Class 12 biology chapter 14 discusses the ecosystem. This chapter explains various concepts and learnings about the ecosystem. You can find detailed explanations and solutions for the chapter in this article. It will help you understand the various aspects and concepts of the chapter and prepare for class. 

The NCERT Solutions for class 12 biology chapter 14 gives students access to many questions and detailed solutions, including match the following, fill in the blanks, short question answers, and true or false. You can find all the answers in the article that will help you ace your class 12 exam.

The NCERT Solutions will help you learn about the living creatures and their interaction among themselves and with their surroundings in a functional unit. It has details about the structure of the ecosystem, input of productivity, transfer of energy, and output. You will learn about the relationship cycles, chains, webs, and their energy flow within the ecosystem and their interrelationship.

NCERT Solutions class 12 biology chapter 14 (Ecosystem)

The chapter on ecosystem explains the interaction of living and nonliving components with themselves and each other in a physical environment. An ecosystem can be a small pond, a large forest, or even a sea. It is a visualised functional unit of nature. The entire biosphere is regarded as a global ecosystem that is a composite of all local ecosystems on Earth. 

The ecosystem is divided into two categories—terrestrial ecosystem and aquatic ecosystem. The terrestrial ecosystem consists of forests, deserts, grasslands, etc. and the aquatic ecosystem consists of ponds, lakes, wetlands, rivers, and many more. 

Let us take a look at the most important topics of chapter 14:

• Ecosystem–Structure & its Structure
• Types of Ecosystems 
• Productivity 
• Decomposition 
• Energy Flow 
• Ecological Pyramids 
• Ecological Succession 
• Nutrient Cycling 
• Ecosystem Services

The details of topics of NCERT Solutions class 12 biology chapter 14 are as follows:

Ecosystem structure & its structure: The ecosystem is a community where living and nonliving components interact with each other. It is greater in size and is a functional unit of nature. The ecosystem comprises two different components—biotic and abiotic. Their description and functions are explained below.

• Biotic components: Biotic components are those which are involved in shaping the ecosystem such as plants, animals, human beings, decomposers, yeast, insects, etc. They are called living things within the ecosystem. 
• Abiotic components: Abiotic components are those which are not involved in shaping the ecosystem such as water, air, soil, sunlight and minerals. They are the nonliving physical and chemical elements in the ecosystem that are obtained from the atmosphere, lithosphere, and hydrosphere.

 

Types of ecosystems: An ecosystem can be as small as an oasis in a desert, or as big as an ocean. There are mainly two types of ecosystem:

• Terrestrial ecosystem: A terrestrial ecosystem is a land-based community of organisms and the interactions of biotic and abiotic components in a given area. The four types of terrestrial ecosystems are forest ecosystem, tundra ecosystem, grassland ecosystem and desert ecosystem.
• Aquatic ecosystem: Organisms present in a water body are part of the aquatic ecosystem. The two types of aquatic ecosystems are marine ecosystem and freshwater ecosystem.

 

Components of the ecosystem consider the followings aspects:

1. Productivity
2. Decomposition
3. Energy flow
4. Nutrient cycling

 

Productivity: The rate of biomass production is called productivity. It is measured by the amount of biomass or organic matter produced per unit area over time by the plants during the process of photosynthesis. It is expressed in terms of g –2 yr –1 or (kcal m–2) or –1 to compare the productivity of different ecosystems. 

Productivity is divided into two parts—gross primary productivity and net primary productivity. Gross primary productivity is the rate of production of organic matter during the process of photosynthesis. Net primary productivity is defined as gross primary productivity minus respiration losses or GPP – R = NPP.

 

Decomposition: The process of breaking down complex organic matter into inorganic substances like carbon dioxide, water, and nutrients by the decomposers is called decomposition. The raw material for decomposition consists of dead remains of animals, dead plants such as leaves, flowers, bark, etc. which constitute detritus for decomposition. This process requires large amounts of oxygen and consists of steps such as fragmentation, leaching, catabolism, humification, and mineralization.

 

Energy flow: Energy is the primary source for almost all the organisms on Earth. It is the main factor that supports the survival of organisms. Energy flow takes place with the help of the food web and food chain. Energy flows from the Sun to autotrophs or producers and then flows from the producers to the consumers. In the ecosystem, the energy never flows backwards, that is, from the consumers to producers. 

Herbivores feed on the autotrophs and change the energy from the plant into energy that they can use. Carnivores subsequently feed on the herbivores and, finally, other carnivores prey on the carnivores.

 

Ecological Pyramids: The graphical representation of the relationship between different organisms is called an ecological pyramid. It represents a different trophic level by each bar. There are three types of ecological pyramids.

• Pyramid of biomass: At each trophic level, the pyramid of biomass represents the graphical portrayal of biomass present in a unit of the territory of different trophic levels. 
• Pyramid of productivity: The pyramid of productivity shows the production or turnover of biomass at each trophic level. It also shows the flow of energy through the food chain. 
• Pyramid of numbers: In each trophic level, it represents the number of organisms, irrespective of their size. The bars are drawn to scale—the more organisms it represents, the wider the bar.

 

Ecological Succession: Ecological succession is a fundamental concept in ecology. It is a process by which the mix of species and habitat in an area change over time. There are two types of ecological succession. 

• Primary succession: It is the ecological succession that begins in essentially lifeless areas, in regions where there is no soil, or soil is incapable of sustaining life. 
• Secondary succession: It is the ecological succession in which plants and animals recolonize a habitat after a major disturbance such as devastating flood, wildlife, landslide, lava flow, etc.
  

 

Nutrient Cycling: It is the process of absorbing, transferring, releasing and reabsorbing nutrients. It is the natural recycling system of mineral nutrients. Nutrients consumed by plants and animals are returned to the environment after death and decomposition, and the cycle continues. Soil microbes play an important role in nutrient cycling. Nutrient cycling rates depend on various factors such as biotic, chemical, and physical. 

 

Ecosystem Services: The products of ecosystem processes are called ecosystem services. For example, healthy forest ecosystems purify air and water, prevent droughts and floods, cycle nutrients, create fertile soils, provide wildlife habitat, maintain biodiversity, pollinate crops, provide storage sites for carbon and aesthetic, cultural and spiritual values. Healthy ecosystems are the base for a wide range of economic, environmental, and aesthetic goods and services.