Bio 1B Ecology

Environmental gradient

are

a steady change in an environmental variable (e.g. temperature) through space

Environmental (elevational) gradient

the measurable and predictable change in environmental conditions, climate, and biological communities that occurs as altitude increases along a slope or mountain

Environmental (latitudinal) gradient

are a

steady change in the

environment across latitude

Abiotic factors

all the non living components of the ecosystem. So that is the temperature, the light availability, the water, the soil, the pH, the nitrogen, phosphorus availability, all of those kinds of non living things that are important to organisms.

biotic factors

the living things within the ecosystem. So this is the microbes, the fungi, the plants, the animals, all of the living organisms.

Species range limits

the geographic or ecological boundaries where a species’ distribution stops, shaped by a complex interplay of abiotic conditions, biotic interactions, and evolutionary constraints

Air circulation

the large-scale movement of air across Earth's surface that redistributes thermal energy and moisture from the equator to the poles

Traditional ecological knowledge

the cumulative, place-based body of knowledge, practices, beliefs, and philosophy regarding the dynamic relationships between living beings and their environment

Equatorial, polar regions

driven primarily by Earth's spherical shape, axial tilt of 23.5°, and the resulting angle of incoming solar radiation

Precipitation

any form of water—liquid or solid—that condenses from the atmosphere and falls to the Earth's surface

Temperature

a measure of how hot or cold something is, based on the average kinetic energy (energy of motion) of the atoms and molecules inside a substance

Equinox

a twice-yearly event when the Sun is positioned directly above the Earth’s equator, making day and night approximately equal in length across the globe

solstice

event that happens twice each year ,when the Sun reaches its farthest northern or southern point relative to the Earth's equator.

Atmospheric pressure

the force per unit area exerted by the weight of the air column in Earth's atmosphere

leeward

the side, zone, or direction facing away from the wind or sheltered from it (downwind)

Windward

positioned on, facing, or moving toward the direction from which the wind is blowing (upwind)

Rain shadow

a dry patch of land on the side of a mountain range that faces away from the prevailing winds (the leeward side)

Arid

land or a climate that is extremely dry and lacks enough moisture or rainfall to support most trees and woody plants

Maritime climates 

a regional weather pattern heavily shaped by the moderating influence of the ocean, featuring mild temperatures, small seasonal variations, and steady, year-round precipitation

temperate/continental

(23.5-~60ºN): highly seasonal, cold winters and warm/hot summers, large landmasses in northern hemisphere

tropical climates 

(0-23.5º): Warm, wet, weakly seasonal (wet/dry seasons)

L13:Describe the factors impacting the development of the current field of western ecology. What other systems of knowledge contribute to our understanding of ecology?

L13:What are the two main abiotic factors impacting organismal distributions on land? How about in the ocean?

Land is temperature and precipitation. And for the ocean it is light and nutrients

L13:Give an example of how one of those factors changes along an environmental gradient. How does the environment change as you go up in latitude from the tropics to the poles? How about when you go up a mountain?

L13:Where do we find the hottest environments, globally? The wettest terrestrial environments? The driest?  Why? Relate it to the angle of the sun and air circulation patterns.

L13:What does it mean for an environmental gradient to be steep or shallow? Give an example contrasting a steep and a shallow environmental gradient, and one that has changed over time.

L13: Why do they go to the beach for summer holidays in December in New Zealand, but have snowmen and sleds on their Christmas cards? Explain with reference to the tilt, angle and rotation of the Earth around the sun, and use the words "solstice" and “equinox”.

L13: Explain why there are deserts at around 30N and 30S, drawing on principles of thermodynamics and Hadley cell circulation.

L13: How does air pressure change as you go up a mountain? How does this affect people? How does the temperature change as you go up a mountain?

L13: One side of the Himalayas (the Tibetan plateau) is very dry. Why does that happen? Use the terms rain shadow, windward, and leeward in your explanation.

Biodiversity

the variety of all living things on Earth and the ecological complexes they form

Latitudinal diversity gradient

the well-documented ecological pattern where species richness and biodiversity increase from the polar regions toward the equator for a vast majority of terrestrial and marine organisms

Alpha diversity

the mean species diversity within a specific site, habitat, or single sample at a local scale

beta diversity

a measure of the difference in species composition between two or more local sites or ecosystems

gamma diversity

the total species diversity (species richness) across a large landscape, region, or biome that includes multiple distinct habitats or ecosystems

Organism environment interactions

Interactions between organisms and their environment form the core of ecology, the scientific study of how living things relate to each other and to the physical world. Abiotic and Biotic

Dispersal

the movement of individuals, species, or propagules (such as seeds, spores, or larvae) away from their birth site or current population to a new location where they may settle and reproduce

Geographic range

the total spatial area where a species lives, moves, or reproduces during its lifetime

Abiotic tolerances

the non-living environmental limits—such as temperature, pH, salinity, and moisture—that an organism can withstand before its internal systems and cellular functions fail

Biome

a large, naturally occurring global or regional community of plants and animals (flora and fauna) adapted to a specific climate, temperature range, and level of precipitation

Primary productivity

the rate at which plants and other photosynthetic organisms convert light or chemical energy into organic compounds

tundra biomes

cold, treeless regions characterized by permanent sub-surface frost, low precipitation, and short growing seasons

tropical forest biomes

a hot, humid ecosystem located near the Earth's equator that features high annual rainfall, extreme biodiversity, and distinct vertical vegetation layers

coniferous forest biomes

a terrestrial ecosystem dominated by cone-bearing, needle-leaved evergreen trees such as pine, spruce, fir, and larch

Chaparral biomes

a shrubland community shaped by a Mediterranean climate of hot, dry summers and mild, wet winters

desert biomes

a dry terrestrial ecosystem that covers about one-fifth to one-third of Earth's land surface and receives less than 25 centimeters (10 inches) of precipitation a year

Mediterranean climate

a temperate climate defined by hot, dry summers and mild, wet winters

Niche

the specific functional role, position, and way of life a species has within an ecosystem

L14:Where on Earth does biodiversity tend to be highest, and what are some hypotheses for why that might be the case?

Tropical Forest because of its high precipitation, wet and dry seasons, temperature high and aseasonal.

L14:How do scientists measure biodiversity, and what types of diversity do we consider? How do we describe changes in biodiversity across a landscape? Why might we want to do this, give an example.

L14:Calculate ꞵ-diversity using the equation on slide 18 for the population pairs S2-S3 (check your answer -  if you get it wrong, do S3-S1 next).

L14:What determines where a species can live? Discuss the role of dispersal, abiotic tolerances, and species interactions.

L14:What is a biome, and what determines the positions of the major terrestrial biomes? to their abiotic conditions and predict their order along a latitudinal or elevational gradient, and give examples of characteristic plants and animals.

Its a major life zone characterized by characteristic plant communities. The location of these biomes is determined by the abiotic conditions, especially temperature and precipitation and terrestrial ecosystems

L14:Why is Berkeley’s climate considered “Mediterranean”? What are the characteristics of a Mediterranean climate?

is characterized by winter rain, so precipitation in the winter, very dry summers, and slight seasonal temperature variation, but it's not as pronounced.

L14:How do the biomes change along elevational and latitudinal gradients, and why are there similarities in the sequence? Compare and contrast an elevational gradient at the tropics versus the poles. 

L15:What are the benefits of biodiversity for humans?

Diverse pollinators support plant reproduction. Soil health and nutrient cycling .Increased primary productivity. Provides resilience to environmental changes. Cultural, aesthetic, and recreational value. Maintain genetic diversity for the future. Food security

15: How does biodiversity impact ecosystem productivity and resilience to extreme weather events?

L15: What traits define the life history of an organism?

Size at birth. Growth pattern. Age and size at maturity. Number, size, and sex ratio of offspring. Age- and size-specific mortality and reproduction. Length of life. Duration and investment of parental care

L15: Contrast the key life history traits that distinguish beech trees, wrasse (reef fish), drosophilid flies, and albatross. How do these map to the r- to K- continuum?

L15:Name the three common types of survivorship curves with example, type 1

Low death rates during early and middle life and a sharp increase in death rates later in life Found in large animals (for example, humans, albatross, and elephants) that produce few offspring but provide them with good care

L15:Name the three common types of survivorship curves with example, type 2

Constant death rate throughout life Found in some rodents, invertebrates, lizards, and annual plants

L15:Name the three common types of survivorship curves with example, type 3

High death rates for the young; death rate steeply declines for survivors of early period die-off

L15:How do the life history characteristics of these species lead to the patterns of mortality shown in their survival curve? (Survivorship curve)

L15:Why don’t organisms live for a long time AND reproduce a lot? Explain the principle of allocation and how it leads to life history trade-offs. Name three key life history trade-offs, and illustrate one of them by explaining why mice abandon their young when facing a food shortage.

Net Primary Productivity

NPP) is the total amount of biomass produced by plants

Resilience

is the ability to bounce back after a setback

Life history traits/strategies

the evolutionary and biological characteristics that define an organism's pattern of growth, development, reproduction, and survival over its lifetime

Life table

is an age-specific summary of the survival and reproductive rates within a population

Demography

is the statistical study of populations

Survivorship/mortality curves

a plot of the proportion or numbers in a cohort still alive at each age, and shows the pattern of survivorship for a population

Resource allocation

how an individual organism, cell, or population distributes its finite supply of energy, nutrients, and time among competing biological functions like growth, maintenance, reproduction, and defense

Life history/resource allocation trade-offs

the evolutionary compromises organisms make when dividing finite resources (such as energy, time, and nutrients) among competing life functions: growth, maintenance, and reproduction

Costs of reproduction

the evolutionary trade-off where investing energy, time, or resources into current offspring reduces an organism’s capacity for future survival, growth, or subsequent reproduction

Somatic maintenance

is energy spent to maintain the body (soma). Often equated with allocating resources to survival (in contrast to reproduction)

Reproductive strategies (semelparous)

reproduces only once (short adult lifespan)

Reproductive strategies ( iteroparous)

reproduces multiple times throughout life (long adult lifespan

r- selection

(r = intrinsic growth rate): elects for life history traits that maximize reproduction and the ability for a population to increase rapidly at low density

K- selection

(K = carrying capacity): (or density-dependent selection) selects for life history traits that enhance an individual’s fitness when a population is fairly high (close to carrying capacity) and stable.

L16:Collared fly-catchers with eggs added to the nest by experimenters laid ______ (less/more) eggs the following year. Why do you think this occurred? Explain this experimental result, with reference to life history trade-offs.

L16:Why do we use models in science? Give three examples of using models to 1) build intuition, 2) make predictions, and 3) understand processes. What important insights could we learn from population growth models?

L16:What are the factors that determine whether populations will grow, shrink, or stay the same?

L16:How do we describe, calculate, or model rates of population growth? What does exponential growth mean, why does it happen, and how would we tell if a population were growing exponentially?

L16:A lily pad in a pond doubles in size every day. If it takes 48 days for the lily pad to completely cover the pond, on which day is the pond half covered?

L16: If we want to know how many individuals will be added to or lost from a population, or how much it will grow or shrink in a certain time period, what is the minimum information, or parameters, you would need to know? How would changing the birthrate, deathrate, or intrinsic rate of population increase alter the population growth rate?

L16: What happens when populations get more dense? Give an example of how density-dependent factors impact organisms, birth/death rates, and population growth.

L16: How do extreme events like cold snaps, volcanic eruptions, storms, or droughts impact population growth rates? Why do we say this is density-independent? How can you distinguish between density-dependent and -independent factors by looking at population growth curves?

L16: What is logistic growth, and why does it look like an S-shaped curve? What is a carrying capacity? Why is there sometimes an overshoot of the carrying capacity? What causes carrying capacity to change?

BIDE model

a fundamental framework used to calculate how a population's size changes over time by tracking four demographic processes: Births (B), Immigration (I), Deaths (D), and Emigration (E

Per capita

"by head" or "per person" in Latin. It is used to measure an average amount for each individual in a specific population

delta (Δ)

typically refers to either a genetic deletion mutation or the Delta notch signaling pathway, which is a crucial mechanism for cell-to-cell communication.

Population growth

the change in the total number of individuals of a species in a specific geographic area over a defined period of time

Parameters: R, r, N, t, B, D

these parameters are the core variables used to model and measure how a population changes in size over time

Parameters: R

R (Net Growth Rate / Population Growth Rate): The absolute change in population size over a discrete time interval. It accounts for the net balance of individuals added to or subtracted from the population

Parameters: r

(Intrinsic / Per Capita Growth Rate): The rate of population increase per individual. It determines how fast a population grows or shrinks on average per organism, mathematically calculated as r = b - d (birth rate minus death rate).

If r > 0, the population is growing.

• If r = 0, the population size is stable (zero population growth).

• If r < 0, the population is declining.

Parameters: N,

(Population Size): The total number of individuals of a single species currently living within a defined geographic area.

Parameters: t

(Time): The duration or specific point in time over which the population is being studied or monitored (e.g., days, months, years)

Parameters: B

(Births): The total number of births occurring in the population during a specific time interval.

Parameters: D

D (Deaths): The total number of deaths occurring in the population during a specific time interval

Exponential growth

a pattern of population increase where the per capita growth rate stays the same, causing the population to grow faster and faster as it gets larger

Logistic growth

a model of population growth where a population's per capita growth rate slows down as the population size approaches a maximum limit imposed by limited environmental resources