Principles of Conservation Biology: an Overview - PowerPoint PPT Presentation

Principles of conservation biology an overview l.jpg
Download
1 / 48

  • 348 Views
  • Updated On :
  • Presentation posted in: Travel / Places

Principles of Conservation Biology: an Overview. Prof. Claire Kremen Univ Cal Berkeley Cal Academy Bioforum Apr 4, 2009. Biodiversity Defined.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

Download Presentation

Principles of Conservation Biology: an Overview

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Principles of conservation biology an overview l.jpg

Principles of Conservation Biology: an Overview

Prof. Claire Kremen

Univ Cal Berkeley

Cal Academy Bioforum

Apr 4, 2009


Biodiversity defined l.jpg

Biodiversity Defined

  • “Biodiversity is the total variety of life on earth. It includes all genes, species and ecosystems and the ecological processes of which they are a part” (Convention on Biodiversity, 1992)


Ecological interactions l.jpg

Ecological interactions

  • Biodiversity is more than the sum of the parts

  • Interactions “structure” communities, maintain diversity, and make ecosystems work

  • e.g. Competition

  • Predation

  • Mutualisms (e.g. pollination, seed dispersal)


Evolution and extinction l.jpg

Evolution and extinction

  • Biodiversity is not static but constantly changing

  • 99% of the species that ever lived have gone extinct

    • Mass extinctions

    • Background extinctions

    • Finite lifetimes


Conservation biology l.jpg

Conservation biology

  • Concerned with loss of biodiversity, not just loss of species

    • “Fundamental loss of resources in genetics, species, community attributes and ecosystemproperties”

    • Flip side: maintenance of biodiversity, ecological and evolutionary processes


Why care about biodiversity l.jpg

Why care about biodiversity?

  • Intrinsic value (Muir, 1838-1914)

    • All species have value independently of their utility to humans

  • Utilitarian value (Pinchot, 1865-1946)

    • Species that provide the “greatest good to the greatest number” (over the longest time) have value

  • Cons Bio : (Leopold, 1886-1948)

    • can include both value systems

    • “To keep every cog and wheel is the first precaution of intelligent tinkering" (Leopold 1943).


Aldo leopold 1886 1948 evolutionary ecological land ethic l.jpg

Aldo Leopold (1886-1948)Evolutionary-Ecological Land Ethic

Biological communities: assemblages of interdependent species

Maintaining the health of natural ecosystems and ecological / evolutionary processes

Humans exist within the ecological community; depend on ecosystem services

Synthetic approach:

Both intrinsic value and utilitarian value


Why be concerned about biodiversity loss if extinction is a fact of life l.jpg

Why be concerned about biodiversity loss if extinction is a fact of life?

Moderate certainty: current extinction rates > by 100 – 1000 times

10 – 30 % of mammals, birds and amphibians threatened

Is extinction outpacing speciation potential?


Major drivers of endangerment l.jpg

From Wilcove 1996

Major drivers of endangerment

What’s missing?


Threats to terrestrial species l.jpg

Threats to terrestrial species

  • Terrestrial habitat loss

  • 39-50% of land surface transformation


Result of habitat loss l.jpg

Result of habitat loss

  • Reduction in total area  decrease in size, # of populations  local extinctionsfewer species

  • Reduction in habitat diversity

    • Reduced species diversity

    • Cascading effects, co-extinctions


Habitat fragmentation l.jpg

The forested areas of Warwickshire, England

From Primack 2002

Habitat fragmentation

  • Above and beyond habitat loss

  • Isolation: reduced immigration, re-colonization

  • Edge effects


Invasion l.jpg

Invasion

The distribution of species on Earth is becoming more homogenous

The rate of invasion is increasing over time

HOMOGENIZATION

Growth in Number of Marine Species Introductions in North America and Europe


Introduced cheatgrass bromus tectorum has transformed the great basin shrub steppe ecosystem l.jpg

Introduced cheatgrass, Bromus tectorum, has transformed the Great Basin shrub-steppe ecosystem

  • Has increased fire frequency from once/80 years to once/4 years!

  • Occupies over 5 million hectares of Great Basin


Climate change effects on biodiversity l.jpg

Climate change effects on biodiversity

  • Range shifts

    • Latitudinal range

    • Altitudinal range

  • Mis-matched interactions

  • Reassembled (scrambled) communities

  • Feedbacks (e.g. vegetation and climate)

  • Species Endangerment


Climate change endangers polar bears l.jpg

Climate change endangers polar bears

  • Sea ice is the key

    • Bottom up: habitat for micro-algae

    • Top down: seal hunting ground; corridors to dens

  • Loss of sea ice  endangers polar bear

  • Loss of top predator: cascading effects on Arctic food web


Climate change can induce coral reef bleaching l.jpg

Climate change can induce coral reef bleaching

http://www.ogp.noaa.gov/misc/coral/98bleaching/

Bleached and normally pigmented Pocillopora colonies


Oceans and freshwater aquatic habitats l.jpg

Oceans and Freshwater Aquatic habitats

  • If anything are more vulnerable to same threats, with enhanced vulnerability to over-exploitation and pollution

  • Freshwater

    • USA: Very high endangerment levels in fish & amphibians (25-40%) and crayfish & molluscs (> 60%) compared to terrestrial vertebrates (15-18%


Over exploitation of global ocean fisheries l.jpg

Botsford 1997

Over-exploitation of global ocean fisheries

  • > 60% of the world’s fisheries are fully to over exploited, or depleted

  • By-catch increases fish-catch by 30%


Conserving biodiversity l.jpg

Conserving biodiversity

  • Genetic level: seed, egg, sperm banks

  • Population and species level – science of managing small populations

    • Captive breeding (zoos/botanical gardens)

    • Reintroductions

    • Population management in the wild

      • Protection (hunting, disease, habitat)

      • Genetic management (translocations)

      • Habitat restoration


Conserving biodiversity habitat species ecosystem level l.jpg

Conserving biodiversity: habitat, species, ecosystem level

  • Protected areas

  • Managing the matrix

    • Restoration

    • Wildlife-friendly agriculture


Protected areas for biodiversity conservation l.jpg

Protected areas for Biodiversity Conservation

  • Select the areas that represent and maintain biodiversity over time…

    (Margules and Pressey 2000)


Representation l.jpg

REPRESENTATION

Including as many different ecosystems and species in the reserve network

Representing the full range of variation (genetic, ecological) present within target species


Reserve design decision support l.jpg

Reserve Design Decision-Support

  • Computer programs

  • Meet conservation targets (e.g. conserve 20% of each habitat type and 3 populations of each species) at least cost


A network of reserves that represents species efficiently l.jpg

A network of reserves that represents species efficiently

  • But it may not be so good at maintaining biodiversity – why not?

Site selection in the Sierra Nevada foothills for conservation prioritization

Grey = already protected


Maintaining biodiversity over time l.jpg

Maintaining biodiversity over time

  • Population persistence (viability)

  • Maintaining ecological processes

    • E.g. migrations

  • Maintaining evolutionary processes

    • Potential for adaptation within populations (genetic diversity)

    • Selecting areas where rapid speciation is occurring

  • Response to climate change


Slide28 l.jpg

Reserve design features for persistence

SIZE

Edge to area ratio

Disturbance regime

Shape

Environmental gradients

Functional units

Corridors

Matrix habitat

CONNECTIVITY


Slide29 l.jpg

SIZE

Larger size 

  • More species (interactions, functions), S-A relationship

  • More habitats (interactions, functions)

  • Larger populations –

  • Protects vulnerable species

    • Area demanding: large-bodied, high-trophic level, rare

    • Habitat specialists (if habitat included)

    • Species requiring multiple habitat types

  • Shape Reduced edge/area ratio, edge effects

  • Disturbance regime: maintenance of disturbance-generated patch heterogeneity

  • Includes whole functional units

  • Includes whole environmental gradients


Size edge effects l.jpg

From

Primack 2002

SIZE & EDGE EFFECTS

Edges create core versus edge habitat

Example: many songbirds experience high nest predation near edges in woodlots within sub-urban areas


Shape and edge effects l.jpg

Meffe & Carroll 1997

Shape and edge effects


Disturbance regime l.jpg

DISTURBANCE REGIME

  • Disturbance promotes habitat heterogeneity

    • By resetting successional sequence in parts of the landscape

    • Creating patchiness in the landscape which is determined by the temporal and spatial scale of the disturbance(s)


Slide33 l.jpg

Spatial and temporal scale of disturbance varies by type


Size disturbance regime l.jpg

SIZE & DISTURBANCE REGIME

  • Disturbance promotes habitat heterogeneity

    • mosaic of patches at different successional stages

  • Habitat heterogeneity:

    • supports species requiring multiple habitat types

    • Supports early successional species (e.g. Heath fritillary butterfly = “Woodman’s follower”)

  • Size of reserve  ideally as big as or bigger than scale of likely disturbances


Slide35 l.jpg

Functionally inter-dependent ecosystems:e.g. “a complex, dynamic patchwork of mangroves, sea grass bed and reefs” (Moberg & Ronnback 2003)

SIZE & FUNCTIONAL UNITS


Slide36 l.jpg

Reserve design features for persistence

SIZE: Bigger is better!

Edge to area ratio

Disturbance regime

Shape

Environmental gradients

Functional units

Corridors

Matrix habitat

CONNECTIVITY


Connectivity l.jpg

CONNECTIVITY

  • Isolation is a key factor causing loss of species from reserves

    • Preventing gene flow, maintenance of genetic diversity

    • Reducing recolonization following extinction (rescue effect)

    • Preventing access between summer/winter grounds for migratory species

    • Preventing access to multiple habitat types needed for different life stages

    • Preventing response to global warming


Connectivity multi scale responses l.jpg

CONNECTIVITY: Multi-scale responses

  • RESPONSE

  • Create corridors between reserves

  • Manage the matrix around reserves

PROBLEM of FRAGMENTATION

  • Preventing gene flow, maintenance of genetic diversity

  • Reducing recolonization following extinction (rescue effect)

  • Preventing access between summer/winter grounds for migratory species

  • Preventing access to multiple habitat types needed for different life stages

  • Preventing response to global warming


Wildlife overpass l.jpg

Wildlife overpass

Transportation Equity Act for the 21st Century provides funding

http://www.fhwa.dot.gov/environment/wildlifecrossings/overview.htm


Managing the matrix l.jpg

Managing the Matrix

Making matrix “friendly” to wildlife

-- Reserve zonation: core, buffer, transition

-- Wildlife friendly farming/Restoration

Noss and Cooperrider 1994,modified from Harris 1984


Connectivity multi scale responses41 l.jpg

CONNECTIVITY: Multi-scale responses

  • RESPONSE

  • Create corridors between reserves

  • Manage the matrix around reserves

  • Protect migratory routes/stop-overs

PROBLEM of FRAGMENTATION

  • Preventing gene flow, maintenance of genetic diversity

  • Reducing recolonization following extinction (rescue effect)

  • Preventing access between summer/winter grounds for migratory species

  • Preventing access to multiple habitat types needed for different life stages

  • Preventing response to global warming


Stop over sites along songbird migration routes l.jpg

Stop-over sites along songbird migration routes

  • Neotropical birds

  • Use radar to detect nocturnal bird movement

    • Timed to get departure events from stopover points (20-40 min after sunset)

    • Signal characteristics

Breeding

wintering

http://www.njaudubon.org/Education/Oases/RadImages.html


Connectivity multi scale responses43 l.jpg

CONNECTIVITY: Multi-scale responses

  • RESPONSE

  • Create corridors between reserves

  • Manage the matrix around reserves

  • Protect migratory routes/stop-overs

  • Include whole functional units, disturbance regimes, environmental gradients within reserves or reserve networks

  • Include elevational or latitudinal gradients within reserves

PROBLEM of FRAGMENTATION

  • Preventing gene flow, maintenance of genetic diversity

  • Reducing recolonization following extinction (rescue effect)

  • Preventing access between summer/winter grounds for migratory species

  • Preventing access to multiple habitat types needed for different life stages

  • Preventing response to global warming


Slide44 l.jpg

Designing Masoala National Park, Madagascar

  • Habitat heterogeneity – connectedness between habitats, marine and terrestrial

  • Species response to climate change: Include elevational gradients within reserve

  • Masoala, Madagascar


New reserve design methods l.jpg

New Reserve Design Methods

  • Represent species or habitats efficiently

  • Minimize edge effects, maximize clustering

  • Maximize connectivity

Leslie et al. 2003 Ecol App.


Conclusions l.jpg

Conclusions

  • Biodiversity has great value, both intrinsically, and also because human life depends on it

  • But, it is under threat, from habitat loss and degradation, invasive species, climate change, pollution and over-exploitation

  • Conservation biologists have many tools to protect biological diversity, from genetic to ecosystem levels.


Conclusions48 l.jpg

Conclusions

  • Protected areas are an important tool for biodiversity conservation.

  • The design of protected areas and reserve networks should foster representation of biodiversity and its persistence.

    • Reserves need to be sited efficiently to represent biodiversity.

    • Size, shape and connectivity of reserves and relationship with the surrounding landscape matrix are essential considerations for biodiversity persistence.


  • Login