Biological Communities and Species Interaction

           

Tolerance Limits and Species Abundance

Law of Tolerance- the maximum and ________ levels beyond which a particular species cannot __________ or is unable to reproduce. The Law of Tolerance describes the degree to which an organism is able to tolerate changes in its environment.

    ex. temperatures, moisture levels, nutrient supply, soil and water chemistry, and living space. 

  • Generalist (snakehead fish) - can occupy a huge range of environmental conditions.
  • Highly specialized species (koala bears)- for some species there may be a _________ factor that determines their abundance and distribution in an area

    ex. saguaro cactus, sensitive to low temperatures, will begin to die in 12 hours of freezing temps.

  • ________ animals have more critical tolerance limits than the adults

 

Niche Specialization

Ecological niche- the total ______ of a species use of the biotic and abiotic resources in the environment. A niche describes where a species lives, what it eats and all of the other resources it uses.

This term is different from habitat. A habitat is the ______ or environment a species lives in.

Law of competitive exclusion states that no two species will _________ the same niche and compete for the same resources at the same time

Gause's principle states that no two species will occupy the same niche at the same time and the less "fit" species will either leave, adapt or _______.

Resource Partitioning- Two species may share the same resource but they do so in a way as to not _______ the same niche.

ex. birds feeding in different parts of a tree or at different times of the day

 

Interactions Among Species

Mutualism- a type of symbiosis in which both members of the partnership ___________. 

ex. Lichen being a combination of fungus and a photosynthetic partner, alga or cyanobacterium
      Clown fish and anemones
      Acacia trees and Ants        

Commensalism- a type of symbiosis in which one member clearly __________ and the other apparently is neither benefited nor harmed.

ex.   Rhinosaurus and cattle egrets
        Shark and remora
        Oak trees and Spanish moss

Parasitism- a form of symbiosis in which one species benefits and the other is ___________.

ex.   Tropical Round worms and Ms. Law

Neutralism- __________ party benefits or are harmed

ex.   Bison and Sunday School Teacher

Predation- an organism that ________ directly upon another living organism with the intent to kill.

ex. lions, tigers and bears

 

Competition

Organisms within a community must compete for all the _________ necessities: energy and matter in usable forms, space, and specific sites for life activites

Intraspecific competition- competition among members of the _________ species

ex. mates, nesting sites

Interspecific competition- competition between members of ___________ species

ex. territory, sunlight , food

 

Keystone Species

Keystone species- a population of species whose very presence contributes to an ecosystems/communities __________. Its extinction (or removal) leads to the reduction of the population size of many other forms of life in the area.

ex. tropical figs, chestnut trees, oak trees

 

Community Properties

Population- group of all the _________ species

Community - a mix of ____________ species

Productivity-

Primary Productivity- rate of ________ production

Gross Primary Productivity- the rate at which plants capture and fix a given amount of chemical energy as biomass in a given amount of time

Net Primary Productivity- the rate at which all the plants in an ecosystem produce net useful chemical energy. Equal to the difference between the rate at which the plants ____________ useful chemical energy and the rate at which they _______ some of that energy during respiration.

  • Rate of photosynthesis minus ____________ by photosynthesizers.
  • Higher net productivity occurs in areas of high temperature moisture and nutrient availability

Abundance and Diversity

Abundance- expression of the total number of organisms in a biological community
Diversity- measure of the number of different _________, ecological niches, or genetic variation present

As you go from the equator towards the poles, generally diversity _________ but abundance ____________

Edges and Boundaries

Edges, where contrasting conditions meet are important features in biological communities.

    Edges reduce habitat quality for interior species.

Ecotones, or zones of transition between two intact habitats, have a greater diversity because they can contain organisms from both areas. (Called the Edge Effect)

 

ENERGY FLOW

Primary Producers- Autotrophs are plants!

Photosynthesis: Plants convert energy from sun along with carbon dioxide and water into _______ and oxygen within the chlorophyll.

Formula:

Consumers- Heterotrophs obtain energy by consuming organisms.

Cellular Respiration: Oxygen consuming producers, consumers and decomposers break down complex organic compounds (glucose, etc) and convert carbon back into carbon dioxide.

Formula:

Types of Heterotrophs

Herbivores

Carnivores/Omnivores

Decomposers- Organsims that ___________ down and/or feed on dead organic matter and waste.

  • Scavenger- Feeds on ________ animals. ex. coyote, vulture
  • Detritivore- Eats decomposing organic matter: leaf litter, dung. ex. ants, worms, beetles
  • Saprophytes- external digestion of dead organic matter and waste ex. bacteria and fungi

Food Chain- A __________ list of who eats who. The arrow points to who is doing the consuming!

Bioaccumulation- the accumulation of a substance in the tissues of a living organisms such as toxins.

Biomagnification- the concentration of toxins increase as you go up the food chain because toxins can't be broken down.

Food Web- A more complex ___________ diagram of which organisms prefers to eat each other. It represents relationships more accurately.

Complexity- how entangled the food web is.

ex. rainforests and coral reefs are very complex

Trophic Levels: Energy Pyramid

   1. Tertiary Consumers- eats ___________ consumers
   2. Secondary Consumers- eats primary consumers
   3. Primary Consumers/Herbivores -eats ____________
   4. Producers/Autotroph- Photosynthesize energy and make their own food

The biomass of each level of the ecological pyramid is _______% less than the one below it! Only _____% of useable energy is transferred up to the next trophic level because so much is lost.

WHY?

Some of the food source many be __________ or indigestible.

Energy may be expended catching the _________ or in respiration.

Energy is degraded through normal ______________ processes (Second Law of Thermodynamics).

 

Ecological Succession
The process by which organisms occupy a site and gradually change environmental conditions by creating soil, shade, shelter, or increasing humidity

Primary Succession- occurs when a community begins to develop on a site previously ____________ by living organisms ex. island, new volcanic flow
pioneer species- in primary succession, the species that _______ colonizes the new area

    often microbes, mosses and lichens   

Secondary Succession- occurs when a community is disrupted and a new one subsequently ___________ at the site

    disruption may be caused by natural catastrophe, human activity

____________ community- in either primary or secondary succession, when a community develops that resists further change
               

Aquatic Succession-process or succession taking place in a body of __________

 

Evolution

Natural Selection-

  • The process whereby organisms better adapted to their environment tend to survive and produce more ____________.
  • The beneficial characteristics that can be inherited are passed down to the next generation.
  • So a range of genetic variation in a species gene is good and can help organisms _________.

Speciation- the formation of species that are only able to breed with each other.

Evolution-

  • The change in the ____________ component of the population.
  • Genetic Drift- the accumulation of changes in the frequency of gene variations (alleles) over time. Over many generations, genetic drift of certain genes are accumulate based on how advantageous these genes are for survival.
    • Environmental factors cause selective pressure and influence fertility or survivorship
    • Small populations are _________ sensitive to the effects of genetic drift than large ones.
  • Evidence for Evolution

    Selection affects individuals, but evolution and adaptation work at the population level, species evolve not individuals

 

 

 

 

 

 

 

 

 

 

 

Species Interactions

Predation



Parasites- organisms that ______ on a host organism or steal resources from it without killing it

Pathogens- microscopic __________-causing organisms for example:

Predation is a potent and complex influence on ___________ balance of communities, it involves

Predation is an important factor in evolution because predators prey most successfully on the slowest, weakest, least fit members of their target population, causing the prey species to evolve with protective or defensive adaptations to avoid predation

Predator Tricks

      Assasin Bug- Beak stabbing monster
      Ambush Bug- Masters of Camouflage

Co-evolution- the process when predators evolve mechanisms to overcome the _________ defenses of their prey

Keystone Species

Keystone species- a species of group of species whose very presence contributes to an ecosystems/communities ________. Its extinction leads to the reduction of the population size of many other forms of life.

ex. tropical figs, chestnut trees, oak trees

Competition

Organisms within a community much compete for all the _________ necessities: energy and matter in usable forms, space, and specific sites for life activites

Intraspecific competition- competition among members of the _________ species

    ex. mates, nesting sites

Interspecific competition- competition between members of ___________ species

    ex. territory, sunlight

Symbiosis- intimate interrelationship of members or two or more species

Mutualism- a type of symbiosis in which both members of the partnership ___________. 
ex. Lichen being a combination of fungus and a photosynthetic partner, alga or cyanobacterium
      Clown fish and anemones
      Acacia trees and Ants        

Commensalism- a type of symbiosis in which one member clearly __________ and the other apparently is neither benefited nor harmed.
ex.   Rhinosaurus and cattle egrets
        Shark and remora
        Oak trees and Spanish moss

Parasitism- a form of symbiosis in which one species benefits and the other is ___________.
ex.   Tropical Round worms and Ms. Law

Neutralism- __________ party benefits or are harmed
ex.   Bison and Sunday School Teacher

 

Defensive Mechanisms-the way that different prey adapt to either hide from or discourage predators

ex.  Camouflage- Spittlebugs, Leaf Mantis Butterfly
        Nasty odor- Stink Bugs
        Poisons in body tissue- Monarch Butterfly
        Spines- Caterpillar
        Eyespots on wings (Self-mimicry)- Butterflies

Plants produce chemical compounds that make them unpalapable or dangerous to disturb
ex. poison ivy, stinging nettles

Batesian mimicry- harmless species that evolve colors, patterns, or body shapes that _______ species that are unpalpable or poisonous
Harmless mimic of Monarch (Batesian Mimicry)- Viceroy Butterfly

Mullerian Mimicry- when two ____________ species evolve to look alike
Different species resembling each other and BOTH having poisons (Muellerian Mimicry)- Poison Dart Frogs

 

Community Properties

Productivity-
primary productivity- rate of ________ production

higher productivity in areas of high temperature moisture and nutrient availability

Net Primary Productivity is the rate at which an ecosystem accumulates biomass. It is the rate of photosynthesis minus ____________ by photosynthesizers.

Abundance and Diversity-
abundance- expression of the total number of organisms in a biological community
diversity- measure of the number of different _________, ecological niches, or genetic variation present

as you go from the equator towards the poles, generally diversity _________ but abundance ____________

Complexity and Connectedness
complexity- how entangled the food web is.

ex. rainforests and coral reefs are very complex

Edges and Boundaries

Edges, where contrasting conditions meet, are important features in biological communities.

    Edges reduce habitat quality for interior species.

Ecotones, or zones of transition between two intact habitats, have great diversity because they can contain organisms from both areas. (Called the Edge Effect)

 

Ecological Succession
The process by which organisms occupy a site and gradually change environmental conditions by creating soil, shade, shelter, or increasing humidity

Primary Succession- occurs when a community begins to develop on a site previously ____________ by living organisms ex. island, new volcanic flow
pioneer species- in primary succession, the species that _______ colonizes the new area

    often microbes, mosses and lichens   

Secondary Succession- occurs when a community is disrupted and a new one subsequently ___________ at the site

    disruption may be caused by natural catastrophe, human activity

____________ community- in either primary or secondary succession, when a community develops that resists further change
               

Aquatic Succession-process or succession taking place in a body of __________