and value of biodiversity? Defining Biodiversity What is the nature and value of biodiversity? Learning Objectives – Describe the global distribution of biodiversity Define the term ‘hotspot’ Describe the global distribution of hotspots

Think at different scales : latitudes; continents; countries Biodiversity Describe the pattern! Think at different scales : latitudes; continents; countries

LATITUDES The pattern is strongly correlated with latitude – highest levels usually in the tropics There is a gradual decrease in higher latitudes CONTINENTS South America Asia Oceania – Australia is unusually high due to ‘endemism’ COUNTRIES Mostly found in developing countries Brazil is ranked 1st

According to levels of biodiversity Brazil comes out on top. 750 species of tree 400 types of bird 100 types of reptile 1500 species of flowering birds

MAP OF GLOBAL BIODIVERSITY Biodiversity is low where there are climatic extremes Biodiversity is greatest in the tropics Biodiversity is generally greatest in the southern hemisphere Seventy per cent of the world's species is found in just 12 countries: Australia, Brazil, China, Colombia, Costa Rica, Ecuador, India, Indonesia, Madagascar, Mexico, Peru and Democratic Republic of Congo

Marine hotspots are essentially coral reef areas in the tropics (contain 24% of world’s coral reefs yet cover 0.017% of oceans) Terrestrial and marine hotspots are often adjacent to each other e.g. Cape Floristic Province, South Africa

Biodiversity Such choropleth maps give an overview of biodiversity distribution by country but this can hide the real picture What’s this about? Is there a link to biodiversity?

Hotspots Def: An area containing a huge number of species, a large % of which are endemic Described as ‘the most remarkable places on Earth and the most threatened’ They (25 hotspots) cover <2% of the Earth’s surface yet contain 44% of the World’s plant species and 35% of the World’s animal species* *Conservation International has recently updated this analysis 34 identified hotspot areas which are home to 50% of the World’s plants and 77% of the terrestrial vertebrates Conservation Intnl has recently updated this analysis 34 identified hotspot areas which are home to 50% of the World’s plants and 77% of the terrestrial vertebrates

Level of threat to species HOTSPOT CRITERIA… 1.) THE NUMBER OF SPECIES (SPECIES RICHNESS) 2.) THE NUMBER OF ENDEMIC SPECIES 3.) THE NUMBER OF SPECIES AT RISK Species richness Endemic richness Level of threat to species Biodiversity hotspot

ENVIRONMENTAL SCIENTIST NORMAN MEYERS ENVIRONMENTAL SCIENTIST DEVISED HOTSPOT CONCEPT AIMED TO IDENTIFY PRIORITY AREAS FOR BIODIVERSITY CONSERVATION

Hotspots

Continental Hotspots Large Island Hotspots Small Island Hotspots 4 CATEGORIES OF HOTSPOT Continental Hotspots Large Island Hotspots Small Island Hotspots Marine Hotspots ATLANTIC FOREST AUSTRALIA MADAGASCAR CORAL REEF

Hotspots The top 25 land-based hotspots are divided into 3 categories Continental hotspots (richest in terms of biodiversity) 2. Large island (or continental island) hotspots (contain diverse & distinctive species inc relict fauna extinct elsewhere) Small island hotspots (low in species no’s but high in proportion of endemics so at great risk of being wiped out)

HOTSPOT: BIODIVERSITY PATTERNS The location of hotspots does not correlate exactly with the location of greatest biodiversity. For example, France does not have a particularly high biodiversity but yet its southern shores are part of the Mediterranean Basin Hotspot. The tropical distribution of both types of hotspot is due to an absence of limiting factors which allows maximum primary productivity. In the tropics high temperatures, high humidity, abundant rainfall, and plentiful nutrients all encourage luxuriant growth of rainforests and reefs

Alterations in ecosystem composition Pollution Invasive species Alterations in ecosystem composition Pollution Threats to Biodiversity Climate Change Over exploitation Habitat loss and destruction

Hotspots at risk China Specific Hotspots: Reasons for High Biodiversity: Signature Species: Threats: Galapagos Islands Reasons for High Biodiversity: Signature Species: Threats: Madagascar Reasons for High Biodiversity: Signature Species: Threats:

ADVANTAGES OF HOTSPOTS Has ensured that the ‘best bits’- areas with the highest levels of biodiversity, substantial levels of endemism (unique/rare species) are conserved and protected. Areas under threat are commonly in the tropics and in developing countries where conservation costs are much lower (cheap labour) – idea of value for money. Hotspots now covers marine area under threats in addition to terrestrial ecosystems

DISADVANTAGES OF HOTSPOTS Even with the additions of marine hotspots under 2% of the earth and 0.017% of oceans are protected by this approach The distribution of areas protected is very uneven. Most hotspots lie in the tropics e.g. rainforests. Many ecosystems such as Tundra, Taiga and Temperate Forest are not included. Huge areas of the world are not covered including many areas under great threat e.g. Arctic Ocean, or many outstanding smaller regions such as Galapagos . These are not protected because they do not meet all three criteria to be a hot spot. Polar bears subsequently face extinction. Hotspots tend to follows protectionist approach. This entails removing people and their activities from areas under threat. This has occurred in tropical countries where indigenous people have been forced off their land in favour of creating big reserves.

TASK: SHOULD THE ARTIC BE A HOTPSOT? PRODUCE AN ARGUMENT IN FAVOUR OF THE ARTIC BE MADE A HOTSPOT. CONSIDER ITS IMPORTANCE AND WHAT THREATENS IT.