Principles of Biology - Biology 102
Spring Quarter
_ Written by: Sue Kloss
Lake Tahoe Community College
Instructor: Ralph Sinibaldi
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Conservation Biology - Ch. 55
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Intro
A. Conservation Biology - integrates ecology, physiology, molecular biology, genetics, and evolutionary
biology to conserve biological diversity at all levels
1. includes social sciences, economics, humanities
B. Restoration Ecology - ecological principles applied to return degraded ecosystems to conditions as
similar as possible to natural, predegraded state
C. Identified 1.8 million species, may be as many as 200 million
1. greatest concentration may be in tropics
2. human population is growing at an alarming rate
D. Human activities are altering natural processes
1. trophic structure
2. chemical cycling
3. energy flow
4. natural disturbance
a. humans have altered ~50% of land on earth
b. use over .5 all surface waters
c. overfishing, over harvesting
d. some estimates, we are doing as much damage as the large asteroid in the Cretaceous
I. Human activities threaten earth’s biodiversity
A. Extinction is part of the natural cycle of birth/death of species
1. current rate of extinction is what is alarming
2. we don’t have good numbers, so we can only guess at the damage
3. rate of species extinction is high
B. Three levels of biodiversity (Fig. 55.2)
1. gene
a. within and between populations
b. loss of genes reduces potential adaptive ability - loss of tools in genetic kit for dealing w
with environment
c. has human impacts- medicines, agricultural stock, etc.
2. species
a. endangered - in danger of extinction thru all or significant portion of its range
b. 12% of birds and 25% of mammals worldwide are endangered
c. of 20k plants in US, 200 have gone extinct since we started keeping records
d. 20% of known fish species are extinct or endangered; in N. America, extinction rates for
freshwater fauna are 5x higher than terrestrial animals
e. 32% of all amphibians are extinct or endangered
f. at current rates, .5 of all known species will disappear in the next 95 yrs. (Fig. 55.3)
3. ecosystem
a. network of interactions among populations of different species
1. loss of one species will affect many others
b. chars of energy flow and cycling of nutrients
1. “pastures” of phytoplankton in ocean may help moderate greenhouse effect
by consuming massive quantities of CO2 for Ps and shell building
C. Biodiversity and Human Welfare
1. biophilia - love of other life
2. future human welfare
3. benefits of species and genetic diversity
a. crops, fibers, meds
b. rosy periwinkle from Madagascar has anti cancer properties (Fig. 55.4)
c. loss of diversity means loss of genes - roughly 4 billion years of evolution
1. unique library of genes in every organism/species
D. Ecosystem services
1. all processes thru which natural systems benefit human life on earth - valued at 33 trillion dollars
per year, GNP of all countries of earth = 18 trillion dollars/yr.
a. purification of air and water
b. reduction of severity of drought and floods
c. generation/preservation of fertile soils
d. detox/decomp of wastes
e. pollination of crops and natural vegetation
f. dispersal of seeds
g. cycling of nutrients
h. contol of pests by natural enemies
I. protection of shoreline from erosion
j. protection from UV
k. moderation of weather extremes
l. provision of beauty
E. 4 Major Threats to biodiversity
1. Habitat destruction
a. ag, development, mining, grazing, forestry, pollution (73% of extinct species attributed
to this)
b. habitat fragmentation is also problem (Fig. 55.5)
c. species in small patches have higher probability of extinction
1. prairie in US is .1% of original acreage
2. 93% of coral reefs impacted, may lose 40-50% in next 50 yrs.
2. Introduced species
a. invasive, exotic, nonnative - moved to new locations, free from predators, pathogens
spread exponentially
1. brown tree snake (Stowaway) in guam in WWII - 12 spp birds, 6 spp lizards
extinct since
2. zebra mussel (ballast) in great lakes and SF Bay
3. kudzu for erosion (Fig. 55.6)
b. more than 50k in US alone
3. Overexploitation
a. harvesting that exceeds rates of replenishment
1. plants/trees, fisheries, game, etc.
2. esp. susceptible are large animals - elephants, whales, rhinos
3. spp w/ restricted habitats vulnerable or that becomes very valuable (bluefin
tuna, 100 dollars/pound - Fig. 55.7)
b. disrupting interactions - eg. keystone species - beaver
1, flying foxes in Samoa - luxury food item - 79% of trees are pollinated or seed
dispersal from them
II. Population consrvation focuses on Pop size, genetic diversity, critical habitat
A. small pops more subject to stochastic influences
1. extinction vortex (fig. 55.9)
a. loss of gv
2. MVP - minimum viable population - smallest size a species can sustain numbers and survive
a. diferent for different species
3. PVA - population viability analysis - probability that population will survive over a particular time
a. allows planners to model management plans and see effects on species numbers
b. should combine theoretical modeling with field study
B. Declining population approach - any population (even if large) that shows downward trends - manage
before it becomes endangered
1. steps for analysis
a. examine pop trends, confirm decline
b. study natural history
c. devel hypoth for factors of decline
d. test most likely first (may be many factors interacting)
e. apply results to management and monitor recovery
2. red cockaded wood pecker - mature pines, holes around nest cause sap flow reducing snakes
a. low veg- < 15 ft understory
b. social structure - main breeding pair and helpers
c. hypoth that structure was most important - habitat maintenance and excavation of new
breeding sites has helped recovery
III. Landscape and regional conservation aim to sustain entire biotas
A. landscape ecology - understand past present and future patterns of landscape use and landuse planning
1. Landscape structure and biodiversity
a. fragmentation and edges (Fig. 55.14)
1. edges are defining features of landscapes
2. edge conditions are different
a. some orgs need edges- both habitats (Deer, cowbirds)
b. interior species decline in smaller patches (Fig. 55.16)
b. corridors connect fragments
1. connect patches
2. reduce loss in passage from one to next
3. can cause spread of disease
2. Establishing protected areas
a. currently 7% of world in protected reserves
b. biodiversity hotspots -30% of birds in 2% of earth’s land area (Fig. 55.17)
1. good choices for reserves, but need more than just that
2. biased towards vertebrates and plants
c. nature reserves and philosophies
1. need larger sizes to conserve species (Fig. 55.18)
a. biotic boundary is 10x larger than legal boundary of yellowstone
d. zoned reserves - extensive region of land with undisturbed areas surrounded by
disturbed areas (Fig. 55.19)
1. devel a social and economic climate that is compatible with long term
viability of protected core area
IV. Restoration Ecology - degraded ecosytems restored to more natural state
A. intro - larger the impacted area, the longer the recovery (Fig. 55.21)
1. assumption of resilient ecosystems - only if healthy
B. Bioremediation - use of living organisms to detox pollution
1. plants, prokaryotes/fungi can assimilate heavy metals
2. oil spills
3. metabolize toxins in dump sites
C. Biological Augmentation
1. organisms can add useful substances - nitrogen fixers
2. Restoration - speed re4establishment of exosystem as similar as possible to undegraded one
3. examples (Fig. 55.22)
D. adaptive mgt – USFS- monitoring mgt strategies to see what works best and using it
V. Sustainable development - long term properity of humans and ecosystems that sustain them
A. ESA- Sustainale Biosphere Initiative - define and acquire ecological info necessary for intelligent and
responsible development, management and conservation of Earth’s resources
1. studies of global change including climate
2. bio diversity and reoe in maintaining ecological structure and processes
3. sustaining natural and artificial ecosystem productivity
4. to do this, must connect sciences and social sciences, economics, humanities
a. reassess values
b. revere processes that sustain us
c. reduce orientation to short term personal gain
B. Read Case study about Costa Rica, biophilia
Ch. 55 objectives
1. Distinguish between conservation biology and restoration biology.
2. Describe the three levels of biodiversity.
3. Explain why biodiversity at all levels is vital to human welfare.
4. List the four major threats to biodiversity and give an example of each.
5. Define and compare the small-population approach and the declining-population approach.
6. Explain how an extinction vortex can lead to the extinction of a small population. Describe how a greater prairie
chicken population was rescued from an extinction vortex.
7. Describe the basic steps that are used to analyze declining populations and determine possible interventions in the
declining-population approach. Describe the case of the red-cockaded woodpecker to illustrate this approach.
8. Describe the conflicting demands that accompany species conservation.
9. Explain how edges and corridors can strongly influence landscape biodiversity.
10. Define biodiversity hot spots and explain why they are important.
11. Explain why natural reserves must be functional parts of landscapes.
12. Define zoned reserves and explain why they are important.
13. Define restoration ecology and describe its goals.
14. Explain the importance of bioremediation and biological augmentation of ecosystem processes in restoration efforts.
15. Describe the process of adaptive management.
16. Describe the concept of sustainable development.
17. Explain the goals of the Sustainable Biosphere Initiative.
18. Define biophilia and explain why the concept gives some biologists hope.