Ecology Exam 219 cards

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1

Resources Required for Life

1. Water 2. Energy: light, organic molecules (C), inorganic molecules 3. Nutrients (N,P, etc) raw materials for development, maintenance, and reproduction Life: energy&nutrients->offspring

2

Energy

-The capacity to do work (e.g. motion) -Neither created or destroyed-changes form (e.g. heat and chemical bonds)

3

Energy2

-Solar energy (rays)-chemical bonds (glucose) :Photosynthesis->used by plant or stored for other organisms (loss at each level)->Glucose to ATP, eventually converted to heat energy (random molecular motion) not available for the most part by biologic

4

Two ultimate pathways that energy enters biological systems

-photosynthesis: (solar energy + CO2 -> Glucose) -Chemosythesis: (inorganic molecule + CO2 -> Glucose) H2S: deep sea vents NH2 & NO2: Nitrifying bacteria in soil. Great ecological importance. -Autotrophs-make their own organic C molecule (glucose

5

Photosynthesis "Carbon Fixation"

Photosythesis (e.g. cyanobacteria, algae, plants) sunlight CO2+H2O -> C6H12O6 (sugar) +O2+H2O -visible light is just right at 45% solar energy -light quality and quantity change spatially and temporally . Heterogenity

6

Heterotrophs

1. herbivores-eat living plants & plant parts 2. carnivores-eat animals 3. detritivores-eat non-living organic matter (dead plants) decomposers -more specialized catagorization (omnivores, insectivores, piscivores, etc) -various ways of maximizin

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Chemical composition and nutrient requirements

-C, O, H, N, P, comprise 93-97% of biomass in organisms (proportion varies) N-amino acids; nucleotides, nucleic acid P-ATP, nucleotides/nucleic acid, phospholipids Plants-C from air nutrients from soil Animals-C and nutrients from food they eat

8

Herbivores

Consume plants and living parts Overcome 2 main problems -low nutritional value and hard to digest plants -physical and chemical defenses of plants

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Herbivores Low nutritional values and hard to digest plants

-strengthening compounds-cellulose and lignin -make C&N ration even higher --most animals cannot digest cellulose and lignin --require help of bacteria,fungi, protists in digestive tract (ruminant stomach) --long digestive tract-eat a whole lot

10

Herbivores Physical and chemical defense of plants

physical:thorns, spines, etc chemical:toxins (kill, impair, or repel) -1,000s isolated by chemicals -more common and higher toxicity in tropics -tobacco plants-nicotine

11

Carnivores

-consume nutrient rich food (prey) -complex predator/prey interactions -carnivores (predators) must overcome prey defenses -camouflage, mimicry -anatomical defenses-spines, shells -behavioral defenses-flight, run, refuges, f

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Carnivores-predator/prey interactions

-predator is the force driving selection and therefore refining the prey's defense -prey size consumed is usually correlated with predator size (size-selection predation)

13

Detritivores

feed on non-living organic matter (dead plant material) food is rich in carbon and energy but very low in N -Macro-decomposers millipedes, some beetles -isopods -earthworms -aquatic insect larvae -Micro-decomposers -bacteria -fungi

14

Energy Limitations

availablity of energy is not the only issue organisms face. The rate at which an organism can take up energy is limited. -individual internal constraints-digestion, handling time(time it takes to process food-chasing prey, cracking shells) -eternal

15

Energy Acquisition Limitations in Plants

plants cannot fix an unlimited amount of carbon even when CO2 and light are in abundance. Shade vs Sun Species-the shaded plant is adapted to be more efficient at fixing C at low light levels

16

Energy Acquisition Limitations in Animals

-all things equal, animals cannot consume an unlimited amount of prey per unit time -3 primary functional response patterns observed as you increase prey density. 1. filter feeding organisms that require very little handling time. 2. most common,

17

Energy Acquisition Limitation in Animals Cont.

Type 2: functional response is most commonly observed in nature. (occurs in both herbivores and carnivores)

18

Energy Economics: the energy budget

Life: energy & nutrients -> offspring principle of allocation:if energy uptake is limited an organism cannot fully meet all energy demands -compromise between competing demands -growth -reproduction -food acquisition -de

19

Optimal Foraging Theory

So predators are selective-search for the perfect prey item