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Lecture

BIOB50H3 Lecture Notes - Caribbean Monk Seal, Javan Tiger, Thylacine


Department
Biological Sciences
Course Code
BIOB50H3
Professor
Marc Cadotte

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of 2
Lecture 1: Ecology
Extinctions
!- Current extiction rate is up to one thousand times higher than the fossil record
!- Projected future extinction rate is more than ten times higher than current rate
!- The rate of extiction is higher and its predicted that it will increase
!- We are losing species that we havenʼt even discovered
!- An example of extiction was due to an astroid hitting the earth and destroying the earth,
!this time its different because humans are causing the extiction of species
!- Extictions: historial (723) [caribbean monk seal, javan tiger, dodo, tasmanian wolf], past 10
!years (7) [west african black rhino, baiji white dolphin, golden toad, !spixʼs macaw] we are in
!risk in the next 20 years of losing 50% of amphibians
!- One reason for extinction is because change the landscape of the world. Species lose
!their habitats. These changes only benefit humans to a certain extent. However these
!actions have long term consequences
What is Biodiversity?
!- Countries came together to say that we have a biodiversity crisis
!- 1992 United Nations Earth Summit in Rio de Janeiro defined biodiversity as “the
!variability among living organisms from all sources, including: diversity within species,
!between species and of ecosystems”
!- Biodiversity is the variation of life, includes variations in genes, forms, and functions
Why conserve biodiversity?
!- Organisms teach us a lot
!- We get most of our medicine from organism
!- They operate in ways that can help us solve many problems
!- Organisms can provide pollination service, an utility in nature
!- They control pests
!- Control water system and/or make it clean
!- Therefore we need biodiversity to help maintain a healthy environment
!- Biodiversity tell us where we came from, tell us about our history
!- Nature helps us understand ourselves, if we protect it we can learn more about ourselves
What is Ecology?
!- Ecology is not conservation or preservation/protecting species, its about understanding
!- It is the study of the interaction between organism and their environment
!- Ecology is the scientific study of interactions between organisms and their
!environment
!- It is a branch of biology. Ecology is not the same thing as environmental science
!- Environmental science incorporates concepts from the natural sciences (including
!ecology) and the social sciences, and focuses on solutions to environmental problems
!- Early ecological views:
!!1. There is a “balance of nature,” in which natural systems are stable and tend to
!!return to an original state after disturbance
!!2. Each species has a distinct role to play in maintaining that balance
!!- Simplistic and not accurate
!- Scientists now recognize that ecological interactions are more complex
!- One view that stood the test of time: events in nature are interconnected
!- Most species interact indirectly with each other through resources
!
Energy
!- The currency in natural system is energy
!!- energy moves between organism
!!- organism consuming organism
!!- energy moves through the system
!- Energy comes from the sun
!!- energy is not recycled, nutrients are recycles
!- Energy moves through ecosystems in a single direction only - it cannot be recycled
!- Nutrients (iron, calcium) are continuosly recycled from the physical environment to
!organisms and back again
Ecology
!- Ecologists study interactions in nature across many levels of organization: individuals,
!populations, communities, or ecosystems
!- Ecology is where we study the organism, we study its interaction with the environment
!- A science where scale is important
!- we can be studying the same thing but explain it from different scales
Ecosystem
!- coupling between the biotic and abitioc world: the species and the flow of water, the
!topography, trees and forest, pond life that uses the water
!
Two types of Scale
!- we can see certain patterns at this scale
!- what species interact with each other in this space
!- what scale we use to study will influence what we learn and how we study the !
!ecology of the environment
!1) Space: Spatial Scale
!!- We have to link the mechanism to the scale we study
!!- Small spatial scale: soil microorganisms; 1m2
!!- Large spatial scale: atmospheric pollutants; 100km2
!2) Time: Temporal Scale
!!- we have to look at time scale
!!- we have to look at the time organisms take to produce for example ! !
!!(some slow, some quick)
!!- Short temporal scale: leaf response to sunlight; 10 seconds
!!- Long temporal scale: how species chance over geologic time; 100,000 !
!!years