Peter Kareiva redefines conservation biology

Who is Peter Kareiva and why do we care about his definition of conservation biology?  Kareiva has been the Chief Scientist at the Nature Conservancy since 2002.  That’s a BIG job, given that the Conservancy employs about 600 scientists.  The huge number of scientists at the Conservancy is one of the reasons why it is unique amongst environmental organizations.  Most environmental organizations employ more lawyers than scientists.

The Nature Conservancy is the “leading conservation organization working around the world to protect ecologically important lands and waters for nature and people,” according to its website.  These measures of its scale are an indication that they aren’t exaggerating:

  • There are over one million members of the Nature Conservancy (of which our household is one).
  • They have protected more than 119 million acres of land, thousands of miles of rivers and created over 100 marine reserves worldwide.
  • They have projects in all 50 states of the US and 35 countries around the world.

The Conservancy restores as well as conserves

Trees destroyed in Chicago for prairie "restoration"
Trees destroyed in Chicago for prairie “restoration”

Another reason why we are interested in the opinions of Peter Kareiva is that the Nature Conservancy engages in some of the most aggressive restorations of which we are aware.  One of their famous projects is the return of tall grass prairie around Chicago, Illinois, which required the destruction of untold thousands of trees, many of which were native.  These projects began decades ago and have generated a great deal of conflict amongst those who value the trees and object to the methods used to kill them, including herbicides and prescribed burns.

Another famous Conservancy restoration is on the Channel Islands, off the coast of California.  Thousands of non-native animals were removed or killed.  Native mice were rounded up in order to carpet-bomb the islands with rodenticides to kill rats.  Feral pigs had been the preferred food of the Golden Eagle, which then turned to the rare Channel Island fox as a substitute when the feral pigs were exterminated.  So, the Golden Eagles were captured and shipped elsewhere.  Thanks to a captive breeding program the Channel Island fox was spared extinction.  Feral honeybees are also being exterminated because they are not native.  This is but a brief description of the extreme measures taken on the Channel Island to rid them of all traces of human habitation.

Channel Island Fox
Channel Island Fox

Peter Kareiva defines conservation goals

We were introduced to Peter Kareiva shortly after he joined the Conservancy, after a long career in academia.  In 2002, he was quoted in an article in the New York Times entitled, “As Alien Invaders Proliferate, Conservationists Change their Focus.”  As the title implies, this article reported on the emerging scientific consensus regarding ecological restorations:  “…a growing chorus of biologists is proposing a new approach to the fast-blending biosphere.  They also say change should be accepted as largely inevitable and choices for managing nature should be based on what is desirable and undesirable, not what is native and foreign.”  Peter Kareiva was one of the scientists supporting this new viewpoint:  “’Conservation biologists are too romantic,’ Dr. Kareiva said, ‘They think what’s good is what’s natural.  Let’s be serious.  A better vision is something that functions and has habitat quality and aesthetic quality.’” 

We have been following Kareiva’s career since that interview and he has become increasingly vocal in his opposition to out-dated notions of creating “pristine” historical landscapes.  He is now one of the proponents of naming the current geological era the Anthropocene in recognition of the reality of man’s pervasive impact on the environment.

In 2012, Kareiva and a co-author published a manifesto redefining conservation biology, which was defined by Michael Soulé in 1985. (1) As defined by Soulé, it was solely a biological science focused on biodiversity, and human influence was perceived as detrimental to its goals.  It was considered a “crisis science” which advocated for action in the absence of data because of the urgency of reversing environmental damage.

The world has changed significantly since 1985.  Human population has increased from 4.8 billion to more than 7 billion in 2011.  Energy consumption has also increased significantly as developing countries approach the standard of living of developed countries.   There is a growing understanding that human activities have altered even remote corners of the earth.  The preponderance of novel ecosystems has rendered irrelevant earlier notions of the importance of co-evolution in static ecosystems.  There is also waning political will to impose standards for conservation that are antithetical to the interests of humans.

Kareiva therefore proposes a new approach to conservation, which he calls conservation science.  It must be a multidisciplinary science which incorporates social science because it must accommodate both biodiversity and the needs of humans.  These are the core principles of conservation science:

  • ”First, ‘pristine nature’ untouched by human influences, does not exist.”
  • “Secondly, the fate of nature and that of people are deeply intertwined.  Human health and well-being depend on clean air, clean water, and an adequate supply of natural resources for food and shelter.”
  • “Third, nature can be surprisingly resilient.”
  • “Fourth…sustainable conservation can be achieved by empowering local people to make decisions for themselves.”

These are the values of an ecological philosophy to guide conservation actions:

  • “First, conservation must occur within human-altered landscapes.”
  • “Second, conservation will be a durable success only if people support conservation goals.”
  • ”Third, conservationists must work with corporations” because they “drive much of what happens to our lands and waters.”
  • “Fourth, only by seeking to jointly maximize conservation and economic objectives is conservation likely to succeed.”
  • “Finally, conservation must not infringe on human rights and must embrace the principles of fairness and gender equality.”

Kareiva concludes:

“Our vision of conservation science differs from earlier framings of conservation biology in large part because we believe that nature can prosper so long as people see conservation as something that sustains and enriches their own lives.  In summary, we are advocating conservation for people rather than from people.”

Bringing this message home

We hope that Kareiva’s viewpoint is driving the Nature Conservancy’s projects, but we don’t have enough detailed knowledge of those projects to know if this is the case.  However, we do know that the many “restoration” projects on our public lands in the San Francisco Bay Area do not conform to Kareiva’s standards because:

  • Local projects do not reflect the wishes of the community.  In most cases, the community was not even aware of the projects until they were completed.  When the public has had an opportunity to object to the projects, their objections are largely ignored.
  • Local projects use pesticides and many conduct prescribed burns.  These methods used to eradicate non-native plant species are harmful to the environment and the people and animals that live in it.
  • Local projects often exclude people by building fences around projects, closing trails, and restricting all recreational access to the trails.  Our local projects treat the public like intruders.

If the world’s largest conservation organization can redefine its goals to accommodate the needs of humans, what possible excuse do managers of our public lands have to ignore the public’s wishes?  The Nature Conservancy is responsible for lands acquired with the voluntary charitable contributions of its donors.  In contrast, the public owns our public lands and pays for the management of those public lands with our tax dollars.  Shouldn’t the managers of our public lands be more accountable to the public (who pay taxes whether they want to or not) than the Nature Conservancy is to its donors (who can choose not to donate)?


(1)    Peter Kareiva and Michelle Marvier, “What is Conservation Science?” BioScience, November 2012, Vol. 62, No. 11

Authenticity: A modern definition of wilderness

Conservation biology is being revised so rapidly that we are struggling to keep up with it.  In our previous post, we introduced our readers to Professor Scott Carroll’s proposal that a more realistic approach to conservation would accommodate non-native species because they are often better adapted to present conditions than their native predecessors.  He calls his approach Conciliation Biology.

Today, we are introducing our readers to another proposal to redefine wilderness to a new standard which acknowledges that the environment has been radically altered by man.  The author of this proposal is Nigel Dudley, a practicing British conservationist.  He calls his new standard “authenticity,” which he defines as follows:

“An authentic ecosystem is a resilient ecosystem with the level of biodiversity and range of ecological interactions that can be predicted as a result of the combination of historic, geographic and climatic conditions in a particular location.”*

Let’s focus for a moment on this portion of that definition:  “…historic, geographic and climatic conditions in a particular location.”  Mr. Dudley explains this particular parameter of his definition of authenticity:  “…some ecosystems have unusually high levels of diversity…through being isolated or undisturbed for exceptionally long periods.  Other ecosystems have already been hugely changed and in some cases impoverished…it will not always be possible either to recover lost elements or to remove additions.  What an ecosystem is likely to contain in the future needs to be based on current realities…”   

Clearly places like the Berkeley Meadow are not candidates for “authenticity.”  This particular native plant museum was the former garbage dump for the city of Berkeley, built on landfill.  This seems an extreme example of denial of current realities.

The Berkeley Meadow, a 72-acre fenced pen for native plants on the former city garbage dump

Choosing candidates for authenticity

Dudley’s point in proposing this new standard is to focus conservation efforts where they are most likely to be fruitful.  Our interest in this new standard is in the stark contrast it provides to the local projects which fail by every measure introduced by Mr. Dudley in his book about authenticity.

  • Natural species composition:  Virtually all predators and grazing animals are gone from the urbanized San Francisco Bay Area.  San Francisco’s Natural Areas Program claims to have designated only “remnants of native vegetation” as natural areas.  In fact, vegetation cover in the 1,105 acres of natural areas is on average only 46% native.  Some of the 31 natural areas are populated by as little as 11% native vegetation.
  • Migrant composition:  Some bird migrations are intact, but others have been changed by existing vegetation such as the tall, non-native trees of which there were few in the native landscape.  Migrations of ungulates are long gone.
  • Invasive species:  Non-native plants and trees outnumber native species throughout the Bay Area.
  • Chemical composition:  Air, water, and soil composition are vastly different than they were 200 years ago.
  • Functioning food web:  The food web has been radically altered by the loss of top predators and ungulates and cannot be recreated in a densely populated urban environment.  Bears may be welcome in the zoo, but are not wandering our streets looking for their next meal.
  • Functioning ecological processes:    Funneling most creeks into underground culverts is an example of a lost ecological process in the urban environment.
  • Regeneration process:  Fire is a regeneration process that is lost in the urban environment.  Prescribed burns are allowed by some managers of public land in the Bay Area, but San Francisco’s Natural Areas Program has reluctantly agreed not to conduct prescribed burns.
  • Resilience:  Although the original goal of San Francisco’s Natural Areas Program was that once “restored” the natural areas would be self-sustaining, fifteen years later, NAP concedes that on-going maintenance will be required to sustain the natural areas.  Dudley says, “Ideally, authentic ecosystems should also be self-sustaining:  they should not need constant and often expensive manipulation to maintain their values.”  Clearly, the “natural areas” in San Francisco’s parks do not meet this criterion for authenticity.
  • Area:  Most of the restoration projects in the Bay Area are too small to be sustainable.  The average size of San Francisco’s 31 natural areas is only 35 acres.  The smallest is only one-third of an acre.  Size is a proxy for the ability to isolate a restored site from repeated re-invasion.  The natural areas are small and are surrounded by non-native vegetation which will quickly return.
  • Connectivity:  Virtually every restoration project in urbanized Bay Area is physically isolated.

It may be possible to compensate for these bad odds of a sustainable, authentic restoration project in the urbanized San Francisco Bay Area.  If so, it will be extremely costly, which is undoubtedly why most projects have not been successful.  The National Park Service has had some success with its projects because they seem to have greater resources than other managers of public land.  But is this the top priority of taxpayers?  As the presidential election season heats up and the debate rages about raising taxes and cutting federal spending, one wonders why these projects are not in the budget-cutting cross-hairs.

Looking on the bright side

Grey squirrel. Creative Commons

We make every effort to end each story with a positive outlook.  In this case, we turn to Mr. Dudley to remind our readers that the environment is not necessarily destroyed by the mere existence of non-native species.  Being British, he uses British examples to make his point.  The North American grey squirrel is considered an invasive species in Britain and the native red squirrel is now rare.  While the British are not happy about the loss of their native squirrel, Mr. Dudley reminds them that the non-native grey squirrel is performing the same ecological functions as its native predecessor.  There is apparently no evidence that the environment has been harmed by this substitution.

We don’t like change.  But is change actually doing any harm?  If not, let’s accept it, because fighting against it is costly and probably futile.  That is the definition of wisdom:  that we accept what we cannot change.


*Nigel Dudley, Authenticity in Nature. Earthscan, 2011

Conciliation Biology: Revising Conservation Biology

Our interest in invasion biology is primarily in its application, specifically to “restoration” projects.  Therefore, as science revises the assumptions of invasion biology we are equally interested in the implications for ecological restorations.

Professor Scott Carroll (UC Davis) is a particularly good candidate to lead the way in revising ecological restoration practices, as informed by current scientific theories of invasion biology.  His study of rapid evolution of the native soapberry bug to accommodate use of non-native vegetation puts him in the forefront of the effort to integrate evolutionary theory into invasion biology.

And so we introduce to our readers, Professor Carroll’s proposal that we turn from efforts to eradicate non-native species in favor of a new approach which manages the co-existence of native and non-native species.  He calls this approach Conciliation Biology.*

Conciliation Biology is based on these premises:

  • The environment has been radically altered by the activities of humans
  • The environment will continue to change in the future.
  • It is not feasible to eradicate non-native species.
  • The cost of attempting to do so is prohibitive.

These are familiar themes on Million Trees and we will not belabor them in this post.  Rather we will focus on those aspects of Professor Carroll’s proposal that are new to us.

Rapid evolution can resolve apparent ecological problems

Garlic mustard. GNU Free

Garlic mustard is an invasive non-native plant which tolerates shade and emits a powerful root toxin known to inhibit the germination of other plants, notably forest trees.  This chemical tool to reduce competition is known as allelopathy,  a weapon used by many plant species, both native and non-native.

Since garlic mustard arrived first in the eastern US and spread slowly west, scientists compared the allelopathic toxicity of a population of garlic mustard known to have arrived 50 or more years ago with a population which arrived only 10 years ago.  The toxicity of the recently arrived garlic mustard was significantly greater than that of the older population.  In fact, the understory and seedling germination were rebounding in the forest with the older population of garlic mustard.

In other words, science informs us that ecological problems caused by the arrival of new exotic species can resolve themselves over time.

New exotic species are sometimes better adapted to the changed environment

Professor Carroll cites a study of two aquatic species (Phragmite and Hydrilla) which provide superior ecological services than their native counterparts because of changes in the environment.  The extreme weather events associated with climate change are subjecting our coasts to unprecedented storm surges.  Native species of marsh grass are not as successful in protecting the coast against the ravages of these storm surges.

We have our own local example of the same phenomenon.  Non-native Spartina marsh grass is being eradicated along the entire west coast of the country.  It grows taller and thicker than native Spartina and it does not die back during the winter months as the native species does.  Since storm surges occur during the winter months, surely the non-native Spartina provides superior protection to our coast.  We have yet to see a scientific experiment which proves this point, but common sense tells us that it is a study that needs to be done, particularly since ornithologists have reported that the eradication of non-native Spartina has been harmful to our dwindling population of endangered California Clapper Rail.

The harmful effects of eradication efforts

Iberian lynx. Creative Commons

We have seen many such harmful consequences of eradication efforts, but Professor Carroll provides his own example.  Iberian rabbits are native to Spain.  They were intentionally imported to Australia where they quickly became a problem.  The Australians imported a virus from South America that killed the rabbits.  The virus was also introduced to Britain for the same purpose.  The virus has spread back to Spain where it is killing the rabbits in their native range.  The rabbits are prey of several rare species of animals in Spain, including the Iberian lynx.  The absence of their prey is now decimating those native predator populations as well.

Biological controls are one of many dangerous games being played by those who share in the fantasy that it is possible to eradicate non-native species without paying a price.  Sometimes that price is greater than whatever cost may be associated with the non-native species.

Simply eradicating non-native species will not necessarily result in the return of natives

Professor Carroll tells us the story of the failed attempt to save the Large Blue butterfly in Britain from extinction to illustrate this point.  This was apparently a spectacularly beautiful butterfly, and so the British spent 50 years trying to bring it back from extinction.  They failed because they figured out too late that the butterfly is dependent upon an ant which lives only in heavily grazed vegetation.  The ant population no longer existed within the range of the butterfly because grazing had long ago been abandoned.

How many other pointless efforts to reintroduce endangered species are there?  We recently told our readers about the effort to reintroduce the endangered Mission Blue butterfly to Twin Peaks in San Francisco.  This is a radically altered environment with high levels of nitrogen and carbon dioxide associated with the urban environment.  The annual brush fires of pre-settlement San Francisco are no longer capable of sustaining the scrub required by the butterfly and the prescribed burns, which are the artificial equivalent, are not allowed in San Francisco.  The scrub is therefore maintained with repeated applications of pesticides which are unlikely to benefit the endangered butterfly.

What is Conciliation Biology

Conservation biology has been “constrained by often futile efforts to restore historical communities, and [does] not appreciate the unavoidable and dynamic contributions of ongoing adaptive evolution.” * Conciliation biology proposes to address these shortcomings by:

  • Taking a longer-term view of the chronic effects of changes in the environment.
  • Making greater use of evolutionary theory
  • Fostering ongoing adaptation by accepting the hybridization that increases genetic variability
  • Identifying and supporting community mechanisms that increase resiliency
  • Improving the effectiveness of the science of invasion biology by using a multidisciplinary approach

How long will It take for this new approach to filter into the minds of those who are busily destroying non-native vegetation and damaging the environment in the process?  How much damage will be done before these destructive methods are abandoned in favor of an approach that accommodates the reality, inevitability, and often the advantages of change?


*Carroll, Scott, “Conciliation biology:  the eco-evolutionary management of permanently invaded biotic systems,”  Evolutionary Applications, 2011, 184-199.