Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Storage effect wikipedia , lookup
Latitudinal gradients in species diversity wikipedia , lookup
Ecological fitting wikipedia , lookup
Theoretical ecology wikipedia , lookup
Occupancy–abundance relationship wikipedia , lookup
Introduced species wikipedia , lookup
Biodiversity action plan wikipedia , lookup
Habitat conservation wikipedia , lookup
Island restoration wikipedia , lookup
Species Interactions Three Basic Types 1. Competition 2. Exploitation 3. Symbioses • Mutualism • Commensalism • Parasitism Competition Any interaction between two or more species for a resource that causes a decrease in the population growth or distribution of one of the species 3 Competition – two species share a requirement for a limited resource reduces fitness of one or both species 4 Intra vs Interspecific Competition • Intraspecific competition: between members of the same species • Interspecific competition: between members of different species Reducing or Avoiding Competition • Resource partitioning: realized niche (more about this later) Black skimmer seizes small fish at water surface Scaup and other diving ducks feed on mollusks, crustaceans, and aquatic vegetation Flamingo feeds on minute organisms in mud Herring gull is a tireless scavenger Brown pelican dives for fish, which it locates from the air Avocet sweeps bill through mud and surface water in search of small crustaceans, insects, and seeds Louisiana heron wades into water to seize small fish Dowitcher probes deeply into mud in search of snails, marine worms, and small crustaceans Oystercatcher feeds on clams, mussels, and other shellfish into which it pries its narrow beak Ruddy turnstone searches under shells and pebbles for small invertebrates Knot (a sandpiper) picks up worms and small crustaceans left by receding tide Piping plover feeds on insects and tiny crustaceans on sandy beaches Exploitation - PREDATION 7 Predation • Members of predator species feed directly on all or part of a living organism of another species Predator Adaptations • Prey detection and recognition – sensory adaptations – distinguish prey from non-prey • Prey capture – passive vs. active (pursuit or ambush) – individuals vs. cooperative – camouflage • Eating prey – teeth, claws etc. 9 Prey adaptations • Avoid detection – camouflage, mimicry – diurnal/nocturnal • Avoid capture – flee – resist – escape • Disrupt handling (prevent being eaten) – struggle – protection, toxins 10 Camouflage – blending in 11 Aposematic colors – warning 12 Is he crazy??? 13 Mimicry – look like something that is dangerous or tastes bad 14 Mimicry – look like something that is dangerous or tastes bad Mullerian mimicry – convergence of several unpalatable species 15 Mimicry – look like something that is dangerous or tastes bad Batesian mimicry – palatable species mimics an unpalatable species model mimics mimic model 16 Exploitation: Herbivory Herbivory puts strong selective pressure on plants – structural adaptations for defense – chemical adaptations for defense 17 Symbiosis: Mutualists, Commensalists and Parasites 18 • Symbiosis and symbiotic relationship are two commonly misused terms • Translation of symbiosis from the Greek literally means “living together” • Any relationship between two species of animals is symbiosis and includes both positive and negative interactions 19 Mutualism – two species provide resources or services to each other enhances fitness of both species 20 Rewards of Mutualism • Food • Protection • Gamete or zygote dispersal (the most common of all) Ex. pollination 21 Pollination (hummingbird/bee and flowering plants) • animals visit flowers to collect nectar and incidentally carry pollen from one flower to another • animals get food and the plants get a pollination service 22 Yucca moth and yucca • Yucca’s only pollinator is the yucca moth. Hence entirely dependent on it for dispersal. • Yucca moth caterpillar’s only food is yucca seeds. • Yucca moth lives in yucca and receives shelter from plant. 23 Obligatory mutualism • Obligatory: An organism can't live without the mutualism--either cannot survive or cannot reproduce. –the common pollinator systems like bees and flowering plants 24 Facultative mutualism • Facultative: This is "take it or leave it" for one or both partners • While the organism benefits when the mutualism is present, it can still survive and reproduce without it –ant mutualisms, such as ants protecting plants from predation 25 Commensalism – one species receives a benefit from another species enhances fitness of one species; no effect on fitness of the other species 26 Commensalists • Benefit from the host at almost no cost to the host • Eyelash mite and humans • Us and starlings or house sparrows • Sharks and remora 27 Exploitation: Parasitism – one species benefits at a cost to the other enhances fitness of parasite but reduces fitness of host 28 Ecological Niche • The role a certain species plays in an ecosystem • the sum total of a species’ use of the abiotic and biotic resources in its environment Habitat vs. Niche • Habitat: the environment in which a species or organism usually lives • Niche: the role that species plays in the habitat – resource use, etc. Competitive exclusion principle No two species can occupy the same niche in the same location in the same period of time! “two species with similar requirements can not coexist in the same community; one species will inevitably harvest resources and reproduce more efficiently, driving the other species to extinction” Experiment that demonstrates competitive exclusion This leads to the idea of the Ecological Niche Ecological Niche has two components: Fundamental niche – set of resources a population is theoretically capable of using Realized niche – the resources a population actually uses Fundamental niche Species A Realized niche F G B E Species A C D Ex. Broad and Narrow Niches • Generalist species • Specialist species Number of individuals Niches of Specialist and Generalist Species Specialist species with a narrow niche Niche separation Generalist species with a broad niche Niche breadth Region of niche overlap Resource use Which of the NW species you presented on would you classify as generalist? Specialist? Types of Species • Native species normally live and thrive in a particular ecosystem • Nonnative species are introduced - can be called exotic or alien or invasive 39 Nonnative Species • Nonnative plant species are invading the nation's parks at an alarming rate, displacing native vegetation and threatening the wildlife that depend on them • At some, such as Sleeping Bear Dunes National Lakeshore in Michigan, as much as 23 percent of the ground is covered with alien species, and the rate of expansion is increasing dramatically. 40 Invasive species in King County • Many noxious weeds are so widespread in King County that eradicating them is nearly impossible • Weeds include: yellow-flag iris, reed canarygrass, Scotch broom, Himalayan and evergreen blackberry, English and Irish ivy, and purple loosestrife. Indicator Species • a species whose status provides information on the overall condition of the ecosystem and of other species in that ecosystem • reflect the quality and changes in environmental conditions as well as aspects of community composition 42 Examples of Indicator Species • • • • • Spotted owls – old growth forests River otters – clean rivers Frogs – pollutants transfer easily through skin Corals – marine environments What is an indicator species? Pika video Common Air Pollution Indicator • Lichen: Symbiotic relationship between Algae & fungi • 3 types – their presence indicates various levels of pollutants. The most sensitive lichens are shrubby and leafy while the most tolerant lichens are all crusty in appearance. (http://www.airquality.org.uk/19.php) “Why did the fungi & algae get together?” • Crustose • Foliose • Fruticose Do Indicator species tend to be considered generalists or specialists? Keystone Species • a species on which the persistence of a large number of other species in the ecosystem depends. • If a keystone species is removed from a system – the species it supported will also disappear – other dependent species will also disappear • Examples – top carnivores that keep prey in check – large herbivores that shape the habitat in which other species live – important plants that support particular insect species that are prey for birds – bats that disperse the seeds of plants 47 Keystone cont. • exerts an impact on its community that is both strong and disproportionate to its abundance The sea star Pisaster ochraceus, the original keystone species, feeds preferentially on mussels on northeast Pacific rocky shores. By doing so, the predatory sea star prevents mussels from taking over the entire shore and allows less competitive species to persist, thus enhancing local species diversity. (Source: Multi-Agency Rocky Intertidal Network) The sea otter Enhydra lutris can be considered a keystone predator because its voracious feeding on herbivorous sea urchins allows kelps to flourish along the rocky coast, along with an entire ecosystem associated with these large marine plants. Photo by Matt Knoth. (Source: Wikimedia Commons) Keystone species vs. Indicator • https://www.youtube.com/watch?v=xRfdDE6s cWA