1. Ch 14 Interactions in Ecosystems 14.1 Habitat and Niche
Abiotic + biotic factors
Ecological niche
Phys, chem, bio factors species needs to survive/reproduce
Niche includes: food, all abiotic factors, and behaviors of species
Ex. Bee vs butterfly

2. Competitive Exclusion
If 2 species are competing for same niche then 1 that is better suited gets it (other move/dies)
Niche partitioning- use different parts
Evolutionary response- divergent evolution to use different resource
Ecological Equivalents
In different geological region/habitats species inhabit similar niches

3. 14.2 Community Interactions
Competition
Interspecific: 2 different species compete same resources
Intraspecific: 2 of same species compete
Predation
Hunting/ killing prey
Natural selection of both predator (how well obtain food) and prey (can they avoid being eaten)

4. Symbiosis: 2 or more species in direct contact
Mutualism
+/+, both benefit
Ex: bee and flower
Commensalism
+/no effect, one benefits other not affected
Ex. Shark and remora
Parasitism
+/-, one benefits and other is harmed
Ex. Dog intestines and worms

5. 14.3 Popln Density and Distribution
= # individuals / area (m2)
Popln distribution
Clumped: in groups
Uniform: territory
Random: no pattern
Clumped
dispersion
Uniform
Random

6. Survivorship Curves Type I Type II Type III
Lots of individuals/ live long
Ex. Large mammals
Type II
Survivorship rate = at all ages
Ex: birds, small mammals, reptiles
Type III
High birth rate, but few survive
Ex. Invertebrates, fishes, amphibians, plants

7. 14.4 Popln Growth Patterns Changes to Popln
+ Births & Immigration (come in)
Deaths & Emmigration (exit)
Exponential Growth (J-curve)
Resources abundant
Popln grows rapidly
Logistic Growth (S-shaped)
Resources limited
Slow growth, exponential growth, stabilizing

8. Density-dependent limiting factors
Carrying capacity
Max amt for environment
Popln crash
Dramatic decline popln
Density-dependent limiting factors
Affected by # of individuals in area
Competition, predation, disease, parasitism
Density-independent limiting factors
Doesn’t matter popln density
Weather, natural disasters, human impacts

9. 14.5 Ecological Succession
biological changes/
sequences to regenerate
or reestablish damaged community
Primary Succession: uninhabited ecosystem
1: 0-15yrs, bare rocks covered moss and lichen
2:15-80yrs, shrubs begin to grow
3:80-115yrs, soil thickens to allow tree growth
4: yrs, diff tree species in direct sunlight

10. Secondary Succession:
Reestablishment of a
damaged ecosystem,
no end to it!
1: 0-2yrs, weeds/ grasses
2: 2-18yrs, grasses and shrub, saplings
3: 18-70yrs, pines and young hardwoods
4: yrs, mature forrests