Biodiversity

What is Biodiversity?

‘The total variability of life on earth’

Ecological Diversity:

‘numbers of species in given areas’

Genetic Diversity

‘variation within and variation between populations of animals measured in variation between genes or DNA sequences’

why do we care?

a. beauty of biodiversity, spice of life, children develop better when exposed to greater diversity, both microbiological and psychologically.

b. Lifeforms provide important sources for new types of medicines, fibers, materials: losing biodiversity means also a loss in access to important biologically active compounds

i. 25% plant based medicines currently in use

c. Genetic diversity in crop plants and diversity in number of crop plants includes the stability of both global and local food sources, by, for instance, protecting populations from diseases.

d. Biodiversity provides other important environmental services such as, for example, carbon sequestration and water capture.

e. Biodiverse crop plantations increase total productivity by 10% by making better use of space: polycultures

f. lack of knowledge: organisms are integrated into a very complex chain of being that we have not deciphered (nor are we likely to do so anytime soon)

g. moral: no reason not to preserve existing diversity of life, there is plenty of food, fiber, and other items without expanding acreages under cultivation or stripping old-growth forests, or drilling new oil wells

ii. how do we measure biodiversity?

a. Uncertainty is a central problem

Numbers of species

1.75 million species scientifically identified.

estimated 30 million species on earth.

estimated 40,000 species rendered extinct annually.

b. what does ‘biodiverse’ mean in practice? example: different varieties of white oak
versus different species of oaks
versus different genera

c. Issue 1: scale of measurement: size of the sample area

i. frogs versus bears; oaks versus lilies

ii. evenness versus dominance

iii. patch type, dimension, geometry

d. Issue 2: Distribution of populations and sampling problematic

e. Issue 3: unit of analysis: population? gene pool? Clade? Genera? What is the appropriate unit for biodiversity analysis?

f. Issue 4: Convention on Biodiversity: the US is supposed to measure biodiversity, but has limited funds for the US Biological Survey and HAS NOT signed the international Convention on Biological Diversity. This has been attributed to an administration unwillingness to fund a program which would almost certainly find new species that would then be subject to protection under the Endangered Species Act.

It takes money to measure biodiversity:

Where does Biodiversity come from?

iii. coevolutionary relationships: mutualism, symbiosis,

iv. allopathy

v. patchiness in landscape ecology

a. landscape biodiversity

b. alpha biodiversity

c. rollover biodiversity

d. is there information in a landscape, and if so how structured?

e. trails, movements of animals and plants, seed dispersals

vi. Niche complexity within a patch

vii. biodiversity hot spots

a. what causes a ‘hot spot’?

viii. species loss rates

a. absolute loss

b. rates of loss

MAP: Biodiversity loss: state and scenarios 2006 and 2050.

greatest losses rank order: Markets First, Security First, Policy First Sustainability First. differences among the regions:

broad-scale land-use changes, especially pastureland and biofuel production infrastructure development,

pollution

climate change,

public policy and conflict

http://www.unep.org/geo/geo4 / http://www.globio.info/region/world/

c. differing across social contexts and geographically

d. differing by patch utilization: some areas are more amenable, systematically more amenable, to human exploitation

ix. Causes of Biodiversity Loss

a. Proximate causes (graphics problems)

First: some very poor graphics

Clear but boring graphics

b. background causes

i. consumption of energy and resources

1. increasing affluence

2. lack of sustainable planning or policies

3. population growth

ii. wastes:

1. toxics,

2. CO2,

3. erosion

iii. unmediated globalization

1. exotic species invasions

2. hot spot development (see i.2 above)