Conservation Biology

Midterm Exam

How people calculate environmental value

market outputs, willingness to pay surveys, travel cost estimates

Marignal Cost

the cost of producing one additional unit of a good or service (total cost still always increasing)

Marignal utility

the additional satisfaction gained from consuming one more unit of a good or service (decreasing like donut example)

Why is marginal cost a u-shaped curve

high upfront costs to get started, then each item cheaper to produce (economies of scale), then rise when shortage or raw material

externality 

a positive or negative consequence of an economic activity experienced by unrelated third part 

Define MSC MPC MEC and their relationship

MSC (marg social cost)=MPC (marg private cost)+MEC (marg externality cost)

How does net present value relate to discount rate? In terms of environment do we want a high or low discount rate?

Net present value with decrease with higher discount rates. In regards to taking environmental action, we want a low discount rate to preserve future value.

Many conservation-oriented projects have high initial cost and perpetual benefit. Are these favored by high or low discount rates?

Benefits spread over a large # years so benefits are down-weighted through a high discount rate.

What are 6 basic ways to estimate value

• Avoided cost

• Replacement cost

• Factor income

• Travel cost

• Hedonic Pricing

• Contingent valuation

Factor income

services provide for enhancement of incomes (better water = better fisheries and fishery jobs)

Hedonic pricing

Buying based on location (ex beach) vs value of actual commodity (house)

Contingent valuation

Surveying willingness to pay (posing hypothetical scenarios)

Willingness to pay char

Describe

Highest willingness to pay is for something you never have experienced, this decreases as you have it more. Anything below true cost of trip is a loss of value for what you pay.

Alternative measures that account for health, natural resources, and wage disparity

• ISEW (Index of Sustainable Economic Welfare)

• Genuine Progress Indicator (26 factors)

• Better Life Index

a=?

b=?

a=consumer surplus

b=producer surplus

• Why were cane toads introduced to Australia?

cane beetles damaging sugar crops

• Why wasn’t it successful?

beetles and toads active at different title and grubs underground, harmed other beetle predators, adult beetles high off ground

• What attributes made Cane toads invasive?

high and fast repro, toxin, lack of predation, adaptability, will eat anything that fits in their mouth

Have the toad stakeholders changed in terms of cane toad introduction vs elimination?

ag interest —> ecological damage mitigation

• How are cane toads evolving?

• Why does this matter?

Evolving due to their spatial selection, which has lead toward a trend of longer-legged toads that can disperse to new areas faster (dispersal favoring traits). Increasing rate of frontal progress (previous estimates underestimate them). 

Indicates that conservation biologists and managers need to consider the possibility of rapid adaptive change in invading organisms. If there is no fitness disadvantage to individual organisms at the invasion front, evolutionary forces are likely to fine-tune organismal traits in ways that facilitate more rapid expansion of the invading population10. Hence, control efforts against feral organisms should launch ASAP

Utilitarianism

The greatest amount of good for the greatest number of people for the longest amount of time

Romantic Transcendentalism 

Nature as a higher moral and spiritual purpose (Muir, Thoreaux, Rooshevelt) 

Who was Gifford Pinchot?

Studied under Muir but also saw nature for utility (forestry and lumber) - Utilitarianism

What was the significance of damming the Hetch Valley

Pinchot saw dam implemented as a source of power, which went along with his “wise-use” agenda. Prompted first grassroots activism project to protect natural parks (“never again mentality”)

Explain the evolutionary-ecological ethic and who prompted it

Aldo Leopold - originated concept of biodiversity and conservation of system not species (foundation of modern conservation biology)

What was the significance of Rachel Carlson’s “Silent Spring”

In 1962 it awakened public to chemical pollutants and bioaccumulation

5 step issue attention cycle

1. Pre-problem

2. Alarmed discovery (optimistic)

3. Realization of costs

4. Gradual decline in public interest

5. post-problem (still there though)

5 step policy cycle

1. Policy formation

2. Policy legitimization

3. Policy implementation

4. Policy evaluation

5. Policy termination or change

what are the issues with small population sizes

• inbreeding depression

• allee effects

• random effects

• founder effects

allee effects

positive correlation between population density and fitness (vice versa)

fisher’s fundamental theorum of genetic diversity

the rate of increase in fitness of an organism is equal to genetic variance in fitness at that time

genetically effectively population size (Ne)

number of individuals that would result in the same level of inbreeding/decrease in genetic diversity as if population were ideal

factors that make Ne lower than N

• spatial partitioning of population

• fluctuating poulation size

• breeding sex ratio

Explain the extinction vortex

Factors that increase likelyhood of extinction often come in a one-two punch as they are associated with one another and encourage eachother (ex: demographics and genetics)

Genetic tools for conservation

• pedigree analysis

• estimation of relatedness

• analysis of parentage and mating systems

• forensics

• species or population identification

• estimation of population size

statutory vs common law - which is environmental law mostly

• statutory = mandates handed down by authorities

• common = precedents set through legal proceedings

environmental law mostly statutory as can’t win in court against rich industry

National Environmental Policy Act (NEPA)

established EPA and procedures for environmental review (1969)

Clean Water Act

inland waters to be swimmable and fishable (1972)

endangered species act

1973

Resource conservation and recovery act (RCRA)

cradle to grave for chemicals (birth defects caused) 1976

CERCLA

polluter pays + superfund cites (1980) - peak environmental movement

Clean air act

S02 permit trading introduced (1990)

NEPA

sets national environmental policy for the first time - sets basis for EIS 1969

what is the only habitat with legal protection

watersheds (through section 404 “navigable waters issue” - along with surface waters - are protected by the clean water act) gutted 2022

What must a habitat recovery plan contain

• what is needed to return sp to healthy state

• criteria for definition of healthy state (know when to consider “recovered”)

• Estimates of cost and timeline

3 organizations that oversee species recovery plans (put in place by EPA)

FWS, NMFS, NOAA

What is an incidental take permit?

land owners can receive if they also submit HCP - habitat conservation plan for the species they want to remove from property

Migratory Bird Treaty Act

1918 - people have to allow some birds to migrate to preserve birds to hunt in future

What are the sources of acid rain

tailpipe emissions, coal combustion, fossil fuels —> all lead to formation of HNO3 and H2SO4

3 gov mechanisms for pollution control

• direct regulation

• emissions tax

• cap and trade

what buffers the effects of acid deposition

soils with basic pH

equilibrium theory of island biogeography

species richness balanced by immigration and extinction rates, both of which are effected by land size and distance from the mainland 

what did ETIB fail to cover?

population size was only expressed by presence or absence of a species (effected by predator prey oscillations)

Describe Huffaker’s Predator-prey experiment 

use oranges an rubber balls with predator and prey mites to determine that there was more stability (less oscillation) when habitat was more hetergeneous (lessens all at once interaction and gives prey time to repopulate)

what are the three main reasons for allee effects

• difficulty finding mate/resources

• difficulty avoiding predation

• inbreeding depression

make distinction between one population, separate populations, subpopulations, and metapopulation

one population: complete genetic mixing, gene flow value = 1

separate populations: non gene flow between organisms of two places even though same species

subpopulations: constrained mixing, gene flow value between 0-1

metapopulation: subpopulations interlinked through dispersal mutually affecting eachother

Describe subpopulations

distinct breeding groups (separate spatially) but some gene flow between

how are metapopulations maintained

balance between colonization and extirpation (colonization greater), suitable habitat (heterogenous) patchily distributed

extirpation

local - regional loss

are all potential habitat patches occupied

NO (temporarily vacant habitat is important to long-term sp survival)

Describe the terms in Levins Metapopulation Model: dp/dt=mp(1-p)-ep

dp/dt = change in patch occupancy

mp(1-p) = colonization rate

-ep = extirpation rate

why is levins model unrealistic

assumes

1. instantaneous patch occupancy

2. equal area and isolation patches

3. patches all operate independently

4. moderate movement

what factors effect balance between local extirpation and recolonization

local birth and death

dispersal flow between habitat patches

how do spatially explicit models fix levins idea

factor in distance and patch size

identify the 5 spatially explicit metapoulation models

• classic levins

• mainland-island

• patchy population

• non-equilibrium

• intermediate case

name and describe this population model

non equilibrium:

limited dispersal

overall extirpations and species decline

typical of rare species

name and describe this population model

mainland-island (also “source-sink” or “core-satellite”):

extirpation resistant core

colonists disperse to small periphery patches (higher prob of extirpation)

source most important for conservation

name and describe this population model

patchy: 

high dispersal

all fluctuation simultaneous (single exterpation resistant entity)

colonists “rescue” other patches constantly

what can relative fitness values among sub populations tell us

they can indicate sources (fitness over 1) and sinks (really low and decimal values)

How did Terry Erwin estimate spp richness? What were the results?

fogging different trees to catch insects in net and count species. extrapolated findings to all tree species —> estimated 30 million insect species

What were hodkinson and Casson’s findings on species richness

study hempiteran bugs on variety of host plants for a year —> projected yet another estimate of number of species

Describe how total number of species can be predicted by knowledge of diversity across taxonomic levels

number of taxa in each group (ex phylum class order) evens out at a certain level after discoveries are made, so based on what we know about one taxonomic level, we extrapolate to total number of species

Why is species richness a commonly used metric for biodiversity

easy to measure (count number of species)

easily understood

how are taxonomic estimates used to preserve biodiversity

you can see which groups of species have similar genes and can focus conservation efforts on those more distinct from the whole (want to pick broad sets of genotypes)

What provides a linear correlation (and therefore is a great predicter of) species diversity

Family diversity (low cost method) has a linear relationship

how does latitude predict biodiversity and why? 

latitudes further from equator (increasing) are less rich in species

• temperature

• day-length

• growing season

• productivity

Mountain gradients have similar effect due to the adiabatic laspe rate of cool air

what is unique about the way diversity on a mountain changes with latitude

“mid-elevational bulge”

why is elevation also a strong predicter of biodiversity

• Temperature

• UV

• Wind

• Cloudiness

• Steep Slopes

• Thin Soils

• Productivity

in a simplified answer “what habitats have highest diversity”

mid elevations of wet tropical mountains

what is beta diversity

number of new species encountered entering a new habitat (basically like rate of species turnover)

what conditions produce high beta diversity

narrow species ranges

what produces low beta diversity

broad and overlapping species ranges (almost all species found everywhere)

how can beta diversity be measured

use a dissimilarity index (inverse equation)

relaxation

Decline habitat area means loss of species (sp with low pop density are especially at risk)

supersaturation

artificially high population density after loss of habitat and remaining area gets overcrowded (can also occur from artificial feeding)

Describe the concept of extinction debt

after habitat loss there is a delay until when consequences (relaxation and supersaturation) happen, if the system returns to equilibrium, there will be

1. reduction in population size for supersaturated sp

2. the extinction of spp without viable habitat

half-life

when half of the extinction debt has happened

extinction is slower to be paid in (blank) fragments

larger

why is mesopredator release a symptom of extinction debt playing out

mesopredators flourish when top predators are removed

List common edge effects

• reserve shape

• moisture gradient - convection caused by temperature difference leads to dry edges

• pet predation

• invasives

characteristics of species most vulnerable to fragmentation

• rare and endemic

• require large habitats

• poor dispersers

• populations that fluctuate

• ground nesting birds!!

• game animals

what percentage of exotics are invasive 

0.1

characteristics of successful invaders

• adaptive

• high density

• good at dispersing

• high reproductive (intrinsic) growth rate

• human tolerant

characteristics of invasible ecosystems

disturbance and low spp diversity

how does enemy release relate to the success of invaders

invaders lack specialist enemies (no one eating only them) so they feel less predation pressure