Conservation Biology
Terms for species living outside it’s native range?
Exotic, introduced, invasive, non-indigenous, nonnative, alien or adventive.
Invasive species
an exotic species that has or is likely to successfully invade an ecosystem causing significant ecological, economic or human health problems.
Are most exotic species invasive?
Where does the greatest source of invasive species come from?
Plankton and planktonic offspring of large species in ballast water of ships.
Reasons for invasive exotics:
Stowaways, subsistence and commerce, recreation(hunting and fishing),science, biological control (introduce the predator of the invasive species how mongooses came to Hawaii), habitat change (ship canal or agriculture expansion).
what’s a problem with hybridization?
It may be causing species to go extinct before they are even created. aka two groups were different enough that given more isolation they would have developed into different species but now they are being hybridized and changed…
How do invasive exotics impact native areas:
Predation and grazing, parasites and pathogen introduction, competition for critical resources and hybridization =/.
tens rule
roughly 1 in ten introduced species will escape into the wild, of those 1 in 10 will become established, of those 1 in 10 will become invasive pests.
what influences an increased success rate for invasion?
the number of invaders, is it an island, predisposal due to low species richness, is the ecosystem disturbed, is the species from Europe.
chemical releases to supress neignboring plants.
Conservation biology vs ecology
Values & tthics science (normative) vs a positive science about organisms and their environment.
Preservationist vs conservationist vs ecologists vs environmentalist
preserving vs careful use vs studying the relationship between organism and environment vs concern for environmental quality.
John Muir and his philosophy
Founder of sierra club. Helped create yosemite and sequoia national park. naturalist who got involved in policy and politics.
Gifford Pinchot
Forester and politician. Founded the U.S. forest service. believe in conservation ethic- sustainable use of our resources.
Aldo Leapold
Ecologist, forester and conservationist. Founder of wildlife management and restoration ecology as a discipline. went from hunter -> conservationist.
When did conservation biology start?
1978 first conference, 1980 first book and 1987 conservation biology journal was launched. (last two by wilox and soule)
The Ethical principles of conservation biology:
diversity of speices and biological communities should be preserved. Untimely extinction should be prevented. Ecological complexity should be maintained and evolution must continue.
people have an innate need for nature.
6 major forces acting on biodiversity:
Global population growth, Clear-cutting and deforestation, land conversion, consumption, non-native species and climate change.
US population and growth rate
308 million and 0.915% growth rate annually.
World population and growth rate
6.8 million with 1.14% growth rate or about 75-90 million a year. about 9000/hr.
Current level of CO2 worldwide and annual world increae:
387 ppmv with 27 billion tonnes per year being released worldwide by humans.
Population of RI and growth rate
1 million and possible a growth rate of -.03.
Two components of ecosystem stability:
Resistance- ability to withstand perturbation and maintain normal function and resilience- ability to recover from disturbance.
resistance vs resilience.
ability to withstand perturbation and maintain normal function vs ability to recover from disturbance.
dilution effect
if the host is abundant and available the pathogen will spread quickly, if the host is diluted than the pathogen won’t spread as quickly.
Does high biodiversity equal high productivity?
No salt marshes are not very biodiverse but are highly productive and healthy.
an approach to designing human settlements and agricultural systems that mimic the relationships found in natural ecologies.
4 dimensions of biodiversity
genetic, spatial, functional, and temporal. (read more in notes)
variety of life on earth at all its levels from genes to ecosystems to environmental impacts.
Why is genetic diversity important?
allows for greater adaption, evolution and ability to survive changes.
what is spatial component important?
different landscapes and regions have cause the same species to behave very differently with unique adaptions and abilities.
Importance of functional diversity?
to insure that all functions important to an ecosystem will continue to occur.
Importance of spatial and temporal diversity?
migration, nesting, different life stages, succession, season diversity, ect.
define genetic diversity
the variation in the nucleotides, genes, chromosomes, or whole genomes and organisms.
does a greater number of genes correspond to greater organisms complexity?
No rice has 46 thousand genes while humans only have 35 thousand.
the physical constitution of an organism that results from its genetic constitution(genotype) and the action of the environment on the expression of genes.
subgroup of phenotype focused just on structure (outside and inside appearance).
population (complex definition)
a group of individuals of the same species that share aspects of their genetics or demography more closely with eachother than with other groups of individuals of that species.
population diversity
variation in the quantitative and spatial characteristics between populations.
Importance of biogeograhpic barriers:
Limit organisms movement, cause isolation and cause populations to diversify.
does population size correlate to genetic diversity?
depends on the number of founders and the type of reproduction the organism uses.
Proportion of total genetic variation within a species due to genetic differences between geographic populations:
high for species that don’t move around easily, lower for birds and marine animals.
What is one of the most overlook tragedy of the biodiversity crisis?
Population variation loss.
What is the importance of population diversity?
to ensure that a species can survive crises, disease, climate change, ect.
species richness vs species diversity
number of species vs species number weighted by measures of importance such as: abundance, productivity or size.
Shannon diversity index:
H= sum of pi ln(pi) where pi is the proportion of total species of specimen i.
measured as individuals or biomass(proxy for resource intake). usually measured as the large number of individuals found per sample.
species richness vs species evenness.
number of species vs how equally species are represented in terms of abundance.
Different definitions of species:
Morphology-speciation based on appearance vs biological- seciation based on interbreeding populations vs phylogenetic- smallest diagnosable cluster of organisms with which there is a parental pattern of ancestry.
cyrptic species
taxonomically they look very similar to each other but genetically they are different species.
When was native phragmities discovered?
2002, it is cryptic.
taxonomic or phylogenetic diversity
another way to look a diversity based on how many taxa or phyla are represented by species in your ecosystem. marine ecosystems typically have more phyla but fewer species than terrestrial ecosystems.
community diversity
variation in the groups of populations and species that share an environment. ( can be community with various populations of the same or different species).
ecosystem diversity
o the diversity of a place at the level of ecosystems. ecosystem= community + physical environment at certain time. determined by climate, time, species interactions, disasters, ect.
spectral signature
used to look at dense forest vs scrub vs grass vs water vs degraded forest.
landscape diversity
variations between landscapes based on the different types of ecosystems they comprise. ecosystems are not islands they are affected by landscape interactions.
relatively large unit of land or water containing a geographically distinct assemblage of species, natural communities and environmental conditions.
“why are these species here or not?” the study of distribution of biodiversity over space and time. it aims to reveal where organisms live and at what abundance. * might be able to assist in migration due to climate change.
a transition area between two adjacent but different plant communities, such as forest and grassland.
Alpha diversity
locally or single site. # of species.
Beta diversity
measures uniqueness between two different sites. only important in context. total species between the 2 areas minus common ones.
Gama diversity
diversity over a large scale, overall diversity, same concept as alpha with a bigger area.
global diversity gradient:
species diversity is lowest near the poles and increases towards the tropics reaching a peak in the tropical rainforest (lots of insects).
eastern US has fewer mammal species than western. why?
more human impact, more developed, geography…
Within a region, vegetation structure is more important than productivity in determining local diversity.
species pool
all species within a region. equal to gamma diversity.
adaptive radiation
a process where species evolve rapidly to exploit empty/vacant niches. often results in endemism.
why is edemism important for conservation biology?
contributes to an area’s uniqueness and special importance of biodiversity.
Languages of Madagascar:
The official languages are Malagasy and French. Area has a very high level of endemism.
Nile perch story
Nile perch in lake victoria caused over 200 species of cichlid populations to crash as perch exploded. native people impoverished. greatly reduced gamma diversity. didn’t happen for 30 years.
cold spot theory
hot spot model causes us to ignore all the cold spots, which have important ecological services.
population health and genetic variation.
generally population health is positively correlated to genetic diversity. heterozygosity is thought to be important but to what extent we don’t know. Loss of it however does suggest serious problems.
higher levels of heterozygosity and life history
tropical more than temperate. broad geographic range more than endemic. generalist vs specialist. ecological extremes. nonterritorial > territorial. small > large. tend to have greater fitness.
fundamental theorem of natural selection
the rate of evolutionary change in population is proportional to the amount of genetic variation.
effective population size
how many individuals are actually breeding.
3 levels of genetic variation
within individuals, between individuals in a population and among diff individuals.
how does genetic variation arise?
ultimate source is mutation which is not very common. sexual recombination is a good source.
monomorphic vs polymorphic
same allele vs different allele where allele is a pair of genes at some locus.
Quantitative genetics
the study of continuous traits (such as height or weight) and their underlying mechanisms.
population variation consists of type of alleles present and their frequencies.
inbreeding vs outbreeding
both can result in a reduced fitness because a ressive allele could gain frequency or heterozygosity could be lost vs loss of adventigous alleles.
what is individual genetic variation important?
can help with captive breeding programs and is the basis for natural selection.
widespread organisms tend to have a higher level of genetic diversity.
all individuals are potential partners. very rare occurrence.
founder effect
loss of genetic diversity that occurs when a new population is established by a small number of individuals.
genetic/allele drift
change in the relative allele frequencies that occurs naturally.
population bottleneck
a species contracts to a small population in a short period of time.
rare alleles are lost from small isolated populations.
most causes of animal extinction:
species introduction and habitat loss.
Tropical forest examples
sao paulo brazil, gutamala and peten forests.
max growth rate per year based just on reproduction size
3 to 4 %
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