Conservation Biology and Climate Change Notes

Ways to Protect Biodiversity

• Restore or preserve habitat of threatened species.
• Establish protected areas.
• Combat climate change and other global environmental changes.
• Establish regional networks of protected areas.
• End overharvesting of species in decline.
• Protect "hot spots" of high biodiversity.

Impacts of Human Activities on Biodiversity

• Human activities alter natural disturbance, trophic structure, energy flow, and chemical cycling, leading to a decline in biodiversity.
• Conservation biology integrates ecology, physiology, molecular biology, evolutionary biology, and genetics to conserve biological diversity.
• Modern rates of extinction are 100 to 1000 times greater than the average background rate.
• We are currently experiencing the sixth mass extinction due to human impact.

Three Levels of Biodiversity

• Genetic diversity within a vole population.
• Species diversity in a coastal redwood ecosystem.
• Community and ecosystem diversity across an entire region.

Genetic Diversity

• Genetic diversity is the total genetic information contained within all individuals of a population, species, or group of species.
• It represents the adaptive capacity of a group and its ability to persist despite environmental changes.
• It is measured as the number and relative frequency of all genes (and their alleles) present in a species.
• Genome sequencing involves sequencing entire genomes of multiple members of the same species.
• Environmental sequencing involves sequencing all or most of the genes or alleles present in a sample from soil or water in a habitat.

Species Diversity

• Species diversity is a key feature of biological communities.
• There are 1.8 million named species of organisms.
• Estimates range from 5 million to 100 million total organisms (named and unnamed).
• Endangered species are in danger of extinction throughout all or much of their range.
• Threatened species are considered likely to become endangered in the foreseeable future.
• Species diversity is high if all species have comparable abundance and low if one or just a few species dominate a community.

Species Diversity and Extinction

• Globally, 13% of birds are endangered, and 22% of mammal species are threatened.
• Of 20,000 known plant species in the United States, 200 are extinct, and 730 are endangered or threatened.
• Since 1900, 123 freshwater animal species have become extinct in North America, and hundreds more are threatened.

Why Should We Care About Biodiversity?

• Biophilia: Our human sense of connection to nature.
• Morality: Other species are entitled to life.
• Obligation: Preservation for future generations.
• Benefits: Species and genetic diversity provide various benefits.

Ecosystem Diversity

• Human activity is reducing ecosystem diversity, the variety of ecosystems in the biosphere.
• For example, more than half of the wetlands in the contiguous United States have been drained and converted to other ecosystems.
• The extinction of one species can negatively impact other species in an ecosystem.
  • For example, the extinction of "flying foxes" (bats) would harm native plant communities because they are important pollinators and seed dispersers in the Pacific Islands.

Ecosystem Services

• Ecosystem services provide economic and social benefits.
  • Provisioning services: provide raw materials like food, fuel, fiber, medicines, genetic resources, and water.
  • Regulating services: part of Earth's life-support system, including climate moderation, soil formation, erosion control, O2 and CO2 regulation, water capture and purification, air cleaning, flood control, storm mitigation, and waste decomposition.
  • Cultural services: enrich quality of life through aesthetics, recreation, education, spiritual value, and human mental and physical health.
  • Supporting services: enable all the other ecosystem services, including primary productivity, nutrient cycling, pollination, and pest control.

Ecosystem Function

• Ecosystem function is a product of the organisms in a system interacting with their abiotic environment.
• Ecosystem function includes the sum of the biological and chemical processes: primary production, nitrogen cycling, decomposition, and carbon cycling.
• Horizontal diversity: the number of species in each trophic level.
• Vertical diversity: the number of trophic levels.

Multiple Interacting Threats

• Habitat loss is the most important factor in declines.
• Marine species are mostly threatened by overexploitation.
• Climate change has had a larger impact on marine species than freshwater and terrestrial species.

Major Threats to Biodiversity

• Habitat destruction and degradation: The conversion of primary forest to agricultural fields.
• Invasive species and diseases: Invasive species, like the Burmese python in the Florida Everglades, are introduced to a new area, multiply rapidly, and threaten native species.
• Overexploitation: Overexploitation is the dominant threat for marine species, especially for large predators in top trophic levels, like endangered bluefin tuna.
• Climate change: Climate change poses different types of threats to different species. For example, some corals become bleached (lose their symbiotic photosynthetic protists) when water temperature warms.
• Pollution: Chemical pollutants have reached every corner of the globe but are particularly threatening to aquatic species.

Habitat Destruction

• Activities include deforestation, damming rivers, dredging wetlands, plowing prairies and grazing livestock, excavation, and housing developments.
• Primary forests have never been cut and have higher biodiversity than restored forests.
• Forests moderate the effects of climate change by storing carbon.
• Deforestation reduces cloud formation/precipitation, leads to soil erosion, and can cause rain forests to become savannahs.

Habitat Fragmentation

• Habitat fragmentation is the breakup of large, contiguous areas of natural habitat into small, isolated fragments.
• Habitat fragmentation leads to the loss of top predators/trophic cascades, forces species into metapopulations, and makes small isolated populations vulnerable to catastrophes.
• Edge effect: More biomass is lost from the edges of fragmented areas.

Pollution

• Nutrient enrichment.
• Toxins and biological magnification.
• Industrial Compounds and Pesticides (EDCs).
• Pharmaceuticals (feminization in fish).
• Plastic Waste.

Overharvesting and Overfishing

• Harvesting of organisms at rates exceeding the ability of their populations to rebound.
  • For example, illegal hunting for the ivory trade reduced populations of African elephants by 22% from 2006 to 2015.
  • For example, the western Atlantic bluefin tuna population declined by over 80% in the 1980s due to increased harvest for the sushi industry in Japan.
  • Experts estimate that humans kill over 100 million sharks every year throughout the globe.
• Protective measures need to be put in place.

Global Climate Change

• Throughout Earth’s history, the average temperature of the atmosphere and local weather patterns have fluctuated.
• Scientists today are not alarmed by the existence of change but rather because the rate of change is unprecedented and caused by human activities.

Cause of Global Climate Change

• Carbon dioxide is a greenhouse gas - a gas that traps heat radiated from Earth and keeps it from being lost to space.
• Increases in the amounts of greenhouse gases have the potential to warm Earth’s climate by increasing the atmosphere’s heat-trapping potential.

The Greenhouse Effect

• In the 1950s, people believed the vast ocean would be able to absorb excess CO_2.
• However, the complex chemistry of the ocean limits the amount of CO_2 it can absorb.
• Other greenhouse gases: methane (CH4), water vapor, and nitrous oxide (N2O).

Rapid Climate Change

• Human population has exploded in size.
• The average per capita use of fossil fuel has skyrocketed—especially in industrialized countries.
• Although the United States represents less than 5% of the world’s population, Americans produce one-sixth of the global CO_2 emissions.
• Electricity generation, transportation and industry are the biggest contributors of greenhouse gasses in the US.

Predictions of Climate Change

• The 2018 Intergovernmental Panel on Climate Change (IPCC) report concludes that the average global temperatures increased 1ºC (1.8ºF) from 1880 to 2017.
• This is double the increase that occurred in the 19th century.
• Predict additional increases of 1.5–2.0ºC (2.7–3.6ºF) by the year 2100 and 0.5–7.0ºC (0.9–13ºF) by 2300.

Biological Effects of Climate Change

• Even though global temperatures have risen only slightly in comparison with projections for the next 50–100 years, biologists have already documented dramatic impacts on organisms.
  • Geographic range shifts and mismatches.
  • Phenological mismatches.
  • Changes in allele frequencies.
  • Extinctions.
  • Ocean acidification due to elevated CO2 and carbonic acid.

Effects on Organisms - Cells

• Resin cells produce less defensive resin in trees that are stressed by drought and rising temperatures.
• Rising temperatures have shortened how long it takes beetles to mature and reproduce.

Effects on Organisms - Individuals

• As temperatures rise, American pikas spend more time in their burrows to escape the heat and less time foraging for food.
• Most pika extinctions occur at sites with high summer temperatures and a small area of habitat.

Effects on Organisms - Populations

• Earlier spring plant growth has resulted in food shortages and a fourfold drop in caribou offspring production, due to a phenological mismatch.

Population Conservation

• Focuses on Population Size, Genetic Diversity, and Critical Habitat
• Two main approaches:
  • Focus on extinction risk in small populations
  • Focus on critical habitat
• Inbreeding and genetic drift can lead to an extinction vortex toward smaller size and eventual loss of all individuals
• One key factor is the loss of genetic variation needed to adapt to changes in the environment
• Critical habitat size is another factor (e.g. territorial species like wolves, bears – conflict with humans is another factor)

The Greater Prairie Chicken in Illinois

• Land cultivation for agriculture fragmented the greater prairie chicken populations in North America
• The Illinois population fell to less than 50 by 1993
• Reduced fertility and genetic variation
• Birds from outside Illinois were added to increase the genetic variation of the population
• The Illinois population rebounded, indicating it was on the way to extinction before the transfusion of genetic variation

Landscape and Regional Conservation

• Conservation efforts have historically focused on saving individual species
• Today, the emphasis is on sustaining the biodiversity of entire communities, ecosystems, and landscapes
• Edge: has its own set of physical conditions, which differ from those on either side of it, might be beneficial to species
• Fragmentation of the landscape due to human activity favors species that thrive in edge habitat and limit others

Movement Corridors

• Movement corridor: narrow strip or series of small clumps of habitat connecting otherwise isolated patches
• Promote dispersal and reduce inbreeding
• In areas of heavy human use, artificial corridors are sometimes constructed

Establishing Protected Areas

• A biodiversity hot spot is a relatively small area with numerous endemic (found nowhere else) and many endangered and threatened species
• The “hottest” biodiversity spots comprise less than 1.5% of Earth’s land but house more than 1/3 of all plants and terrestrial vertebrates

Costa Rica

• Manages zoned reserves, buffer zones, water, forest products, hydroelectric power, ecotourism and sustainable agriculture.
• Face Challenges like loss in forest cover

Restoration Ecology

• Restoration ecologists return degraded ecosystems to a more natural state
• Conversion of the Kissimmee River to a 90-km canal caused the surrounding wetlands to dry up, threatening fish and bird populations
• Filling part of the canal and reestablishing part of the river has helped restore the wetland ecosystem

Bioremediation

• Bioremediation: use of organisms—mainly prokaryotes, fungi, or plants—to detoxify polluted ecosystems
• For example, the bacterium Shewanella oneidensis metabolizes uranium to an insoluble form, less likely to leach into streams and groundwater
• Ethanol can feed these microbes

Indigenous Knowledge & Storytelling in Conservation

• Ecological Wisdom: Generations of knowledge about species, seasons, and sustainable practices.
• Storytelling as Science: Oral traditions share land-use strategies and environmental insight.
• Cultural Connection: Stories reflect spiritual ties and respect for the land.
• Modern Impact: Indigenous leadership and traditional ecological knowledge (TEK) is now vital in co-managed and community-led conservation efforts.
• “You can’t protect a place unless you understand it, and you can’t understand it unless you listen to the stories told by those who’ve lived there longest.”

Urban Ecology

• The field of urban ecology examines organisms and their environment in urban settings
• One critical area of research focuses on quality and flow of water and organisms living in urban streams
• Restoration projects may involve stabilizing stream banks, removing introduced plants, and planting native trees and shrubs

Take-Home Message

• We now face the most serious global environmental crisis in the history of our species
• There is an enormous potential for change, and biology is giving us the tools to make an important, positive impact

Portland Area Carbon Emission Data

• A study by Dr. Andrew Rice examined carbon emission data in the Portland area.

Figure 1: The Study Area

• The study area includes locations such as Sauvie Island (SIS), Portland State University (PSU), and Southeast Portland (SEL).

Figure 2: Higher CO2 at urban sites (PSU and SEL)

• Demonstrates the impact of urban activity.
• δ^{13}C values in CO2 help distinguish between different carbon sources.
• δ^{13}C in urban area are lower than background air → 75-80% of the CO2 from petroleum sources, remaining from natural gas.

Figure 3: Wind Directions

• Wind directions are predominantly from the northwest to north.
• SIS is established as a reference for background CO_2 levels.
• Enables comparisons with urban sites to assess the impact of regional CO2 sources on urban CO2 concentrations.

Figure 4: Hourly ΔCO_2

• Hourly ΔCO_2 between the urban sites (PSU and SEL) and the upwind rural site (SIS).
• CO_2 concentrations are generally higher at the urban sites compared to the rural site.
• Mean enhancements of 5.1 ppm at PSU and 5.5 ppm at SEL.
• This highlights the impact of urban emissions on local CO_2 levels.

Figure 5: Diurnal Cycles

• Diurnal cycles of [CO_2] and δ^{13}C values at the three monitoring sites.
• [CO_2] highest in the early morning and lowest in the afternoon at all sites.
• Urban sites (PSU and SEL) exhibit higher CO_2 levels compared to the rural site (SIS), particularly during the daytime when anthropogenic emissions are significant.