Ecology

Any plant or man who dies
adds to Nature's compost heap
becomes the manure without which
nothing could grow nothing could be created
Death is simply part of the process
Every death even the cruellest death
Drowns in the total indifference of Nature
Nature herself would watch unmoved
if we destroyed the entire human race
I hate Nature
-Peter Weiss ... Marat ...Sade 1965


This outline has Campbell and Reece
Chapter 50 - Ecology and the biosphere
Chapter 52 - Population ecology
and
Chapter 54 - Ecosystems
as well as some issues (Community ecology, Chapter 53, is on a separate outline)

Ecology
Population-one species in area
Community-interaction of species in area
Ecosystem-physical environment and species
Biosphere-highest level of integration

Terrestrial biomes TRANSPARENCY Fig. 50.10 (named after vegetation), depends on temperature and water
TRANSPARENCY (Fig. 50.24) world map
SLIDES of No. America
Tundra - treeless plain - Arctic
seasons short- forget-me-nots, carribou migration is awesome, reindeer. There are a lot of mosquitos since puddles where larvae breed endure through the summer season
permafrost (always frozen just under the surface) - this is very fragile
In the early 1970's, there was a debate as to whether to tap a big Alaska oil field since the pipeline to bring oil to port might damage this area (and block migrants). This oil was in the freighter Exxon Valdez which later wrecked, in 1989, causing ecological damage along the shore.
Alpine tundra- as you go up the mountain, you cross a conspicuous "tree line" above which trees do not grow.
Coniferous (conifers) forest - northern taiga (From northern US through much of Canada)
The forest floor is nearly bare of small plants because the canopy (shade) is year-round since these conifers are evergreens.
Moist coniferous forest (this is a small biome)- redwoods - in California. There is a lot of fog, and these big old moist trees are very resistent to fire. Redwoods (not the wider sequoias which are in more inland locations like Yosemite National Park) are for very enduring soft woods for building decks and saunas, and there is controversy over logging with few virgin forests (like Muir woods north of San Francisco) left.
There are also pine forests of So. Mississippi valley,

Here in Missouri:
Deciduous (trees that lose their leaves in the fall) forest from eastern Kansas out east. - Water is needed, and this region gets water from Gulf of Mexico while west of this area is in rain shadow TRANSPARENCY Fig. 50.14 of the Cascade Mountains. There are beautiful Spring wild flowers before the trees foliate and the canopy is dense.
Some pictures I shot on April 6, 2002 (because of several cool spells in March wild flowers were a bit late):
Forest. This is when trees were still bare but wild bushes (honeysuckle) leaves were starting - note that forest floor is lush with what looks like grass (actually a bulb, star of Bethelham).
mayapple coming up, a group of mayapples, trilium (early), Dutchman's breetches and bloodroot.

Grassland (vs. savanna) are cool (temperate). These are the "amber waves of grain" with agriculture. There are few trees.
Savanna - this is the tropical version of the grasslands
Here is where you would visit for an African safari. There is an awesome migration of wildebeestes. You would see wild dogs and a lot of the favorite zoo specimens.
Chaparral and brushland (another small biome with areas in California) between desert and grassland in moisture with plants like sage brush.
Desert - in which cactus or Joshua tree are famous- No leaves is an adaptation to limit transpiration. There are lots of annual plants with seeds which germinate during short rainy season.
There are consumers which often live underground.
Tropical forest - most productive biome- microorganisms recycle. Amazon rain forest is being burned to support human agriculture with sad losses of important plants (which might produce important drugs) and animals many of which have not been catalogued.

Ocean 71% of Earth TRANSPARENCY Fig. 50.22
shows continental shelves, intertidal zonescoral reefs, pelagic zones, and abyssal zones
also TRANSPARENCY Fig. 50.13 - marine zones
Coastal 10% area, 85% productivity Continental shelf (intertidal too)
Estuaries (like Chesapeake Bay in Maryland) very productive but not very diverse Crabs Oysters
Pelagic, phytoplankton near top "photic zone" good light
chemisynthetic bacteria near vents "Benthic zone"
"aphotic" Abyssal (deep) cold 3oC - cannot freeze (ice floats), but some oxygen
Coral reefs very complex - shallow, sheltered
cnideria
upwelling of nutrients- Humbolt current el Nino

TRANSPARENCY Fig. 50.15 Lakes, cold, low oxygen deep not much mixing except as seasons change. In summer, there is a thermocline.
eutrophication "organic" pollution, algal blooms
Pollution is an enduring problem: Lake Superior is 450 feet deep and takes 180 yrs for half turnover of water

Streams - continuous mixing, no plankton, different from lakes

Productivity TRANSPARENCY Fig. 54.3 (look ahead)
This figure summarizes all the above statements in terms of percent of Earth's area, productivity and percent of Earth's productivity
Of course, productivity in different areas depends on angle of Sun light
TRANSPARENCY Fig. 50.11
Interestingly, only 0.03 % of Sun light is used in photosynthesis, so there might be potential to capture and use more of the Sun's energy for Humankind's energy needs
TRANSPARENCY (Fig. 54.11) [anticipates food chain, below] illustrates this loss from sunlight to biology with a pyramid of productivity (more on pyramids below)

Climate
TRANSPARENCY Fig. 50.12 explains seasons in terms of Earth's axis (angle relative to plane of Earth's rotation around Sun
TRANSPARENCY Fig. 50.13 global wind patterns - while there are a lot of west to east winds (westerlies) there are also east to west (trade) winds
Note that winds also go up and down and affect rainfall, etc.

Ecology
abiotic factors - temp, light, water
biotic - competition, predation, shade, etc.

POPULATION ECOLOGY Campbell Chapter 52

Human population growth is exponential - TRANSPARENCY Fig. 52.20
From other organisms, this is assumed to be the beginning of a curve that will level off.
(note big dip during bubonic plague [black death])
5.6 billion in 1994, 8 in 2017
Zero population growth:
Fertility rate (infants/woman or couple) = 2.5
If that had been started in 1980, population would still go up to 6.3 billion in AD2070 before leveling off (in other words there is momentum in this system because there are many people in their reproductive years).
This is a common theme in the contemporary "Philosophy of doom" (Thomas Malthus was the classic philosopher of doom who stated that human population growth should be exponential [1798 - Essay on the Principle of Population] from whom Darwin had borrowed ideas heavily) -- that if the contributions to the problem are eliminated immediately there would still be enough momentum in the system to make the problem grow worse for a considerable time. In this example, it would be because of the large number of people that are of reproductive age. Thus countries like China which perceive a real population "problem" dictate to undertake more heroic measures, even lower fertility rates.
Otherwise level at 10.5 billion in AD 2110
Problems of continued population growth worse in developing countries:
Demographics - age structure: more young in Mexico for example TRANSPARENCY Fig. 52.23
However, with age structure like developed countries have, there will be other problems -- social security will be a problem when "baby boomers" retire

Sex ratios can vary, but nature tells us that that might not matter much -
There are harems - elk, multiple matings - buck vs. doe
And also species which are monogamous for life - Canada geese

Exponential growth (Malthus)
J-shaped means birth rate > death rate TRANSPARENCY Fig. 52.11
S-shaped reach carrying capacity (K)
TRANSPARENCY (Fig. 52.9) recovery of endangered whooping crane

Survivorship curves TRANSPARENCY Fig. 52.3 I - human, II, III - oyster

r-selection, semelparous salmon, annuals (lots of seeds - only 1 plant needs to reproduce)
high reproductive rate determines life history
K-selection iteroparous polar bear
few offspring with good survival

Limiting factors:
density independent - physical (climate)
density dependent-biotic (resource, predation, parasitism)
CYCLES
Lynx and snowshoe hare TRANSPARENCY (Fig. 52.19) (NOTE (on axis of graph): more prey, relates to pyramids of biomass covered above and later - it takes more prey to feed predator)
TRANSPARENCY (Fig. 52.17, there has been a long term study of moose and wolves on Isle Royale, MI
There is a well-known story about Arctic Lemmings (mouse-like) (Norway) which have a 3-4 yr. population cycle TRANSPARENCY (two Larson Far-side cartoons)
It had been reported that they run into sea, but this was a hoax; they migrate and die from
lack of food, predators, diseases, stress, and lack of water.

Campbell Chapter 54 - Ecosystems

Food chains - Trophic levels TRANSPARENCY (Fig. 54.1)
TRANSPARENCY (Fig. 53.10)
producers (autotrophs)
primary consumers, heterotrophs herbivores prey
secondary consumers, heterotrophs , carnivores predators
tertiary
bioaccumulation eg of DDT at highest levels TRANSPARENCY Fig, 54.25
TRANSPARENCY (Fig. 53.11) chains are actually webs
web: omnivores
detritus eaters - earthworms, nematodes, insects
decomposers - fungi, bacteria

Pyramids of biomass TRANSPARENCY Fig. 54.12
Think of trees, with wood (mostly cellulose, the most abundant organic molecule of life) as part of the most massive block in the pyramid of biomass.
TRANSPARENCY Fig. 54.14
When people eat meat such as beef, there is a 10:1 loss of calories because the animal was metabolizing during its whole life.
Since chickens grow faster and live shorter lives, there is only a 3:1 loss.
The western animal-rich diet may seem extravagant, but remember that it is hard to get balanced essential amino acids from grains and other vegetables.
Also remember that cattle can forage and eat grass in areas difficult to use for agriculture.

Carbon cycle TRANSPARENCY Fig. 54.17 - this pertains to global warming
CO2 has a fast exchangeable pool - short term
Burning fossil fuels contributes to CO2 in atmosphere.
TRANSPARENCY (Fig. 54.26)
0.029% in 1860, 0.033% now, the momentum will double atmospheric CO2, and, unless changes are made, CO2 will quadruple.
Greenhouse effect - energy comes to Earth as light, but CO2 in atmosphere blocks infrared (heat) radiation back to space.
4oC by middle of this century, 6-7oC for ice age
There is also a long term pool of CO2 storage in CaCO3 (calcium carbonate, limestone, White cliffs of Dover) making a big reservoir.
Limestone SLIDE

TRANSPARENCY Fig. 54.23
Acid rain is a related but very different problem since burning sulfur containing coal puts acid into the atmosphere which comes down in rain. In basalt rock areas, like New York, there is little buffering; limestone areas have lakes with better buffering against increases in acidity.

TRANSPARENCY Fig. 54. 27 Ozone depletion is a very different atmospheric problem. Ozone (O3), if put into one layer of the atmosphere, would be 3/4 cm thick. It blocks UV light. DNA absorption peaks at 260 nm and protein peaks at 280 nm, while ozone used to block above 300 nm, so there is a potential of damage to living organisms as ozone is depleted.Big hole in ozone layer ofer Antarctica in the winter

Nitrogen cycle TRANSPARENCY Fig. 54.18 (like Fig. 37.9 in plant nutrition chapter)
N2 80% used for proteins, nucleic acids
N2 to NH3 nitrogen fixation (plants use ammonia)
NH3 to NO3- (nitrate)nitrification
NO3 to NH3 (nitrate reduction) in plant roots
Rhizobium in root nodules of legumes
try to make new genetic strains of plants

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