Chapter 9, Problem 2CR

To determine

The two key concepts for the given section. The differences among old-growth (primary) forests, second-growth forests, and tree plantations. The ecological and economic benefits provided by the forests. The efforts of scientists and economists in putting a price tag on the major services provided by the ecosystem and forests.

Answer to Problem 2CR

The two key concepts given in the section are that the ecosystem services provided by the forests have much more value as compared to the raw materials obtained from them. Also, the climate change and human activities provide threat to the forest ecosystem. The old-growth, second-growth, and tree plantations differ on the basis of their development and biodiversity. The major ecological and economical benefits provided by forests include removal of CO₂, providing habitats, and health benefits. The scientists and economists estimated the worth of 17 ecosystem services provided by the earth’s ecosystem to be at least $33.2 trillion per year. They also estimated the worth of ecosystem services provided by ocean to be in the range of $4.4 trillion to $5.2 trillion.

Explanation of Solution

The two key concepts for the given section are as follows:

(i) Forest ecosystems provide the services that are far greater in value than the value of raw materials obtained from the forests.

(ii) The unsustainable cutting and burning of forests and projected climate change are the chief threats to forest ecosystems.

The difference among old-growth forests, second-growth forests, and tree plantations are as follows:

No.	Characteristics	Old-growth forests	Second-growth forests	Tree plantations
1	Development of forest	These are uncut or regenerated forests that have not been disturbed by human activities or natural disasters.	These forests develop after the trees in an area have been removed by human activities	It is done on land that was cleared of an old-growth or second-growth forest.
2.	Biodiversity	These forests are reservoirs of biodiversity as they provide ecological niches for a multitude of wildlife species.	The second-growth forest contains a stand of trees formed from the secondary ecological succession.	It is a type of managed forest that contains only or two species of trees that are all of the same age.

The major ecological and economic benefits provided by forests are as follows:

(i) Forests play a major role in global carbon cycle by removing CO₂ from the atmosphere and storing it in organic compounds. This helps in stabilizing the average atmospheric temperatures and climate conditions.

(ii) They provide habitats for about two-thirds of the earth’s terrestrial species and are home to more than 300 million people.

(iii) Forests provide important health benefits, for example: traditional medicines are derived mostly from the plant species that are native to forests.

The scientists and economists have found various ways to estimate the economic value of major ecosystem services provided by the world’s forests and other ecosystems. In 1997, a team of ecologists, economists, and geographers estimated the monetary worth of 17 ecosystem services provided by the earth’s ecosystem to be at least $33.2 trillion per year. In 2002, other researchers estimated that preserving the ecosystems in a global network of nature reserves occupying 15% of the earth’s land surface and 30% of the ocean would provide $4.4 trillion to $5.2 trillion worth of ecosystem services