Chapter 8 – Sustaining Biodiversity: Saving Species and Ecosystem Services

Pollination

Vital ecosystem service provided by honeybees

European honeybees

Main pollinators in U.S. agriculture; reliance on one species violates sustainability principles

Colony Collapse Disorder (CCD)

Disorder since 2006 causing massive honeybee population decline

Biological extinction

Complete disappearance of a species from Earth

Mass extinction

Large-scale extinction of many species in a short geological period; Earth has had 5

Background extinction rate

Natural, baseline rate of extinction (before humans)

Human-driven extinction rate

100–1,000× higher than background; projected to be ~10,000× higher by 2100

Speciation crisis

Too few habitats/resources left for new species to evolve

Ecosystem interdependence

Extinction of one species affects many others

Ecosystem services

Benefits humans get from nature (food, fuel, medicine, lumber, resilience)

Ethical perspective

All species have a right to exist, even if not useful to humans

Orangutan

Tropical forest species endangered by habitat loss, slow reproduction (1 offspring every 8 years), and wildlife trade

HIPPCO

Acronym for major threats: Habitat destruction, Invasive species, Population growth, Pollution, Climate change, Overexploitation

Habitat fragmentation

Splitting of large habitats into smaller patches; creates “habitat islands” and disrupts migration

Invasive species

Nonnative species that spread rapidly, outcompete natives, and lack natural predators

Examples of deliberate introductions

Purple loosestrife, European starling, African honeybee, nutria, salt cedar, wild boar

Examples of accidental introductions

Sea lamprey, zebra mussel, Argentine fire ant, Formosan termite, brown tree snake

Pesticides (e.g., DDT)

Chemicals that kill non-target species, threaten ~20% of endangered species

Bushmeat hunting

Harvesting wildlife for food, threatens African species, spreads diseases (HIV, Ebola)

CITES (1975)

International treaty banning hunting, capturing, and selling endangered species (178 signatories)

CBD Treaty

Agreement by 193 countries (not U.S.) focusing on ecosystems, genetic resources, and invasive species prevention

Wildlife refuges

Protected areas; U.S. has 560+ (¼ of endangered species live there), though some allow harmful activities

Seed banks

Store genetic diversity; example: Svalbard Vault in Arctic

Botanical gardens

Preserve ~3% of plant species

Wildlife farms

Breed endangered species for sale, reduce wild hunting pressure

Captive breeding

Zoo method to increase species populations (egg pulling, artificial insemination, embryo transfer, cross-fostering)

Case Study: Asian Carp | Introduction

Case Study: Asian Carp | Flooding allowed spread into Mississippi River system

Invasiveness

Outcompete native fish, difficult to catch, little economic value

Conservation concern

Spread threatens ecosystems; considered the most invasive fish in U.S