Transcript Parasitism
Ecology Unit Chapter 17 Biological Communities Interactions w/ defenses • Herbivores protection – production of defensive chemicals • Ex. Production of mustard oil which is toxic to most insects. • Caterpillars of the cabbage butterflies are the only insects than can eat plants of the mustard family b/c they have evolved the ability to break down mustard oils into harmless chemicals. Symbiosis • • • • • Mutualism Commensalism Parasitism Predation Competition Mutualism Both organisms benefit from the activity of each other • Ex. Ant/Acacia Tree – The ant keeps predators away from the acacia tree – The acacia provides shelter and food for the ant • Ex. Ant / Aphid (pg 364) – many ants are found in the vicinity of aphids. The ants feed on the sugary fluid released by the aphids, and the aphids are protected by the ants • In some cases the organisms must live together to survive. – EX. Protists living inside a termite » Protists – digest the cellulose from wood (food & habitat) » Termite - gets digested wood (food) Mutualism Tiny fig wasps reproduce inside unripe figs wasps and fig trees cannot reproduce without the wasps. The crocodile bird cleans the teeth of the crocodile which will open his mouth for the bird. In return the crocodile provides protection for the bird. Plants & Bees Plants provide food Bees help pollinate Commensalism • one organism benefits and the other organism is neither harmed nor does it benefit – Ex. Clown fish /Sea Anemones – Ex. Barnacles / Whales – Ex. Remora fish / Sharks Commensalism Remora fish (gets food & protection) & Shark Clown fish (protection) & Sea Anemones Barnacles (habitat & protection) & Whales Parasitism • Parasitism – one organism (the parasite) benefits at the expense of the other (the host). The host is harmed in some way. • Usually the parasite will not kill its host EXAMPLES » » » » » Mosquito on an animal Tape worm in an animal Tick on an animal Mistletoe on a tree Lice on an animal Parasitism Mosquito (parasite) & Human arm (host) Mistletoe (parasite) on Tree (host) Lamprey (parasite) on A larger fish Tick (parasite) Predation • Predation – one organism (the predator) benefits by killing the other (the prey) for food. – Lions eating zebras – Snakes eating mice – Spides eating insects Predators Section 2 how competition shapes communities • Competition – both organisms have the same needs or requirements. These could be for food, space, territory or mates. This may involve the same species (intraspecific competition) or different species (inter-specific competition). For example: sponges competing for space with corals. • Niche – how an organism lives the “job” – What it eats – When it eats – Where it eats • Do NOT confuse niche with habitat ! • Fundamental niche – Entire range of resource opportunities an organisms potentially has available • Realized niche – Actual part of the fundamental niche that the organism occupies • • G.F. Gause proved that two competitors CANNOT coexist on the same LIMITED resources. This demonstrates the principle of COMPETITIVE EXCLUSION Major Biological Communities • Biome – major biological community that occurs over a large area of land • Two most important abiotic factors that affect a biome • TEMPERATURE • MOISTURE Terrestrial Biomes 1. Tropical Rain Forest 2. Temperate Grasslands 3. Temperate Deciduous Forest 4. Temperate Evergreen Forest 5. Desert 6. Savannas 7. Taiga 8. Tundra Tropical Rain Forest • Lush vegetation,abundant rain, and uear-round warm temperatures • Most rainfall of any biome on Earth • Avg. of 180in/year (rains every day) • Richest biome in term of species diversity • Poor soil quality Soil contains few nutrients • • Most nutrients are inside the plants not the in the soil • Most animals live in trees or on the vegetation Relation to equator • Closer an area is to the equator, the greater the diversity of species. – Longer growing season – greater diversity – Warmer temperatures – Greater rain fall • Tropical Rain forest lies the closest to the equator • Tundra lies the farthest away Savannas • The world’s great dry grasslands. • Low annual precipitation / Seasonal rainfall • Prolonged annual dry seasons /Seasonal drought • 35 to 60 in rain/year • Open, widely spaced trees • Herds of grazing animals » elephants, giraffes, lions Tundra • • • • • • • • • • Located between the taiga & North Pole. Covers 1/5 of the Earth’s land surface Low annual precipitation Water – usually unavailable most of the year b/c it is frozen Permafrost – main characteristic of the tundra Permafrost – thick, continually frozen layer of ground in the northern tundra Few large trees – permafrost restricts root development Does have summer and a winter season Summer – short ( plants must be able to grow & mature quickly) Animals – Penguins, foxes, caribou, polar bears, mosquitoes Taiga • Winters – long, cold, • Summer - wet climate / moderate temp • Coniferous trees are the predominate trees ( cone bearing) • Northern Forest • One of the largest land biomes on Earth Desert • Driest biome on Earth • Less than 10in rain/year • Most extensive in the interiors of continents • Vegetation is sparse (not much) • Animals – mainly reptiles/active at night » » dry scaly skin to help prevent water loss lay amniotic eggs – help prevent water loss Temperate Grasslands • • • • • Highly productive for agriculture Soil is fertile Bread basket of the world Also have herds of grassing animals Nebraska Kansas Temperate Deciduous Forest • • • • Mild climate / plentiful rain Warm summers / cold winters Eastern United States Trees are generally hardwoods (oak, hickory and beech) Temperate Evergreen Forests • Southeastern and western United States • Pine trees are predominate Aquatic Biomes • Two main aquatic biomes – Freshwater – Marine • Estuary – area between. Where sea water and fresh water mix. Freshwater • Lakes / Ponds / Streams / Rivers • Ponds & lakes have three zones. – Littoral – shallow – near shore (photosynthetic organisms) – Limnetic – close to surface but farther away from the shore – Profundal – deep water zone (bottom feeders) Marine Biome • Nearly ¾ of the earth’s surface is covered by ocean. Almost all of the earth’s surface water is contained in ocean ecosystem –Intertidal Zone –Open sea surface –Deep ocean Marine (Ocean) • Shallow (intertidal zone) – Greatest diversity in ocean – Location of the world’s greatest fisheries – Nutrients wash out from the land Marine Surface of open sea • Apx. 40 % of the earth’s photosynthesis occurs in this region • Plankton – found in this region Deep Ocean • • • • • Deepest waters of the sea Greatest diversity on ocean organisms Marine communities live in total darkness NO light Organisms with light-producing bosy parts are found in this region » Great squids / angle fish Intertidal Shallow Surface Deep Deep Surface Surface Estuary Area between fresh & ocean water