Habitat

1
Habitat Niches
2
Habitat

• Type of environment in which a population or
  species regularly lives.
• Physical and biotic environment
• Vegetation
• Forest, meadow, pasture, coniferous forest, etc.

3
Habitat

• Habitats may be subdivided into layers or zones
• Microhabitats
• Forest canopy leaves, branches
• Shrub layer leaves, branches, trunks
• Herb layer leaves, stems, mosses, ferns
• Litter dead fallen leaves, logs,
• Varies in depth, quality
• Soil topsoil, subsoil

4
Niche

• Species/populations role in its community
• Dimensions of a niche
• Habitat microhabitat (Space occupied)
• Food spectrum, essential nutrients
• Reproductive requirements
• Nutrition, nest/den sites
• Seasonality When are resources required, used.

5
Niche

• Fundamental niche
• All resources that could be used in absence of
  competition.

6
Niche

• Realized niche
• Resources actually used in presence of competitor.

7
Niche

• Fundamental niche
• All resources that could be used in absence of
  competition.

8
Niche

• Realized niche
• Resources actually used in presence of competitor.

9
Niches

• Competitive exclusion
• When forced to compete, one species eliminates
  other(s)

10
Niches

• Resource partitioning avoids competition
• Realized niches divide resources (caterpillars)
  among several species of warblers.

11
Niches

• Resource partitioning avoids competition
• Realized niches divide resources (insects) among
  several species
• woodpeckers, nuthatches, creepers.
• Each species evolved adapted to specialized
  diet.

12
Niches

• Invasive species competitively exclude native
  species
• Imported fire ant
• Kudzu

13
Niches

• Invasive species competitively exclude native
  species
• Purple loosestrife
• Zebra mussel

14
Niches

• Invasive species competitively exclude native
  species
• Sea lamprey

15
Invasive species

• Kudzu
• Fire ant
• Zebra mussel
• Purple loosestrife
• Leafy spurge
• Asian long-horned beetle
• Emerald ash borer
• Japanese beetle

• African honeybee
• Tiger mosquito
• Brown snake
• (in Guam)
• European starling
• House sparrow
• More, more,