Biodiversity and Conservation Biology

What is biodiversity? “the sum total of all organisms in an area, taking into account the diversity of species, their genes, their populations, and their communities.” Text, pg 456 According to Edward Wilson, who wrote The Diversity of Life, “the variety of organisms considered at all levels, from genetic variants belonging to the same species through arrays of species to arrays of genera, families, and still higher taxonomic levels; (biodiversity) includes the variety of ecosystems, which comprise both the communities of organisms within particular habitats and the physical conditions under which they live.” The United Nations Environmental Porgramme (UNEP) and other organizations agreed on the definition of “the variety of life in all its forms, levels and combinations.” ****It is NOT just a count of species***

Biodiversity encompasses several levels of life’s organization Ecosystem diversity - The number and variety of ecosystems in a specific area More diverse ecosystems can support more biodiversity Species diversity – The number or variety of species in the world or in a specific region. Includes species richness (the number of species) and evenness of species Classified by taxonomists on physical appearance and genetic makeup (KPCOFGS) Genetic diversity – The differences in DNA composition between individuals of the same species May decrease as species adapt, but the more diversity a population has the better chance they may have if the environment changes.

Species vs. Subspecies Though still the same species, as scientists recognize substantial differences in the genetics between individuals of different populations, they may classify them as a different subspecies. The tigers are an example of such subspecies classification

How do we measure biodiversity? Can be measured by species richness (number of species) – locally, nationally and globally. In 2002, 1.75 million species of plants, animals and microorganisms were counted. It is estimated that there are somewhere between 3-100 million species. It is difficult to measure because many areas of Earth are unexplored, some species are so small that it is difficult to count them, and many are difficult to identify. It is also a monotonous and potentially boring job to count everything in an area. Kevin Kelly, the co-founder of Wired Magazine, created the All Species Foundation, aimed at c ounting all the living organisms on Earth. He believed it would take 25 years to do so, and $1-3 billion to accomplish. It still continues, yet the process is much slower than the start.

How can you help measure biodiversity? There are many local efforts in local areas to count species Bioblitz – a contest to survey every species that can be found within 24 hours in a given area. In 1996, during the first Bioblitz, 1000 species were found in a park in Washington DC. The record is held for finding 2,519 species in a park in Connecticut. These continue to occur worldwide today.

Distribution of Biodiversity – even or not?

Not! Living things are distributed across the planet unevenly Not all groups of organisms contain equal numbers of species. Some groups only have a few species, others have many species. Species diversity varies according to biomes. Forests and rainforests are more diverse than tundra and deserts. Typically, species richness increases as you approach the equator – known as latitudinal gradient. More sunlight, heat and humidity at tropical latitudes lead to more plant growth, making areas nearer to the equator more productive and able to support larger numbers of species.