In social forestry programmes aimed at quickly greening large areas and meeting fuelwood and timber needs, which of the following fast growing tree species is most commonly planted?

Introduction / Context:
Social forestry is a programme in which trees are planted on village commons, roadsides, canal banks and other community lands to provide fuelwood, timber and environmental benefits to local people. The choice of tree species is important, because social forestry aims for fast growth, high biomass yield and adaptability to different soils and climates. Some species have become especially popular because they grow quickly and can be harvested within a few years. This question asks you to identify the tree species most commonly associated with social forestry plantations.

Given Data / Assumptions:

• Social forestry requires fast growing species that can be harvested in a relatively short period.
• The options include Peepal, Gulmohar, Eucalyptus and Mango.
• Peepal and Mango are often valued for religious or fruit purposes but are slower growing.
• Gulmohar is mainly an ornamental tree for avenues and gardens.
• Eucalyptus is known for rapid growth, straight stems and high biomass production.

Concept / Approach:
Eucalyptus species, especially those introduced from Australia, have been widely used in social forestry because they grow quickly, have straight stems suitable for poles and fuelwood, and can be planted in dense plantations. They can tolerate a variety of soil conditions and reach harvestable size in a few years, making them attractive for meeting local demands. However, there are also environmental debates about their water use and impact on soil. Peepal is a sacred fig tree, usually planted near temples and not typically used for short rotation biomass plantations. Mango trees are grown for fruit and take longer to mature, and Gulmohar is mainly valued for its bright flowers and ornamental appearance, not for timber yield. Therefore, among the options, Eucalyptus is the tree most commonly associated with social forestry programmes.

Step-by-Step Solution:
Step 1: Identify the key goals of social forestry: rapid greening, fuelwood production, small timber and environmental benefits. Step 2: Consider which species are fast growing, produce straight stems and are suitable for short rotation harvests. Step 3: Recognise that Eucalyptus is widely planted in many social forestry schemes because it meets these criteria and has been promoted by various agencies. Step 4: Evaluate Peepal and Mango and note that they are slower growing, and Peepal is mainly a sacred tree while Mango is mainly a fruit tree. Step 5: Note that Gulmohar is used primarily as an ornamental avenue tree and not for large scale fuelwood plantations. Thus, Eucalyptus stands out as the correct answer.

Verification / Alternative check:
Forestry and environmental management documents describe large scale plantation programmes in which Eucalyptus has been a major component species. Reports often mention Eucalyptus plantations on farmer fields, roadside plantations and community lands, especially during the early years of social forestry initiatives. While other species like Acacia and Casuarina are also used, Eucalyptus is frequently highlighted in examination oriented general knowledge as the typical social forestry species. There is also considerable discussion about its ecological impacts, which further underlines how common its use has been. These references confirm that Eucalyptus is the species most associated with social forestry among the options given.

Why Other Options Are Wrong:
Option a, Peepal, is mainly valued as a sacred and shade tree and is not commonly planted in dense, short rotation social forestry plantations.

Option b, Gulmohar, is primarily an ornamental tree known for its bright red flowers and is planted for aesthetics rather than timber or fuelwood.

Option d, Mango, is cultivated for fruit production and has a longer maturity period, making it less suitable for fast rotation social forestry.

Common Pitfalls:
Learners may tend to choose trees that are familiar in everyday life, such as Mango or Peepal, without considering the specific requirements of social forestry projects. Another pitfall is to focus only on religious or ornamental value instead of growth rate and timber yield. To avoid these errors, remember that social forestry emphasises fast growing, high biomass species, and that Eucalyptus is often used as the example of such a species in exam oriented materials and reports, even though there is ongoing debate about its environmental effects.

Final Answer:
The tree species most commonly used in social forestry is Eucalyptus.