Ecology (4 Major Threats to Biodiversity (Introduced Species (when humans…
4 Major Threats to Biodiversity
when humans move intentionally or accidentally from species native locations to new locations
Has contributed to 40% of extinction
harvesting of wild organisms at rates exceeding the ability of populations to rebound
Locations such as small islands and larger organisms that reproduce at lower rates are more susceptible
Examples include, NorthAtlantic bluefin Tuna, declined by 80%
human alteration of a habitat, single greatest threat to biodiversity and can lead to extinction of species
Alters the fabric of Earth's ecosystem at regional and global scales.
Examples include, acid precipitation that harms natural habitats, denatures proteins and alters soil composition. Also Global warming heating up many habitats.
3 Levels of Biodiversity:
Endangered v Threatened
Threatened: very close to endangered
very close to extinction
extinction can lead to loss in genetic diversity
Earth's ability to provide services that would other wise cost humans a lot of money to do manually
Purify water and air
Detoxify and decompose waste
Reduce impacts of extreme weather and flooding
pollinate crops, control pests and preserve/create soils
Due to the interaction of populations in an ecosystem, a local extinction could have a negative impact on the ecosystems and the other species within the ecosystem
Genetic Diversity: Individual genetic variation and genetic variation within a group
Changes on Earth Due to Humans
Toxins in Environment: Humans release many toxic chemicals into the environment
Example: Birth control, for some fish who are extremely susceptible from hormones when human waste is cleaned it then goes into the streams and the hormones are still in the cleaned water and so this can cause fish to swap sexes so that there are too many females.
Biological Magnification: accumulated toxins are harmful do to the fact that they become more concentrated in successive trophic levels of the food web.
Top level carnivores tend to be the most affected
Greenhouse Gas Effect: gasses that intercept and absorb much of infrared radiation that hearth emits
Climate Change: when there is a direction change in global climate that lasts for 3 decades or more.
This keeps Earth heated
Too many greenhouse gasses are bad for the planet, they cause the planet to heat up and even to a point where no return.
Nutrient Enrichment: Human activity takes nutrients from one part of Biosphere and adds them to another.
Example: fertilizers, fertilizer is added to the soil to increase the nutrients for the plants being grown, when the fertilizer is washed into rivers and streams this creates an increase in nutrients in the water. As a result an algae bloom will happen. However when the algae dies this will take in all the oxygen in the water and will cause there to be a dead zone where there are no living organisms in the water they have all died due to lack of oxygen.
Critical Load: amount of an added nutrient usually nitrogen or phosphorus, that can be absorbed by plats without damaging the ecosystem's integrity.