Biogeography: Class I: Biogeographic regions Similarity

The pattern: different parts of the world have similar types of species The challenge: How do we set the boundaries of those places? Biogeographic regions

First: differentiate climate and evolution New Guinea Costa Rica SIMILAR in their vegetation type and structure, climate, soils, etc DIFFERENTIATED by plants and animals with very different evolutionary histories BIOMES BIOGEOGRAPHIC REGIONS

Presence Absence The process → Speciation Dispersal Extinction Species is: The raw data

Latitude Temperate Tropics Temperate Species similarities Species richness Raw data and patterns Count Similarity Endemic Cosmopolitan Species distributions

Latitude Temperate Tropics Temperate Building the pattern Jaccard: Simpson:

McKnight et al, PlosBiology 2007 GLOBAL PATTERN OF BETTA DIVERSITY Amphibians Birds Mammals Very dissimilar Very similar

Problems: choice of scale and need for a hierarchy Realms Regions Provinces Sub-divisions How did you get to be here? The problem of scale: here → my desk here → Honolulu here → Hawaii here → USA here → Earth

Problems: choice of taxonomic level CountryGenusSpecies CanadaLarixlaricina Piceaglauca Piceamariana Pinusbanksiana RussiaLarixsibirica Piceaobovata Pinussylvestris Simpson coefficient

Problems: choice of taxa Speciation Dispersal Extinction Wallace’s Line Simpson, Proceedings of the American Philosophical Society 1977

Potential impacts of climatic change upon geographical distributions of birds Problems: temporal changes (Climate change) HUNTLEY et al. IBIS 2006 NOW 2070

Problems: temporal changes (Climate change) North Sea fishes are shifting north with climatic warming snake blenny Number of species Average north shifting: 172 km between 1977 and 2001 Perry et al, Science 2009

Climate change and deepening of the North Sea fish assemblage: a biotic indicator of warming seas Problems: temporal changes (Climate change) Dulvy et al, journal of Applied Ecology 2008 Fishes are not going extinct now but are moving deeper

Problems: temporal changes (Climate Change) Cheung et al. Fish and Fisheries 2009 Invasion and local extinctions can change the structure of local assemblages by up to 60% by 2050

Problems: temporal changes (Anthropogenic) LALIBERTE & RIPPLE, Bioscience 2004 Human Influence index Low High

Problems: range shifts (Invasive species) SPECIES ARE MOVING AROUND GLOBAL SHIPPING LINES Schofield, Aquatic Invasions 2009

There is no clear cut way to define biogeographical regions

Udvardy, IUCN 1975 Biogeographical regions of the world: Udvardy's system

Biogeographical regions of the world: WWF Olson et al, Bioscience 2001

Robertson and Cramer, MEPS 2009 Biogeographical regions of the world: problems at small scales

Biogeographical regions Difficult to define Scale Taxonomic rank Taxonomic group Change over time Very variable Summary