Lecture 4 Exam 1 Flashcards
What causes global variation in climate?
the angle at which the sun’s rays hit the earth
- differences in what the rays are striking (water, land), and how the heat and moisture are distributed (wind and water currents)
- when sunlight strikes earth at lower angle it covers a greater area
-at higher angle, covers a smaller area
What does the spherical shape and tilt of earth’s axis cause?
- uneven heating of earth’s surface
- drives air circulation patterns and precipitation patters
What is the Coriolis effect?
- causes deflection of surface winds clockwise in the N hemisphere and counterclockwise in the S hemisphere
- is a deflection of moving objects when they are viewed from a rotating reference frame
What is soil?
a complex mixture of living and nonliving material
- classification based on vertical layering (soil horizons)
- profile provides a snapshot of soil structure in a constant state of flux
What are the different horizon soils?
- O: organic layer freshly fallen organic material - mostly superficial layer
- A: mixture of minerals, clay, silt, and sand
- B: clay, humus, and other materials leached from A horizon - often contains plant roots
- C: weathered parent material
What are climate diagrams?
- summarize climatic information using a standardized structure
- temperature on left y axis, precipitation on right y axis
- 10 C equivalent to 20 mm precipitation
- relative position of lines reflect water availability
- adequate moisture for plant growth when precipitation above temperature
How are biomes distinguished?
- primarily by their predominant plants and are associated with particular climates
How do we measure the vegetative characteristics of an ecosystem?
- gross primary production: total energy assimilated by photosynthesis
- net primary production: total energy available to consumers
- the difference between the 2 is the energy used in respiration and maintenance/biosynthesis
Tropical rainforests
- equatorial
- always moist and lacking temperature/seasonality
-evergreen tropical rain forest - organisms add vertical dimension
- little temperature fluctuation (around 26C)
Tropical seasonal forest/savanna
- summer rainy season and “winter” dry season
- seasonal forest, scrub, or savanna
-grasslands with scattered trees - extreme fluctuation in precipitation
-fires play a role in biodiversity and nutrient turnover
subtropical desert
- little to no precipitation, little seasonality
- highly seasonal, arid climate
- desert vegetation with considerable exposed surface
- major bands at 30 N and 30 S
- water loss usually exceeds precipitation
-life in deserts have to conserve water and have adapted accordingly - line of precipitation close to 0
- animal abundance low but biodiversity may be high
woodland/shrubland
- also known as Mediterranean/chaparral
- wet winters, severe summer drought
- thick evergreen shrubby vegetation 1-3m tall with deep roots and drought resistant foliage
-fires are frequent and most plants have either fire-resistant seeds or root crowns that re-sprout soon after fire - summer drought period and moist cool season
temperate rain forests
- warm temperate zone
-occasional frost often with summer rainfall maximum - temperate evergreen forest, somewhat frost sensitive
-mild winters, heavy winter rains, summer fog: extremely tall evergreen forests - high constant precipitation
temperate seasonal forests
- nemoral
- moderate climate with winter freezing
- frost resistant, deciduous, temperate forest
- aka deciduous forests
- hot summers, mild winters with freezing
- rainfall abundant with long growing season, curves with temperature
- higher biodiversity than boreal forest
- fertile soils/biomass can be high
temperate grassland/desert
- continental (cold deserts)
- arid with warm or hot summers and cold winters
- grasslands and temperate forests
- aka prairies or steppes
- drier than temperate forests but in same latitudal range
- rich soils used for crops
