Exam 2 conservation biology

Protected Areas (PAs)

are legally recognized spaces to conserve nature and ecosystem services

The 4 Rs of Reserve Design

Representation,Resiliency,Redundancy,Reality

Representation

Include as many biodiversity features (species, habitats) as possible.

Resiliency

Large enough to remain healthy and adapt to change (e.g., climate).

Redundancy

Multiple examples of each ecosystem or species to reduce extinction risk.

Reality

1. Must have the funds, staff, and political support to manage effectively.

Designing Protected Areas-Best Practices for Design:

• Larger areas support more species and large-ranging animals.

• Round shapes reduce edge effects; irregular shapes increase fragmentation.

• Corridors between reserves promote dispersal and gene flow.

• Include buffer zones and manage as metapopulations.

2. Enhancing Small Reserves for Diversity and Abundance:Strategies to improve biodiversity in smaller reserves

• Create corridors to connect them for migration and gene flow.

• Add artificial keystone resources (e.g., ponds, nest boxes).

• Use zoning to allow sustainable human use while protecting core areas.

• Maintain buffer areas to reduce outside disturbance.

• Manage with adaptive strategies (ongoing monitoring and adjustment).

• Include fire management and grazing substitutes when natural processes are missing.

3. Six Characteristics Associated with Species Vulnerable to Extinction

1. Narrow geographic range (e.g., island endemics).

2. Small population size or few populations (increases chance extinction).

3. Large body size and slow reproduction (e.g., elephants, whales).

4. Specialized niche or limited dispersal ability (cannot adapt or move easily).

5. Seasonal migration or aggregation (depend on multiple habitats or group events).

6. Overexploitation or hunting pressure (e.g., thylacine, dodo).

Other contributing factors:

• Low genetic variation.

• Island habitats (limited competition/predators).

• Human contact or invasive species exposure.

4. Extinction Vortex (Explain with Words)

As populations become small, multiple processes reinforce each other, driving them toward extinction

• Small populations lose genetic diversity through genetic drift and inbreeding.

• This causes lower fitness, reduced reproduction, and higher mortality.

• Environmental and demographic fluctuations have a stronger impact.

• As the population gets smaller, these effects intensify, creating a self-reinforcing downward spiral—the extinction vortex.

5. Umbrella Species

Species whose protection automatically helps protect many others sharing the same habitat

• Example: Protecting a tiger preserves the forest ecosystem and all species living within it.

Reintroduction:

Release captive-bred or wild-caught individuals into an area within their historical range where they’ve disappeared.
→ Used to restore species and ecosystems (e.g., wolves in Yellowstone).

Reinforcement (Restocking/Augmentation):

Add individuals to an existing population to increase size or genetic diversity.
→ Used when populations are small or unbalanced.

Introduction (Assisted Colonization):

Move species to a new area outside their historical range when the original habitat is unsuitable.
→ Used if climate change or habitat destruction prevents survival in native range.

Soft Release:

• Gradual introduction to the wild with temporary support (food, shelter, acclimation pens).

• Helps animals adjust to sights, sounds, and resources.

• Common for captive-bred or naïve animals

Hard Release:

• Animals released directly into the wild without assistance.

• Works best for wild-caught individuals that already know how to survive.

Advantage of Soft Release:

Increases survival rates and allows monitoring before full independence

Benefits of Ex Situ Conservation Strategies

• Research opportunities.

• Education and advocacy.

• Safeguard species during crises (“buy time”).

• Maintain genetic material (Genome Resource Banking).

• Reintroduce species once threats are reduced.

Challenges of Ex Situ Conservation Strategies

• Extremely costly.

• Limited genetic diversity and adaptation to captivity.

• Ethical issues (animal welfare, natural behaviors lost).

• Cannot replicate natural selection of wild environments

9. Best Long-Term Strategy: In Situ vs. Ex Situ

In situ (in the wild) is the best long-term strategy for protecting biodiversity because it maintains natural selection, ecosystem interactions, and evolutionary processes.
Ex situ serves as a temporary backup or complement when populations are critically low.

10. Advantages of Marine Protected Areas (MPAs)

• Preserve nursery grounds for fish and marine life.

• Maintain water quality and ecological processes.

• Protect biodiversity hotspots and endangered marine species.

• Provide opportunities for recreation and ecotourism.

• Contribute to sustainable fisheries and coastal protection.
  (Challenges: weak enforcement, funding shortages, pollution control.)

Extinction:

When no individuals of a species remain alive.

Extinct in the wild:

• Survives only in captivity.

Locally extinct / extirpated:

Gone from a specific area but found elsewhere.

Functionally/ecologically extinct:

Still present but no longer affects ecosystem.

Extant:

Still existing.

Anthropocene:

The current human-dominated geological era marked by high extinction rates.

Extinction debt:

• Future species loss due to past habitat destruction.

Island biogeography model:

Predicts species richness based on island size and isolation.

Species-area relationship:

Larger areas support more species

Endemic species:

Found only in one specific geographic area.

Population bottleneck:

Sharp reduction in population size and genetic diversity.

Founder effect:

New population started by few individuals with limited genes.

Genetic drift:

Random changes in allele frequencies in small populations.