Ecology Flashcards
Ecology
-Science which allows one to study the interactions of the organism (biotic factors) with the environment (abiotic factors)
biotic
- living things
- organisms
abiotic
non-living things
Population
all organisms within an area belonging to the same species
Species
a group of interbreeding subpopulation that share a gene pool and are reproductively isolated from other species
Communities
consist of all the various populations interacting at a locale or a specific area of the ecosystem
Ecosystem
contains communities (biotic) and non-living things (abiotic factors)
Biosphere
that portion of the earth’s surface where living things exist.
Two parts of the biosphere
land or terrestrial biomes
Aquatic biomes
Terrestrial biomes (land biomes)
Are categorized based on the climate, type of vegetation and type of animals.
Tropical rain forest
has a large number of trees. The temperature and amount of rainfall are high. Types of animals found in this biomes include monkeys, snakes, and birds
•Ex. Costa Rica
Savanna
grassland with scattered trees. The temperature is high and the rainfall is low. Type of animals: giraffes, zebras, and lions
•Ex: Kenya
Desert
Biome with little or no vegetation. It has sparse rainfall. Daytime temperatures are high and night time temperature often drops to freezing. Animals are nocturnal (sleeping in the day and active at night) They include ants, lizards and snakes
•Ex: Deserts of Southern California
Chaparral
a region of dense, spiny shrubs. Climate: mild and rainy winters and long, hot and dry summers. Animals: deer, fruit-eating birds, lizards and snakes
•Ex: Canyons of Southern California
Temperate grassland
this biome is relatively treeless. It is found in region of relatively cold winter. It has moderate rainfall and moderate temperature. Animals of the grassland include bison, gazelles, and sheep
•Ex: Prairies in central North America
Temperate deciduous forest
Characterized by deciduous trees (these are trees that drop their leaves before winter because of ineffective photosynthesis). Temperature range from very cold winters to hot summers. High rainfall. Animals include whitetail deer, bobcats, and mountain lions
•Ex. Eastern United States
he taiga (coniferous forest).
- Vegetation: cone bearing trees such as the pines and spruce trees.
- Temperature: Harsh winters and short summers
- Animals: squirrels, deer, beavers
Tundra
Characterized by a condition known as permafrost. There is little light for long periods of time
•Temperature: bitterly cold temperature with high winds
•Vegetation: no trees.
•Animals: musk oxen and caribou
Aquatic biomes
- Covers about 75% of the planet surface.
* Two types: freshwater and marine
Freshwater biomes
include lakes, ponds, rivers and streams
Marine biomes
include estuaries and the ocean
Estuaries
the area where a freshwater stream or river merges with the ocean
Ocean-can be divided into different zones:
–Intertidal zone-the area where the land meets the sea
–Pelagic zone-open ocean itself
–Benthic zone-the seafloor
Population Ecology
This area of ecology focuses on factors that influence a population size (number of individuals), growth rate of the population (rate of change in population size), density (number of individual per unit area), and features of the population structure (relative number of individuals of different ages)
Population dynamics
how individuals or different species react with one another when they share the same natural resources such as water and food supply. If focuses of the relationships that exists among the different species in a community
Population density
Factors which affect population density include logistic growth and carrying capacity of the land
Logistic growth
affected by environmental factors that restrict the population growth. This include the available nutrients and space. (GROWTH CURVE_
Carrying capacity of the land
The number of individuals of a population that the environment can just maintain with no net increase or decrease in population size
Two general type of factors that limit population growth
- Density dependent growth factors
2. Density independent growth factors
Density dependent growth factors
population growth is limited by the density of the population. There is a limited food supply and a buildup of toxic waste. Such factors depress a population’s growth rate by increasing the death rate and decreasing the birth rate.
Density independent growth factors
population growth is limited by natural disasters such as the climate or earthquake.
A community
an assemblage of all the organisms living together and potentially interacting in a particular area.
Competition
a relationship where two populations compete for the same resources (food, space, light)
–Two types of competition
•Interspecific-competition between two population
•Intraspecific -competition within or among a population.
Predation
an interaction where one species eats another. The consumer is called a predator and the food or species eaten is called the prey
Symbiotic relationships
A close association between two or more species during part or all of their life cycle. Types of symbiotic relationships include parasitism, commensalism and mutualism
Parasitism
directly benefit one species and harms the other. Example: Liver flukes in the intestines of large animals
Commensalism
directly helps one species but does not affect the other much, if at all. Example: birds roosting in a tree. The birds are protected but the tree get nothing in return nor is it hurt
Mutualism
a relationship where two species take advantage of their partner in ways that benefit both.
•Example: relationships that exist between flowering plants and insects. The hummingbird is a pollinator for some flowering plants. The plant provides the bird with nutrients (nectar)
The ecosystem
is composed of autotrophs (self-feeders or plants) and heterotrophs (non-self feeders_
Autotrophs
are the primary producers of the system. They secure energy from the environment for the entire system
Heterotrophs
are also known as consumers. They extract energy from compounds that are made by the primary producers.
Types of heterotrophs
- Herbivores-eat plants
- Carnivores-eat animals
- Ominovores-eat both plants and animals
- Parasites-extract energy from their host
- Decomposers-obtain energy by breaking down the remains of organisms
trophic levels
Organism can be classified in terms of the hierarchy of feeding relationships
producers
the first trophic level of the food or energy pyramid
primary consumers
the second trophic level of the food or energy pyramid. They feed directly on the producers.
secondary consumers
the third trophic level of the food or energy pyramid. consume primary consumers.
Tertiary consumers
the fourth trophic level of the food pyramid. They consume secondary consumers
Energy transfer in the ecosystem
As one moves from one trophic level to the next, there is a loss of metabolic energy into waste material. This means that useable energy flowing through the trophic level declines at each energy transfer. Only about 10% of the energy is transferred.
Difference between fresh water and salt water biomes
amount of salt which affects vegetation
lag phase
plenty of nutrients and space. period of adjustments
log phase
exponential growth, low in nutrients, low in space
stationary phase
phase or carrying capacity of land. birth=death
types of heterotrophs
herbivores: only eat plants
carnivores: eat plants and animals
omnivores: eat both
parasites: extract energy/nutrients from a host
decomposers: obtain energy from dead/decaying organisms
