Ecosystems and Communities

Cycles of matter Unlike energy, matter is constantly being recycled in an ecosystem. Known as biogeochemical cycles

Transpiration The release of water from the leaves of plants. Water is exchanged through a plant’s stomata. Evaporation is the second process that releases water into the atmosphere.

Carbon Cycle 1. Biological processes (photosynthesis, respiration, decomposition) 2. Geochemical processes (volcanoes) 3. Biogeochemical (fossil fuels) 4. Human activity (factories, deforestation, car exhaust)

Nitrogen Cycle All organisms need nitrogen to live. Most abundant gas in atmosphere (80%) Nitrogen gas is unusable for plants Must be “fixed” or changed into the nitrate or nitrite form by bacteria in the soil. Known as nitrogen fixation

Phosphorus cycle P is important in the production of DNA and RNA. Unlike water,oxygen, and nitrogen, phosphorus is NOT found in the atmosphere. Found in rocks and minerals.

Nutrient Limitation When a single nutrient is scarce for a particular ecosystem and limits the growth of organisms in that ecosystem. Assignment: page , 12, 15, 16, 18, 22, 23, 29 Page

4-1 The Role of Climate What is Climate? __Weather__: day-to-day condition of Earth’s atmosphere at any particular time and place __Climate_____: average, year-after-year conditions of temperature and precipitation in a particular region; depends on Heat trapped by atmosphere Latitude Heat transport wind & ocean current Amount of precipitation Shape & elevation of land

The Greenhouse Effect ________Atmosphere_____: serves as natural insulating blanket that maintains a suitable range of temperature on Earth _______Greenhouse gases____: CO 2, methane, water vapor, and other gases that trap the heat energy of sunlight inside Earth’s atmosphere and maintain Earth’s temperature range  this is called the… __Greenhouse Effect!

Sunlight Some heat escapes into space Greenhouse gases trap some heat Atmosphere Earth’s surface

4-2 What Shapes an Ecosystem? Biotic and Abiotic Factors ________Biotic_______ FACTORS: biological influences on organisms within an ecosystem; entire living cast of characters with which an organism might interact _________Abiotic_____ FACTORS: physical, or nonliving, factors that shape ecosystems (temp, precipitation, humidity, wind, nutrients, soil type, sunlight) ______Ecosystem__: area where an organism lives: both factors determine the survival, growth and productivity of the organism

BIOTIC FACTORS: _frog, algae ABIOTIC FACTORS: water, sunlight

The Niche _Niche_: full range of physical and biological conditions in which an organism lives and the way it uses those conditions (occupation) (ex) what it eats, how it gets food, predators, physical conditions for survival, when/how it reproduces, place in food web, etc. No two species can share the same niche in the same habitat but different species can occupy similar niches…for example:

Three Species of Warblers and Their Niches Bay-Breasted Warbler Feeds in the middle part of the tree Yellow-Rumped Warbler Feeds in the lower part of the tree and at the bases of the middle branches Cape May Warbler Feeds at the tips of branches near the top of the tree Spruce tree

Community Interactions Interactions between organisms can powerfully affect an ecosystem: 1. _Competition __: compete for same resource in same place at the same time 2. _Predation_____: predator kills & eats prey 3. __Symbiosis___: when 2 organisms live closely together – 3 different types of relationships: MUTUALISM: both benefit (ex) flower/pollinator COMMENSALISM: one benefits, other neither harmed nor helped (ex) barnacles/whales PARASITISM: one lives in or on another and harms it (ex) fleas, ticks, tapeworm, lice

2)predation

3) Symbiosis - _mutualism__

Symbiosis - __commensalism____

Symbiosis - parasitism

Feeding relationships all food chains start with energy from the sun first level of all food chains is plants most food chains usually go up only 4 or 5 levels all levels connect to decomposers Food chains Fungi Level 4 Level 3 Level 2 Level 1 Decomposers Producer Primary consumer Secondary consumer Tertiary consumer Top carnivore Carnivore Herbivore Sun Bacteria

Feeding levels How much energy can you get from food? only the energy that is stored in the organism Approximately 10% energy lost from one level to next food chain can only have 4 or 5 levels

Food webs Food chains are linked together into food webs Who eats whom? eating meat? eating plants? Many connections throughout ecosystem

Energy flows through… sun secondary consumers (carnivores) primary consumers (herbivores) producers (plants) loss of energy

Food chain pyramid Loss of energy between levels of food chain can feed fewer animals in each level 1,000,000, , Numbers

Ecological Succession Do ecosystems change? ___Yes____!! They are constantly changing in response to natural & human disturbances…this is called: Ecological_SUCCESSION: series of predictable changes that occurs over time in a community ___Primary_SUCCESSION: occurs on lands where no soil exists, just ash & rock (ex) volcanic eruptions build new islands ___Pioneer_ORGANISMS: first species to populate area ___Secondary_ SUCCESSION: when a disturbance is over and the community interactions tend to restore the ecosystem to its original condition (ex) after wildfires or land is cleared

Primary_ SUCCESSION

Secondary SUCCESSION

Succession in a Marine Ecosystem 3 Stages in the Succession of a Whale-fall Community 1. A disturbance caused by a whale sinking to the bottom of the ocean; scavengers and decomposers come 2. Most of the tissues are eaten; decomposing body enriches surrounding sediments 3. Skeleton remains are decomposed by bacteria, releasing oils that are used by chemosynthetic bacteria (support diverse community near the bones)

SCAVENGERS & DECOMPOSERS: amphipods, hagfishes, sharks

Carcass supports fishes, crabs, snails, worms

Whalebones encrusted with bacterial mats  chemosynthetic bacteria support mussels, limpets, snails, worms, crabs, clams