What is the basis of variations in the physical and chemical conditions of different habitats?

(A) The variations in the physical and chemical conditions of different habitats are primarily determined by two major factors:
$(a)$ Abiotic factors: These include Temperature,Water,Light,and Soil. These non-living components significantly influence the environment of a habitat.
$(b)$ Biotic factors: These include pathogens,parasites,predators,and competitors with which an organism interacts constantly.
Key Abiotic Factors:
$1$. Temperature: It is the most ecologically relevant environmental factor. It affects enzyme kinetics,basal metabolism,and physiological functions. Organisms are classified as Eurythermal (wide range) or Stenothermal (narrow range).
$2$. Water: It is essential for life. Productivity and distribution of plants depend on water. For aquatic organisms,water quality ($pH$ and salinity) is crucial. Organisms are classified as Euryhaline (wide range of salinity) or Stenohaline (narrow range of salinity).
$3$. Light: Essential for photosynthesis in autotrophs. Many plants are adapted to low light conditions. Light also acts as a cue for animals for foraging,reproduction,and migration based on photoperiods. Spectral quality is also vital,as $UV$ components can be harmful.
$4$. Soil: The nature and properties of soil (composition,grain size,percolation,water-holding capacity) determine the vegetation and,consequently,the animal life in a habitat.