Transcript ppt

Ecological Restoration
Image from Wikimedia Commons
Ecological Restoration
George Perkins Marsh
(1801 – 1882)
Man & Nature (1864)
Contemporaneous with
Romantic-Transcendalists
(e.g., Emerson, Muir, Thoreau)
Marsh’s “key insight” –
anthropogenic imbalances in Nature
“did not correct themselves automatically…
Humans had to restore what humans had disturbed.”
Photo of Marsh (U.S. diplomat & philologist) from Wikimedia Commons; Quote from S. Kingsland (2005)
Ecological Restoration
Aldo Leopold
(1887 – 1948)
A Sand County Almanac (1949)
Milestone for plant community restoration –
Leopold & colleagues restored ~120 ha
of forest & prairie at U. Wisconsin Arboretum;
1930s
Photo from Oregon State University
Ecological Restoration
Jared Diamond
(b. 1937)
Collapse (2005)
Human history is replete with examples of over-exploitation
& habitat destruction without restoration that resulted in
societal collapse (i.e., societies that were not
operating sustainably)
Photo of Diamond from Wikimedia Commons; image of book jacket from amazon.com
Ecological Restoration
Jared Diamond
(b. 1937)
Collapse (2005)
Final paragraph of Collapse: “My remaining cause for hope…
we have the opportunity to learn from the mistakes of distant
peoples and past peoples. That’s an opportunity that no past
society enjoyed to such a degree…”
Photo of Diamond from Wikimedia Commons; image of book jacket from amazon.com
Ecological Restoration
“…the process of intentionally altering a site to establish a defined, indigenous,
historic ecosystem. The goal of the process is to emulate the structure,
function, diversity and dynamics of the specified ecosystem…”
(Society for Ecological Restoration 1991)
Crissy Field, San Francisco
Before restoration
Photos of a restoration success story from Wikimedia Commons
Crissy Field, San Francisco
After restoration
Ecological Restoration
Groom et al. (2006) recognize several sub-categories:
Rehabilitation – improves a site from its degraded state
Enhancement or augmentation – improves a few ecosystem
functions in a site from its degraded state
Reclamation – often associated with mines or waste dumps,
in which the initial goal is detoxification & terrain stabilization
Replacement – specifies a novel community type for the site
to achieve a particular conservation goal; often to
improve ecosystem processes with less regard for
ecosystem structure
Ecological Restoration
Trajectories of restoration projects
Ecosystem
processes
ORIGINAL ECOSYSTEM
Biomass & nutrient
cycling
Replacement
Restoration
Replacement
Rehabilitation
Enhancement
No action?
DEGRADED ECOSYSTEM
No action?
Species & complexity
Modified from Fig. 15.1 in Groom et al. (2006)
Ecosystem
structure
Ecological Restoration
Additional sub-categories from Groom et al. (2006) & other texts:
Remediation (similar to reclamation) – removes chemical contaminants
from polluted areas – by biotic, chemical or physical means –
especially to protect human & ecosystem health
Re-creation (similar to replacement) – constructs a new biological
community on a site in which anthropogenic disturbance
essentially removed the entire native community, often in an attempt
to match a particular historic condition
Ecological Restoration
U. S. Legislation – e.g., Clean Water Act (1972)
“to restore & maintain the chemical, physical & biological
integrity of the Nation’s [surface] waters”
Requires mitigation: if unavoidable impacts to waters & wetlands occur, those
responsible must restore / re-create comparable ecosystems elsewhere
Photo of wetland mitigation project in Australia (outside jurisdiction of CWA) from Wikimedia Commons
Ecological Restoration
U. S. Legislation – e.g., Surface Mining Control
& Reclamation Act (1977)
Aims to prevent adverse effects of surface mining (especially coal)
& requires mining companies to restore mined sites
(usually initiated through reclamation)
Photo of coal strip mine in Wyoming from Wikimedia Commons
Ex situ breeding reintroduction
Whooping Crane (Grus americana)
The tallest bird species in N. America; one of the most
endangered (41 wild birds in 1941; ~350 today)
Photo from Wikimedia Commons
Ex situ breeding reintroduction
Whooping Crane (Grus americana)
Cross-fostering with Sandhill Cranes failed, due to imprinting on foster
parents (which resulted in inappropriate mate choices later)
Captive breeding, followed by migratory training using light aircraft, has
re-established an eastern migratory population (Wisconsin–Florida)
Photo from Wikimedia Commons
Translocation
Wolves (Canis lupus) in Yellowstone
Photo of translocation of wolves from Alberta, Canada to Yellowstone, Jan. 1995, from Wikimedia Commons
Translocation
Wolves (Canis lupus) in Yellowstone
Photo of Alberta wolf in acclimation pen in Yellowstone, Jan. 1995, from Wikimedia Commons
Translocation
Wolves (Canis lupus) in Yellowstone
Photo of translocated Alberta wolf in Yellowstone, from Wikimedia Commons
“Restoring Yellowstone’s
Aspen with Wolves”
Photo from Wikimedia Commons; Figure from W. J. Ripple & R. L. Beschta (2007) Biological Conservation
“Restoring Yellowstone’s
Aspen with Wolves”
“combined effects of a behaviorallymediated and density-mediated trophic
cascade”
Density-mediated – indirect carnivore
effect on plants owing to lethal direct
carnivore effect on herbivore density
Behaviorally-mediated – indirect
carnivore effect on plants owing to
non-lethal carnivore effect
on herbivore behavior
Figure & quote from W. J. Ripple & R. L. Beschta (2007) Biological Conservation
Re-wilding North America with Pleistocene Megafauna
Some Conservation
Biologists have made
a serious proposal
that we should recreate the N. Am.
Pleistocene fauna with
modern analogs
e.g., African
elephants, South
American camelids…
Artist’s re-creation of North American Pleistocene fauna from Wikimedia Commons
Re-wilding North America with Pleistocene Megafauna
… and carnivores,
such as African lions &
Siberian tigers
(modern analogs of
Smilodon [Sabertoothed cat])
It’s a serious
proposal, but is it
a good idea?
Skull & artist’s re-creation of Smilodon from Wikimedia Commons
Key ecological goals for restoration
1. Restore natural ecosystem processes
2. Re-establish native species and their functional roles (especially
key players, e.g., ecosystem engineers, foundation species, etc.)
3. Remove / control / monitor exotic species
4. Others?
“Seabird Islands Take Mere Decades to
Recover Following Rat Eradication”
Photo of New Zealand seabird colony from Wikimedia Commons
“Seabird Islands Take Mere Decades to
Recover Following Rat Eradication”
15 islands off
NE coast of
New Zealand
Black dashed
lines = Control
islands (never
invaded by
rats)
Red dashed
lines = Positive
Control islands
(rats currently
present)
Figure from H. P. Jones [Ph.D. 2010 Yale School of Forestry & Environ. Sci.] (2010) Ecological Applications
“Seabird Islands Take Mere Decades to
Recover Following Rat Eradication”
“I show that soil, plant, and spider marine-derived nitrogen levels
and C:N ratios take mere decades to recover even after
centuries-long rat invasion. Moreover, active seabird restoration
could speed recovery even further, giving much hope
to quickly conserve many endemic species on islands worldwide.”
Quote from H. P. Jones [Ph.D. 2010 Yale School of Forestry & Environ. Sci.] (2010) Ecological Applications
“Rapid Recovery of Damaged Ecosystems”
Meta-analysis
240 published
studies
Figure from H. P. Jones [Ph.D. 2010 Yale School of Forestry & Environ. Sci.] & O. J. Schmitz (2009) PLoS ONE
“Rapid Recovery of Damaged Ecosystems”
Meta-analysis
Figure from H. P. Jones [Ph.D. 2010 Yale School of Forestry & Environ. Sci.] & O. J. Schmitz (2009) PLoS ONE
“Rapid Recovery of Damaged Ecosystems”
Meta-analysis
“We provide startling evidence that most ecosystems globally
can, given human will, recover from very major perturbations
[a.k.a. disturbances] on timescales of decades to half-centuries.”
“The message of our paper is that recovery is possible and can
be rapid for many ecosystems, giving much hope for humankind
to transition to sustainable management of global ecosystems.”
Quotes from H. P. Jones [Ph.D. 2010 Yale School of Forestry & Environ. Sci.] & O. J. Schmitz (2009) PLoS ONE
“The Rise of Restoration Ecology”
Cover of Science – July 31, 2009
“Enhancement of Biodiversity & Ecosystem Services
by Ecological Restoration”
Meta-analysis
(89 restoration assessments;
response ratio = ln[Restored / Degraded or Reference])
Provisioning = e.g., fish, food crops, timber
Supporting = e.g., nutrient cycling, primary production
Regulating = e.g., climate, water supply, soil characteristics
Figure & quote from J. M. Rey Benayas et al. (2009) Science
“Enhancement of Biodiversity & Ecosystem Services
by Ecological Restoration”
Meta-analysis
(89 restoration assessments;
response ratio = ln[Restored / Degraded or Reference])
“Ecological restoration increased provision of biodiversity and ecosystem
services by 44 and 25%, respectively. However, values of both remained
lower in restored versus intact reference ecosystems.”
Figure & quote from J. M. Rey Benayas et al. (2009) Science
Ecological Restoration
Trajectories of restoration projects
Ecosystem
processes
ORIGINAL ECOSYSTEM
Biomass & nutrient
cycling
Replacement
Restoration
Replacement
Rehabilitation
Enhancement
No action?
DEGRADED ECOSYSTEM
No action?
Species & complexity
Modified from Fig. 15.1 in Groom et al. (2006)
Ecosystem
structure
Ecological Restoration
Image from www.portlandonline.com