ES 100: Biodiversity ConservationES 100: Biodiversity Conservation

November 15th, 2006

“The current extinction rate is now approaching 1,000 times the background rate and may climb to 10,000 times the background rate during the next century, if present trends continue. At this rate, one-third to two-thirds of all species of plants, animals, and other organisms would be lost during the second half of the next century, a loss that would easily equal those of past extinctions.” -Peter Raven (1999)

Announcements:

Next Wednesday: Field Trip to Ellwood 10% of course grade:

1/2 background research assignment, 1/2 field trip assignment Background Research Assignment posted on website

Do before field trip: will enhance your experience Sign up for Van Transportation in Section this week You may complete field trip early, on your own

Field trip assignment and directions will be posted on website tonight.

You must sign release form in section

Last Time: WWF and MPA’s

WWF: “draws circles”; tries to conserve biodiversity Today: How do ecologists ‘draw circles’ (decide that

one area is more important than another) Highlighted importance of social factors that

shape the success of MPA’s Today: Another social component is the awareness

and acceptance of intrinsic changing nature of communities (and what it means for conservation) Succession

Who Wins?Early vs. Late Succession Species

Early• shade intolerant• nutrient demanding• short-lived• poor competitors

Late• shade tolerant• adapted to lower nutrient

conditions• long-lived• good competitors

Who wins in the beginning?

Secondary succession• space, light, and nutrients are abundant• classic r-selected species (opportunists)

Primary succession• space and light are abundant• nutrients may not be• N-fixing plants are common

• convert atmospheric N2 into NH4+

How does succession happen?Facilitation

• early succession species alter conditions to favor the growth of late succession species

• N-fixers make soil richer• dune grass stabilizes sand

Acceleration•late succession species alter conditions to favor their own growth and prevent the growth of early succession species

•some plants produce toxic litter

Predestined Communities?• A community is a group of living organisms

that occupy a certain area and interact with one another.

Clement’s climax community theory

Classic Succession

Clements’ idea of “climax community” • eventually, a given system reaches a predictable

steady-state • independent of the early succession community

• Community predestined by climate?

Mixed Beech-Maple Forest

Oak-Hickory

Willow shrub

Cattail marsh

Aquatic plants

Swamp

Oak woodland

Sumac-Pine

Broomsedge

Aster-Goldenrod

Annual weeds

Old field

Oak forest

Pine forest

Poplars

Dune grass

Sand dune

The Role of Randomness (aka Stochasticity)

2 species are equally suited to be next “successors” Outcome is CHANCE (dispersal, weather,

ect.)

What is the relationship between disturbance and diversity?

Disturbance frequency or intensity

Div

ers

ity

ab c

Intermediate Disturbance Hypothesis-Joseph Connell, UCSB, 1978

Fire Fire-adapted systems

(Fire in pine forest prevents hardwoods from establishing)

(Some) Seeds germinate after fire Why doesn’t So. Cal have nice,

intermediate fires? Human values/perceptions

Why Is Succession Important?

Understanding ‘natural’ disturbance recovery can aid human’s restoration efforts.

Biotic and Abiotic processes are important

Management plans must recognize that disturbance is not intrinsically bad!

Where is damage most prominent?Conservation International: Biodiversity Hotspots

CI quantified by number of endemic plant species and threat

Assessing Biodiversity

Indicator species: Species that are present only under strict environmental conditions

Can be used to detect healthy/unhealthy ecosystems Example: steelhead, certain diatoms

Species diversity/richness: number of species in sample-diversity: number of species within a single habitat type-diversity: difference in species composition between habitats

Species evenness: equality of relative abundance Unevenness might indicate unhealthy ecosystem

Biodiversity Index

CommunityRobin Mallard Crow Cardinal Geese

I 0.2 0.2 0.2 0.2 0.2

II 0.3 0.07 0.1 0.5 0.03

III 0.25 0.25 0.25 0.25

Relative Abundance

Shannon-Wiener Biodiversity Index

Where:

H = the Shannon-Wiener biodiversity index

pi = proportion of each species in the sample (relative abundance)

loge = the natural log of pi

s = the number of species in the community (species richness)

∑=

−=s

iiei ppH

1

log

Community H indexRobin Mallard Crow Cardinal Geese

I 0.2 0.2 0.2 0.2 0.2 1.61

II 0.3 0.07 0.1 0.5 0.03 1.23

III 0.25 0.25 0.25 0.25 1.39

Relative Abundance

H(Community II) = -(.3*ln(.3)+.07*ln(.07)+.1*ln(.1)+.5*ln(.5)+.03*ln(.03))

Protection of Species or Habitat?

Will one protect the other? Endangered Species Act:

Attempts to preserve endangered species. Forbids federal agencies from actions that are:

“likely to jeopardize the continue existence of any endangered or threatened species or result in the destruction or modification of their habitat.

Hunting permits…. ect. Development of federal land

Cost was not considered….

Endangered Species Act: Species Protection vs. Property Rights

““Shoot, Shovel, and Shut Up”Shoot, Shovel, and Shut Up”

Pombo Bill: Elimination of “critical habitat”Passed in House, will go to Senate next

 Pombo's bill, which has some Democratic support in the House, would also require the federal government to compensate a require the federal government to compensate a developer or property owner if land use is restricted as a result of the act. developer or property owner if land use is restricted as a result of the act.

    Moreover, the bill is designed to expedite development decisions by giving federal officials a six-month deadline to determine whether a proposed project would harm a species protected under the act.

    The bill would eliminate the requirement for an independent group of scientists to arbitrate endangered species disputes and put the secretary of Interior in charge of determining the "best available science" regarding protected species.

    One controversial amendment, by Rep. Greg Walden (R-OR), would exempt the use of pesticides from regulation under the Endangered Species Act for five years. The amendment removes the requirement limiting the use of a pesticide known to kill an endangered species.

Species Protection

Minimum Viable Population (MVP) Inbreeding, genetic drift Genetic bottleneck Minimum Viable Area—habitat protection

Genetic bottleneck-Population loses much of its genetic diversity from a population decline

Most geneticdiversity isretained

Which Species to Protect?

Umbrella species

Flagship species

Keystone species

Habitat Protection: Reserves

One large or many small? Shape? Connectivity?

SLOSS Debate: Single Large vs. Several Small

Species-area curve

Management implications: Management implications:

•Small reserves: area = speciesSmall reserves: area = species

•As area increases, diminishing returnsAs area increases, diminishing returns

To consider:Genetic exchangeExtinction eventsEdge effectsFuture PressuresCost/Flexibility

Reserves…. Size matters!

Shape Matters too! Cores and Buffers:

Connectivity: Nodes and Corridors

Is connectivity important in MPA’s?

Habitat Conservation Management Tools

Conceptual diagrams Collaboration (with stakeholders, community) Mathematical/computer models GIS (Geographic Information Systems) Remote sensing Bioassessment Environmental Impact Reports

The new trend……

Ecosystem Based Management (EBM)"EBM looks at all the links among living and nonliving

resources, rather than considering single issues in isolation . . . Instead of developing a management plan for one issue . . ., EBM focuses on the multiple activities occurring within specific areas that are defined by ecosystem, rather than political, boundaries."

US Ocean Commission Report, 2004

http://ebm.nceas.ucsb.edu/faq/definition/