(i) Ground fire: Which is flameless and subterranean.
(ii) Surface fire: Which consumes the herbs and shrubs.
(iii) Crown fire: Which burns the forest canopy.
Effects of fire
1. Fire has a direct lethal effect on plants.
2. Burning scars are the suitable places for the entry of parasitic fungi and insects.
3. It brings out the alteration of light, rainfall, nutrient cycle, fertility of soil, pH, soil flora and fauna.
4. Some fungi which grow in soil of burnt areas called pyrophilous.
Example: Pyronema confluens

Co-evolution: The interaction between organisms, when continues for generations, involves reciprocal changes in genetic and morphological characters of both organisms. This type of evolution is called co-evolution. It is a kind of co-adaptation and mutual change among interactive species.

Thermal Stratification
It is usually found in aquatic habitat. The change in the temperature profile with increasing depth in a water body is called thermal stratification. There are three kinds of thermal stratifications.

1. Epilimnion - The upper layer of warmer water.
2. Metalimnion - The middle layer with a zone of gradual decrease in temperature.
3. Hypolimnion - The bottom layer of colder water.

(a) Life cycle is completed within a short period (Ephemerals)
(b) In succulents the stem possess a water storage region
(c) Root hairs & root caps are also well developed

1. Many herbivores are predators. Cattles, camels, goats etc., frequently browse on the tender shoots of herbs, shrubs and trees. Generally annuals suffer more than the perennials. Grazing and browsing may cause remarkable changes in vegetation. Nearly 25 percent of all insects are known as phytophagous (feeds on plant sap and other Parts of Plant).
2. Many defense mechanisms are evolved to avoid their predations by plants. Examples:  Calotropis produces highly poisonous cardiac glycosides, tobacco produces nicotine, coffee plants produce caffeine, Cinchona plant produces quinine. Thorns of Bougainvillea,  spines of Opuntia, and latex of cacti also protect them from Predators.

1. Cuscuta is a total stem parasite of the host plant Acacia, Duranta and many other plants Cuscuta even gets flower inducing hormone from its host Plant.
2. Balanophora, orobanche and Refflesia are the total root parasites found on higher plants.

(a) Mutualism: It is an interaction between two species of organisms in which both are benefitted from the obligate association. The following are common examples of mutualism.
(b) Nitrogen fixation : Rhizobium (Bacterium) forms nodules in the roots of leguminous plants and lives symbiotically. The Rhizobium obtains food from leguminous plant and in turn fixes atmospheric nitrogen into nitrate, making it available to host plants.
Other examples:
Water fern (Azolla) and Nitrogen fixing Cyanobacterium (Anabaena) .

Aerosols with small particles is reflecting the solar radiation entering the atmosphere. This is known as Albedo effect.
Effects:
1. It reduces the temperature limits, photosynthesis & respiration.
2. The sulphur compounds are responsible for acid rain due to acidification of rain water and destroy the ozone.

The differences between habitat and niche are as follows.

S. No	Habitat	Niche
1	A specific physical space occupied by an organism (species).	A functional space occupied by an organism in the same eco-system
2	Same habitat may be shared by many organisms (species).	A single niche is occupied by a single species.
3	Habitat specificity is exhibited by organism.	Organisms may change their niche with time and season

Vivipary seed germinate in the fruits of mother plant itself.
Example: Halophytes