microenvironment

Short definition from Wiktionary

Noun

1. 1
   A very small area that has different characteristics than its surroundings; the milieu (set of conditions) within this area.
2. 2
   A very small area that has different characteristics than its surroundings; the milieu (set of conditions) within this area: Synonym of microhabitat.
3. 3
   A very small area that has different characteristics than its surroundings; the milieu (set of conditions) within this area: The very small environment in the immediate vicinity of an organism.