Chapter 4: Ecosystems and Communities 4-1 The Role of Climate
Climate Climate: long-term, averages, over entire biome Weather: short-term, local day to day Greenhouse Effect It’s a good thing! CO2, H2O, CH4 all trap heat and hold it next to the surface Keeps the temp suitable for life Solar Energy
The Effect of Latitude on Climate Earth has 3 climate zones due to unequal heating because of the angle of the sun. Most intense heating is near the equator. Polar Temperate Tropical
Heat Transport Ocean and wind currents help produce Earth’s climates The ocean is a huge heat sink for the earth. Currents and winds are affected by land masses and Earth’s rotation
4-2 Niches and Community Interactions
The Niche Niche – Where and How something lives; its role Habitat is the organism’s address Niche is the organism’s occupation
Dendrobates tinctorius dyeing poison dart frog http://animaldiversity.ummz.umich.edu/site/accounts/information/Dendrobates_tinctorius.html Contributors Matt Jolman (author), Michigan State University. James Harding (editor), Michigan State University. References Obst, F. 1988. The completely illustrated atlas of reptiles and amphibians for the terrarium. Neptune City, NJ: T. F. H.. Walls, J. 1994. Jewels of the rainforest. NJ: THF. An analysis of niche Poison Dart Frog – discovery Camouflage
What defines a niche? Where it lives What it eats What eats it How it reproduces Humid, wet habitats; on or close to ground (skin is not waxy enough to prevent dehydration) South America Tadpoles eat almost anything Adults = insectivores; ants termites, spiders Few predators – poisonous Eggs laid on land, male fertilizes directly over top and then carry the nearly hatched tadpoles on his back to water.
What defines a niche…cont… What nutrients it needs Movement Range of tolerance How it interacts with others/abiota Role it plays in energy flow and nutrient cycling Needs natural diet to create poisons. Toxins not produced on captive diets (lack alkaloids) Finger & toe tips have glandular adhesive pads that enable climbing 70-80F, 60% humid, 10hr light, Cl-free water Stands out b/c it’s poisonous Respires through skin, consumer (omnivore)
COMMUNITY INTERACTIONS Problem: 2 niches overlap WHAT IS YOUR SOLUTION? Migrate Change feeding habits Adapt behavior Suffer a sharp population decline Become extinct in that area What type of species overcome this more easily? Generalists or Specialists? generalist
Phrased another way: I want something that you want… Will we compete? Will I eat you? Will we work together some how? In nature, there are 3 basic types of interactions… Competition Predation Symbiosis Phrased another way…
Community Interactions Competition Organisms compete for resources Ex: Food, Mates, Shelter Competitive Exclusion Principle – no 2 organisms occupy same niche at same time. Predation One organism (predator) captures and feeds on another (prey).
Community Interactions Symbiosis Mutualism – both benefit Ex: Flowers & insects Egrets & Alligators Clown Fish & Sea Anemone Commensalism – one benefits, the other is not helped or harmed Ex: Barnacle & Whale Parasitism – one benefits, other is harmed Ex: tapeworms, fleas, ticks, lice
Community Interactions Symbiosis Mutualism – both benefit Ex: Tapeworm Commensalism – one benefits, the other is not helped or harmed Ex: Parasitism – one benefits, other is harmed Ex: tapeworms, fleas, ticks, lice Species Interactions
Examples of Symbiosis
Invasive vs. Native Species Indicator Species Keystone Species Specialty Niches Invasive vs. Native Species Indicator Species Keystone Species
Invasive Species Purple loosestrife & Kudzu Introduced by accident (zebra mussels like quaga mussel in life after people and green crab); introduced on purpose (ornamental loosestrife & kudzu to control erosion in the southeast but took over) Purple loosestrife & Kudzu Carcinus maenus, the European Green Crab, was introduced to North America in the 1800's. This predator now ranges from Nova Scotia to Delaware.
3 examples: Macquarie Island / Pythons/Asian Carp http://www.youtube.com/watch?v=QOxoZB6PxpU&playnext=1&list=PLB127E4EA44F5FC28 http://www.youtube.com/watch?v=PjaM7wBWWoc&feature=relmfu http://www.youtube.com/watch?v=mUssO68D2eM (to 6:30)
Native Species
Indicator Species Indicates the health of the ecosystem
Keystone Species Kelp forest Sea Otter Dung Beetle A keystone species is a species that plays a critical role in maintaining the structure of an ecological community and whose impact on the community is greater than would be expected based on its relative abundance or total biomass. Kelp forest Sea Otter Dung Beetle
Foundation Species species that create habitats for themselves and a wide range of other species
4.3 ECOLOGICAL SUCCESSION Biosphere Ecosystems Communities Populations Organisms 4.3 ECOLOGICAL SUCCESSION
What is succession? TIME
Is Disturbance a Good Thing? Life is always changing and then responding to that change. Plant (& therefore animal) species are constantly being replaced with more complex species This is called ecological succession
Arrange the pics in the correct order…
Ecological Succession Primary OR Secondary Succession? Depends on starting conditions: Is there any soil present? Does not matter if life had been there previously or not
PRIMARY SUCCESSION Lifeless beginnings Starts WITHOUT SOIL. Examples: Bare rock exposed by glaciers or severe erosion Newly cooled lava Abandoned highway or parking lot Newly created shallow reservoir
PRIMARY SUCCESSION Life begins with PIONEER SPECIES Hardy, small Population grows quickly Grow close to the ground Ex: bacteria, moss, lichens
SECONDARY SUCCESSION Starts WITH SOIL. start from roots or seeds remaining or seeds carried in by wind or animals Examples: Abandoned farms Heavily polluted streams Ponds from dams or flooding
Succession of Plants Pioneer species make an area suitable for more plants A process called “facilitation” Early successional species Can withstand little nutrient availability A little taller than pioneers: small herbs, grass
Plant succession continued Mid-successional species Need more fertile soil w/ moisture Must wait for some decomposition Tall grass & low shrubs, eventually sun-loving trees Late-successional species Need deep, fertile, moist soil Slow growth rate shade tolerant trees
Climax Community Succession is unpredictable While it generally proceeds from small to tall, each disturbance is unique and each pioneer is unique…leading to unique community developments The most mature community is called the climax community
Primary on top, secondary on bottom: difference is soil starting point
http://www.fs.fed.us/photovideo / 38
Disturbances can lead to opportunity for others Hurricanes… In S. Fla. the Everglades depend upon the periodic hurricanes for the continued existence of the mangrove. Why? Primary or secondary? Importance of Mangroves
PUT IN ORDER OF SUCCESSION POND SUCCESSION Review PUT IN ORDER OF SUCCESSION 40
M&M’s Weather vs. Climate Red = Warm and Sunny Yellow = Warm and cloudy Green = Cool with light rain Blue = Cold with steady rain Orange = Hot, sunny Brown = Hot very humid and sunny