Conservation and Ecology

• Conservation is the study of maintaining the natural world

Evolutionary - Ecological Land Ethic

• This acknowledges species' connections and interactions
• An action is deemed right when it preserves the biotic community and wrong when it tends otherwise
• Everything needs to be present for a system to thrive

Island Biogeography

• Island biogeography started in the 1960s with Wilson & MacArthur
• It examines the relationships between an island's area and the species present or its diversity
• Closeness to the mainland correlates to an increased likelihood of colonization
• An increase in area typically corresponds to an increase in diversity
• Habitat fragmentation caused by human development can create "islands" within ecosystems
• Highways in the middle of ecosystems can act as barriers for animals
• Habitat fragmentation induces the "Edge Effect," potentially increasing diversity, but is often undesirable
• Edge effects occur with vector or square shapes
• Ideal shapes for habitat are large and together
• Circular configurations are preferred over square or rectangular ones

BDFFP

• The Biological Dynamics of Forest Fragments Project examines how island habitats impact diversity
• Studies involve cutting down trees in the Amazon, Brazil, to create "islands" and assess the effects of habitat size and fragmentation.
• The project has generated approximately 600 scientific publications

SLOSS (Single Large or Several Small)

• This considers whether a single large or several small habitat areas are better for conservation
• The single large or several small question has measures of size, number, proximity, connectivity, and shape
• Large habitat is generally better
• Having many small habitats may result in too much fragmentation
• Spaces need to be close and connected when possible
• Circular shapes are preferable to long rectangles

Biodiversity

• Richness refers to the number of different species, and evenness to the distribution of individuals within those species
• Both richness and evenness are about species present
• Compositional biodiversity is about who or what species are present
• Functional biodiversity is how the things that are there are actually functioning and connecting
• Structural biodiversity refers to physical components

Indicator Species

• Biodiversity can tell us something about a habitat
• The presence/absence or abundance of certain species reflect local environmental conditions
• Caddis fly and mayfly larvae in streams and rivers indicate good water quality
• Lichens indicate good air quality in the forest
• Scarlett tanagers living in deep woods indicate high quality habitat

Species

• Similarities within its genetic composition are a species
• The ability to produce viable offspring that are also fertile is a characteristic of a species
• Mules are not fertile, and therefore not a species

Phylogenetics

• Phylogenetics is the study of evolutionary relationships, often based on taxonomic trees
• A monophyletic group consists of an ancestral species and all its descendants
• A paraphyletic group has a common ancestor but not all its descendants
• A polyphyletic group consists of species without an immediate common ancestor

Endemic Species

• These are unique to one area, found nowhere else on Earth

Hotspots

• Hotspots are losing around 70% of their primary vegetation
• They contain around 0.5% or 1,500 of the world's Earth species as endemics

Defining Biodiversity

• Species richness is the count of total species present in a given area
• Species evenness refers to the balance of a given community, taking abundance into account; its value ranges from 0-1
• Simpson's Index measures probability; its range is 0-1
• Shannon Index relates to richness and evenness to uncertainty; a diverse area has a hight value

Alpha Diversity

• This is richness in a given habitat or community

Beta Diversity

• This is the rate of change in species composition
• A higher value means more change between regions; a lower value means the regions are more similar

Gamma Diversity

• This is the total number of species in an entire region, not just one habitat

Latitudinal Diversity Gradient (LDG)

• Diversity typically peaks in the tropics, near the equator, and decreases as one moves poleward
• This pattern exists across most species
• Conifers and cave-bearing trees do not follow this pattern

Hypothesis of the Latitudinal Diversity Gradient

• Food availability, energy, and productivity lead to warmer temps and more consistent light
• Consistent light and longer growing periods create ideal parameters

Latitudinal Variation in Biodiversity

• Closer to the poles corresponds to less diversity, and diversity peaks around the equator and the tropics
• The theories for this observation are are food availability and vegetation growth
• Climate consistency and legacy of glaciation may also be factors
• Temperature is a key factor because temps are warm and consistent in the tropics
• The increase in temperature increases productivity and therefore impacts food availability
• Temperatures support a lot of organisms and are key to the rate of metabolism

Species Richness and Energy

• Evapotranspiration is water moving through plants and evaporating
• Resources available can determine the necessary elements for plants
• Higher evapotranspiration allows for plants to photosynthesize at a higher rate
• Available energy usually dictates richness, where more energy equals more biomass supported
• Evapotranspiration can reduce the risk of extinction
• Primary production (photosynthesis) is a key form of energy
• ON LAND- determined by temperature, precipitation, and nutrients
• IN OCEAN- temperature is valuable, but limited by nutrients
• One notable exception to this are salt marshes, which are highly productive but don't support high diversity

Disturbance Diversity

• Intermediary amount of disturbance peaks diversity
• Patterns exist due to open space and niches
• No disturbance allows climax species domination, little change for future speciation

Preservation Rationales

• This helps to preserve evolutionary potential and keeps adaptation possible
• Inherent, psychological value
• Actual economic value, resources, medicines, species, and ecotourism

Ecosystem Services

• These services include medicines, sequestering carbon, water cleaning, protection from storms, nutrient cycling, and absorbing pollution

Guilt

• To preserve thriving ecosystems for future generations and prevent single-organism homogenization

Threats to Biodiversity

• Natural causes include natural disasters, diseases, and genetic drift
• Human causes include invasive species, habitat loss, climate change, pollution, and overexploitation

Extinction

• 5 mass extinctions have occurred across millions of year intervals
• Historic extinction is difficult to understand due to lack of direct observation
• Fossil records are incomplete
• Potential causes are habitat destruction, modification, and continental drift
• The human age correlates directly to mammal extinction due to deforestation and other climate factors

Vertebrates and Invertebrates (excluding fish)

• Humans can overexploit water supplies, cause habitat loss, and over-pollute air and soil

Bioaccumulation vs. Biomagnification

• Bioaccumulation is the increasing concentration of a toxin in a single organism over time.
• Biomagnification is the increasing concentration of a toxin as it moves up the food web.

Invasive Species

• Climate change can force species to migrate into cooler areas

Indirect Impacts / Human Impacts

• The ripple effect can result in one species affecting many
• An example would be the hunting of sea otters contributing to kelp collapse and urchin overgrowth

Habitat Loss + Degradation

• 83% of terrestrial land is impacted by humans

Bobcat Habitats

• Although almost extinct previously, they now number in the millions due to more hunting regulations in state
• Threats include wildfires, rat poison, and prey loss
• Habitat loss/fragmentation also causes concern

Ripple Effect

• The process can also affect human health
• Minimizes risks posed by prey which has disease

Florida Panthers

• Has been inbreeding and losing members
• Texas has been cross-breeding panthers to save the species

Habitat Fragmentation

• This comes from a reduction in components of suitable habitat
• This can be natural or human-made

Metapopulations

• This is based on population and dispersal issues
• Patches may be occupied or unoccupied allowing for dispersal

Habitat Patches

• These would have connectivity or allow for dispersal

Dispersal

• Ex: birds are able to traverse these areas, while mammals must stay put and find mates which can limit populations

HAB Fragmentation

• Habitat dynamics help animals to traverse areas and disperse safely

Fragmentation Process

• Creates gaps to allow changes to vegetation and to increase space for organisms
• Abundance shifts

Site Tenacity

• Used in birds, makes species vulnerable to change and loss

Fragmentation Findings

• 70% of forests are within 1 km of edge
• 20% of remaining forests are within 200m of edge
• Frag reduces diversity by 13-75%, impairs ecosystem functions

Habitat Fragmentation: Biological consequences

• Some species only occur in the 'destroyed' portion of the landscape, making it difficult to rebuild populations
• Thinking about island biogeography has small, separated areas more vulnerable to extinction

Edge Effects

• Anytime areas are destroyed, a loss of core habitat occurs
• This leads to an ecological trap, or reduced species selection
• There are unique issues such as increased deaths from cars, barrier use, and change in dispersal

Barro Colorado Island

• Panama case study with a hill turned into an island
• Overtime had a reduction in species

Degradation & Loss

• Degradation may be temporary and not affect all species
• Loss can be more severe, directly related to endangered species

Degradation & Loss: Drivers

• Things like growth, urbanization, development, dams, mining, forestry, pollution and Invasive species

Deforestation

• 60% of deforestation is by agricultural conversion
• Other issues include reduced harvest, species loss, permanent habitat
• As soon as we cut down trees, the carbon goes back into the atmosphere

Grasslands

• Covering over 40% of Earth, supports grazers and animals
• Reduction has resulted in loss of species

Overexploitation

• Harvesting wild species at a faster rate than that of natural reproduction

1960's

• Skyrocketed number of fish, then collapsed

Sharks

• With fewer eggs and late maturity, overfishing will ruin the species

Sustainable Exploitation

• Understanding population dynamics and rates

Max Sustainable Yield

• Can be more sustainable
• Harvest is taken at the best sustainable rate, where it is growing