Download Climate Limits to Vegetation

Climate Limits to Vegetation
Geog403
Ecosystem: a linkage of plants (or animals) to their environment in an
open system as far as energy is concerned (solar energy is
absorbed and chemical and heat energy are lost).
Example: Sunlight phytoplankton carbohydrates (food substance;
these food producing plants are called autotrophies) small larvae
and other tiny life forms in the pond called zooplankton small fish
large fish
Meanwhile plants and animals die in pond
and decay, releasing chemicals back into
water to be used by autotrophies
Ecological efficiency: 15% of food produced
by autotrophies are consumed by the next
participants in the food chain, and less in a
higher trophic level (loss of chemical food
energy)
In Africa, Savanna, the autotrophies are
grasses and other plants, next is herbivores,
then carnivores
For entire ecosystem, desert ecosystems
have the lowest efficiency of all, less than
0.1%; Swamp in tropical areas have the
highest 4%.
Plant successions
1.
Linear autogenic succession: plants themselves initiate changes in the
land surface that consequently cause vegetational changes (the order is
not repeated) (example: growth of vegetation in an area that have been a
lake)
2.
Cyclic autogenic succession: one kind of vegetation is replaced by
another, which is in turn replaced by the first or possibly the original
vegetation follows a series of two or three others. (example: Tundra
vegetation of grasses, sedges and bare ground willow scrubs and
spruce trees developed after permafrost melt in summer; Then a layer
of litters insulates ground and permafrost rebuilt)
3.
Allogenic succession: outside environmental force causes vegetation
change. (nuclear radiation, epidemic disease, climate change)
Final stage: climax community of vegetation: vegetation and ecosystem are in
complete harmony with the soil, climate and other parts of the
environment; stable amount of accumulated energy, constant stored
energy of the biomass.
Vegetation distribution
Two major factors: climate and terrain
Climate factors:
1. atmosphere and its circulation system
(moisture)
2. Solar radiation (energy)
Terrain factors:
1. distribution of landmass and ocean basins
2. the topography of the continents
Figure 27-1. Global distribution of the
principal terrestrial biomass
Tropical rainforest: tall, closely spaced
evergreen trees, great diversity in
species and forms (40 species trees
per hectare-2.5 acres)
Tropical savanna: transitional
environmental between rainforest and
desert. Tropical grassland with
widely spaced trees. Bulbous plants,
thorn forests characterize by dense,
spiny, low trees. Deciduous, lost
leaves in dry season.
Desert Biomes: (1) emphemerals,
completing their entire life cycle in a
single growing season. (2) Perennialcactuses and euphorbias (spurges);
Succulents: plants with fleshy waterstoring leaves or stems.
Temperate grassland biomes: occurs over large
continental interiors, perennial and sod-forming
grasses. Corn belt, livestock farming
Temperate forest:
1.
Deciduous forest biomes: eastern US, Europe and
eastern China, oak, beech, birch, walnut, maple,
elm, ash, and chestnuts. Agricultural activities
2.
Evergreen forest biomes: western coasts in
temperate latitudes where abundant precipitation js
the norm.
Mediterranean scrub: shores of the Mediterranean sea,
coast of California, central Chile, in south Africa’s
cape province, in southern and southwestern
Austria. Widely spaced evergreen or deciduous
trees (pine and oak) and dense, hard-leaf
evergreen scrub, thick waxy leaves are adopted to
long, hot, dry summers. (Chaparral or maquis in S.
Europe, or Mattoral in Chile, or Fynbos in S.
Africa). Vine yards, olive groves.
Northern coniferous forest
(boreal forest, snow forest or
taiga: spruce, hemlock, fir
and pine withstand drought
resulting from long periods of
freezing conditions
Tundra: most continuous of all
the biomes it occurs almost
unbroken along the poleward
margins of the northern
continents. Mosses, lichens,
sedges, and sometimes
dwarf trees.
90N
Tundra
Northern coniferous forest
60N
Evergreen forest
grassland
Mediterranean shrub
Deciduous forest
desert
desert
savanna
Rainforest
30N
rainforest
0N
Climate limits for Crops
Wheat: grow almost anywhere due
to large varieties of species.
Annual precipitation ranges from 1545 inches, most extensively on
where P not exceeds 30
inches. In humid regions, the
diseases (rust, scab, mildew
and leave spots) affect crop,
or difficult in preparing the
ground in seeding and in
harvesting and caring for
crops due to excessive growth
and lodging.
Most cultivation in regions where
frost-free period is 100 days or
higher, mean summer month’s
temperature at or above 57F.
A: oats;
B: Barley;
C: wheat
D: rye
Why wheat gained its popularity?
(1) Its carbohydrates and proteins are wellbalanced
(2) Produced economically with nearly
complete mechanization
(3) Can be grown in a wide variety of
climates throughout the world
Climate limits-rice
Rice: is of tropical origin, varieties are
adopted to a wide range of climatic
situations (tropical to temperate
climate).
At least 4 month of mean temperature of
20°C, cannot survive freezing.
Largest rice growing area is on monsoon
climate regimes; with bi-modal rainfall
distribution patterns, the double
cropping is practical.
For germination, needs a minimum
temperature of 52-54F, for flowering,
72-73F, and grain formation 69-70F,
mature days range from 120-140 days.
Climate limits-maize
• Maize: cultivated second largest
areas (after wheat) among cereals.
Of American origin, optimum
temperature is 25°C, temperature
range for growth is 15°-45°C, cannot
grow where mean summer
temperature is less than 66°F or
mean temperature during 3 summer
month falls below 55°F.
• Water requirement is 500-600mm
during growth season period; P
varies from 10 to 200 inches.
• Mature days range from 90-190
days.
Climate limits-others
Potatoes: favor in moist, cool
temperature and a deep friable
soil. Decreases in tube production
at constant temperature above
68°F and complete inhibition at
84°F, Freezing point temperature
is 29°F.
Rye: more resistant to low
temperature and grow further north
than any other cereal.
Barley: more drought and cold
resistant than wheat (survive with
annual rainfall of 8 inches)
Climate limits (continue)
Oats: more resistant to disease than
other small grains.
Sorghum: native to tropical but is
adopted to temperate regimes.
similar T range as maize but can
support higher maximum
temperatures; It requires frost free
day of 130-140 days and long-time
mean July temperature of 70F. water
requirement is 400mm during growth
period. It grows where is too hot
and too dry for corns, but cannot
produce grains without any summer
rainfall.
Millet: same temperature range as
sorghum, water requirement is 300350mm during growth period.
Tapioca: originate from dry tropic and
drought resistant. Adopted to a wide
range of environment from swamp
forest to semi-desert regions.
Cultivations are occurred in relatively
humid region of tropic compared
with other grains.
Vegetable categories
A.
1.
2.
Cool-region crops that prefer 60 to
65°F and are intolerant of high
summer temperature (monthly mean
above 70-75F)
Very hardy crops that normally may
encounter freezing weather without
injury: (a) Cabbage and related
plants: cabbage, Brussels sprouts,
kale, turnips, rutabagas, kohlrabi,
collards, sprouting broccoli,
horseradish. (b) Spinach and beets;
(c) parsnips.
Cool-season crops usually damages
by freezing weather: (a) cauliflower
and heading broccoli; (b) lettuce; (c)
carrots and celery; (d) peas; (e)
potatoes
Vegetables (continue)
B. Crops adapted to a wide range of
temperature but not tolerant to
freezing
1.
Crops adapted to monthly means of
55 to 75°F and tolerant to frost under
certain conditions: Onions, garlic,
leeks, shallots
2.
Crops adapted to monthly means of
65 to 80°F but not tolerant to frost or
prolonged exposure near freezing:
(a) Muskmelons, cucumbers, squash,
pumpkins; (b) beans, all kinds; (c)
tomatoes, peppers (some varieties);
(d) sweet corn
Vegetables (continue)
C. Distinctly warm-region, longseason crops that are
intolerant of cool weather
(will not thrive below a
mean of about 70°F).
1.
Watermelons
2.
Sweet potatoes
3.
Eggplant, peppers (some
varieties)
4.
Okra
D. Perennial crops: Asparagus,
globe artichoke, rhubarb
Fruits and nuts
Temperature is the most important climatic factor
for fruit and nut crops. There are three groups
based on their climatic requirements
1. Strictly tropical fruits and nuts. Fail to withstand
freezing temperatures and injured by
prolonged exposure to T many degrees above
freezing. Examples: bananas (only adopted to
above 50°F), breadfruit, mangoes, papayas,
durians, animas, sapotes, and mongosteens;
coconuts, Brazil nuts, and cashews. (coffee
and cacao, pineapples adopted slightly cooler
conditions)
Fruit and nuts (continue)
2. The subtropical fruits:
endure temperatures
slightly below freezing
without injury; require some
cool weather for proper
development (do not grow
well in strictly tropical
climates).
Oranges, grapefruit, lemons,
limes, kumquats,
cherimoyas, avocados,
litchis, jaboticabas, olives,
figs, and dates.
Fruits and nuts (continue)
3. The hardy fruits: produced on
deciduous trees or bushes that
during the dormant season go into
a rest period, which it takes a
period of cold weather to break.
They are unadapted to tropical
climates because of their
requirement of a period of cold.
Apples, peaches, pears, cherries,
plums, and prunes, grapes,
apricots, blackberries, and
raspberries (strawberries are
evergreen plants, only semi hardy).
Agricultural revolution and domestication
When (b.c.)
Where
What
10,000
Southwest Asia
Wheat, barley, sheep, goats domesticated
8000
Mexico
Chiles and squash domesticated
8000
Peru
Lima beans domesticated
7000
Southwest Asia
Bread wheat developed; flax for fabric
7000
Southwest Asia and
New Guinea
Pigs domesticated
6000
Northern China (first
agriculture in China)
Millet domesticated
6000
Middle East
Apples cultivated
6000-4000
Southwest Asia (modern
Armenia)
Grapes cultivated for wine
5000-6000
Southwest Asia
Cattle, chickpeas, lentils domesticated
5000
Yangtze River delta,
China; Central India
Rice domesticated
4000
Southwest Asia
Olives domesticated
3000
Southwest Asia
Cities, irrigation, wheel, plow, sail
2686-2181
Egypt
Pyramid building
2500
China
Water buffalo domesticated
Food Categories
Based on Bangladesh, there are five food
categories
A.
B.
Strength giving foods: general refer to
rich protein food or vitamin and nutritious
food. Examples: butter, milk, big fish
and fish heads, young chicken, sheep’s
head, etc. Sometimes, rice depending
on how it is prepared (not eat alone).
Also, almonds, cashews, pistachios,
currants, and raisins are considered as
strength giving food.
Blood producing foods: the food that has
ability to replenish blood supply in the
body. These include certain types of
fishes that can stay alive a few days in a
small amount of water after caught
(because they have visible evidence of
blood in their body). Examples are
Shing, Magur, koi (Bangladesh naming).
Food Categories (continue)
C. Hot and Cold foods: It is believed that the balance
of forces within an individual is essential for the
physical and mental health of a person, and the
imbalance caused through overheating or overcooling of the body resulting from eating of “hot”
and “cold” foods may result in illnesses or
aggravate the existing imbalance. Cold foods
include chicken, mutton, citrus fruits, mango,
lentils, yoghurt, etc. Hot foods include beef,
duck, jackfruit, lichees, shrimp, milk. In general
hot foods are considered to be hard to digest
and more harmful than cold food. Contrary to
Bangladesh, hot foods in Mexico are believed to
be more digestible.
D. Fault and disease free foods: hot or cold exist in
balanced proportions (so neither hot nor cold).
They include most vegetables except pumpkins,
eggplants, and a few others.
E. Bitter foods: the local medicines. Old saying
“eating of bitter-tasting foods prevents diseases
and cleanses the blood”. They include bitter
tasting vegetables like karolla (bitter melon) and
uste (varieties of bitter gourds). They are
believed to prevent illness especially during
summer time.
Why its cool to like it hot
Hot comes from Wasabi root, fresh ginger, horse radish, mustard seed
or grinded pepper, chilly pepper
Hot and spice are two different sensation:
Hot is physical reaction in the mouth that causes burning feeling
Spicy is sensed in the nose
Why hot is good?
1)
2)
3)
4)
“burn” created by capsaicin (an ingredient in chilly pepper) activates pain
receptors in the mouth, which causes the brain to release endorphins
(‘feel good’) chemicals that may produce a brief high.
Capsaicin also can turn on appetite-suppressing brain cell (people tend to
consume less calories)
Hot dish may temporary boost adrenaline to temporary speed up
metabolism and stimulate the breakdown of the fats
Capsaicin helps us sweat by activating the body’s natural cooling system.
(Parade Magzine, Nov 16,2003, p22)