Community Interactions Relationships Between Organisms PredatorPrey Relationships Predators

Community Interactions Relationships Between Organisms

• Predator-Prey Relationships – Predators can affect the size of prey populations in a community and determine the places prey can live and feed • Ex: Fox and rabbit populations

• Herbivore-Plant Relationships – Herbivores can affect both the size and distribution of plant populations in a community and determine the places certain plants can survive and grow • Ex: White tailed deer and food plants

Keystone Species: – A species of great importance to a community – If it’s population changes it can cause dramatic changes to structure of community

– Ex: • Sea Otters off Pacific Coast of North America – Links to Sea urchins, kelp and many other species – http: //www. youtube. com/watch? v=e. Yp. Mq. DNKzs&safe=active

• Beavers (a keystone species) http: //www. youtube. com/watch? v=k. ZVb. Kw. Dmr-o&safe=active

Symbiotic Relationships • Organisms live in close association with each other and at least one benefits. • Relationships that help one or both species to survive • Symbiotic Relationships: • http: //www. youtube. com/watch? v=n. Rk. Wz Lz. Ci 2 U&safe=active

Mutualism: – Both species benefit Ex: • Clown Fish and Sea Anemone • Ants and aphids • “Cleaning Stations” (Rhino and “Tick Bird”)

• Ex: Protozoa in digestive tracts of termites – Termites have cellulose digesting microorganisms in their digestive tract – Provide food and a place to live – Termites could not get nutrients from wood without them. http: //www. youtube. com/watch? v=Ci. BAq 2 a 6 qj. Q&safe=active

• Ant and Butterfly Symbiosis: • http: //video. nationalgeographic. com/video/ animals/bugs-animals/ants-andtermites/ant_caterpillarsymbiosis/ • Goby and Shrimp • http: //www. youtube. com/watch? v=d. Ku. Wl. B j. UFo 8&safe=active

Commensalism: • One species benefits, the other species is neither harmed nor benefitted – Ex: Remora and pilot fish and shark – Eats scraps from sharks meal – Barnacle and whale – Whale travels about, allowing them to get a constantly new supply of food

Parasitism: • One organism benefits and the other is harmed • Generally parasites weaken, but do not kill the host – EX: – Tapeworms in digestive tract – Mistletoe plant: sends roots into host plant and absorbs water, minerals and nutrients – Cowbird (brood parasite) – Leeches, Ticks, Fleas, Lice (feed on blood and skin of animals)

• Check out this Crazy Fungal Parasite! • Cordyceps: http: //www. youtube. com/watch? v=Xu. Kj. BIBBAL 8&safe=a ctive • Body Invaders: • http: //www. youtube. com/watch? v=v. MGLWy. Nc. As&safe=active

• Symbiotic Relationships: • http: //www. youtube. com/watch? v=z. Sm. L 2 F 1 t 81 Q&safe=active

Ecological Succession

Succession in Communities • Changes that take place to communities over time (especially after disturbances). • Living organisms alter their environment making it more suitable for some, less suitable for others • Original organisms slowly replaced by others until climax community is reached • Takes decades or even centuries to develop

Islands of Hawaii • How did they become a tropical paradise? • Started off as volcanic rock.

Primary Succession: • Colonization of new sites (lifeless areas) • Bare rock, new volcanic islands, sand, stream bank (no organic material present) – Slow process – Begins with soil formation

Soil Formation: • Starts with rocks • Erosion by wind/rain causes pieces to break off • Freezing/thawing of water causes cracks to form

Pioneer Organisms: first organisms to colonize barren areas Ex: Lichens: (mutualistic symbiosis between fungus/algae) – Cling to rocks, secrete acids that help break down rock – When they die, they add layer of organic material that starts soil formation http: //teachertube. com/view. Video. php? video_id=182733

• Plants like mosses now can grow in the thin layer of soil • When they die out the soil layer gets thicker and thicker eventually allowing plants with deeper and deeper roots to thrive. • Eventually a climax community develops

Primary Succession

How Long Does it Take? Note: Animal life will also change with the succession of plants Ex: grass eaters – shrub dwellers – tree livers

Climax Community: • Community at the end of line of succession that is mature and stable – Described in terms of dominant plant forms – Type of climax community depends on the physical factors in environment • Ex: – Good soil/good rainfall = forest community – Good soil/less rainfall = grassland community – Climax Communities: – http: //www. youtube. com/watch? v=i. ZA 5 yfrz. LV 8&safe=active

• Examples of Climax Communities: • Sphagnum Bog: shallow lake/pond, peat moss • Mangrove Swamp: muddy tidal flat, mangrove trees • Pine Barrens: sandy peat soil, pine trees

Secondary Succession • Occurs in an area where the climax community has been destroyed • However, SOIL IS STILL THERE! • Occurs at a faster rate, soil is already present. – Ex: – Forest fire, flood, volcanic explosion, human development • • Succession after Fire: http: //www. youtube. com/watch? v=C 2 ZRe_k. IRd. A&safe=active

• Pine Barrens Fire Note: some species require catastrophe to reproduce Ex: Certain pine cones will only release seeds if heated by fire

Secondary Succession Can Happen Here Soil is Established

Succession in Lakes and Ponds • Sediment, fallen leaves, debris gradually accumulate on the lake bottom • Plants take root in the shallower water along edge • Pond eventually becomes a marsh • Eventually fills up becoming dry land

• Succession Summary: • http: //educationportal. com/academy/lesson/ecologicalsuccession-from-pioneer-to-climaxcommunities. html

Biomes of the Earth

Biomes: large geographical regions characterized by a particular type of climax community Have similar: temperature range annual precipitation sun exposure type of soil type of plants and animals

• Temperature Differences: – Not all parts of the earth get the same amount of sunlight – Five times stronger at equator than at the poles – Seasons change due to tilt of Earth’s axis and amount of sunlight over course of the day

• Topography: – Mountain ranges can affect rainfall patterns from one side of mountain to another – Can often see changes in plant communities with increasing altitude as temperature changes

Types of Terrestrial Biomes

Tundra http: //educationportal. com/academy/lesson/biomestundra-taiga-temperate-grassland-and -coastlines. html • Characteristics: – – Low average temp, short growing season Long cold winters where ground is completely frozen Only thin top layer thaws in summer, rest is permafrost Average precipitation 10 -12 cm per year (mostly snow)

Tundra • Vegetation: – lichens, moss, grasses, sedges, shrubs – Almost no trees due to permafrost and short growing season – Nutrient poor soil due to slow rate of decomposition (nutrients recycled slowly)

Tundra • Animals: – Reindeer, mush oxen, caribou, wolves, arctic hares, arctic foxes, lemmings, snowy owls – During warm season: a lot of insects like flies and mosquitoes bring birds, ducks, geese to nest and breed in safety because of relative absence of certain predators

Taiga http: //dsc. discovery. com/tv-shows/other-shows/videos/assignment-discovery-shorts-iii-biomes-taiga. htm • Characteristics: • Cold severe winters, short mild summers • Ground thaws completely in summer (no permafrost), so can support tree growth • Precipitation 35 -40 cm a year with a lot of fog

Taiga • Vegetation: • Mostly coniferous pines, firs, spruce (evergreens) • Soil often acidic due to pine needles

Taiga • Animals: • Moose, wolves, bears, lynx, deer, elk, wolverines, martens, snow shoe hares, porcupines, rodents, birds, insects

Deserts • • • Characteristics: Driest biome Sandy soil, nutrient poor Rainfall less than 25 cm per year (arid) Temp. varies widely during day

Deserts • Vegetation: • Special adaptations to conserve water • Widespread shallow roots to get maximum water when available • Cactus, yucca, mesquite trees, sagebrush, creosote bushes

Deserts • Animals: • Many active at night, sleep during day due to heat • Adaptations to conserve water and radiate excess heat • Fennec, snakes, lizards, spiders, scorpions, foxes, coyotes, hawks, owls, kangaroo rat http: //www. youtube. com/watch? v=7 Ifk 9 IJl 0 A 0&safe=active

Temperate Deciduous Forests • • Characteristics: Cold winters, hot and humid summers Growing season about 6 months of year Rainfall 75 -150 cm per year

Temperate Deciduous Forests • • Vegetation: Soil: thick top layer of humus Mostly deciduous trees Period of plant dormancy during winter (lose leaves) • Oak, maple, hickory, beech, chestnut, birch, shrubs, herbaceous plants, ferns and mosses

Temperate Deciduous Forests • Animals: • Many hibernate during winter • Wolf, fox, bobcat, deer, raccoon, squirrel, chipmunk, rabbits, salamanders, birds (many migrate during winter)

Grasslands • Characteristics: • Prairies, steppes, pampas, savannah • Occurs in both temperate and tropical climates • Rainfalls is 25 -75 cm per year (usually with dry season) • Soil deep and rich, (good farmland) • http: //www. youtube. com/watch? v=msd. Y-JJilz. M&safe=active

Grasslands • Vegetation: • Many species of grass (rye, oat, wheat) and wild flowers • Where more water present, shrubs and some trees may develop.

Grasslands • Animals: • North America: coyote, rattlesnake, prairie dog, jack rabbit, bison, pheasant, prairie chicken, hawk, owl • Africa: zebras, giraffes, gazelles, lions, elephants

Tropical Rain Forests • Characteristics: • Most biologically diverse ecosystem • Greatest number of species per unit area • Uniform warm wet climate through year • Constant rainfall 200400 cm per year

Tropical Rain Forest • Vegetation: • Broad leaved plants, most do not lose leaves • Little light hits lower canopy • Only shade tolerant trees, vines and shrubs, grow below tall trees • Little organic material in soil (poor farmland) • Organic materials decay quickly and recycle back into living plants

Tropical Rain Forest • Animals: • Wide variety, many are adapted to live at a particular level of the canopy • Monkeys, bats, parrots, snakes, lizards, tapirs, insects

Aquatic Ecosystems • Major Abiotic Factors: – Water depth: • Photic Zone: sunlight can reach it, photosynthesis can occur • Aphotic Zone: deeper water, photosynthesis cannot occur – Amount of dissolve gasses and nutrients • Oxygen and Carbon Dioxide, Nitrogen, Phosphorus

Aquatic Ecosystems • Marine Biomes (saltwater oceans) – Largest most stable biome (70% of earths surface) – Most photosynthesis on Earth is done here by algae near ocean surface – Oceans absorbs and hold large quantities of heat and help to regulate Earth’s temp. – Temperature very stable, changes less during the day than on land

• Marine Animals: • Ocean floor (benthic life): Sponges, corals, barnacles, anemones, starfish, clams, snails, crabs • Free Swimming: squid, fish, turtles, seals, whales

• Plankton: float near surface and are carried by currents • Phytoplankton: Photosynthetic producers • Zooplankton: Consumers • Form basis of food web for whole marine ecosystem

• Zones of the Oceans • Intertidal Zone: – High tide: submerged – Low Tide: exposed to air & sunlight • Coastal Ocean (Littoral Zone) – Shallow, slopes to open ocean – Contains nutrients carried into ocean by rivers and streams • Open Ocean – Deep water, photic & aphotic zones – Most photosynthesis happens here • Deep Ocean – No sunlight, under high pressures – Food webs based on dead organisms that fall from above or on chemosynthetic organisms

• Estuaries: – Saltwater meets freshwater (where river meets the sea) – Excellent nurseries to raise young aquatic wildlife (offers protection)

• Freshwater Biomes – Ponds, lakes, streams, rivers, wetlands (swamps and bogs) – Provide most land animals with fresh drinking water – Many be nutrient rich or poor depending on amount of sediment