Edaphic factors are the abiotic factors related to soil, include the physical and chemical composition of the soil formed in a particular area.

Earnest Haeckel defined "Ecology is the study of the reciprocal relationship between living organisms and their environment."

It is a technique of encasing seeds in a mixture of clay & soil humus & scattering them on to suitable ground, not planting of trees manually.

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

Certain plants can also be used to remove cadmium from contaminated soil, this is known as phytoremediation.
Example: Eichhornia

The interaction of organisms with their environment results in the establishment of grouping of organisms
Levels of ecological hierarchy

1. It deals with the study of environment in relation to organisms.
2. It can be studied by considering individual organisms, population, community, biome or biosphere and their environment.

(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

(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.

(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) .

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

Advantages of seed dispersal:
1. Seeds escape from mortality near the parent plants due to predation by animals or getting diseases and also avoiding competition.
2. Dispersal also gives a chance to occupy favourable sites for growth.
3. It is an important process in the movement of plant genes particularly this is the only method available for self-fertilized flowers and maternally transmitted genes in outcrossing plants.
4. Seed dispersal by animals help in conservation of many species even in human altered ecosystems.
5. Understanding of fruits and seed dispersal acts as a key for proper functioning and establishment of many ecosystems from deserts to evergreen forests and also for the maintenance of biodiversity conservation and restoration of ecosystems.
Seed ball:
1. It is an ancient Japanese technique of encasing seeds in a mixture of clay and soil humus (also in cow dung).
2. It also includes the soil humus scattering them on to the suitable; not planting of trees manually.
3. This method is suitable for barren and degraded lands for tree regeneration and vegetation before monsoon period where the suitable dispersal agents become rare.

i. Free floating hydrophytes: These plants float freely on the surface of water. They remain in contact with water and air, but not with soil. Examples: Eichhornia, Pistia and Wolffia (smallest flowering plant).
ii. Rooted floating hydrophytes: In these plants, the roots are fixed in mud, but their leaves and flowers are floating on the surface of water. These plants are in contact with soil, water and air. Examples: Nelumbo, Nymphaea, Potomogeton and Marsilea. Lotus seeds showing highest longevity in plant kingdom.
iii. Submerged floating hydrophytes: These plants are completely submerged in water and not in contact with soil and air. Examples: Ceratophyllum and Utricularia.
iv. Rooted-submerged hydrophytes: These plants are completely submerged in water and rooted in soil and not in contact with air. Examples: Hydrilla, Vallisneria and Isoetes.
v. Amphibious hydrophytes (Rooted emergent hydrophytes): These plants are adapted to both aquatic and terrestrial modes of life. They grow in shallow water. Examples: Ranunculus, Typha and Sagittaria.