Keystone Species Concept in Ecology and Conservation

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Will the extinction of a single species cause the loss of many other species?. You forgot your fortune cookie. Keystone Species Concept in Ecology and Conservation.
Will the extinction of a single species cause the loss of many other species?You forgot your fortune cookieKeystone Species Concept in Ecology and ConservationCan we identify a set of species that are so important in determining the ecological functioning of a community that they warrant special conservation efforts?Keystone Species = limited number of species whose loss would precipitate many furthur extinctionsSnow LeopardThis is known as an extinction cascade or extinction vortexSea StarsRemovedNatural StateResultMiddleinter-tidalLowerinter-tidalScene OneSea StarsRemovedNatural StateResultMiddleinter-tidalLowerinter-tidalScene TwoSea StarsRemovedNatural StateResultMiddleinter-tidalLowerinter-tidalScene ThreeFour types of Keystone Species 1. Predator- considered keystone if they control the density of ecologically significant prey species, or on overall community compositionSea Otter Sea Otters are one component of a very interesting ecosystem, which includes kelp beds, shellfish and sea urchins Kelp Red Sea Urchin 2. Keystone Prey Lynx, Arctic Hare, Snowshoe Hare System on Newfoundland3. Keystone Plant- species of plants upon which certain animals are dependent, may also be referred to as a keystone mutualist Lobelia plants native to the Hawaiian IslandsThe i'iwi (Vestiaria coccinea) is oneof the Hawaiian honeycreepersrecords from the past century showthat these birds fed primarily on Hawaiian lobelioidsdecurved bill specifically adapted forextracting nectar from a flower with a long fused corolla25% of Hawaiian lobelioids, once common in the understory, and found only in Hawaii, are now extinctmost of the remaining species arethreatened or endangeredover the past 100 yrs, over-grazing by non-native herbivores, such as feral pigs and goats, and competition from non-native plant species are the cause of the extinction of many lobelioids4. Keystone modifier- activities of one species greatly effect the habitat structure which,in turn, effects species compositonFruit Bats a.k.a Flying Foxes Nearly 200 speciesNative to the old world tropicsMany species confined to islands in the South Pacific and Indian OceansCase StudyFruit Bats serve as valuable pollinators and seed dispersers, often the only ones for a particular plant speciesIn Samoa 80-100% of the seeds found on the forest floor were deposited by Flying FoxesMany co-evolved features, such as night blooming flowers, prevent other pollinators from taking over in the absence of the flying foxesOn the island of Guam, where two species of endemic Flying Foxes have gone extinct, certain plant species have stopped blooming Mexican Long-tongued bat (Cheoronycteris mexicana)Roosting in a cave, note that the entire head and part of the wing are covered with pollen.Many of the plants pollinated by bats are of significant economic value both to local and international markets including; ebony mahogany many medicinal speciesFlying Foxes are also critical to forest regeneration after man-caused disturbancesFlying Fox declines are due primarily to Hunting- since they are colonial, thousands can be “harvested” in a single nightHabitat distruction- due to farming and fuel-wood collectionThe decline of Flying Fox species will undoubtedly lead to massive extinction cascadesSummary- Important implications for the identification of keystone species1. The elimination of a keystone species from a community will precipitate the loss of many other species2. In order to protect a species of interest, it may be important to protect the keystone species on which it depends3. If the keystone species in a community can be identified, then they should be carefully protected, and even enhanced
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