Ecosystems. Sounds like a fancy word, right? But it’s just nature’s way of saying, “Hey, I’m a big family of plants, animals, and microorganisms!” 
So, let’s take a fun dive into NCERT Solutions for Class 12 Biology: Chapter 14: Ecosystem of Class 12 Biology and break it down like you’re at a party with Earth and all its creatures! 
What Exactly is an Ecosystem? 
An ecosystem is like the ultimate team project in nature, where every plant, animal, and microorganism plays a role. Together, they all interact, exchange energy, and maintain balance. The biotic components (living things) interact with the abiotic components (non-living things like water, sunlight, and soil) to form a functional system. Think of it like a big potluck dinner, where everyone contributes something delicious. 
Types of Ecosystems 
There are two major types of ecosystems: terrestrial and aquatic.
- Terrestrial ecosystems are land-based. From forests
to deserts 
, and even the polar regions 
, they all have distinct features. - Aquatic ecosystems cover the vast waters of the Earth, including freshwater (rivers, lakes
) and marine (oceans 
). Yes, the underwater world is basically its own realm with ecosystems that might just be cooler than land!
Food Chain & Food Web: Who Eats Who? 
In an ecosystem, there’s always a food chain. Imagine the sun as the starting point – giving plants (producers) their energy. Then comes the herbivores (plants’ biggest fans 
), followed by carnivores (meat lovers 
), and the decomposers (the unsung heroes like fungi and bacteria, cleaning up the leftovers). It’s like nature’s version of a social media influencer chain, but with less drama!
A food web is like a network of interlinked food chains. So, animals aren’t just stuck eating one thing – they have a whole buffet to choose from! 
Energy Flow in Ecosystem 
In ecosystems, energy flow is key! Energy starts with the sun, passes through producers (plants), and then moves to consumers (animals). But here’s the twist – 90% of the energy is lost as heat! 
So, if you thought plants had unlimited energy, think again – they’re working hard to keep things flowing!
The energy pyramid shows how energy decreases as you go up the levels – like how you start strong with breakfast and then slowly lose energy by the afternoon. 
Nutrient Cycling 
Everything in an ecosystem must be recycled. That’s right, folks – nutrients like nitrogen, carbon, and phosphorus are passed around between plants, animals, and the soil in a never-ending cycle. Plants absorb nutrients from the soil, animals eat the plants, and when they decompose, the nutrients return to the soil. Talk about a green circle of life! 
Ecological Succession: The Circle of Life 
When an ecosystem undergoes a major change, like after a forest fire 
or flood 
, it’s not the end. In fact, it’s just the beginning of something new! This is called ecological succession, where one community of organisms slowly replaces another, until the area reaches a stable state. Think of it as an ecosystem’s way of resetting to its best version.
