Ecosystems-Cont.. Think Aloud Ecosystems are made up of Individual Organisms (living things)
Ecosystems Part 1. Levels of organization What is a species? Basic unit of biological...
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Transcript of Ecosystems Part 1. Levels of organization What is a species? Basic unit of biological...
Ecosystems
Part 1
Levels of organization
Levels of organization
What is a species?
Basic unit of biological classification
Organisms that resemble each other, that are similar in genetic makeup, chemistry, and behavior, and that are able to interbreed and produce fertile offspring
Is it a species?
Vocab
Intra = “within” Intraspecific interactions = ??
Inter = “Between” Interspecific interactions = ??
Population Dispersal patterns
Clumped – most individuals are together In environments with patchy resources Most common in nature
Random – little interaction between members of a species In environments with consistent resources
Uniform – found when distance between neighbors is maximized Arises from competition for a resource
Population dispersal patterns – the visual
Ecological Niches Definition: ??? Influenced by the physical environment Take into account:
Interactions with the biotic and abiotic environment
Available resources To describe:
Organisms adaptive traits Habitat Place in the food web
Generalist vs. specialist
Generalist: live in broad niches and withstand a wide range of environmental conditions (K-selected)
Specialist: live in narrow niches and sensitive to environmental change (r-selected)
Who has the advantage in the environment?
Law of Tolerance
The existence, abundance, and distribution of each species depends on the species tolerance to both the physical and chemical factors of the environment
Limiting factor: any factor in the environment that limits the growth of a population
Resource partitioning
Species “share” a resource and avoid direct competition with each other
Types: Temporal: use resource at different times Spatial: use the resource in different areas Morphological: evolves different
characteristics to use the resource
Ecosystem Community Characteristics
1. Physical appearance: relative size, stratification, distribution of the populations and species
2. Species diversity: number of different species
3. Species abundance: number of individuals of each species
4. Niche structure: number of ecological niches, how they resemble or differ from each other, species interactions
Biological Interactions amongst species
Interaction Description ExampleAmensalism One species suffers and
the other is not affected-due to scarce resource-usually occurs with when one organism engages in chemical warfare
Black walnut tree releases a chemical to kill neighboring plants
Commensalism One species benefits and the other is not affected1)Transportation2)Housing3)Use of something created
1) Shark and ramora
2) Epiphytic plants
3) Hermit crabs
Biological Interactions amongst species
Interaction Description Example
Competition 1) Interference – directly between individuals
2) Exploitation – indirect by depleting a common resource
3) Apparent – indirectly when sought by same predator
1) Elk and moose foraging
2) Grass and trees using water
3) Wolves hunting elk and moose
Mutualism Interaction where both species benefit
Trees and mycorrhizal fungi
Biological Interactions amongst species
Interaction Description Example
Parasitism One species benefits and the other is harmed
-Tapeworm-cuckoo bird
Predation Predator hunts and kills prey for food
-??
Saprotrophism Obtain nutrients from dead or decaying matter
-Fungi-vultures-dung beetles
Key Stone Species
A species whose presence contributes to the diversity of life and whose extinction would lead to extinction of other forms of life Dramatic shifts in the ecosystem can
occur when a keystone species is removed
Keystone species examplesSea Stars “Starfish” Sea stars prey on
muscles, urchins, and other shell fish
When removed muscle populations explode and out compete other organisms
Sea urchins rise to the point they destroy coral reefs
Sea Otter Prey on sea urchins Sea urchins eat
through kelp holdfasts, which anchor the kelp to the ground, causing entire kelp forests to float away
Wolves in Yellowstone
Homework: Download the article from my website Read and annotate
# paragraphs Highlight main ideas Write a one paragraph summary