Transcript Ecosystems
Ecosystems Relationships and Populations Biotic and Abiotic Factors (Living and Non-Living) Abiotic Factors Biotic Factors ECOSYSTEM Niche Part of the environment that an organism uses ROLE + HABITAT Warbler Niche Cape May Warbler Feeds at the tips of branches near the top of the tree Bay-Breasted Warbler Feeds in the middle part of the tree Spruce tree Yellow-Rumped Warbler Feeds in the lower part of the tree and at the bases of the middle branches Community interactions Competition individuals or species trying to use the same limited resource Competition competitive exclusion principle – 2 species cannot occupy the same niche in the same habitat at the same time Predator/Prey - +/-the predator catches the prey - One organism captures and kills another http://www.wallpaperbase.com/wallpapers/animals/tiger s/tiger_6.jpg http://inspectorgadget.files.wordpress.com/2007/12/tiger.jpg Symbiosis Two species living closely together http://sugarmtnfarm.com/blog/uploaded_images/ClownInBubbleAnemone200511-780236.jpg Symbiosis a. Mutualism - +/+ both species benefit Symbiosis b. commensalism - +/0 – one benefits, the other is not helped nor harmed Example – a bird’s nest in a tree OR barnacles on whales Symbiosis c. Parasitism - +/one species benefits (parasite), one is harmed (host) Ecological Succession – natural progression of an environment 1. primary succession – starting where there is no soil http://www.v-liz.com/galapagos/isabela/puntam~1/lavacac-.jpg 2. secondary succession – where there was a community, but it has been removed Climax Community – last stage of succession, ecosystem has reached equilibrium Important characteristics of populations •geographic distribution – the area inhabited by a population •density – number of individuals per unit area •growth rate – depends on birth rate and death rate •density – number of individuals per unit area low density high density Exponential growth ideal conditions unlimited resources Growth rate of bacteria •some bacteria can divide every 20 minutes •first 20 minutes – there will be two bacteria •in one hour - there will be 64 bacteria •in one day – there would be: 4,720, 000,000,000,000,000,000 or 4.72 x 1021 Logistic growth as resources become limited •growth rate slows or stops •carrying capacity is reached •Carrying Capacity – maximum population size an area can support Logistic Growth – S shaped curve, levels off at the Carrying Capacity Carrying capacity Time (hours) Limiting factors nutrient space carbon dioxide level density-dependent – competition, predation, disease, parasitism density-independent – weather, human activities, seasonal cycles Populations are dependent on Predator/Prey Relationships Age-structure diagram shows number or percentage at each age