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 are going extinct Species are going extinct

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

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

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

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

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

Offspring species survive and continue to evolve Extinction Natural Extinction Offspring species survive and continue to evolve

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

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

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

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

How many species have been thoroughly studied ? Biodiversity How many species have been thoroughly studied ? Only 1 - 2 % We have done little more than name most of the species that we know about

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

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

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

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

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

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

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

Rainforest destruction threatens countless species Habitat Alteration Rainforest destruction threatens countless species

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

Will Global Climate Change be the greatest habitat alteration of all? According to the IPCC, a warming of 1.5 – 2.5 0C would place 20 - 30% of species at increased risk of extinction

Will Global Climate Change be the greatest habitat alteration of all? According to the IPCC, a warming above 3.5 0C would place 40 - 70% of species at increased risk of extinction

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

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

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

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

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

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

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

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

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

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

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

Ethics Reasons for Concern 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

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

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

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

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

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

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