Chapter 12 Sustaining Biodiversity: The Species Approach

Key Concepts Human effects on biodiversity Human effects on biodiversity Importance of biodiversity Importance of biodiversity How human activities affect wildlife How human activities affect wildlife Management of wildlife Management of wildlife

67% Secure or apparently secure 1% Other 16% Vulnerable 8% Imperiled 7% Critically imperiled 1% Probably extinct US Diversity

What Increases Biodiversity? Physically diverse habitat Physically diverse habitat Moderate environmental disturbance Moderate environmental disturbance Small variations in conditions Small variations in conditions Middle stages of ecological succession Middle stages of ecological succession

What Decreases Biodiversity? Environmental stress Environmental stress Large environmental disturbance Large environmental disturbance Extreme environmental conditions Extreme environmental conditions Severe limiting factors Severe limiting factors Introduction of alien (exotic) species Introduction of alien (exotic) species Geographic isolation Geographic isolation

Projected Status of Biodiversity 1998–2018 Critical and endangeredThreatenedStable or intact ANTARCTICA NORTH AMERICA EUROPE AFRICA ASIA SOUTH AMERICA AUSTRALIA Pacific Ocean Antarctic Circle Pacific Ocean Tropic of Cancer Tropic of Capricorn Indian Ocean Atlantic Ocean 150°90°60°E0°30°W90°120°150°0° 60° 30°N 30°S 60° Arctic Circle

Strategies for Protecting Species

Species Extinction Local Extinction: when a species is no longer found in the area that it once inhabited (but is still found elsewhere in the world) Local Extinction: when a species is no longer found in the area that it once inhabited (but is still found elsewhere in the world) Ecological Extinction: so few members of a species are left that it can’t play its ecological role Ecological Extinction: so few members of a species are left that it can’t play its ecological role Biological Extinction: species is not found anywhere on earth (permanent) Biological Extinction: species is not found anywhere on earth (permanent)

Endangered and Threatened Species Endangered Species: so few survivors that the species could soon become extinct Endangered Species: so few survivors that the species could soon become extinct Threatened Species: still abundant in its natural range but is likely to become endangered due to declining numbers Threatened Species: still abundant in its natural range but is likely to become endangered due to declining numbers

Extinction Risks Low reproductive rate (K-strategists): blue whale, giant panda Low reproductive rate (K-strategists): blue whale, giant panda Specialized niche: giant panda Specialized niche: giant panda Narrow distribution: island species Narrow distribution: island species Feeds at high trophic level: Bengal tiger, bald eagle Feeds at high trophic level: Bengal tiger, bald eagle Rare: island species, orchids Rare: island species, orchids Commercially valuable: elephant Commercially valuable: elephant

How Do We Estimate Extinction Risks? Population viability analysis (PVA): risk assessment to predict whether a population will persist for a certain # of generations Population viability analysis (PVA): risk assessment to predict whether a population will persist for a certain # of generations PVA is based on: resource needs, current and predicted habitat conditions, genetic variability, interactions with other species, reproductive rates PVA is based on: resource needs, current and predicted habitat conditions, genetic variability, interactions with other species, reproductive rates

Continued… Minimum viable population (MVP): smallest number of individuals necessary for the survival of a population in a region Minimum viable population (MVP): smallest number of individuals necessary for the survival of a population in a region Minimum dynamic area (MDA): the minimum area of habitat needed to maintain the MVP Minimum dynamic area (MDA): the minimum area of habitat needed to maintain the MVP

Why Should We Care About Biodiversity? Humans value nature in different ways Humans value nature in different ways Instrumental value: usefulness to us Instrumental value: usefulness to us Intrinsic value: because they exist, regardless of use Intrinsic value: because they exist, regardless of use Utilitarian (use): goods, services, recreation Utilitarian (use): goods, services, recreation Nonutilitarian (nonuse): aesthetic Nonutilitarian (nonuse): aesthetic

Value of Nature Instrumental Intrinsic UtilitarianNonutilitarian (human centered) (species or ecosystem centered) Goods Ecological services Information Recreation Existence Aesthetic

Causes of Depletion of Wild Species Human population growth Human population growth Failure to value the environment Failure to value the environment Increasing resource use Increasing resource use Poverty Poverty

Overfishing Habitat loss Habitat degradation Introducing nonnative species Commercial hunting Sale of exotic pets and decorative plants Predator and pest control Pollution Climate change Basic Causes Population growth Rising resource use No environmental accounting Poverty

Type of Nonnative Organism Annual Losses and Damages Crop disease Crop weeds Rats Feral cats and outdoor pet cats Crop insects Livestock diseases Forest insects and diseases Zebra mussels Common pigeon Formosan termite Fishes Asian clam Feral pigs Starlings Fire ant $23.5 billion $23.4 billion $19 billion $17 billion $14 billion $9 billion $4.8 billion $3 billion $1.1 billion $0.8 billion $0.6 billion Damage from Nonnative Species

Characteristics of Successful Invader Species High reproductive rate, short generation time (r-selected species) Pioneer species Long lived High dispersal rate Release growth- inhibiting chemicals into soil Generalists High genetic variability Characteristics of Ecosystems Vulnerable to Invader Species Similar climate to habitat of invader Absence of predators on invading species Early successional species Low diversity of native species Absence of fire Disturbed by human activities

What Can Be Done to Reduce Threat from Nonnative Species? Identify characteristics that make species successful invaders and use this information to screen out invaders Identify characteristics that make species successful invaders and use this information to screen out invaders Increase inspections of goods coming into a country Increase inspections of goods coming into a country Pass laws to ban the transfer of harmful invader species Pass laws to ban the transfer of harmful invader species

Biome % of Area Disturbed Temperate broadleaf forests Temperate evergreen forests Temperate grasslands Mixed mountain systems Tropical dry forests Subtropical and temperate rain forests Cold deserts and semideserts Mixed island systems Warm deserts and semideserts Tropical humid forests Tropical grasslands Temperate boreal forests Tundra 94% 72% 71% 70% 67% 55% 53% 44% 37% 26% 18% 0.7% Habitat Disturbance by Biome

Hunting and Poaching

Wild African Elephant 1970: 2.5 million 1970: 2.5 million Today: 300,000 Today: 300,000 Killed for tusks (worth about $ ) Killed for tusks (worth about $ ) Bleed to death Bleed to death 1989 ban on sale of ivory from elephants 1989 ban on sale of ivory from elephants Caused increased killing of walruses and hippos for ivory Caused increased killing of walruses and hippos for ivory

DO NOT POST TO INTERNET

Protecting Wild Species I Bioinformatics: managing, analyzing, and communicating biological information Bioinformatics: managing, analyzing, and communicating biological information Involves: 1. building computer databases 2. developing computer tools to analyze the information 3. communicating the information Involves: 1. building computer databases 2. developing computer tools to analyze the information 3. communicating the information Example: Species global research project with the goal of providing information about all species on earth Example: Species global research project with the goal of providing information about all species on earth

Protecting Wild Species II International Treaties International Treaties Convention on International Trade in Endangered Species (CITES) 1972 Convention on International Trade in Endangered Species (CITES) 1972 Signed by 152 countries Signed by 152 countries Lists 900 species that cannot be commercially traded Lists 900 species that cannot be commercially traded Restricts international trade of 29,000 other at-risk species Restricts international trade of 29,000 other at-risk species

Protecting Wild Species III National Laws National Laws Lacey Act of 1900: prohibits transportation of live or dead animals (or their parts) across state borders without a permit Lacey Act of 1900: prohibits transportation of live or dead animals (or their parts) across state borders without a permit Endangered Species Act of 1973: illegal for Americans to import or trade any product made from an endangered or threatened species Endangered Species Act of 1973: illegal for Americans to import or trade any product made from an endangered or threatened species

Protecting Wild Species IV Habitat Conservation Plans Habitat Conservation Plans Compromise between endangered species and private landowners Compromise between endangered species and private landowners Landowners are allowed to kill a certain # of endangered species on private land in exchange for taking steps to protect the species Landowners are allowed to kill a certain # of endangered species on private land in exchange for taking steps to protect the species Possible steps: setting aside a preserve for the species, paying to relocate the species, paying for government buy habitat elsewhere

Other Approaches to Protecting Wild Species Wildlife refuges and protected areas Wildlife refuges and protected areas Gene banks (storing plant seeds), botanical gardens (cultivation of rare and endangered plants), and farms (raise for commercial sale) Gene banks (storing plant seeds), botanical gardens (cultivation of rare and endangered plants), and farms (raise for commercial sale) Zoos and aquariums Zoos and aquariums

Wildlife Management Laws regulating hunting and fishing Laws regulating hunting and fishing Harvest quotas Harvest quotas Population management plans Population management plans Improving habitat Improving habitat Laws for migrating species Laws for migrating species