Intro Flashcards
Environment?
Complex of physical, chemical and biotic factors that act on an organism/ecological community and ultimately decide its form and survival
Environmental biology?
- A scientific study of the origins, functions, relationships, interactions and natural history of living populations, communities, species, and ecosystems in relation to dynamic environmental processes
Individual/organism
Any organism/living thing with its own characters in physiology, evolution and behavior in relation to environmental factors
Population
A group of individuals of the same species living in the same area and producing fertile offspring by interbreeding
Community
A collection of populations of different species living in the same area and interacting with each other
Ecosystem
An ecosystem is a collection of communities as well as abiotic factors with which they interact with
Biosphere
Includes the entire portion of earth that is inhabited by life
What are the organizational levels of the environment
Individual
Population
Community
Ecosystem
Biosphere
What are abiotic components
Non living components (physical and chemical factors)
Ex: water, air, light, temperature, nutrients, sunlight, soil
Where are abiotic resources obtained from
Lithosphere, hydrosphere and atmosphere
What do abiotic components limit?
The geographic range (distribution) and abundance of species
What are biotic components
Living components of the ecosystem which include plants, animals, fungi, bacteria and protists
Define niche
Niche is the role a particular organism plays in an ecosystem. Or how an organism makes it’s living
What are the factors involved in deciding a niche
- How an organism gets its energy (what an organism eats) and how they pass that energy through the ecosystem
- How an organism interacts with other organisms
- Role in recycling nutrients
- Tolerance to environmental conditions such as temperature and soil moisture
Define habitat
The physical area a species lives naturally
What are the environmental factors used to describe a habitat?
- Average amount of sunlight received each day
- Average Annual rainfall
Whats the difference between habitat and ecosystem?
The habitat is the actual place of an ecosystem, whereas the ecosystem includes both biotic and abiotic components
What are the 3 interactions between abiotic and biotic components of the environment?
Biotic- biotic interactions
Biotic-abiotic interactions
Abiotic-abiotic interactions
Examples for biotic-biotic interactions
Competition
Feeding relationships
Symbiotic relationships between individuals and species
Examples for biotic-biotic interactions
Water uptake of plants from soil
Examples for abiotic-abiotic interactions
Chemical reactions occurring in soil
Define trophic level
Arrangement of feeding levels of an ecosystem
How are trophic levels represented?
Producers - 1st trophic level
Herbivores- 2nd trophic level
Primary carnivores - 3rd trophic level
Top carnivores - other levels
Define food chain
A linear sequence of organisms through which nutrients and energy pass from one trophic level to another trophic level of an ecosystem, starting from primary producers
Define primary producers
They are autotrophs and most often photosynthetic organisms such as plants, algae or cyanobacteria
These organisms convert light energy to chemical energy (produce organic matter)
Define primary production
The amount of organic matter produced by autotrophs in a given area during a given time period
Unit: gm-²day-¹ or kgha-¹year-¹
What are primary consumers
Organisms that eat primary producers
(Usually herbivores, though they may be algae eaters or bacteria eaters)
Define secondary consumers
Organisms that consume primary consumers
(Generally carnivores)
Define tertiary consumers
Organisms that consume secondary consumers
(Carnivore-eating carnivores, such as eagles or big fish species)
What’s a food web?
An interconnected feeding relationship of an ecosystem
What’s a food web?
An interconnected feeding relationship of an ecosystem
Describe energy loss along food chains
- energy flow is always unidirectional
- in each trophic level about 90% of potential energy is lost as heat and respiration
- organisms in each trophic level pass on about 10% of energy to the next trophic level
- this limits no. of trophic level to 4 or 5
- short food chains are more ecologically efficient as more energy is available for top members
- Because of this energy tapering, an energy pyramid called ecological pyramid is formed
Define ecological pyramid
Geaphical representation of no. of organisms, biomass and productivity at each trophic level
In a natural ecosystem do isolated food chains exist?
No
Features of ecological pyramids
- tropical structure of an ecosystem is indicated by an ecological pyramid
- also called Eltonian pyramids as they were found bt Charles Elton
- highest trophic level is at top of food chain.
What are the 3 ecological pyramid types?
Pyramid of energy
Pyramid of biomass
Pyramid of numbers
What do energy pyramids describe?
they describe overall nature of ecosystem
Why are energy pyramids always upright and vertical
As a considerable amount of energy is lost from one organism to another
Define number pyramid
It depicts the relationship in terms of the no of producers, herbivores and carnivores at each trophic level
What are the 2 types of number pyramids
- upright: on most cases
- inverted: host — parasite — microorganisms in parasite
Describe biomass pyramids
- fundamental ecological pyramid
- as fresh weight of biomass contains a large amount of water, dry weight represents amount of energy available in form of organic matter in an organism
2 types of biomass pyramids
Upright: gradual decrease of biomass in upper trophic levels
Ex: forest ecosystems
Inverted: some aquatic ecosystems w phytoplankton
Define biome
A large geographical area which is classified based on predominant vegetation adapted to that particular environment
What determines the biome in an area
Climate and geography of a region
How do biomes vary from each other
differences in
Climate
Topography
Soil conditions
What are the major terrestrial biomes
Tropical forest
Savanna
Desert
Chaparral
Temperate grassland
Temperate broadleaf forest
Northern coniferous forest
Tundra
