Conservation Biology Chapter 7

What are ecosystem services?

The wide variety of benefits ecosystems provide to humanity — everything we eat, drink, and breathe comes from living organisms and biological processes.

What are examples of consumable goods from ecosystems?

Food and building materials.

What are examples of non-consumable services from ecosystems?

Flood control and biological control of diseases.

What are examples of cultural services from ecosystems?

Recreation and tourism.

Why are ecosystem services said to be "provided for free"?

They are naturally performed by ecosystems without human cost, though humans depend on them for survival.

What was the significance of clear-cutting at Hubbard Brook?

It helped show the value of ecosystem services by studying environmental impacts of deforestation.

When did environmental economics begin and what concept did it introduce?

In 1952, it introduced externalities—detrimental effects of a business not paid by the business but by the public.

How does the concept of externalities connect with social justice?

It shows how environmental damage often affects the public and marginalized groups rather than the polluters.

Who was Robert Costanza and what did he do in 1997?

He estimated the global value of ecosystem services at $16–54 trillion per year (average $33 trillion).

What was the Millennium Ecosystem Assessment (2000)?

A UN-commissioned study involving 95 countries to evaluate the state of global ecosystem services.

What were the findings of the Millennium Ecosystem Assessment?

60% of ecosystem services have been degraded and used unsustainably.

Leads to irreversible biodiversity loss.

Threatens UN sustainability goals.

Reversing degradation requires national and international cooperation.

What are supporting services?

Ecological processes that control ecosystem functioning and support all other services (e.g., biomass production, decomposition, nutrient cycling).

What are provisioning services?

Products people obtain from ecosystems (e.g., food, timber, water, medicines).

What are regulating services?

Benefits from regulation of ecosystem processes that reduce harmful variation and provide stability (e.g., clean air/water, climate regulation, pollination).

What are cultural services?

Non-material benefits like recreation, tourism, and mental/physical well-being.

What is Gross Primary Productivity (GPP)?

The total amount of carbon fixed and turned into tissue through photosynthesis.

What happens to some biomass during respiration?

It is lost as energy is used for metabolic processes.

What is the equation relating productivity?

GPP - R = NPP (Net Primary Productivity)

What is secondary productivity?

Energy transfer to consumers; includes losses from respiration and feces—transfer efficiency is lower.

When does decomposition begin?

At the moment of death, continuing until organic matter becomes inorganic.

How is decomposition accomplished?

Through interactions of many organisms.

Do plants and animals decompose differently?

Yes — they involve different organisms and processes.

What are the two main stages of decomposition?

1. Autolysis – the organism’s own enzymes break down tissues.

2. Putrefaction – microbial breakdown producing gases and odors (mercaptan attracts vultures).

What organisms mainly decompose woody plants?

Fungi and beetles.

What three crops represent 80% of the world's food supply?

Rice, corn, and wheat.

What are major externalities of conventional farming?

Use of pesticides, fertilizers, and diesel fuels.

What are the issues with pesticide use?

Farmers must buy them (economic cost).

Kill non-target species (like wasps) that provide natural pest control.

Can cause human health problems (e.g., cancer from improper use).

How can pesticides be avoided?

Use natural predators like bats, birds, wasps, and ladybugs.

What elements are mainly in fertilizers, and what problem do they cause?

Phosphorus and nitrogen—cause runoff leading to eutrophication (nutrient over-enrichment in aquatic environments).

What local example demonstrates fertilizer runoff problems?

Dead zones in the Chesapeake Bay.

How can fertilizer use be reduced?

Using nitrogen-fixing microbes/fungi, no-till farming, and crop rotation.

What is evapotranspiration?

The sum of evaporation and plant transpiration, representing water loss as vapor through stomata.

Where do raw materials come from?

The environment — all materials humans use originate from ecosystems.

Where do most medicinal compounds come from?

Originally from plants and animals.

What ecosystem questions relate to water?

Where does it come from?

How is it delivered?

How is it purified?