Keystone Species

Kirsten Randolph, Kelly Spady, Lindsey Kirschman,

Sarah MartinESRM 201

Initial Keystone Species Concept

• The idea was developed in 1969 by Dr. Robert Paine during his time at the University of Washington as a zoology professor. The idea also originated from his work with the Makah Indian Tribe and lands along Washington’s Pacific coastline.

Initial Keystone Species Concept

• A keystone species is a species whose whose impact on its community or ecosystem are larger and greater than would be expected from its relative abundance or total biomass in the environment.

• Originally, keystone species were characterized as a predator species that feed preferentially on the dominant competitor among its prey species, preventing the dominant prey from excluding other species.

• The presence of keystone species maintain higher species diversity in ecosystems than if keystone species were absent.

Keystone Species Concept• Since 1969, non-predator

keystone species have been identified and studied, such as beavers (Castor canadensis), bison (Bison bison), kangaroo rats (Dipodymys spp.), and plant species such as the quaking aspen (Populus tremuloides).

• The two keystone species we will be identifying later are salmon and wolves native to the PNW.

Importance of Keystone Species

• Conservation efforts tend to focus on the preservation of keystone species to stabilize the entire biological community, as the loss or decline of a keystone species within an ecosystem has serious consequences for the continued productivity, structure and function of the ecosystem.

"[Keystone species] importance convinced managers and

conservationists alike that the ecological impact of single species

matters. That is, in order to manage, understand, and restore ecological assemblages, the roles of individual species have to be understood and

considered." – Dr. Robert Paine

Salmon as a Keystone Species

-Salmon play a vital role in PNW ecosystems-They help support approximately 137 different species

-41 mammals-89 birds-5 reptiles-2 different amphibians

Without salmon as a keystone species, we could see a tremendous decrease in dependent creatures.

Salmon as a Keystone Species

Pacific salmon are unique because immediately after reproduction they die. When salmon return from the ocean, they bring vital nutrients with them to the watersheds where they were hatched. Through their decomposing carcasses, the salmon spawning process offers a vital source of food not just for salmon and other riparian species, but for a whole host of organisms in the watershed.

Salmon as a Keystone Species

From the original amounts of nutrients only 5 - 7 % is currently delivered by salmon to streams because the decrease in salmon in the environment. The streams are being stressed from a lack of nutrients, and that lack is also hurting the ability of the next generation of salmon to survive.

Example of Salmons importance

-In 1981, at McDonald Creek, more than 600 bald eagles gathered to feed on Kokanee salmon carcasses. When a non-native shrimp was introduced in an adjacent lake, the shrimp competed with the salmon for zooplankton - the salmon run lost.

-In 1989, only 25 eagles were found at McDonald Creek.

-The loss of salmon caused what is called an "ecosystem collapse."

Northwest species now struggling because of depleted salmon runs include

the following:Black Bear

Bald Eagle

Grizzly Bear

Caspian tern

Harlequin duck

Osprey

…Dependent species continued

Orca

Sea lion

River Otters

Canis lupus

• Traditionally had the largest range of any terrestrial mammal

• Extirpated from U.S. by farmers, settlers and hunters in the early 20th century

Epiphany…after 60 years• Just kidding….we actually

do need wolves.• Why?

– Controls elk populations– Increased elk browse

negatively effects growth of seedlings along riparian areas

– Decreased growth of riparian vegetation causes river bank erosion and widening

– This has negative effects on salmon and other aquatic life, and increases flooding and nutrient loss from the soil

Bringin’ em’ back home…

• Endangered Species Act (1974)

• Reintroduction to Yellowstone and central Idaho (1995, 1996)

• Recent sightings in Washington State and Oregon

The controversy concluding predatory keystone species

• Wolves are beautiful creatures until they start killing your livestock or pets

• Do you want really want to meet him when you are out on a hike?

• Also too many wolves would put stress on prey species such as elk and deer.

ConclusionsThe key is to keep the ecosystem and human in balance

and keystone species are an important part of that balance. Predatory keystone species, such as wolves, play an important part in regulating the growth of subdominant prey species. Non-predatory keystone species, such as salmon, play roles in bringing important nutrients to a particular niche or community that cannot be easily gotten elsewhere.

But nearly anything in too great of a quantity will have a negative effect; and this rule does not exclude keystone species. Wolves in too large of numbers have shown to be dangerous; both to human and natural processes. Even salmon would have negative impacts if its population was out of control.

Things that could be done to protect keystone species in the wild.

Salmon – Preserve clean streams that are vital to

successful salmon spawning – Protect riparian area, vegetation, and

species. – Decrease the amount of water being drained

from salmon designated streamsWolves– Already efforts are being made to

reintroduce wolves into PNW areas.– Monitor populations and pack health– Introduce wolves into areas that are

relatively human free and there is ample space and game to support the packs.

Works CitedNovember 1996. Keystone Species Hypothesis. 3 December 2008.

Available from: http://www.washington.edu/research/pathbreakers/1969g.html.

Duffy JE. 7 October 2008. Keystone Species. 3 December 2008. Available from: http://www.eoearth.org/article/keystone_species

Mayell H. October 11, 2001. Hi-Tech Tracking Tool Tested in Wolf Recovery Efforts. Modeling Gray Wolf (Canis lupus) Habitat in the Pacific Northwest, U.S.A. Tad Larson and William Ripple, 2006. <http://www.journalconsplanning.org/2006/volume2/bb9b/finalmanuscript.htm>. Accessed on Dec 3 08.

Ripple W, Beschta R. July 2005. Linking Wolves and Plants: Aldo Leopold on Trophic Cascades. BioScience, volume 55, number7.

Wolves, trophic cascades, and rivers in the Olympic National Park, USA. "Upstream: Salmon and Society in the Pacific Northwest ." 1996 <http://books.nap.edu/openbook.php?record_id=4976&page=R1>. Accessed Dec 3 2008.

Los Angelas Times, "salmon is keystone species for region.“ July 2008 <seattletimes.nwsource.com>. Accessed: 3 Dec 2008.