Principles of Conservation Biology BIOL 4160

Biodiversity

Species Diversity Genetic Diversity Ecosystem Diversity

Species Diversity What is a species anyway? o A group of individuals that is morphologically, physiologically, or biochemically distinct from other groups. Morphological Species Concept o A group of individuals that can potentially interbreed in the wild and don’t (usually) interbreed with other species. Biological Species Concept

Difficulties with morphology

Species definitions can be tricky....

How do we classify species?

Taxonomy The practice and science of classification

Speciation vs. Extinction Present rate of extinction: times faster than rate of speciation

Back to looking at species diversity

Figure 2.9

Ecosystem Diversity Ecosystem: a biological community, together with its associated physical and chemical environment

Species interactions Competition Predation Mutualism Symbiosis

Food webs Fig 2.13

Species “importance” Figure 2.14

Loss of keystone species, like otters, can drastically altering ecosystem dynamics

Ecosystem Engineers

Keystone Resources (examples) Deep pools in streams and springs Salt licks and mineral pools Hollow trees Rotting wood What else?

Ecosystem dynamics Resistance: ability to maintain the same state with ongoing disturbance Resiliance: ability to return to the original state following a disturbance

Patterns of Biological Diversity

Tropical rainforests 7% world’s land area >50% world’s species 5-30 million insect species 1,300 bird species (not incl. migrants or island endemics)

Figure 3.1 Madagascar

Contains 28/35 animal phyla on earth today Incredibly high productivity Great Barrier Reef 400 coral spp 1500 fish spp 4,000 mollusks 252 birds 6 turtles mid-Atlantic Seaboard 250 fish spp

Productivity – 2500g/m2/yr compared to 125g/m2/yr Clip

Factors influencing diversity Climate Environment Topography Geological age Others?

Species richness Climate and Environment

Species richness Complex Topography Great geological age Topography, Geological Age, Habitat Size Habitat size

Correspondence in species richness between different groups of organisms

Habitat size can have a large effect – Indian Ocean and west Pacific have a much larger reef area and correspondingly high richness compared to the west Atlantic

France Thailand 674,843 km mammal species 283 bird species 513,120 km mammal species 971 bird species plant species

Why so many species in the tropics? 1)Solar Energy, abundant rainfall leads to high productivity and large resource base 2)Longer periods of stability 3)Warm temperature, high humidity favorable for growth

Why so many species in the tropics? 4) High competition, high niche specialization due to predictability of environment 5) Pressure from parasites, disease 6) Large geographic area

How many species are there?

Vertebrates – 62,305 Invertebrates – 1,305,250 Plants – 321,212 Fungi – ,000

Canada