Understanding the Biodiversity Crisis

Biodiversity Crisis

• Species extinctions are happening 500-1000 times faster than normal.
• High extinction rates will cause a sharp decrease in the planet's biodiversity within the next 100-200 years.
• Many "invisible" species in tropical rainforests like the Amazon are at risk.
• Deforestation is rapidly destroying rainforests, which are the most diverse ecosystems.
• Almost 20% of the Amazon rainforest was lost between 1970 and 2011.
• The lowland rainforest in Madagascar is an example of a high biodiversity habitat; only 10% of the original coastal lowland forest remains.

Understanding Biodiversity

• Biodiversity includes the number of species and the number of individuals within each species (relative abundance).
• Genetic diversity is now included to help focus preservation efforts
• Biodiversity loss the reduction of biodiversity due to species' displacement or extinction.
• The extinction rate could cause the loss of tens of thousands of species in our lifetimes.
• Human populations depend on ecosystems.
• Agriculture began after humans modified their environments, making it harder to recognize dependence on other living things.
• Ecosystems provide food, medicine, clean air/water, recreation, and inspiration for humans.

Types of Biodiversity

• Biodiversity is the number of species in a location.
• Bird biodiversity in North and Central America is measured at 2078 species.
• Forests with equally common tree species are more diverse than those dominated by one species.
• Genetic diversity is the variety of genes within a population, and is essential for adaptation.
• Ecosystem diversity is the number of different ecosystems in a location.
• Prairie ecosystems once spanned from Canada to Mexico but are now largely gone.
• Soil productivity has declined because the interactions in the original ecosystem are lost.

Current Species Diversity

• Only 13% of eukaryotic species have been named.
• Describing species involves determining an organism's unique characteristics.
• Describing species is not simply accounting, the research is valuable to humans and ecosystems.

Patterns of Biodiversity

• Biodiversity is not evenly distributed across the planet.
• Lake Victoria once had almost 500 species of cichlids, all endemic to the lake, until a mass extinction occurred after the introduction of an exotic species.
• Endemic species are found in only one location, making them vulnerable to extinction,
• Latitude and age are factors influencing biodiversity patterns.
• Biogeography studies the distribution of species in the past and present.
• Conservation biogeography focuses on species protection and restoration.
• Biodiversity increases closer to the equator.
• The tropics have stable climates which promote speciation

Importance of Biodiversity

• Loss of biodiversity can have consequences on ecosystems.
• The extinction of one species can lead to the extinction of others.
• Biodiversity impacts human health, ability to produce food, and harvest wild animals.

Human Health

• Medications come from natural chemicals from organisms.
• Contemporary societies have knowledge about medicinal plants.
• Humans and great apes self-medicate with plants; older knowledge was compiled in herbals.
• Aspirin, codeine, digoxin, atropine, and vincristine come from plant compounds.
• Antibiotics are largely derived from fungi and bacteria
• By 2007, the FDA approved five drugs based on animal toxins to treat diseases such as hypertension, chronic pain, and diabetes.
• It is argued humans benefit psychologically from living in a biodiverse world due adaptation to living in a natural environment.

Agricultural

• Human agriculture began over 10,000 years ago through breeding and selecting crop varieties.
• Crop diversity matched the cultural diversity of human populations.
• Potatoes were domesticated 7,000 years ago in the Andes with varieties adapted to different conditions.
• Disease resistance is a chief benefit to maintaining crop biodiversity.
• Seed companies breed new varieties, but participate in declining varieties by focusing on selling less.
• The ability to create new crop varieties relies on the diversity of varieties available
• Government agriculture departments maintain seed banks of crop varieties.
• The Svalbard Global Seed Vault in Norway stores seeds as a backup.
• The Svalbard seed vault is carved deep into the Arctic rock; conditions are maintained at ideal temperature and humidity for seed survival.
• While crops are largley under our control, the ability to grow then still depends on the biodiversity of the ecosystems in which they are grown.

Ecosystem Services

• Ecosystem services are valuable conditions carried out by an ecosystem.
• Ecosystem services include nutrient cycles and soil maintenance.
• Pollination provides $1.6 - $6.7 billion per year of value in the United States.
• Honeybee populations are suffering large losses caused by colony collapse disorder.
• Humans compete for their food with crop pests.
• Pesticides control these pests, but are costly and lose effectiveness and cause collateral damage.
• Landscape complexity increases the effect of pest-suppressing organisms.

Wild Food Sources

• Humans obtain food from wild populations, especially wild fish populations.
• Aquatic resources provide the main source of animal protein for about one billion people.
• Production from global fisheries has declined since 1990.
• Fishery extinctions lead to a restructuring of marine ecosystems.
• The collapse of fisheries affects local human populations and leads to a loss of an inexpensive protein source.