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TODAY’S THREADS:

THE GOOD, BAD & UGLY OF NATURAL

DISTURBANCES

Good: Natural Disturbances, Higher Ecosystem

Health with animals/plants adapted to disturbances

& habitats maintained by disturbances

Ugly: Humans as Disturbance Agents & Societal

Collapse - due to Droughts, Too much rain, Bad

land-use and economic decisions [Nazca, Maya

example]

CASE STUDIES of Humans as Disturbance Agents:

Resource combustion that imbalances carbon and

nutrient cycles, e.g., acid rain [air pollution]

Political decisions to control minority people and

their access to resources by centralized government

organizations that stimulates the cutting of old growth forests for

economic gain and reduces forest health and biodiversity

FACTS: THE GOOD NATURAL DISTURBANCES

Good: Disturbances and Higher Ecosystem Health with

animals/plants adapted to disturbances

Eliminate disturbances and you will lose ecosystems,

species & habitats

Take-home message: Disturbance is a

normal component of most natural

ecosystems and exerts a powerful control

on vegetation characteristics. Many plants

and animals are well adapted to particular

kinds of disturbances and often can’t

survive without them.

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“Before the late 1960s, fires were generally believed

to be detrimental for parks and forests, and

management policies were aimed at suppressing fires

as quickly as possible”

http://en.wikipedia.org/wiki/Yellowstone_fires_of_1988

Some tree species, like

Lodgepole pine, become

highly flammable,

produce resins that burn

well, lots of dead

branches that contribute

and cause large scale

fires when trees are over

100 years old

They use fires to

eliminate competition

since most trees not

survive fire. They need

bare ground to germinate

their seed [serotinous

cones]

Note lots of flammable

materials, e.g., lots of dead

lower branches that catch

on fire easily

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Every tree or shrub is

burned up

It looks like nothing

survived BUT….

Serotinous cones need

fire to melt the wax that

keeps seeds closed inside

of the cone. Cones open

with a fire and seeds fall out

to start next forest.

BEFORE a fire

AFTER a fire

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LOOK a seedling is

starting to grow!!

Talk about being adapted to the disturbance - you kill

competition that can’t survive fires

Since Lodgepole pine makes the environment a ‘tinder box’, it

controls the timing of fire. This occurs every 100 years or so.

New Lodgepole Pine

Forest emerging!

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Why should we care about natural disturbances?

Impacts how landscapes planning efforts work for resource extraction – Harvard Forest and Hurricane of 1938 that knocked down a forest

Management of natural areas – loss of habitat areas that need disturbance to persist.EX: Fire control – loss of prairies by trees that are more competitive when no fire

Endangered species management – if species endangered need disturbances to keep their habitat, they will not survive and outcompeted by others when they lose their ‘living environment’

Why should we care?

Understanding basic ecology can advise management

Management of natural areas

Impacts on planning

Following the massive hurricane of 1938, Al Cline, then-director of the Harvard Forest, surveys one of many local ponds used to store the enormous volume of trees that were salvage-harvested. Photo courtesy of the

Harvard Forest Archives.

Planned cutting

cycles for the entire

Harvard Forest was

useless after 1938

hurricane blew down

huge areas of the

forest. Hurricane

damage in photos.

Impacts of landscapes planning efforts work for resource extraction – Harvard Forest and Hurricane of 1938

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Management of natural areas – loss of habitat areas that need disturbance to persist. EX: Fire control – loss of prairies by more competitive forests when no fire

Unexpected consequences of fire control – loss of prairies by

forests encroaching into the meadows. Fire keeps forests out. Fire

control lets forests out compete and encroach into meadows.

Many Native American

root crops are collected

in prairies and they are

actively introducing fire

to get prairies back

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Prairie dog range

http://animals.nationalgeographic.com/animals/mammals/prairie-dog/

Photograph by Raymond Gehman

QUESTION?

What is happening to our

prairies & grasslands?

Does it matter for prairie

dogs??

ANSWER: Much Great Plains converted to farms or pastures

.. Where prairie dogs .. not welcome. NO FIRE allowed but

NEEDED TO KEEP THE PRAIRIE

Endangered species management – if species endangered need disturbances to keep their habitat, they will not survive and be outcompeted by others when they lose their ‘living environment’

COMMENT: Because of their destructive landscaping, they are often killed

as pests. During 20th century, ~98% of all prairie dogs were exterminated -

their range shrunk to ~5% of its historic spread

Black

footed

ferrets –

another

endangered

specieshttp://www.pc.gc.ca/pn-

np/sk/grasslands/edu/edu1/

f.aspx

‘When prairie dogs .. poisoned with Rozol ..pesticide..not just ..

prairie dogs .. perish. ..countless other species ..rely on prairie

dogs for food and shelter.

Black-footed ferrets rely on large prairie dog colonies for food

and shelter. Black-footed ferrets can only survive where

..enough prairie dogs for them to feast on. http://www.defendersblog.org/category/wildlife/prairie-animals/prairie-dog-2/

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NOW We shift to the Ugly:

Human Disturbances & Societal

Collapse - due to Droughts or

Excessive Rainfall that

follow bad land-uses and

economic development

decisions

[Nazca, Maya examples]

Common elements

of Societal Collapse

are:

MESS up our ECOSYSTEMS

• Societal mistreatment of the soils

• Cutting down forests and loss of

soil needed for agriculture

FOLLOWED BY CLIMATE

CHANGE (SPECIFICALLY

DROUGHT)

• Societal collapse

You would think we

would learn, wouldn’t

you??

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Nazca culture, Peru; http://www.nazcaflights.com/cahuachi.htm

Ugly: Disturbances & Societal Collapse - due to

Droughts & bad land-use and economic decisions

[Nazca example]

Flourished

from 100

BCE to 800

CE on dry

southern

coast of

present

day Peru

Humans as Disturbance Agents:

Class Reading: The

location of the Nazca

Culture in SE Peru

BBC News 2009

Google map showing Peru in line green

CASE: Climate Change (El Niño) caused tipping point

following Bad Land-use Decisions = COLLAPSE

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BBC News 2009

An enormous “Nazca Line” as seen from the air on Peru’s SW desert

coast; the Nazca civilization, known for its complex weavings, beautiful

pottery, and the “Nazca Lines,” visible only from high above the

ground, mysteriously collapsed around the middle of the first

millennium, C.E.

In his book "Chariots of the Gods?" Erich von Daniken argued …

lines are the remains of a giant extraterrestrial airport…

This gave rise to the name of this figure, but it is also known as the

Shaman, with one hand raised in a blessing.

http://gosouthamerica.about.com/od/nazcalines/ig/Nazca-Lines/Astronaut--Nazca-Lines.htm

See the

astronaut

and airport

landing

lines in the

Nazca Lines

image??

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QUESTION: Is it possible that the Nazcas destroyed themselves

due to a self-inflicted ecological disaster?BBC News 2009

A Nazca

Mummy

KNOWN FACTS why Land-use Decisions

and mega-El Niño event caused societal

collapse:

This is a very arid [dry] region

Nazca subsistence was mostly agriculture

Nazca people created an aqueduct system

to sustain life in the exceedingly arid

environment. WATER Channels dug until

reached aquifers under the surface

Area struck by extreme El Niño events

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http://tectonicablog.com/?p=22631

Over 50 underground

channels built in the Nazca

region, most are still

functioning and relied

upon to bring fresh water

into the arid desert

Famous underground

channels, locally known as

Puquios (Quechua word

describes natural spring)

‘The huarango tree (Prosopis pallida) is a

unique tree with many qualities and had

vital role in the habitat, protecting the

fragile desert ecosystem, the scientists

say. Can live to 1,000 years. Nazca region

heavily wooded during earlier times’

BBC News 2009

What is forest-climate change link to collapse??

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Huarango tree is a keystone ecological

species that:

• stabilizes soils in these arid regions

• huarango roots penetrate 180 feet to subterranean

water channels to suck up water for the tree, but bring

it into the higher subsoil, creating a water resource for

other vegetation [a plant water pump]• source of food for humans and animals.

The huarango (Prosopis pallida)

is a leguminous hardwood tree

that grows well in arid regions

[it has nitrogen fixing

bacteria on its roots]

http://news.discovery.com/history/archaeology/nazca-civilization-collapse-trees.ht

1.

Deforestation:

Forests

Replaced by

Agriculture

(pollen records:

maize and

cotton)

2 KEY Events triggered

Nazca society collapse

2.

Mega El Nino

event:

hit the south

coast of Peru in

about 500 CE

and brought

lots of rain

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• Deforestation and occurrence of

Extreme El Niño event resulted

in heavy floods

• Floods caused the loss of

surface irrigation systems used

to grow crops

• Dry winds of the desert blew

away soil

Important Point in PAST:

FORESTS PROTECTED against

extreme climatic events

http://news.discovery.com/history/archaeology/nazca-civilization-collapse-trees.htm

An artist's rendering depicts the ceremonial sacrifice of a jaguar during an ancient Maya ceremony. A new study suggests that Maya rulers' growing demand for animals of symbolic value may have caused a decline in big game in ancient Mesoamerica. Image courtesy H. Tom Hall/NGS, http://news.nationalgeographic.com/news/bigphotos/78214485.html

Reasons Why

Civilizations

COLLAPSED during

changing

CLIMATES-

• Over-exploitation of

resources locally &

people consuming resources

beyond the landscape

capacity to deliver them –

fighting over resources

• climate change resulted in

DROUGHT!!

Maya!

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Did Pulses of Climate Change Drive the Rise and Fall of the

Maya?Science 9 November 2012: vol. 338 no. 6108 730-731

A detailed climate record from a stalagmite in a cave

in Belize (left) links a rise in Maya warfare (right) to a

drying trend in the 7th century C.E.

CREDITS (LEFT TO RIGHT): DOUG KENNETT; (DRAWING/PHOTOGRAPH) BY LINDA SCHELE, © DAVID SCHELE, COURTESY FOUNDATION FOR THE ADVANCEMENT OF MESOAMERICAN STUDIES, INC., WWW.FAMSI.ORG

Orange are number of monuments built

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Shift from Natural Disturbances to

how human societies become

disturbance agents:

Acid Rain: We create disturbances as

externalities of industrial development.

Eventually societies pay to mitigate since

have human health effects, kill forests,

impacts human cultural resources

Akha people in China & Thailand:

Political objectives can trigger ecosystems

& societies dependent upon them to

become unhealthy

CASE 5.2. Acid rain, air

pollution and forest decline

(John L. Innes)

COMMENT: Notice how a common human land-use

impact is the enrichment of soils to artificially high levels

with a limiting nutrient – NITROGEN - that natural

ecosystems are not adapted to

Humans as Disturbance Agents:

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FACTS: What is the Role of Nitrogen in Acid Rain and other

Environmental Problems?

Acid rain describes any form of

precipitation or rain with high levels of

nitric and sulfuric acids.

It can occur in the form of snow, fog, and

tiny bits of dry material that settle to Earth

Depletes soil nutrients so difficult for plants

to grow

Causes eutrophication (oxygen depletion)

of water bodies

Weedy species grow really well under high

nitrogen levels. Weedy species outcompete

native species and change landscapes.

It kills forests

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Remember: most

ecosystems have low

nitrogen in the soil that

limits plant growth each

year

Remember: mycorrhizal

associations formed under

low nitrogen levels in soils?

Biggest culprit producing acid rain is

burning of fossil fuels by coal-burning

power plants, factories, automobiles

When humans burn fossil fuels, sulfur

dioxide (SO2) and nitrogen oxides

(NOx) are released into the

atmosphere

FACT: Most acid rain falls because

of human activities

NOTE: Rotting vegetation and erupting volcanoes do release

some chemicals that can cause acid rain

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Acid Precipitation, 2000

37

More acidic rainLess

Acidic

rain

Where are the

industries located?

Of course, everyone's heard the jingle "Sister Sally took a drink, but she shall drink no more, for what she thought was H20 was H2SO4".

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Acid Rainfall affects:

Plants -

directly

(weakens or

kills plants)

Soils - directly

(leaching of

base cations

e.g., Ca & Mg)

Plants - indirectly

(insects attack

weak trees)

Frazier fir stand, Mount Mitchell, Appalachian

Mountains of North Carolina

Red spruce and Fraser fir trees, North Carolina

Trees fell victim to balsam wooly adelgids after

being weakened by effects of acid rain

Photograph by Tina Manley/Alamy; http://environment.nationalgeographic.com/environment/wallpaper/mitchellacidtrees.html

Balsam wooly adelgid

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Photograph by David Woodfall/Getty Images, http://environment.nationalgeographic.com/global-warming/acid-rain-overview/

Spruce forest impacted by acid rain

CURE:

The only way to fight acid rain is to

stop the release of pollutants that

cause it

This means burning LESS fossil fuels

and conserving energy

http://environment.nationalgeographic.com/global-warming/acid-rain-overview/

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This statue, crafted in medieval times, has remained relatively

intact for several hundred years. However, with the Industrial

Revolution, and increasing acidity in the rainfall falling on the

statue, the surface has eroded severely in last few decades.

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CAN YOU IMAGINE BUT In Europe talked about

encasing outdoor statues in a glass bubble filled

with nitrogen to prevent further exposure to these

acids and their damage – 1970s

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• A large part of the problem is coal. Burning coal emits sulfur

dioxide, which further oxidizes in the atmosphere and then

combines with water to produce sulfuric acid.

• Mr. Huang visited the mountainside relics at Xiangtangshan and

Yaowangshan, both in heavily polluted areas of northern China,

and told officials there to shut down or move cement factories. In

some cases, officials complied, and where they could not they

built glass enclosures around the statues, Mr. Huang said.

A nearly 50-

foot Buddha

is being

restored.

Credit Gilles

Sabrie, The

New York

Times

EVEN TODAY in CHINA

People

cleaned their

teeth at

communal

taps

Rivers became little

more than trickles

The 1976 drought in England coincided with acid rain

damage of forests - blistering hot summer coupled with meager

rainfall so water levels fell to dangerous levels. http://environment.uk.msn.com/climate-

change/gallery.aspx?cp-documentid=7445886

Woodland and heath fires

were a daily occurrence

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COMMENT:

Acid rain may not be so

bad by itself but

impacts of acid rain

really bad when

combined with a

drought

Case 3.3. Forest

Communities in China

and Thailand

(Janet C. Sturgeon)

STORYLINE: Political decisions to

control minority people and their

access to resources by centralized

government organizations that stimulates the

cutting of old growth forests for economic

gain and reduces forest health and

biodiversity

Humans as Disturbance Agents:

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What does it mean to be a Shifting Cultivators?

Shifting cultivation (slash-and-burn

agriculture) - traditional agricultural system of

semi-nomadic people, in which a small area of

forest is cleared by burning, cultivated for 1–5

years, and then abandoned as soil fertility and

crop yields fall and weeds encroach.

• In tropics, shifting cultivators

seen as forest destroyers by

governments that need to be

modernized

• States either force migration of

shifting cultivators to lowlands

(Indonesia), to excluding

upland farmers from the forest

(Thailand) to sedentarizing

their land uses so they can’t

move around in the landscape

(China, India, Philippines)

• Few governments see value of

shifting cultivators

How are Shifting Cultivators viewed by Governments?

Thailand

Laos

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Case 3.3. Forest Communities in China and Thailand (Janet C. Sturgeon)

Akha are shifting

cultivators who

originated in China -

spread to hilly parts of

Burma, Thailand, Laos,

Vietnam

Akha Region -http://www.akha.org/images/maps/akharegionalmap.jpg

Elaborate headdress and jewelry mark this

woman as an Akha. Her people grow rice in

the hills of northern Laos and adjacent

Myanmar, Thailand and China

Janet

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Elaborate, helmet-like head-dress, made up of silver coins, beads,

feathers and fur.

Clothing - long-sleeved jacket over short skirt ending just above the

knees [indigo-died cloth often made with home-grown cotton].

Clothing decorated with embroidery, buttons, cowrie shells and seeds.

Pendant earrings and broad neck bands of silver highly prized – neck

bands worn with multiple strings of brightly covered beads.

Akha

women =

http://www.goeringo.com/wp-content/uploads/Akha-Woman-505x400.jpg

Akha villages generally lie at elevations of 3,500-4,000

feet; The thatched roofs of the Akha hill tribe village, in

northern Thailand, http://en.wikipedia.org/wiki/File:Akha_village.jpg

http://www.google.com/imgres?imgurl=http://www.frontierlabourersforchrist.org/images/Akha_.jpg&imgrefurl=http://www.frontierlabourersforchrist.org/ethnicpeoples.html&h=239&w=240&sz=78&tbnid=okvfsg-_NTFGdM:&tbnh=110&tbnw=110&prev=/images%3Fq%3Dpictures%2Bof%2BAkha%2Bshifting%2Bcultivators%2BThailand%2BChina&hl=en&usg=__Hc0H7zr7zQHeU7-SKnI4ez2lBN0=&ei=jL7XS5CpI4r4sgOaraCFBg&sa=X&oi=image_result&resnum=2&ct=image&ved=0CAgQ9QEwAQ

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Chinese Akha

Gate leading to Akha hilltribe

village

http://en.wikipedia.org/wiki/File:Gate_leading_to_the_akha_hilltribe_village.jpg

Entering an Akha village you

will see a wooden frame which

you should not touch – it is the

"spirit gate".

Spirit gate has many carvings

- some are appealing, others

grotesque. Purpose of the gate

is to ward off the evil spirits

from the village while inviting in

the benign ones.

Should an evil spirit manage to

enter an Akha village, each

household has its own barrier

to keep them out.

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Look up to the roof of the house and

you'll see any number of elaborate,

ornate wooden carvings. Their purpose

is to protect the house and its dwellers

- the more carvings the stronger the

protection

Not uncommon for societies to ward

of evil spirits:

Why do you think

boys are given a

blue blanket and

females a pink

blanket?

Why are the exterior

of houses in Spain

painted turquoise?

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China – Akha

lived in Mengson

for 250 years

Thailand, Akha

lived > 80 years

in Akhapu

China:

as citizens

as grain producers

as property holders

as forest managers

Perceptions

of the Akha

in China

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Perceptions

of the Akha

in Thailand

Thailand

as “hill tribe” (not citizens)

as forest destroyers

as interlopers without property rights

State foresters are forest managers – not

Akha

Shifting cultivators

regenerate the

forest and

manage it for

biodiversity

Impact of how Akha were

treated by each government

and the forest condition today:

China –

Forest species richness was 51.7

species in 1 hectare of forest

land

Species dominance mainly old

growth

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Impact of how Akha were

treated by each government

and the forest condition

today:

Thailand –

Forest species richness was

9.3 species in 1 hectare of

forest land

Species composition mainly

pioneer, early successional

species

NOTE: community forests

planted into tea; shifting

cultivation fields planted

with pine trees belonging to

the forestry department

Thailand –

• Thai government logged forests for economic

development

• Ethnic minorities identified as criminal users of

state assets

• Most famous “drug lords” in Golden Triangle

treated this area as his domain to buy, produce

heroin in local factories (eventually evicted by

Thai govt)

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http://blog.tourismthailand.org/EugeneTang/wp-content/uploads/2009/08/akha-1.jpg

Until fairly recently,

Akha were deeply

involved in opium

cultivation

Today many villages

are wracked by

problems of opium addiction

TODAY’S THREADS:

THE GOOD, BAD & UGLY OF NATURAL

DISTURBANCES

Good: Natural Disturbances, Higher Ecosystem

Health with animals/plants adapted to

disturbances & disturbed habitats

Ugly: Humans as Disturbance Agents & Societal

Collapse - due to Droughts & bad land-use and

economic decisions [Nazca, Maya example]

CASE STUDIES of Humans as Disturbance

Agents:

Resource combustion that imbalances carbon

and nutrient cycles, e.g., acid rain [air pollution]

Political decisions to control minority people

and their access to resources by centralized government

organizations that stimulates the cutting of old growth

forests for economic gain and reduces forest health and

biodiversity