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
Occupancy–abundance relationship wikipedia , lookup
Biodiversity action plan wikipedia , lookup
Latitudinal gradients in species diversity wikipedia , lookup
Habitat conservation wikipedia , lookup
Ecological fitting wikipedia , lookup
Introduced species wikipedia , lookup
Island restoration wikipedia , lookup
0011 0010 1010 1101 0001 0100 1011 • Community Ecology -Types of Species -Species Interactions 1 2 4 General Types of Species 0011 0010 1010 1101 0001 0100 1011 Examining roles of various species in ecosystems: • Native species = a species that, other than as a result of an introduction, historically occurred or currently occurs in an ecosystem (Indigenous) 1 2 4 • Invasive species = an alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health. (non native species, exotic, introduced etc.) Some characteristics of Invasive Species: 0011 0010 1010 1101 0001 0100 1011 • High rate of reproduction • “pioneer species” • High dispersal rates • Tolerant of a wide range of conditions • Generalist • Impact on native ecosystems 1 2 – Invasive species impact 3050% of the species currently listed as Threatened or Endangered under the U.S Federal Endangered Species Act. 4 – (Second only to habitat destruction.) Examples of Non-natives (Invasive) 0011 0010 1010 1101 0001 0100 1011 • Non-native herbivores, like gypsy moth, directly affect the flow of energy captured by plants from the sun. • Non-native earthworms can dramatically increase decomposition in soils. • Non-native bee species (killer bees) • Rats (Sandy Cay) • Cane Frog (Tortola) 1 2 4 Keystone species ….play pivotal roles in the structure, function, and integrity of an ecosystem… affect the health and survival of other species. Their strong interactions with other species, and the fact that they process material out of proportion to their numbers makes them a Keystone Species. Keystone Species Critical roles Include: Pollination of flowering plant species by bees, hummingbirds, bats Dispersion of seeds by fruit eating animals Predation by top carnivores to control the populations of various species Habitat modifications: bats and birds regenerate deforested area by depositing plant seeds in their droppings Loss of keystone species can lead to pop. Crashes and extinction of species that depend on it for certain services. Indicator Species Can be described as species that serve as early warnings that a community or an ecosystem is being damaged or not stable. One example would be: Apex species (top carnivores or top predators) Are always the first to be affected by any change in their ecosystems and therefore, how their numbers indicate the health of the ecosystem Birds as Indicator Species Birds are excellent bioindicators because they are found almost everywhere, and they respond quickly to environmental change. Migratory paths Habitat loss and fragmentation Amphibians The indicators for Tropical Caribbean eco-region (Marine) Species: All Sharks Blacktip shark Carcharhinus limbatus Blacktip reef shark Carcharhinus melanopterus Blue shark Prionace glauca Bull shark Carcharhinus leucas Caribbean reef shark Carcharhinus perezi Great hammerhead shark Sphyrna mokarran Carcharhinus perezi Grey reef shark Carcharhinus amblyrhynchos Lemon Shark Negaprion brevirostris Nurse shark Ginglymostoma cirratum Tiger shark Galeocerdo cuvier Whale shark – Vulnerable Rhincodon typus Species: All Marine Turtles Most experts recognize seven species of marine turtles: the green, hawksbill, loggerhead, Kemp's ridley, olive ridley, leatherback, and flatback. All but one - the flatback - can be found in the Latin American and Caribbean region, and all are threatened by extinction. Community structure • Community~ an assemblage of 0011 0010 1010 1101 0001 0100 1011 populations living close enough together for potential interaction • Richness (number of species) & abundance……. • Species diversity • Hypotheses: •Individualistic~ chance assemblage with similar abiotic requirements •Interactive~ assemblage locked into association by mandatory biotic interactions 1 2 4 Species Interactions: Predation Predator: feeds directly on all or part of a living organism Prey: organism fed on. Predator-prey relationship: One organism is clearly harmed. However at the population level there are benefits: improve access to food, and improve the genetic stock. Prey acquisition: herbivores vs. carnivores (pursue or ambush) Predator Avoidance: speed, highly developed senses,protective coverings Predator Avoidance by Prey Span worm camouflage Poison dart frog Chemical warfare Warning coloration Wandering leaf insect camouflage Viceroy butterfly mimics monarch butterfly mimicry Bombardier beetle Chemical warfare Hind wings of io moth resemble eyes of a much larger animal Foul-tasting monarch butterfly Warning coloration When touched, the snake caterpillar changes shape to look like the head of a snake Deceptive looks Deceptive behavior Figure 8-11 Page 177 Slide 18 Predation defense • Cryptic (camouflage) coloration 0010 1010 1101 0001 0100 1011 •0011 Aposematic (warning) coloration • Mimicry~ superficial resemblance to another species √ Batesian~ palatable/ harmless species mimics an unpalatable/ harmful model √ Mullerian~ 2 or more unpalatable, aposematically colored species resemble each other 1 2 4 Symbiotic Relationships Symbiosis is a relationship in which species live together in an intimate association. There are three types: Parasitism (special form of predation) Mutualism Commensalism Interactions Interspecific (interactions between populations of different species within a community): Symbiotic Species Interactions: Mutualism Reproductive mutualism: pollination Nutritional mutualism Nutritional/protection mutualism Fig. 8-12 p. 179 Symbiotic Species Interactions: Commensalism Indirect: i.e., small plants growing in shade of larger plants (redwood sorrel) Direct: i.e., epiphytes (orchids and bromeliads), remoras Fig. 8-13 p. 180 Symbiotic Species Interactions: Parasitism 0011 0010 1010 1101 0001 0100 1011 Parasite: organisms that feeds on another by living in or on another living organism. Parasite benefits. Host: Organism that a parasite feeds on and lives in or on. Host is harmed. (rarely killed) 1 2 4 Endoparasites: parasites found inside the host organisms body. Ex.tapeworms,disease causing microorganisms. Ectoparasites: organisms found outside the host organisms body. Ex. Fleas, ticks, mosquitoes Species Interactions: Competition Intraspecific competition: within a species for resources and territoriality. Interspecific competition: between different species for limited resources (niche overlap) Competing species must: Migrate to another area Shift its feeding habits or behavior through evolution and natural selection Suffer a sharp decline in population Extinction Species Interactions: Competition Interference competition: 0011 0010 1010 1101 0001 0100 1011 One species influences another’s access to some resource regardless of its abundance. Ex. hummingbird Exploitation competition: 1 2 4 Two competing species have roughly equal access but differ in how fast or efficiently they exploit it. Competition: a closer look Competitive exclusion principle: by 0011 0010 1010 1101 0001 0100 1011 Gauss describes how one species eliminates another in an area through competition for limited resources. 1 High Relative population density Paramecium aurelia 4 Paramecium caudatum Low 0 2 4 6 8 10 12 Days Both species grown together 2 14 16 18 Figure 8-8 (2) Page 174 Slide 14 Competition evidence 0011 0010 1010 1101 0001 0100 1011 • Resource partitioning ~ sympatric species consume slightly different foods or use other resources in slightly different ways • Character displacement~ sympatric species tend to diverge in those characteristics that overlap 1 Ex: Anolis lizard sp. perching sites in the Dominican Republic 2 4 Ex: Darwin’s finch beak size on the Galapagos Islands Resource partitioning 0011 0010 1010 1101 0001 0100 1011 1 2 4 Resource Partitioning 0011 0010 1010 1101 0001 0100 1011 Resource partitioning: a method to reduce competition, dividing up the resource so that species with similar needs use them at different times, in different ways, or in different places. 1 2 4 Fig. 8-9 p. 175; Refer to Fig. 7-13 p. 152 & Fig. 8-10 p. 175 The Niche 0011 0010 1010 1101 0001 0100 1011 • Ecological niche~ the sum total of an organism’s use of biotic and abiotic resources in its environment; its “ecological role” √ fundamental~ the set of resources a population is theoretically capable of using under ideal conditions √ realized~ the resources a population actually uses • Thus, 2 species cannot coexist in a community if their niches are identical 1 2 4 Ex: Barnacle sp. on the coast of Scotland