Biodiversity Biodiversity

What is Biodiversity? The number and variety of species in an ecosystem More inclusive of all diversity: the totality of genes, species, and ecosystems of a region

How many species are there on Earth How many species are there on Earth? Estimates range from 5 to 100 million ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... 10,000 ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ×500 ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... minimum ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ........... ...........

The relatedness of identified species can be found here: Click Phylogenetic Tree The relatedness of identified species can be found here: Click

How do we know? It can be hard to estimate total diversity within an ecosystem 4 main sampling techniques are used Canopy fogging Quadrant sampling Transect Sampling Netting SEE TABLE 3.1 ON PAGE 90

Why is Biodiversity Important? Still a topic of much scientific research Main Idea more biodiversity = more resistance to change

One organism can fill the niche of another More feeding relationships may result in less overall effects of changes in the ecosystem One organism can fill the niche of another What happens if insecticides are used? What happens if Grouse are hunted?

Why is Biodiversity Important? More biodiversity = more resistance to change More niches filled means more nutrient cycling Maintenance of ecosystem services Potential for new discoveries (eg. medicines) Economic benefits (exploitation / ecotourism) Natural beauty / fascination / personal connection

What are Ecosystem Services? Through the natural processes that take place in nature, ecosystems perform a number of seemingly free services which sustain humanity and all other life on earth

eg 1 - Transfer of energy The sun’s energy is captured and moved through food webs which provides food for all creatures on the planet

eg 2 - Water purification Many ecosystems ultimately provide clean purified water as a result of the biotic and abiotic features within them. Marsh ecosystems are particularly important natural water filters.

eg 3 - Oxygen cycle The huge variety of autotrophs on Earth remove carbon dioxide from the atmosphere and replenish oxygen supplies

Biodiversity Hotspots 25 identified regions of particularly large plant diversity which are under particularly strong threats of habitat loss (at least 70% lost of original habitat) Established in 1999 Some estimated that they contained 44% of earth’s plant species and 35% of terrestrial vertebrates They covered about 11.8% of earth’s land surface Now they have been reduced to only about 1.4%

Threats to Biodiversity Habitat Loss Over-exploitation Pollution Invasive species Climate Change

Habitat Loss

Threats to Biodiversity Habitat Loss Changes in land use by humans Growing cities / urban sprawl Expansion of farmland / habitat fragmentation Draining wetlands Habitat Fragmentation Larger habitats become divided into smaller sections by highways, roads, farms, urbanization, etc.

Over-exploitation

Threats to Biodiversity Over-exploitation Over-hunting eg. Dodo bird hunted to extinction Over-fishing eg. in 1992 it became illegal to catch Atlantic cod Deforestation See http://rainforests.mongabay.com/deforestation.html Relentless consumption eg. The average Canadian ecological footprint may be around 7 or 8 times larger than the footprint of countries in the developing world

Pollution

Threats to Biodiversity Pollution Pollutant are chemicals with known toxic effects on one or many species Human activity has introduced waste products and contaminants throughout the biosphere Air, land and water have been affected nearly everywhere Egs. Industrial waste, municipal waste, pesticides, sewage containing hormones, heavy metals, pharmaceuticals, etc.

Invasive Species

Threats to Biodiversity Invasive species Non-native species of plants and animals that establish in new habitats These may disrupt local ecosystems and/or displace local species causing extinction or population reduction Eg. in Canada: purple loostrife, mountain pine beetle, asian longhorned beetles, zebra muscles Eg. in Australia: prickly pear cactus, cane toads, feral pigs, red foxes, european rabbits, camels

Climate Change

Threats to Biodiversity Climate Change Rapid disruption of ecosystem stability Changes in global geography (eg. melting of permafrost) Unpredictable changes to ecosystems around the world