Midterm 2 Flashcards
True or false: Fungi are much MORE sensitive to strong acid conditions than bacteria or actinomycetes.
false
Which of the following human actions results in a long-term increase in soil pH?
irrigation with high sodium salt-containing waters
Which statement about plants using C4 pathways is FALSE?
their stomata are closed during the day and open during the night.
True or false: a tree that lives for more than one year is known as an “evergreen” tree.
false
What kind of trees of the temperate climate zone dominate in montane (high elevation) regions and
on nutrient-poor sandy soils?
[Hint: These trees also dominate the temperate rainforest of the U.S. Pacific Northwest.]
evergreen needle-leaf
Plants adapted to low-nutrient environments are characterized by
increased leaf longevity
Graphs showing number of seeds per stem vs mean weight and Body mass vs litter size
These data support the trade-off that
size of offspring is correlated with number of offspring
The nomenclature of Soil Taxonomy is characterized by all but which?
the names give a clear indication of the modes of genesis of the soil
The demographic age pyramid of a rapidly growing population is
wide at the base, narrow at the top
A population that is increasing in size has an intrinsic rate of population growth (r) that is
> 0
True or false: You would expect the cation exchange capacity of Alfisols to be greater than that of Ultisols if the soil textures are about the same.
True
As population size (N) increases, the per capita
the birth rate decreases and the death rate increases
In which soil order would you find a soil with a master horizon sequence O-A-C?
True or false: a soil with an ochric epipedon could generally be expected to be more strongly weathered than one with an umbric epipedon.
false
In populations of animals that defend an area for their own exclusive use or in plants that compete intensively for belowground resources such as water or nutrients, the spatial distribution of individuals is usually
uniform
Which of the following is a density dependent factor that may limit the growth of a population?
shelter availability
Which photosynthetic pathway is shown?
Mesophyll and bundle sheath cell.
Organic acid -> CO2 -> Calvin cycle
C4
Plants can rapidly reduce water loss by
closing their stomata
Investigating the soils of northern Canada one summer, you dig a soil pit easily through fairly uniform peat material until, at 75 cm deep, your shovel hits a layer that is frozen solid. Into which type of soil are you most likely digging?
Histel
True or false: intraspecific competition affects the populations of two or more species adversely and is a cornerstone of evolutionary ecology. Ecologists distinguish exploitation and interference.
false
Match the soil pH to its properties
pH 7-8.5
pH 5-7
pH <3.5
The dark reactions of photosynthesis use ___ and produce ____
NADPH
sugars CHECK THIS ONE IDK
the soil is covered by a hard, white crust, and plant growth is suppressed
salinity; salty water has evaporated from the surface, and the soil water has a high sodium content and electrical conductivity
the soil has a pH >8.5, low electrical conductivity (<4 dS/m), and there are signs of erosion (subsidence, gullies)
sodicity; the cation exchange capacity of the soil is dominated by exchangeable sodium
Explain why the availability of the plant macronutrient phosphorus is low in both acidic (<pH 5.5) and alkaline (>7) soils, and commonly limits the productivity of terrestrial ecosystems. [Assume that phosphorus is present in the parent material.]
Phosphorus is not available at low and high pH because at low pH it is combined with Al and in high pH it is with calcium. It doesn’t like to be in solution, it likes to be in a solid form so the plants can’t use it.
State factor that best explains distribution of histosols,vertisols, and andisols
State factor that best explains distribution of gelisols, oxisols
climate
State factor that best explains distribution of entisols and ultisols
time
Plants adapted to growing in the shady understory of a forest tend to have a _____ light compensation point than plants that make up the upper (sunnier) canopy of the forest.
lower
Soils with organic materials extending down to an impermeable layer
Histols
Soils with permafrost within 100 cm
Gelisols
Soils with 30% or more clay to 50 cm and shrinking/swelling properties
Vertisols
Soils formed on volcanic ash rich in amorphic/short-range-order minerals such as allophane and ferrihydrite
Andisols
Oxygen is produced from [molecule] during the light reactions of photosynthesis.
water
forest die-back due to acid rain
death of aquatic communities due to the drainage of extremely acid waters (acid mine drainage)
