Assessment 2 Notes - Bio 10B PDF

Assessment 2 Notes - Bio 10B Week 3 Lab Notes Bar Graph ○ Categorical data Scatterplot ○ Continuous data Week 3 Lecture Notes Introduction to Ecology Ecology: the study of the abundance and distribution of organisms as shaped by environmental factors ○ Ecologists are very interested in how biotic an...

Assessment 2 Notes - Bio 10B Week 3 Lab Notes Bar Graph ○ Categorical data Scatterplot ○ Continuous data Week 3 Lecture Notes Introduction to Ecology Ecology: the study of the abundance and distribution of organisms as shaped by environmental factors ○ Ecologists are very interested in how biotic and abiotic factors influence this ○ What are the “environmental factors” that ecologists might be interested in? Abiotic factors Precipitation, sunlight, nutrients, weather patterns Biotic factors Predators, prey, mutualists, parasites, mates, any living organism that can influence other living organisms ○ How is this the same as and different than the way evolutionary biologists consider environmental factors? Same: the environment is the environment; the processes both of these types of scientists are interested in are the same; they are inextricably linked - the organisms that we see today are a product of their evolutionary history, the environmental factors that they’ve been exposed to over time have shaped the phenotypes that we see and those phenotypes are what’s interacting with one another and the environmental factors that exists today Different: ecologists and evolutionary biologists look at life in different time scales - Ecologists study what’s going on with organisms in real time while evolutionary biologists study what’s happened to organisms in deep time, over hundreds if not millions of years ○ ○ There are different scales of organization or study From bottom to top: Organismal ecology aka physiological ecology: How do the physiological processes of an organism dictate its distributions and abundance Ex: lizards - usually you don’t see reptiles in the colder/pole regions, this is because of the physiology of lizards such that they are ectotherms and depend on external heat sources to fuel their internal temperature, if they lived in the poles they would never warm up to even move. Lizards in the early morning move pretty slow but after heating up in the sun they become quite fast Population ecology Studies multiple individuals that belongs to the same species A bunch of individuals of the same species living in a location Population ecologists are interested in the factors that affect birth and death rates so they’d like to look at how populations are growing or shrinking over time Community ecology Study of all of the species that live close enough in a location to interact ○ Ground squirrels, snakes, butterflies, the trees, ants, bacteria, fungi All of the species that are in this area that potentially have interactions with one another Ecosystem ecology Broader These are the living members of the community and the abiotic components that interact with those living members of the community ○ The water cycle, carbon cycle, nitrogen cycle, fire, any abiotic factor that affects the community, or cycles within the community ○ Carbon cycle: carbon is a molecule and exists in different types of forms and lots and lots of carbon is contained in living organisms, when those living organisms die that is returned to the soil, carbon is also in our atmosphere in the form of carbon dioxide That illustrates that abiotic and biotic interaction Biosphere This level of organization deals with the whole planet Ecosystems of these large biomes and large geographical areas that are very similar but the biosphere is the collection of all the biomes on the planet. ○ These the processes that influence the entire globe Biomes ○ Biomes are dictated by two factors Precipitation and temperature Week 7 (Week 6 content) Lab Notes What do we know about the rocky intertidal & community ecology? Community ecology: My response: ○ Study between species that live in a community and how these interactions affect their distribution and abundance. ○ Study of all of the species that live close enough in a location to interact Ground squirrels, snakes, butterflies, the trees, ants, bacteria, fungi All of the species that are in this area that potentially have interactions with one another Class Response ○ Interspecific interactions include competition, predation, & symbiosis (mutualism & parasitism) ○ Diversity depends on survival of species & their relative abundance ○ Ecology is the study of how environmental factors affect the distribution & abundance of species Rocky intertidal My response: ○ In the tidal area, like near the ocean, we understand that there are tides. There’s high/upper tide, mid tide, and low tide. This in of itself is its own type of biome or environment for species to be living in. The species that live here are called the rocky intertidal communities. They have adapted/changed/evolved over time to be able to live and thrive in the “rocky intertidal” area. Many such species have to be able to live in both water and land. They need to be able to handle constant heat from the sun, dry periods of time, and be strong and hard enough to survive the force of the tides on them against the hard rocks. Many of them also don’t want to be pulled off to the deep sea so a lot of them know how to stay stuck to the rocks. ○ 3 zones: low, middle, high Changes in the tide caused by gravitational pull of moon + sun High zone (exposed to air >50% of the day) Mid zone Low zone (submerged >50% of the day) ○ Organisms are impacted by the exposure ○ Predation Terrestrial organisms or aquatic ○ Ex: In SoCal there are 2 high tides and 2 low tides in a day ○ Ex: -0.50 Means that 0.5 feet below the mean tide levels Doesn’t mean negative tide ○ Usually takes about a few hours to tides to rise and lower ○ Competition Especially for space It’s a generally small area Many are sessile ○ “Don’t move” ○ Ex: Barnacles Some competition for food But many are filter feeders ○ Mid + low zones are favorable habitats Class Response: ○ Rocky intertidal zone is exposed to both land & H2O during the day ○ Zones include high, mid, & low Each zone is defined by certain species ○ Competition for space is high ○ Prolonged competition can lead to local extinction or partitioning of the niche ○ 2 low and 2 high every day Challenges of the upper intertidal zone Wave force Desiccation (drying out) ○ High temps Terrestrial predators Changes in salinity Class Hypothesis Diversity will be highest in the low Diversity will be lowest in the high Diversity will be intermediate in the mid Independent variable = zone Dependent variable = diversity Shannon's index practice 𝐻= 𝑃𝑖 Species − Σ𝑃𝑖𝑙𝑛𝑃𝑖 𝑃𝑖𝑙𝑛𝑃𝑖 1 0.1 0.230 2 0.05 0.150 3 0.05 0.150 4 0.8 0.179 H=> 0.708 1 0.25 0.347 2 0.25 0.347 3 0.25 0.347 4 0.25 0.347 H=> 1.386