bio eco 3

Communities

different species and abiotic factors they interact with

Interspecific interactions

relationships between different species in a community

Competition

-/-, decreases resource availability

Competitive exclusion

two species with the exact same ecological niche can’t coexist in a community

Resource partitioning

A species shifts their niche to prevent competitive exclusion

Example of resource partitioning

similar species of tree lizards adopted different perches, tree tops vs fence posts

Fundamental niche

the ideal niche occupied by a species without competition

Realized niche

the actual niche occupied with competition, ex: blue and brown mussels

Predation

+/- predator and pray coevolve

Predator adaptations

vision, hearing, senses, teeth, claws, venom

Prey adaptations

cryptic coloration(camo), aposematic coloration, mechanical defence, chemical defense, Batesian mimicry

Aposematic coloration

bright colors warn predators, Ex: poison dart frog

Mechanical defense

Porcupine and its quills, thorns on a rose

Chemical defense

Skunk with bad smell, and Squid ink

Batesian mimicry

Harmless species mimics harmful one, Ex: coral snake and king snake

Herbivor

(+/-), deer eating grass

Parasitism

(+/-) parasite derives nutries from host

Ectoparasite

outside

Endoparasite

inside

Mutualism

+/+, ex: pollinators + flowers, nitrogen fixing bacteria associating with plants, humans + dogs

Commensalism

+/o, one species benefits and the other is unaffected, Ex: sea turtle + barnacles, sea anemone + clownfish

Amensalism

-/o one species dies/harmed while other is unaffected, Ex: humans stepping on bugs

Species Diversity

variety of species that make up a community

Pros of Species Diversity

more resilient to disturbances like fires, floods, disease, required for nutrient cycling + energy transfer through food webs, more productive + more stable, more resistant to invasive species

Trophic Structure

Feeding relationships

Primary Producers

photosynthesizers + antotrophs, most numerous (plants)

Primary Consumers

Herbivores that eat primary producers (bugs)

Secondary Consumers

Carnivores that eat primary consumers (mouse)

Tertiary Consumers

eat secondary consumers (snake)

Quarternary Consumers

ea tertiary consumers, least numerous (hawk)

Food Webs

complex network of food chains, shows flow of nutrients/energy through an ecosystem

Biomass

mass of living things, only 10% energy stored at 1 trophic level is used at next, rest is lost to heat

Most Biomass

Primary Producers

Least Biomass

Quarternary Consumers

Dominant species

most abundant species with the most biomass, Ex: kangaroos in Australian grassland

Keystone Species

exert strong control over community structure due to important niche, usually predatory, their removel can collapse ecosystem, Ex: sea stars keep the # of mussels + barnacles under control

Ecosystem Engineers

species that dramatically alter the structure of their ecosystem, Ex: beavers building dams.