The core idea
Biodiversity includes variation within species, between species and among ecosystems. Healthy habitats support relationships such as pollination, decomposition and water regulation. Forest-cover area is one useful measure, but it does not count every species or describe every ecological relationship.
1. Three levels of biodiversity
Genetic diversity is variation within a species, such as differences among varieties of a crop. Species diversity concerns the different kinds of organisms in an area. Ecosystem diversity concerns different living systems, such as forests, wetlands, grasslands and coasts. These levels are connected. A landscape with many habitats can support organisms with different needs. Variation within a crop species can provide options when conditions change. Biodiversity is therefore not simply the number of large animals seen on a safari; plants, fungi, insects and microorganisms also contribute to the system.
Sources: National Biodiversity Authority: Biodiversity and conservation FAQs ↗
2. Energy flows and materials cycle
An ecosystem includes living organisms and non-living surroundings such as soil, water and sunlight. Plants use light energy to build organic material. Herbivores eat plants; other consumers eat animals or mixed foods. Decomposers break down dead material and help return nutrients to the environment. A food chain shows one feeding route; a food web shows several connected routes. Removing one part can affect others. A flowering plant may depend on pollinators, while birds may depend on insects that live near the same plants. The relationships are the lesson, not merely a list of names.
Sources: National Biodiversity Authority: Biodiversity and conservation FAQs ↗
3. Different habitats do different work
Mangroves are coastal ecosystems adapted to saline, tidal conditions. Wetlands connect water, sediment and organisms; grasslands support species suited to open habitats. A healthy grassland is not an unsuccessful forest. Planting trees everywhere can damage an ecosystem that naturally needs open space. Conservation begins by identifying what the place is and which organisms use it. Habitat connections also matter: an animal may need to move between feeding, resting and breeding areas. A patch can look green yet become less useful if roads, walls or disturbance sever those connections.
Sources: National Biodiversity Authority: Biodiversity and conservation FAQs ↗ · Forest Survey of India: State of Forest Report 2023 ↗
4. What India’s forest-cover measure records
Forest Survey of India uses satellite interpretation and field information to assess forest resources. Forest cover is based on tree-canopy area and specified mapping thresholds; it is not identical to the legal category of recorded forest land. A plantation can contribute to canopy cover without reproducing the diversity of a mature natural forest. Tree cover is reported separately for trees outside the forest-cover category under the assessment method. These definitions make national measurement possible, but an ecological assessment also needs information about species, age structure, connectivity and disturbance.
Sources: Forest Survey of India: Assessment methodology ↗ · Forest Survey of India: State of Forest Report 2023 ↗
5. The 2023 figures: area is not the same as change
India State of Forest Report 2023, released on 21 December 2024, reported forest cover of 715,343 km² and tree cover of 112,014 km². Together they make 827,357 km², or 25.17% of India’s geographical area. These are a dated assessment, not a live counter. Subtracting tree cover from forest cover gives 603,329 km², but that difference compares two categories in the same assessment; it does not measure a gain over time. A change calculation needs comparable figures from two different assessment periods.
India’s forest and tree cover · ISFR 2023
6. Work it out: improve a school’s small habitat
A school wants to “increase biodiversity” by buying 100 identical ornamental plants. Count alone cannot establish success. A better plan first records shade, soil, water availability and existing organisms with local guidance. It selects locally suitable plants, avoids invasive introductions and protects useful existing habitat. Then learners monitor survival, flowering and visiting insects over time without handling wildlife. Ten surviving suitable plants with a maintenance plan may contribute more than 100 neglected pots. The project succeeds through ecological fit and care, not the size of a planting-day photograph.
Sources: National Biodiversity Authority: Biodiversity and conservation FAQs ↗
PUT IT INTO PRACTICE
Draw one local food web
- Choose a familiar garden or pond and name a producer, consumer and decomposer.
- Draw arrows from food to eater and add water, soil or shelter connections.
- Explain how removing one habitat feature could affect two organisms, then propose a small suitable improvement.
Check your understanding
Is biodiversity only the number of species?
No. It also includes variation within species and among ecosystems, as well as the relationships that sustain them.
Why might tree planting harm a natural grassland?
It can change the open habitat needed by its species. Conservation should protect the appropriate ecosystem rather than make every place look like a forest.
Do 715,343 and 112,014 km² describe two different years?
No. They are forest cover and tree cover in the same 2023 report. Their difference is not annual growth.
What makes a planting project more convincing than a plant count?
Suitable species, habitat fit, survival, maintenance and observed ecological use show whether the effort continues to help.