World Forest Resources

Soil Resources of the Planet

Natural Resources (Part 2)

Lecture 4

About 26.3% of the planet’s total area is land (134 mln sq.km). In comparison with the mainland square, the share of land is much larger – up to 89.9% (the other territory is occupied by icy deserts of the Arctic and Antarctic). About 30% of soils is hardly efficient.

All the land holdings of a territory are the territory’s soil resources.

Soil resources are generally split into:

1) agricultural holdings (сельскохозяйственные угодья), tillage (пашня) and pastures are included. Pastures occupy only 10% of total land resources. The largest pastures are in the USA, India, Russia, China and Canada.

Russia has a huge land fund, but pastures are limited due to non-favorable climate (7.8% of the total territory).

2) special usage holdings (угодья специального назначения или антропогенные ландшафты). These include plants, houses, storage ponds and reserves (земли государственного запаса).

About 75% of soil has little productivity as it lacks warmth and moisture.

Human activities make soil degrade as well. Soil erosion is a natural process, but the fertile layer is impoverished so quickly due to human agricultural and industrial activities.

Dusty storms do a lot of harm: they lift the fertile layer up and take it for vast distances. Storm circulation from Africa to America is regularly observed by meteorological services.

Biological resources of the world include forest resources, resources for hunt, fish and herbs. Forests are of the greatest importance among all other biological resources.

The main indicators used to estimate the world forest resources are the following:

· forest-covered territory (лесная или лесопокрытая площадь) characterizes the size of a territory covered with forests (can as well be counted per capita),

· forest-covered to total territory ratio (лесистость территории) is counted by dividing the size of a forest-covered area by the total size of the territory (of a country, region, etc.),

· standing timber reserves (запасы древесины на корню) is counted by multiplying the average amount of timber (in cubic meters) one gets from a square meter by the size of the forest-covered area.

Forests occupy 4 billion hectares (more than 30% of mainland). One distinguishes two forest zones:

· the northern zone with coniferous woods prevailing,

· the southern zone covered mainly with deciduous woods.

Most of the wooded territories are in

Latin America,

CIS (Commonwealth of Independent States – СНГ),

Africa,

North America,

Asia.

The least wooded territories are in Europe, Australia and Oceania.

The following countries are considered to be the most wooded:

Russia,

Canada,

Brazil,

USA,

China.

Guyana and Surinam have the highest forest-covered to total territory ratio (about 90%) (Самый высокий показатель лесистости (около 90%) имеют Гайана и Суринам).

The following countries have medium ratio (50%) (Средним показателем лесистости (50%) характеризуются):

The Congo,

Peru,

Sweden,

Finland.

South African Republic, Algeria, Afghanistan have a very low ratio (about 1 %). Such countries as Saudi Arabia, Kuwait, United Arab Emirates have the ratio within 0.1-0.5%. Iceland, Egypt, Chad and Libya are practically forestless. The ratio is below 0.01% in these countries and there are mainly artificial green plantations.

There are 350 billion cubic meters of standing timber reserves in the world. The richest standing timber countries are Russia, Brazil, Canada, USA.

Each year the size of tropical forests diminishes by 11-12 mln hectares. Only 1/3 of tropical forests is still left on the planet.

Deforestation has a significant impact on the climate. Factors of deforestation are the following:

· forests are destroyed to expand agricultural, industrial territories, transport networks, urban centers,

· timber is a good building material,

· timber is used as fire-wood,

· air and soil pollution makes forests degrade and disappear,

· forests are often destroyed by fire.

Дата добавления: 2014-01-11