Forests and it's Importance | Agriculture Optional Notes for UPSC PDF Download

Forest

A forest is defined as a piece of land covered with trees. According to the Food and Agriculture Organization of the United Nations, a forest is characterized by land that spans more than 0.5 hectares, with trees exceeding a height of 5 meters and a canopy covering more than 10 percent of the land, or trees that can potentially reach these criteria. This definition excludes land primarily used for agriculture or urban purposes.

Applying this definition, the Global Forest Resources Assessment 2020 determined that approximately 4.06 million hectares or 10 million acres of land, equivalent to 31% of the Earth's total surface area in 2020, can be classified as forested.

Forests play a crucial role in the survival of all living creatures. They are essential for our existence, providing us with oxygen, sustenance, shelter, fuel, and a means of livelihood for indigenous people residing in and around forested regions. Forests are habitats for 80% of the world's terrestrial biodiversity and serve as the primary source for meeting the fundamental needs of nearby human settlements. From the air we breathe to the wood used for fuel and construction, forests are a self-sustaining system that supports various life forms. Each forest's ecosystem encompasses both living (biotic) and non-living (non-biotic) elements. Biotic components include plants, trees, shrubs, vines, grasses, mosses, algae, fungi, insects, mammals, birds, reptiles, amphibians, and microorganisms.

Forests are Made of Four Main Layers as Shown Below:

• Emergent Layer: The uppermost section of the forest consists of exceptionally tall trees, reaching heights of approximately 200 feet. These trees have wide leaves and receive copious amounts of sunlight.
• Canopy Layer: Situated directly beneath the emergent layer, the canopy layer is densely populated with a network of smooth, oval-shaped leaves and branches. This layer serves as the primary layer of the forest.
• Understory Layer: Sunlight does not penetrate this layer, positioned beneath the canopy, which prompts plants to develop larger leaves in order to capture available light.
• Forest Floor: The forest floor remains perpetually in shadow, devoid of sunlight, creating a dark and humid environment. This layer is a fertile ground for the proliferation of fungi. Dead leaves, branches, and deceased animals decompose in this layer.

There are three major forest zones based on the distance from the equator, which are

• Tropical, 
• Temperate, and 
• Boreal forests.

Tropical rainforests have different subcategories as follows:

• Evergreen
• Seasonal
• Dry
• Montane
• Tropical and subtropical

Subcategories of temperate forests include moist conifer, evergreen broad-leaved, dry conifer, Mediterranean, and temperate broad-leaved rainforest. Boreal forests grow in higher latitudes, where the temperatures reach the freezing point.

Types of Forests

Forests, in general, are Earth's predominant terrestrial ecosystems, widespread across the planet's surface. The majority of forested land is concentrated in just five major countries: Brazil, the United States, China, Canada, and the Russian Federation. Approximately 45% of forested areas, the largest share, is located in the tropical zone, followed by temperate, boreal, and subtropical regions.
These forests can be categorized into three main types as follows:

Tropical Forests

• Tropical forests typically span between latitudes 23.50 N and 23.50 S.
• These forests maintain a relatively constant temperature between 68 and 77 degrees Fahrenheit year-round.
• They receive an annual rainfall of approximately 100 inches, resulting in the absence of a distinct winter season.
• Tropical forests feature predominantly broad-leaved trees, often reaching heights of 82 to 115 feet.
• Other vegetation includes vines, ferns, mosses, orchids, and palms.
• Variants of tropical forests encompass evergreen, seasonal, dry, montane, tropical and subtropical, coniferous, and subtropical types.

Temperate Forests

• Temperate forests can be further divided into two subcategories: temperate deciduous forests and temperate coniferous forests.
• Temperate deciduous forests are commonly found in regions such as Japan, China, Europe, parts of Russia, the eastern United States, and Canada.
• These forests experience year-round precipitation and distinct seasons, with rain in spring, summer, and fall, and heavy snowfall in winter.
• They receive an annual rainfall ranging from 30 to 60 inches, resulting in fertile soils.
• The forest floor is covered with ferns, mosses, and wildflowers, while oak, apple, and birch trees are prevalent.

Temperate forests are predominantly located in regions with coastal areas receiving heavy rainfall and mild winters, as well as inland mountain regions with similarly mild climates.

• They can be found in regions such as New Zealand, Southern Japan, the Pacific Northwest in the United States and Canada, South-Western South America, and some parts of North-Western Europe.
• These forests have an extended growing season, high precipitation, and a humid climate.
• Rainfall ranges between 50 and 200 inches annually.
• The soil in these forests is enriched with a thick layer of decaying organic matter.
• Coniferous trees are the dominant species, known for their towering growth due to the ample rainfall and moderate temperatures.

Boreal Forests

• Boreal forests, also referred to as taiga forests, are typically situated between 50 and 60 degrees north latitude.
• These forests can be found in regions like Siberia, Canada, North Asia, and Scandinavia, with approximately 65% concentrated in Scandinavia.
• Boreal forests are characterized by long winters and short summers.
• They receive an annual precipitation of 15 to 40 inches, mostly in the form of snow.
• The cold temperatures result in a slow decomposition rate and a thin soil layer.
• Evergreen trees, including pine, spruce, and fir, are the prevalent tree species.
• Due to their dense canopy, these forests support limited vegetation

What is the Importance of Forests?

Forests serve as natural habitats for numerous animal species. They play a crucial role in oxygen production, influence regional precipitation patterns, and provide a wide range of resources such as wood, medicines, food, perfumes, paper, and clothing.

Additionally, trees act as the world's largest carbon reservoirs, a critical factor in regulating global temperatures. The escalation of carbon levels is identified as the primary driver of global warming. Despite the numerous benefits that forests offer, deforestation has become increasingly widespread in the modern age, resulting in a host of problems including pollution, soil erosion, and climate change. This underscores the significance of forests for all living organisms and the need for their proactive preservation.

The Role of Trees in Absorbing Greenhouse Gases

• Forests play a vital role in maintaining the ecosystem by absorbing greenhouse gases, particularly carbon dioxide, which is recognized as a key factor in climate change.
• Carbon is stored within the biomass of forests, and tropical forests alone house an immense carbon reservoir, estimated at roughly a quarter of a trillion tons. The release of such carbon into the atmosphere could have catastrophic consequences.

The Significance of Trees in Providing Natural Habitats

• Forests offer a sustainable environment crucial for the survival of countless animal species.
• They serve as habitats for various creatures, including snakes, turtles, crocodiles, insects, birds, butterflies, monkeys, and other wildlife, providing an ecosystem for their flourishing.
• The forest floor is also a fertile medium for microorganisms, essential for breaking down dead matter into nutrients. Forests are home to indigenous populations who rely on them for their livelihood.

Forests' Importance as Watershed Regions

• Forests play a vital role in preserving water sources, including groundwater, rivers, streams, and lakes. The green canopy shields water reserves from the sun's radiation.
• Notably, the Amazon forest is home to the world's largest watershed and river system.

Forests' Role in Supporting Biodiversity

• Globally, nearly 90% of species, including diverse plants and animals, thrive within forest ecosystems.
• Forests provide the essential habitats necessary for supporting biodiversity, effectively safeguarding the genetic diversity of life on Earth.

Trees' Significance in Air Purification

• Photosynthesis, a crucial function of plants, generates food and energy. During the daytime, plants, shrubs, and trees absorb carbon dioxide from the atmosphere and release oxygen.
• An acre of mature trees is estimated to produce oxygen for 18 people, effectively acting as large-scale air purifiers by removing carbon dioxide and maintaining oxygen levels in the atmosphere.
• Trees absorb noxious odors and pollutant gases like ammonia and sulfur dioxide, trapping these toxins within their leaves and bark.

Forests' Role in Temperature Regulation

• Forests provide green cover that absorbs solar radiation, thereby helping to regulate temperatures and prevent overheating.
• They contribute to temperature regulation through processes like evapotranspiration and breezes, also promoting rainfall that sustains the water table and maintains a cooler climate.
• Notably, deforestation has the opposite effect, leading to a significant rise in global temperatures.

Forests' Importance in Soil Enrichment

• Dead leaves and broken branches undergo decomposition, ultimately enriching the soil with valuable nutrients.
• Soil microorganisms play a crucial role in converting biodegradable materials into simpler substances that can be utilized by plants.
• Trees, with their robust root systems, help prevent soil erosion in hilly regions and along riverbanks by slowing runoff and stabilizing the soil. Uncontrolled soil erosion can result in the loss of fertile soil, leading to barren conditions.

The Significance of Forests in Regulating the Water Cycle

• Forests play a crucial role in the water cycle, overseeing processes like evaporation, condensation, and precipitation.
• They contribute to the nourishment of aquifers, effectively replenishing groundwater reservoirs.
• Trees facilitate the percolation of rainwater into the soil, preventing stormwater from carrying pollutants into the ocean.
• Acting as substantial sponges, they filter and recharge the water table, preserving water quality and availability.

The Importance of Forests in Human Life

• Forests house a rich diversity of medicinal herbs, plants, and trees.
• Extracts, seeds, leaves, and bark from these botanical resources are utilized for treating various ailments, all while remaining non-toxic to the human body.
• Some notable examples of these resources include quinine, curare, rosy periwinkle, wild yams, extracts from willow trees, calabar bean, and samambaia.

Forests Provide Economic Benefits

• Forests offer a wide array of resources to humanity, with every part of a tree, including leaves, branches, stems, bark, fruits, seeds, and roots, being valuable. These natural environments supply wood, timber, raw materials, vegetables, and fruits, all of which hold substantial economic significance. Timber is used extensively in construction and furniture production, while wood is a vital component in paper manufacturing. Trees, including rubber trees, yield products used in various industries. Even green waste from forests has economic value.
• However, to meet the growing needs of a burgeoning population, millions of trees are felled annually. It is imperative to take proactive measures to conserve forests and expand green cover to benefit the countless living creatures reliant on them.
• There are two categories of economic benefits provided by forests: direct and indirect benefits. For example, forests make an increasing contribution to India's national income, with forest resources accounting for approximately 2.9% of the country's net domestic product. Forests also provide sustenance for a vast number of livestock, making them the home to around 500 animal species.
• Forests support full-time employment for approximately 1.5 million people engaged in various forest-related industries. Forests are also the habitat for marginalized communities, including around 3.8 million tribal people who reside in various forested regions. Forests contribute to ecological and economic well-being by hosting diverse wood species, with many of them having commercial value for extracting various products like acetic acid, methyl alcohol, acetone, oils, and valuable drugs.
• The total timber volume, particularly non-coniferous, is substantial in the country, serving as an economically viable resource. Forests provide indirect economic benefits through their role in regulating climate, increasing atmospheric humidity, influencing precipitation patterns, and mitigating violent floods. They also help maintain a continuous water supply, reduce soil erosion, and offer an invaluable defense against aerial attacks by providing extensive canopy cover over the land. Forests support the ecosystem by facilitating the decomposition of organic matter, making it suitable as a nutrient source for plants.