6: Threats to Biodiversity Flashcards
What does ‘extinct’ mean
Species is extinct when, after a thorough search, no member of the species is found alive anywhere in the world
What is extirpated
Species not extinct, but extinct in a specific area/region
What is ecologically/functionally extinct
Number of animals so small that they no longer play a significant role in ecosystem function; or the population is no longer viable
What is the 6th extinction
Spread of humans causing many species to go extinct due to: hunting, loss of habitat, competition, invasive species
What are indirect threats
Agriculture, residential development, industry, energy production, mining, logging, transportation and roads
Leads to direct threats
What are direct threats to biodiv
Habitat loss, fragmentation, degradation, overexploitation, invasive species, disease, climate change
What is loss of biodiversity
Extinction of species/pops
Degradation of ecosystems
Erosion of genetic diversity
Slide 7
Know diagram
What is coral bleaching
Water is too warm, corals expel the algae living in their tissues causing coral to turn white
Corals are not dead, can survive bleaching but are under stress and subject to mortality
What are some causes of coral reef destruction
Reef trampling
Natural hazards
Tourism
Poor anchoring
Scientific research
Overfishing
Collection of coral
Dynamite fishing
What are the main 7 threats to animal populations
- Exploitation: 37%
- Habitat degradation and change: 31%
- Habitat loss: 13%
- Climate change: 7%
- invasive species: 5%
- Pollution: 4%
- Disease: 2%
What are the main threats to birds? Mammals? Fish? Reptiles/amphibians?
Birds = habitat loss/degradation
Mammals = habitat loss/degradation, overexploitation (domestication & hunting)
Fish = overexploitation
Reptiles/amphibians = habitat loss/degradation
Reptiles/birds undergo a lot of speciation, meaning?
Group within a species separates and develops unique characteristics
Lots of intraspecies competition
The three habitat-related threats
Fragmentation -> degradation -> loss
What are the diff types of habitat loss
Aesthetic vs ecological
Permanent vs temporary
Functional (utility gone) vs structural (composition changes)
What is the problem with palm oil production?
Major driver of deforestation and degradation of natural habitats in tropical Asia and Central/South America. Put up forests nearly impenetrable to local fauna to grow the palm trees
193 critically endangered species related to palm oil production
What is habitat fragmentation
Creates edges, barriers, conduits in habitats
Limits dispersal and alters movement of individuals
Sub-divides, isolates or intersects populations
Stages of loss/fragmentation
Dissection -> perforations -> fragmentation -> attrition (erosion)
What is the usual cause of habitat degradation?
Pollution
- chemical (to air, water, soil)
- light, noise, electromagnetic
Four causes of habitat degradation
Pollution, conversion, climate change, anthropogenic disease
What are microplastics? Where do they come from?
Extreme pollution problem
1um-5mm diameter
Personal care products, plastic manufacture/degradation, polyester clothing
