lectures is to familiarize you with the major vegetation communities on Earth.
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Biomes The objective of this set of lectures is to familiarize you with the major vegetation communities on Earth. Biomes are (pg 418) “somewhat arbitrary, descriptive classifications, rather than quantitative or objective categories” The lines between biomes are often vague. Even so, this system is generally useful for understanding the diversity, and ecology, of the Earth’s vegetation.
18.2 The distribution of biomes is determined by climate Precipitation and temperature are the two most important controls on biome formation and stability. The distribution of biomes across the planet depends, largely, on those factors. So… although we are going to give names to some biomes- you can imagine that the biome itself (and boundaries between biomes) are variable across temperature and precip gradients. You need to understand this concept, and have a general idea of how biomes abut, and vary, across these gradients.
18.2 The distribution of biomes is determined by climate General Classification Scheme • -Tundra • -Taiga/Boreal Forest • Mixed Conifer Forest • Deciduous Forest • Savanna • Shrublands • Grasslands • Desert • Subtropical & Tropical
Tundra Tundra
Tundra • Climate • Soils/Setting • Dominant Vegetation • Characteristic Animals • Misc
Tundra Tundra is the characteristic ecosystem in extremely cold climates. Plants are mostly crawling and woody, or herbaceous. Animals often migratory. Soils are often deep with frozen layers of organic matter. Permafrost is a characteristic feature of the soils
Tundra Soggy soils in summer, pock marked, low herbaceous vegetation.
Tundra Willow and alder are common/typical species in tundra areas. Crawling, and extremely tolerant of cold. They are easily overcome/outshaded by other species (spruce and fir, in particular) if conditions improve. Alder is a nitrogen fixing plant, and has an interesting “successional” relationship with other species. In the winter, (and in extremely cold areas, tundra can be expansive snow and ice fields. http://www.youtube.com/watch?v=3XbJpevfNAs Willow: Salix sp. Alder: Alnus sp.
Caribou (Rangifer tarandus) - herds, migratory http://www.youtube.com/watch?v=5AYHvkR-0Qo Polar bear (Ursus meritimus) Weight: 1500 lbs Height: ~9 feet Polar bears hunt on ice sheets, ripping seals from the ice like sardines from a can. Tundra http://www.youtube.com/watch?v=DxVMnJXWvdM
18.2 The distribution of biomes is determined by climate General Classification Scheme • -Tundra • -Taiga/Boreal Forest • Mixed Conifer Forest • Deciduous Forest • Savanna • Shrublands • Grasslands • Desert • Subtropical & Tropical
Taiga aka Boreal Forest aka Spruce-Fir Forest
Taiga aka Boreal Forest aka Spruce-Fir Forest
Taiga/Boreal Forest Boreal forest are circumpolar, taking up vast areas of North America, Europe, Siberia, etc. They are areas that are cold enough that deciduous species are at a competitive disadvantage. What does that mean? Soils are covered by a deep organic layer of fallen needles, which decompose VERY slowly. These forests are dominated by two genera of tree…
Taiga/Boreal Forest Fir: Abies Spruce: Picea
Moose (Alces alces) Height: 6-7 feet Weight: 1500 lbs
Grey Wolf (Canis lupus) ~100 lbs This critter is badly misunderstood. There are very few records of wolves attacking people. It only happens if the wolf has been (a) conditioned by idiots at parks who feed wolves their Big Macs or (b) something odd is happening- the animal is injured and starving, etc. It is 1 billion%* more likely that you will be bitten by Aunt Edna’s “Pom Pom” than by a wolf, even if you lived in an area where wolves were present. * An approximation
Wolves are ultra important to ecosystem structure. We will read some primary lit. later in the semester about wolf reintroduction. By the way, wolves do not blow down pighouses, hide in grammas cloths, and (despite photographic evidence- to the right) they most likely did not nurse the founders of Rome, i.e., Romulus and Remus.
18.2 The distribution of biomes is determined by climate General Classification Scheme • -Tundra • -Taiga/Boreal Forest • Mixed Conifer Forest • Deciduous Forest • Savanna • Shrublands • Grasslands • Desert • Subtropical & Tropical
Mountain gradients. Rain shadows. Climate.
Ponderosa pine (Pinus ponderosa). Enormous size: 200 ft tall Fire Ecology Ecological importance http://www.youtube.com/watch?v=mjdRgBAY278
18.12 An old-growth temperate rainforest in the Henry Cowell Redwoods State Park, CA
Coastal Redwood (Sequoia sempervirens) ~1500 years 380 feet tall Tallest living thing on Earth
Coastal Redwood (Sequoia sempervirens) Captures and imbibes water from fog using foliage. Translocates this water down the stem. Not sure how….
Giant Sequoia (Sequoiadendron giganteum) Largest known living organism on Earth ~300 feet tall (max) ~30 feet diameter (max) Ages ~2,000 Distribution is into drier parts of the West Coast, especially into the Sierra Nevadas
Douglas-fir Pseudotsuga menziesii 390 feet (one was taller than redwood, but has since been lost) ~1500 years
Some of you have “real Christmas trees” every year, and you probably buy the tree from Lowes of something- if so, the tree has a good possibility of being Douglas fir (Pseudotsuga menziesii). You might also have this tree planted in your yard. Why would someone plant a tree from Washington State in your yard? I have no clue
Douglas-fir is neither a Douglas, or a fir. It is a tree that is relatively closely related to firs which are the genus ________. It reaches enormous size. More than 300 feet tall. Competing with coastal redwood for the tallest tree in the world. It is also enormous at the base. You might be able to drive Aunt Edna’s Lexus right through the base if some moron cut a tunnel in one.
Douglas-fir is of enormous ecological and economic importance. It is one of the most widespread species in North America, with varieties ranging basically across the whole “conifer forest” area. It is extremely valuable for lumber.
Cougar; mountain lion; catamount; panther = Puma concolor • - top predator. Avoids humans, but rare occasions of people being stalked and killed. • Length ~ 8 feet (including tail), Weight ~200lbs. • Can run ~ 55 mph, vertical leap = 18ft
By comparison : Fastest dude ever period = top speed around 26 mph (cougar = twice as fast)
http://www.youtube.com/watch?v=tE8d35l_YXM Vertical leap = ~40 inches
http://www.youtube.com/watch?v=tE8d35l_YXM Vertical leap = ~40 inches Yawn…..
18.15 In their natural state, temperate evergreen forests are one of the most endangered habitats Issues of Conservation
18.14 This old-growth temperate rainforest in Oregon is being “clear cut”