BSCI103 - Conservation Biology

Conservation Biology

An application-oriented science that seeks to understand and counter the loss of biodiversity.

Biodiversity

The variety of living things, including different levels of complexity.

Biodiversity levels

Includes ecosystem, species, and genetic diversity.

Ecosystem diversity

The biosphere has a number of different ecosystems, and some regions have many of them in a small area. Ecosystems provide services, like water filtering, protection against natural catastrophes, and food.

Species diversity

The number of species in a given place. Species can be lost, leading to their total extinction or extirpation ("local" extinction) from a region.

Keystone species extinction impact

Extinction of keystone species can affect the whole ecosystem (e.g., predators in MD impacting deer populations and forest structure).

Endangered Species Act

Passed by the US government to protect threatened species.

Threatened species statistics

12% of birds, 20% of mammals, 20% of freshwater fish, and 32% of amphibians are threatened. Of 20,000 plants in the US, 200 have become extinct in the last several hundred years.

IUCN

The international agency that categorizes species in terms of their conservation needs, which helps define policies; however, not all species have been assessed.

Genetic diversity

Includes genetic variation among populations of organisms; loss of populations means loss of diversity. This has implications for the ability of species to evolve or survive when exposed to pathogens (important for genetic diversity in food).

Drivers of biodiversity loss

Habitat loss, invasive species, pollution, overharvesting, and global climate change.

Habitat loss

Results when natural systems are replaced by other land uses (agriculture, urbanization, logging, etc.), almost exclusively due to human actions. Over 50% of the land and aquatic surface is human altered, and habitat destruction is implicated in 73% of modern extinctions.

Invasive species

Disrupt natural ecosystems by predation, competition, and lack of interspecific interactions (enemy

Pollution

Has negative effects on natural communities; can be chemical, physical, or both.

Biomagnification examples

Pesticides like DDT and chemicals like PCBs can increase in concentration in food chains (biomagnification), reaching toxic levels and causing endocrine dysfunction in top predators (including humans). Plastics and microplastics affect aquatic life (physical and physiological effects) and can also accumulate by biomagnification.

Ozone layer depletion

Has been thinning because of the release of chlorofluorocarbons (CFCs), used as refrigerants, propellants, and in manufacturing. The ozone layer protects us from UV light that can cause cancer and harm phytoplankton.

Fertilizer pollution

Can cause nutrient pollution blooms of algae and cyanobacteria, depleting oceans, rivers, and lakes of oxygen, creating dead zones.

Overharvesting

Harvesting of species at a rate that exceeds replacement (e.g., rosewood in tropical forests, blue crabs, rockfish, and oysters in Chesapeake Bay, cod in the Atlantic).

Global climate change (warming)

Rapid warming is changing the global climate. Greenhouse gases (CO2, methane, nitrous oxide) are increasing in the atmosphere and trapping heat.

Human drivers of global warming

Humans drive current global warming by burning fossil fuels to create energy (producing CO2 and nitrous oxide); livestock and landfills produce methane.

Temperature increase (past/future)

Global warming has increased temperatures 0.8 degrees C in the last 100 years (and 0.6C in the last 30 years). Ocean temperatures are also rising. Expected 1.5

Climate change effects

Warm days start earlier and are more abundant, cold nights and frost are less frequent, and heat waves are more common. Precipitation patterns change, and hurricanes are more frequent and powerful as oceans warm. The effect is greater over land than over sea, with the greatest change in the Northern Hemisphere.

Climate change & Carbon cycle

The effect of these gases and human activity on climate change is explained by the Carbon cycle (natural processes vs. human activity). Deforestation reduces carbon storage, and burning fossil fuels unlocks long

Global climate change impacts

Affects biomes, ecosystems, populations, and communities. Warmer oceans lead to losses of biodiversity (e.g., coral reefs).

Observed climate change effects

Ice caps and glaciers are shrinking, and wildfires are more common because of advance of snowmelt. Changes in climate are already affecting and will affect different ecosystem services.

Organismal response to climate change

Organisms depending on different environmental cues may get out of sync (some use temperature, others use photoperiod). Distributions of many species have moved north or south with warming.

Species at risk from climate change

Mountain top species and polar species may have no place to go. Disease

Adaptation to climate change

Some species may adapt, but most may not. Species with large amounts of phenotypic plasticity may be able to respond to rapid changes (e.g., Great tits adjusting reproduction to early caterpillars, Red squirrels advancing breeding times).

Protecting endangered species

One of the goals of conservation biology. Threats reduce population sizes, leading to isolation, decline, genetic drift, and inbreeding, reducing ability to cope with change. Breeding programs can be key, especially for keystone species (zoos play a role).

Protecting landscapes

Another way of protecting species. Landscapes are regional assemblages of ecosystems (forests, fields, wetlands, streams). Landscape ecologists study structure and dynamics to preserve biodiversity.

Habitat fragmentation

When habitats become fragmented, movement corridors between patches may conserve species by providing opportunities for movement and out

Protected areas

Can slow the loss of biodiversity. Biodiversity hot

Limitations of protected areas

Protecting only hot

Zoned reserves

Reserves and parks surrounded by populations following specific production practices. These zones combine people and preserved regions (e.g., Costa Rica), promoting new productive activities.

Yellowstone to Yukon (Y2Y)

Conservation Initiative attempts to preserve biodiversity by connecting large protected areas. It's a 3,200 km long wildlife corridor from Wyoming to Alaska, initiated by studying wolf behavior to allow migration and deal with climate change.

Habitat restoration

Tries to bring degraded areas closer to their natural state and function, using ecological principles.

Bioremediation

Using biological agents (e.g., microbes) to clean up oil spills or remove pollutants (common in water treatment plants). Plants can remove heavy metals (zinc, nickel, lead, cadmium) from soil.

Waterway restoration

Removing dams allows rivers to recreate wetlands (e.g., Kissimmee River in Florida), leading to strong increases in diversity, better water quality, and increased fish populations.

Why care about biodiversity

Provides resources (food, fiber, nutrients, building materials, oxygen). 25% of prescription drugs come from plants (e.g., rose periwinkle for anticancer drugs).

Ecosystem services (value)

Ecosystems provide services like reducing flood severity and biological control of pests, valued at $33 trillion per year in the US, plus pollination and water quality. There is also cultural value to nature and a sense of connection to the living world.

Sustainable development

The ultimate goal: balancing the needs of human beings with the natural processes of the planet. The UN has set Sustainable Goals, requiring integration of life sciences with economy, social sciences, humanities, traditional, and indigenous knowledge.

IPCC

IPBES report

Biodiversity conservation responsibility

Not biologists' responsibility only, but requires participation of every person through professional and private action