Biodiversity

What is Biodiversity? Biological Diversity or Biodiversity “The variety of life in all its forms, levels and combinations. Includes ecosystem diversity, species diversity, and genetic diversity” (IUCN, UNEP and WWF, 1991).

Biodiversity Biodiversity is currently declining Species are going extinct

Extinction Extinction is a natural process ~ 99% of all species have become extinct

Extinction Natural Extinction Typically occurs at slow pace A few species disappearing over long time periods

Extinction Natural Extinction though there have been rapid, mass extinctions though there have been rapid, mass extinctions

Accelerated Extinction Extinction Occurring at a rapid pace Many species are disappearing every year

Extinction Natural Extinction Often old species evolve into new species over time

Extinction NaturalExtinction Offspring species survive and continue to evolve

Accelerated Extinction Extinction Species are disappearing too rapidly to evolve into new species No evolutionary or genetic legacy remains

We are currently experiencing the greatest extinction event of the last 65 million years – since the disappearance of the dinosaurs Peter Raven Extinction

Biodiversity How many species have been identified ? Approximately 1.4 million species have been named and described Approximately 1.4 million species have been named and described

Vertebrates Mammals 4,000Mammals 4,000 Birds 9,000Birds 9,000 Reptiles 6,300Reptiles 6,300 Amphibians 4,200Amphibians 4,200 Fish 19,000Fish 19,000 Biodiversity Insects 750,000 Plants 250,000 Non-insect arthropods 125,000 Other species 200,000

How many species have been thoroughly studied ? Biodiversity Only % We have done little more than name most of the species that we know about

How many species are currently alive on Earth ? Biodiversity We do not know !

How many species are currently alive on Earth ? Biodiversity In the past, estimates were 3 –5 million species

How many species are currently alive on Earth ? Biodiversity Recent estimates are more than 10 million species

How many species are currently alive on Earth ? Biodiversity The higher numbers of more recent estimates are due to recognition of vast, unknown biodiversity in tropical rainforests

How many species are currently alive on Earth ? Biodiversity Many species will disappear before we can even identify and name them

What is the primary cause of the current high rates of extinction of species ? Biodiversity Habitat Alteration

The most significant single factor in extinctionsThe most significant single factor in extinctions Habitats are destroyed as human societies alter ecosystems

Habitat Alteration Rainforest destruction threatens countless speciesRainforest destruction threatens countless species

Human activities have significantly altered an estimated 50-75% of the ice-free land surface of the EarthHuman activities have significantly altered an estimated 50-75% of the ice-free land surface of the Earth Habitat Alteration

Will Global Climate Change be the greatest habitat alteration of all?Will Global Climate Change be the greatest habitat alteration of all? Habitat Alteration According to the IPCC, a warming of 1.5 – C would place % of species at increased risk of extinction

Habitat Alteration Will Global Climate Change be the greatest habitat alteration of all?Will Global Climate Change be the greatest habitat alteration of all? According to the IPCC, a warming above C would place % of species at increased risk of extinction

Human Pressures on Species Habitat AlterationHabitat Alteration - most important by far - Commercial Hunting and Poaching Commercial Hunting and Poaching Introduction of Alien Species Introduction of Alien Species Pest and Predator Control Pest and Predator Control Other pressures include:

Commercial hunting and fishing have resulted in decline of whales, sea turtles, and other speciesCommercial hunting and fishing have resulted in decline of whales, sea turtles, and other species Human Pressures on Species

Poaching threatens elephants, rhinos and other speciesPoaching threatens elephants, rhinos and other species Human Pressures on Species

Introduction of alien species and diseases often threatens native speciesIntroduction of alien species and diseases often threatens native species Human Pressures on Species

Efforts to control pests and predators can harm species and ecosystemsEfforts to control pests and predators can harm species and ecosystems Human Pressures on Species

Vulnerability of Species Ecological factors make some species more vulnerable to extinction Critical population size Dietary specialists Dietary specialists Limited geographic range Limited geographic range Larger size species Larger size species Tolerance to human presence Tolerance to human presence

Vulnerability of Species Critical population size Once a population falls to a small number, particularly a social species, the population may not be able to recover Once a population falls to a small number, particularly a social species, the population may not be able to recover

Limited geographic range Vulnerability of Species Species with a small geographic range are more vulnerable to extinction than are geographically widespread species Species with a small geographic range are more vulnerable to extinction than are geographically widespread species

Dietary specialists Vulnerability of Species Species with highly specialized diets are more vulnerable to extinction than are dietary generalists

Larger size species Vulnerability of Species Larger species more directly compete with humans Larger species more directly compete with humans Larger species tend to have lower reproductive rates Larger species tend to have lower reproductive rates

Tolerance to human presence Vulnerability of Species Some species do not tolerate human presence and will not inhabit areas where humans are found Some species do not tolerate human presence and will not inhabit areas where humans are found

Reasons for Concern Biodiversity is Rapidly Declining Why should we care and be concerned ?

Reasons for Concern Ethics We have the power to destroy or save species We have the power to destroy or save species It is wrong for us to destroy other species It is right for us to save other species

Reasons for Concern Aesthetics The diversity of species gives beauty to our world and the experiences of life

Reasons for Concern Economics A tremendous portion of our economy depends on biological species Species extinctions deny us potential economic opportunities Species extinctions deny us potential economic opportunities

Reasons for Concern New Medicines Many of our medicines are based upon biological species Many of our medicines are based upon biological species Species extinctions deny us potential new medicines Species extinctions deny us potential new medicines

Reasons for Concern New Foods All of our foods are based on biological species All of our foods are based on biological species Species extinctions deny us potential new foods Species extinctions deny us potential new foods

Reasons for Concern Ecosystem Stability Complex ecosystems with greater species diversity are more stable over time Complex ecosystems with greater species diversity are more stable over time Species extinctions makes ecosystems less complex and less stable

Reasons for Concern Future Generations We must preserve the biological wealth of the Earth for the sake of our children, grandchildren, and countless future generations We must preserve the biological wealth of the Earth for the sake of our children, grandchildren, and countless future generations