Human Interactions: The Tropical And The Subtropical Regions - CBSE Class 7 Geography

Understanding Tropical and Subtropical Regions

Earth is a diverse planet, and its different regions have unique characteristics that shape human life. Tropical regions are generally located between the Tropic of Cancer (23.5° N) and the Tropic of Capricorn (23.5° S). These areas typically experience hot and humid climates year-round, with abundant rainfall, leading to lush vegetation like dense rainforests. The Amazon Basin is a prime example of a tropical region. Subtropical regions, on the other hand, are located just beyond the tropical zones, extending approximately between 23.5° and 40° latitude in both hemispheres. These regions experience a more moderate climate with distinct seasons, including hot summers and mild to cool winters. They receive less rainfall than tropical regions, supporting different types of vegetation like deciduous forests and grasslands, and are often densely populated. The Ganga-Brahmaputra Basin in India is a classic example of a subtropical region. Understanding these fundamental differences in climate and natural environment is key to comprehending human interactions and adaptations in these areas.

Life in the Amazon Basin (Tropical Region)

1. Climate and Environment — The Amazon Basin, located in South America, is known for its hot and wet climate throughout the year. It's home to the world's largest rainforest, the Amazon Rainforest, characterized by dense vegetation and rich biodiversity. The temperature is high, and humidity is intense, making it a challenging environment.
2. Occupations and Livelihood — Indigenous people of the Amazon largely practice 'shifting cultivation' (slash and burn agriculture). They clear small patches of land by cutting down trees and burning the vegetation, then grow crops like tapioca, pineapple, and sweet potato. After a few harvests, the soil loses its fertility, and they move to a new patch. Hunting and fishing are also crucial for their diet. Some communities collect forest products like rubber and medicinal plants.
3. Housing and Transportation — People live in thatched houses or large apartment-like structures called 'Malocas' with steeply slanting roofs. The dense forest and numerous rivers make roads difficult to build. Therefore, rivers are the primary means of transport, with canoes and boats being essential for movement and trade.
4. Modern Developments — With the construction of the Trans-Amazon Highway, parts of the rainforest have become accessible. This has led to deforestation, as timber is extracted and land is cleared for cattle rearing and agriculture. Modern development brings infrastructure but also poses threats to the traditional way of life and the delicate ecosystem of the Amazon.

Life in the Ganga-Brahmaputra Basin (Subtropical Region)

1. Climate and Environment — The Ganga-Brahmaputra Basin in the Indian subcontinent is a subtropical region with a monsoon climate, meaning it experiences distinct wet and dry seasons. The fertile plains are formed by the deposits of the Ganga and Brahmaputra rivers and their tributaries, making the land highly suitable for agriculture.
2. Occupations and Livelihood — Agriculture is the main occupation here, with rice being the chief crop due to sufficient rainfall. Other crops include wheat, maize, sorghum, gram, and millet. Cash crops like sugarcane and jute are also grown. Fishing is important, especially in the rivers and the Bay of Bengal. Large cities like Allahabad, Kanpur, Varanasi, Lucknow, Patna, and Kolkata are located along the riverbanks, supporting industries and services.
3. Population and Settlements — The fertile land and availability of water have led to a very high population density in this basin. People often live in permanent houses, forming large villages and towns. Transportation is well-developed with an extensive network of roads, railways, and waterways connecting various parts of the region.
4. Tourism and Culture — The Ganga-Brahmaputra Basin is rich in cultural heritage and tourist attractions. Pilgrimage sites like Varanasi, Haridwar, and Allahabad draw many visitors. The Taj Mahal in Agra, Buddhist stupas in Bihar, and the Kaziranga National Park (famous for its one-horned rhinos) in Assam are other major attractions, contributing to the region's economy.

Exam Tip: Comparing Tropical and Subtropical Life

When asked to compare life in tropical and subtropical regions, focus on key aspects like climate, vegetation, population density, primary occupations, types of housing, and transportation methods. For instance, tropical regions (like the Amazon) have hot, wet climates, dense rainforests, sparse populations, and depend on shifting cultivation/hunting/gathering. Subtropical regions (like Ganga-Brahmaputra) have monsoon climates, fertile plains, high population density, and primarily agricultural economies. Mention specific examples of crops, animals, and cultural practices for both regions to score full marks!

Practice Questions with Solutions

• Q: What is shifting cultivation, and why is it practiced in the Amazon Basin?
  A: Step 1: Define shifting cultivation. It's a farming method where a patch of forest is cleared by cutting and burning, crops are grown for a few years, and then the farmers move to a new patch when soil fertility declines.
  Step 2: Explain its relevance to the Amazon. It is practiced in the Amazon Basin due to the dense forest cover and generally less fertile soil (nutrients are in the vegetation, not soil). This method allows the forest to regenerate over time in abandoned plots, fitting the traditional lifestyle of indigenous communities.
  Final answer: Shifting cultivation is a farming technique involving clearing and burning forest patches, cultivating crops for a short period, and then moving to new land. It is practiced in the Amazon Basin by indigenous people because the dense forest makes large-scale permanent farming difficult, and the method suits the relatively less fertile soil by allowing it to recover.

• Q: Name two major occupations of the people living in the Ganga-Brahmaputra Basin.
  A: Step 1: Recall the primary economic activity of the Ganga-Brahmaputra Basin. Given its fertile plains and monsoon climate, agriculture is dominant.
  Step 2: Identify another significant occupation. With numerous rivers and large population centres, fishing and industrial/service sector jobs are also prominent.
  Final answer: Two major occupations of the people living in the Ganga-Brahmaputra Basin are agriculture (growing crops like rice, wheat, and jute) and fishing (in the rivers and the Bay of Bengal). Many also work in industries and services within the large cities.

• Q: How is transportation in the Amazon Basin different from that in the Ganga-Brahmaputra Basin?
  A: Step 1: Consider the geographical features of the Amazon Basin that influence transport. The dense rainforest and network of rivers make land transport difficult.
  Step 2: Consider the geographical features of the Ganga-Brahmaputra Basin. The flat, fertile plains and extensive river systems allow for various transport modes.
  Step 3: Compare and contrast. In the Amazon Basin, rivers are the primary means of transport, with canoes and boats being crucial. In the Ganga-Brahmaputra Basin, there is a well-developed network of roads, railways, and waterways, making transportation much more varied and extensive.
  Final answer: In the Amazon Basin, due to the dense rainforest and numerous rivers, water transport (canoes, boats) is the main mode. In contrast, the Ganga-Brahmaputra Basin has a well-developed and diverse transportation system, including extensive roads, railways, and waterways, reflecting its flat terrain and high population density.

• Q: What impact has the Trans-Amazon Highway had on the Amazon Rainforest?
  A: Step 1: Identify the main purpose and immediate effect of the highway. The Trans-Amazon Highway was built to increase accessibility to remote parts of the Amazon.
  Step 2: Describe the consequences of increased accessibility. It has led to significant deforestation, as land is cleared for logging, cattle ranching, and new agricultural areas. This development impacts the traditional lifestyle of indigenous communities and threatens the biodiversity of the rainforest.
  Final answer: The Trans-Amazon Highway has opened up previously inaccessible parts of the Amazon Rainforest. While it brought some development, its major impact has been widespread deforestation, as large areas are cleared for timber extraction, cattle rearing, and agriculture, significantly affecting the environment and the traditional life of the region's inhabitants.

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