Conservation of Biodiversity

The Impact of Invasive Species

  • Lionfish
      - Play important roles as top predators in their native environments.
      - Attractive aquarium specimens.
      - In 1985, some were dumped into the Atlantic.
      - Lack predators in the Atlantic, allowing for rapid population increase.
      - By 2000, became a predominant predator in the Caribbean.
      - Diet includes over 50 types of fish.
      - Introduction has reduced coral reef biodiversity.

How Florida is Handling Invasive Lionfish

  • Visual: Dirk-Jan Mattaar/iStock/360/Getty Images

Conservation Biology & Biodiversity

  • Conservation Biology:
      - Focuses on studying biodiversity to conserve natural resources for current and future generations.
      - Integrates many subfields of biology.
      - Aims to develop scientific concepts and apply them to real-world issues.
      - Emerged due to the extinction crisis faced by the Earth.
      - Primary goal is management of biodiversity, the variety of life.

Sources of Problems in Conservation Biology

  • Conservation biologists identify sources of biodiversity loss and develop corrective actions.

  • Collaborate with government officials at various levels.

  • Emphasize public education and larger biosphere connections.

  • Goals include:
      - Maintaining high levels of biodiversity.
      - Positively influencing ecosystem stability.
      - Supporting overall human health.

  • Decreased biodiversity can lead to reduced ecosystem stability, resulting in adverse effects on human populations.

Conservation Biology Response to Extinction Crisis

  • Wildlife extinction rates:
      - 10–20% of currently living species may become extinct within the next 20 to 50 years.
      - Planned actions are essential.
      - Public awareness needed on:
        - Concepts and importance of biodiversity.
        - Causes of extinctions.
        - Prevention strategies for future extinctions.
        - Consequences of decreased biodiversity.

  • Utilizes bioinformatics for collecting and analyzing biological data with modern technology.

Subdisciplines Supporting Conservation Biology

  • Basic Biology Subfields:
      - Systematics, behavior, physiology, ecology, genetics, field biology, evolutionary biology.

  • Applied Biology:
      - Wildlife management, agronomy, range management, forestry, veterinary science, fisheries biology.

Biodiversity Defined

  • Biodiversity:
      - Refers to species variety on Earth, with approximately 8.7 million extant species (not including bacteria or viruses) and possibly higher estimates.
      - Endangered species face immediate extinction risks throughout most of their ranges.
      - As per the U.S. Fish and Wildlife Service:
        - Over 718 animal species and 943 plant species in the U.S. are endangered.
        - Nearly 30,000 species globally are at risk of extinction.

  • Threatened Species:
      - Organisms likely to become endangered soon.

Number of Described Species

  • Over 2.0 million described species worldwide, with insects comprising more than half.

  • Total species estimates range from 8.7 to 50 million, including undescribed species.

Levels of Biodiversity Organization

  • Three levels of biological organization according to ecologists:
      1. Genetic diversity
      2. Community diversity
      3. Landscape diversity

Genetic Diversity

  • Genetic Diversity:
      - Refers to genetic variations among individuals in a population.
      - High genetic diversity in populations enhances chances of survival amidst ecosystem changes.
      - Low genetic diversity (small or isolated populations) increases extinction risk.

Community Diversity

  • Community Diversity:
      - Depends on species interactions within a community.
      - Diverse community compositions foster higher biodiversity.
      - Conservation efforts might focus on species critical to ecosystem health to protect communities.

Landscape Diversity

  • Landscape Diversity:
      - Involves analyzing interactions across various landscapes.
      - A landscape comprises interconnected ecosystems (e.g., mountains, rivers).
      - Habitat fragmentation disrupts reproductive capacity, food sources, and seasonal behaviors.

  • Some ecosystems are so fragmented that only small patches of undeveloped land connect them.

Example of Community Diversity

  • Opossum Shrimp:
      - Introduced as prey for salmon, competed for zooplankton, causing declines in eagle, salmon, and bear populations.

Distribution of Biodiversity

  • Biodiversity Distribution:
      - Not uniformly distributed; highest in the tropics and decreases towards poles.
      - Biodiversity hotspots:
        - High species concentration, including 44% of known higher plant species and 35% of terrestrial vertebrate species.
        - Represent 1.4% of Earth's land area.
      - Examples include: Madagascar, Cape region of South Africa, Indonesia, California coast, Great Barrier Reef in Australia.

Value of Biodiversity

  • Direct Value:
      - Species that provide economically valuable services:
        - Medicinal Value
        - Agricultural Value
        - Consumptive Use Value

Medicinal Value

  • Most prescription drugs used in the U.S. are derived from living organisms, worth over $200 billion.

  • Example: Rosy Periwinkle produces chemicals for treating leukemia and Hodgkin’s disease, significantly increasing survival rates for children.

  • Researchers estimate potential for discovering hundreds of new drugs in tropical rainforests may have an economic value exceeding $100 billion.

Direct Value of Wildlife

  • Managing species that provide economic value is critical. Examples discussed in the text include flowers and armadillos.

Agricultural Value

  • Wild plants such as wheat, corn, and rice are sourced for yielding higher agricultural productivity through genetic modification.

  • Animals play essential roles, such as pollinators for flowering plants.

  • USDA estimates honeybee pollination supports $15 billion in agricultural production yearly, contributing to more than 130 types of fruits and vegetables.

  • Colony Collapse Disorder threatens over 30% of the honeybee population in the U.S. Researchers search for mite-resistant wild honeybee populations.

  • Introduction of natural predators to agricultural systems reduces pest impacts on crop yields.

Consumptive Use Value

  • Humans cultivate crops, domesticate animals, and grow trees commercially.

  • Most freshwater and marine catches require hunting rather than aquaculture for consumption.

  • Additional products include wild fruits and vegetables, skins, fibers, beeswax, and seaweeds, providing economic benefits.

Direct Consumptive Value of Biodiversity

  • Wild fish species are essential for human diets.

  • Ocean fishing has led to overexploitation in 11 of the 15 major oceanic fishing areas.

Indirect Value of Biodiversity

  • Refers to ecosystem services providing significant benefits without measurable economic value:
      - Biogeochemical Cycles
      - Waste Recycling
      - Provision of Fresh Water
      - Prevention of Soil Erosion
      - Regulation of Climate
      - Ecotourism

Biogeochemical Cycles

  • Ecosystems exhibit energy flow and chemical cycling.

  • Biodiversity enhances functionality of water, carbon, nitrogen, phosphorus, and other cycles.

  • Humans depend on these cycles for fresh water and nutrient uptake; disturbances lead to negative consequences.

Waste Recycling

  • Decomposers convert dead organic matter and waste into inorganic nutrients for producers, aiding human waste management.

  • Millions of tons of waste from human activities impact ecosystems; decomposition is crucial for environmental purification and maintaining soil health.

Provision of Fresh Water

  • Water cycle: Supplies fresh water vital for human usage and ecological diversity.

  • Natural ecosystems help manage flooding by regulating water release post-rain.

Prevention of Soil Erosion

  • Healthy ecosystems retain soil and prevent erosion, significantly affected by land-use changes like deforestation.

  • Degradation results in silt buildup, diminishing coastal ecosystem productivity.

Regulation of Climate

  • Trees reduce local temperatures and energy costs.

  • Globally, forests regulate climate by sequestering carbon dioxide.

  • Deforestation adversely impacts gas emissions and climate stability.

Ecotourism

  • Ecotourism generates economic benefits for many regions, including $67 billion annually for Florida due to tourism.

  • Countries capitalize through ecotours while preserving biodiversity and natural settings.

Biodiversity and Ecosystem Functionality

  • Biodiversity Impact on Ecosystem Performance:
      - Increased biodiversity improves ecosystem functionalities such as photosynthesis and adaptability to environmental changes.

Community Productivity and Species Diversity

  • Higher biodiversity within plant species correlates to increased photosynthetic rates within experimental communities.

Causes of Extinction

  • Confirmed extinction causes include:
      - Habitat loss (85%)
      - Exotic species (50%)
      - Pollution (24%)
      - Overexploitation (17%)
      - Disease (3%)
      - Percentages exceed 100% due to multiple concurrent threats.

Habitat Loss

  • A major cause across ecosystems, particularly in tropical forests and coral reefs due to rich biodiversity.

  • Coastal degradation linked with population density along coasts.

  • Up to 60% of coral reefs are destroyed or threatened, with potential total loss in the next 40 years.

Exotic Species

  • Exotic Species: Non-native species introduced into new ecosystems, often through human action (horticulture, accidental transport).

  • Example:
      - Kudzu vine displacing native plants in the southern U.S.
      - Mongooses in Hawaii, initially to control rats, preying on native birds.

Exotic Species Impact on Islands

  • Islands are especially vulnerable to exotic species.

  • Local species less competitive with introduced exotics due to specialized adaptations.

  • Examples include myrtle trees and brown tree snakes disrupting ecosystems in Hawaii and Pacific islands respectively.

Pollution

  • Encompasses environmental contaminants harming organisms.

  • Major threat to biodiversity includes:
      - Acid deposition
      - Eutrophication
      - Ozone depletion
      - Synthetic organic chemicals

Acid Deposition

  • Results from pollutants like sulfur dioxide and nitrogen oxides creating acids upon contact with moisture, weakening trees and aquatic ecosystems.

  • Many northern lakes are lifeless due to acid precipitation impacts.

Eutrophication

  • Excess nutrient runoff causing algal blooms reduces oxygen levels in aquatic systems, leading to deaths of fish and organisms.

Ozone Depletion

  • Destruction of ozone in the stratosphere leads to increased UV exposure, impairing crops, ecosystem health, and immune function.

Organic Chemicals

  • Chemicals like nonylphenols disrupt hormonal functions in wildlife, with detrimental effects on species such as juvenile salmon, impairing their life cycle.

Climate Change

  • Climate change manifests through erratic weather and temperature rises linked to greenhouse gas emissions.

  • Resulting shifts in climate zones will cause more extinctions as species struggle to adapt or migrate.

Climate Change and Coral Reefs

  • A rise in temperatures threatens coral reefs, leading to bleaching, with potential shifts in coral distributions affecting ecosystems.

Overexploitation

  • Refers to excessive extraction of wild populations beyond natural replacement capacity, leading to population declines.

  • The trade value of wildlife is around $20 billion, with $8 billion from illegal activities.

  • CITES established in 1973 aims to protect endangered species from unsustainable trade practices.

Overexploitation Examples

  • Poaching endemic mammals, like the Siberian tiger (valued over $500,000), drives species toward extinction.

  • Sustainable fishing practices are critical to maintain fish populations. Aggressive fishing methods, like purse-seine fishing, devastate dolphin populations alongside target fish species.

Conservation Techniques

  • Habitat preservation and restoration are essential to biodiversity conservation.

  • Focus on biodiversity hotspots for saving diverse organisms.

  • Keystone Species: Species that significantly influence community viability; their loss can lead to further extinctions.

  • Flagstone Species: Charismatic species that engage public emotion, encouraging conservation efforts.

Keystone Species Example: Gopher Tortoise

  • Each gopher tortoise's burrow supports more than 350 dependent species, making it vital for ecosystem health.

  • A relocation program in Florida assists in preserving this keystone species.

Metapopulations

  • Metapopulation: A large population divided into isolated smaller populations due to habitat fragmentation.

  • Differentiates between source populations (stable/growing) and sink populations (sustained by source but less viable).

Landscape Preservation

  • Protect entire ecosystems to benefit species within that habitat, enhancing overall ecological integrity.

The Edge Effect

  • An edge is the boundary where one habitat meets another, affecting the ecosystem interior.

  • Edges are often less hospitable, altering both microclimates and species presence, known as the edge effect.

Habitat Restoration

  • A subdiscipline of conservation ecology focusing on returning ecosystems to their natural states.

  • Principles of restoration ecology:
      1. Act promptly before habitats are lost.
      2. Use biological techniques based on historical understandings for restoration.
      3. Aim for sustainable, self-sustaining ecosystems while serving human needs.