Biomes 1

BiomesThe objective of this set of lectures is to familiarize you with the major vegetation communities on Earth.

Biomes are 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.

Figure 23.1

Tropical and subtropical moist broadleaf forests

Tropical and subtropical dry broadleaf forests

Tropical and subtropical coniferous forests

Temperate broadleaf and mixed forests

Temperate coniferous forests

Boreal forests/taiga

Tropical and subtropical grasslands, savannas,and shrublands

Temperate grasslands, savannas, and shrublands

Flooded grasslands and savannas

Montane grasslands and shrublands

Tundra

Mediterranean forests, woodlands, and scrub

Deserts and xeric shrublands

Mangroves

Paleartic

Oceania

Neartic

Indo-Malay

Oceania

NeotropicAfrotropic

Australasia

Antartic

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

•Climate•Soils/Setting•Dominant Vegetation•Characteristic Animals•Misc

Tundra

Tundra is the characteristic ecosystem in extremely cold climates. Plants are mostly very low in stature. Animals often migratory. Soils are often deep with frozen layers of organic matter. Permafrost is a characteristic feature of the soils

http://upload.wikimedia.org/wikipedia/commons/b/ba/Circum-Arctic_Map_of_Permafrost_and_Ground_Ice_Conditions.png

Tundra

Soggy soils in summer, pock marked, low herbaceous vegetation.

Tundra

Willow: Salix sp.

http://www.youtube.com/watch?v=3XbJpevfNAs

Alder: Alnus sp.

Willow and alder are common/typical species in tundra areas. The particular species found in tundra are “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.

Caribou (Rangifer tarandus)- herds, migratory

Tundra

Polar bear (Ursus meritimus)Weight: 1500 lbsHeight: ~9 feet

Polar bears hunt on ice sheets, ripping seals from the ice like sardines from a can.

http://www.youtube.com/watch?v=5AYHvkR-0Qo

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 Forestaka

Spruce-Fir Forest

Taiga akaBoreal ForestakaSpruce-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 feetWeight: 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 very important to ecosystem structure. We will focus on this later in the semester.

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

-Mixed Conifer Forest

Mountain gradients.Rain shadows.

Climate.

Ponderosa pine (Pinus ponderosa).Enormous size: 200 ft tallFire EcologyEcological importance

http://www.youtube.com/watch?v=mjdRgBAY278

Moist Conifer Forests of the Pacific Northwest

Coastal Redwood (Sequoia sempervirens)~1500 years380 feet tallTallest living thing on Earth

Coastal Redwood (Sequoia sempervirens)

Coastal Redwood (Sequoia sempervirens)

Captures and imbibes water from fog using foliage. Translocates this water down the stem.

Not sure how….

Douglas-fir Pseudotsuga menziesii390 feet (one was taller than redwood, but has since been lost)~1500 years

Douglas-fir Pseudotsuga menziesii

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 beingDouglas 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 ________.

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

Issues of Conservation

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

Deciduous Forest

Deciduous ForestRegions

American beech: Fagus grandifolia

OaksFamily: FagaceaeGenus: Quercus

MaplesFamily: AceraceaeGenus: Acer

Specifically:Red mapleSugar maple

Live oak

Longleaf pine- a particular example of fire adaptation

Coyote (Canis latrans)Length (not counting tail): 2.5 feetWeight: 20-45 lbs

Attacks on humans extremely rare- Aunt Ednas “pom pom” much more likely to hurt you. Might kill your cat, though. And they do kill small mammals mice, rabbits, raccoons- also snakes, deer, and they eat carrion.

http://www.youtube.com/watch?v=97I-IDIKVSU&feature=related

White-tailed Deer (Odocoileus virginianus)

Shoulder height: 40 inches or soWeight: 100-300 lbs, largest known = 500 lbs

Populations of deer in eastern North America are growing explosively. Why? (a) Unchecked by predators, and (b) living in environments that are highly conducive to population growth, they have become a major problem.

http://www.insurancejournal.com/news/national/2012/10/24/267786.htm

Link

blue jay (Cyanocitta cristata )

Corvidae

northern cardinal (Cardinalis cardinalis)

Cardinalidae

Link

Link

American robin(Turdus migratorius)

Turdidae

Biomes 1