soils part 2 Flashcards
what is the smalles of the Protozoa
Flagellates
how many soil orders are there
12
what are endogeic species
upper soil species of earthworms - not permenant burrows
what are epigeic species
surface soil and litter species of earthworms - small and adaptable
Ultisols *
well developed soils with a relatively fine-textured subsoil horizon that has a base saturation of less than 35 %
Vertisols
soils with more than 30 % clay which appreciably expand upon wetting and contrast upon drying
when are bacteria more competitive?
when labile (esy to metabolize) substrates are present
what di fungi usually grow as?
long threas or strands called hyphae
what can nematodes be used for
indicators of soil quality because they respond to changes in moisture and temperature
Oxisols*
highly weather soils of the tropics
what do mutualists do
colonize plant roots (add nutrients in exchange for carbon dioxide)
forests are observed to increase in _____ as ______ increases
productivity … fungal biomass
what are Protozoa
single celled animals
how many athropods will a square yard of soil contain
500 - 200000
andisols
soilds of volcanic orgin
what is the middle sized protozoa
amoebae
what do earthworms do?
stimulate microbial activity, mix and aggregate soil. Increas infiltration, improve water holding capcity, provide channels for toot growth, and bury and shred plant residue
what is the other name for decomposers
saprophytic fungi
based on biomass what are the most predominant group of soil invertibrates in the soil
earthworms
what are nematodes
nonsegmented worms
Histosols *
soils composed of relatively think(usually 16 inches or more) organic materials (muck and peats)
what is responsible for the fresh smell of soil?
Actinomycetes
what type of soils suppress nitrifyinh bacteria
forest soils
where are the majority of all soil species confined to
the top 3 inches
what are the six categories of the soil taxonomic system
order, suborder, great group, sub group, family, and series
what are anthropods
jointed body invertebrates that have an exoskeleton == bugs
Saprophytic fungi are commonly active around what
woody plant residue
what do nematodes do
nutrient cycling, Grazing, dispersal of microbes, food source, disease suppression
what do protozoa do
play an important role in mineralizing nurtrients release ammonium (NH4+) and regulate bacteria populations
Entisols *
soils with little or no horizon development
what do earth worms help with
water pollution by run off and they can till soil instead of machines which can improve soil structure and life
where are nematodes
concentrated. More common in coarser textured soils because they move in soils — more common in forests then grass lands then agricultural areas
what is the other name for mutualists
mycorrhizal fungi
aridisols
dry soils that occur in arid or semi-arid regions
what do denitrifying bacteria do?
convert nitrate to nitrogen (N2) or nitrous oxide (N20) gas
Inceptisols *
soils of humid regions with profile development sufficient to exclude them from the Entisols, but insufficient to include them is spodosols, Ultisols, or other well developed soils. Soils that appear to be like Mollisols but have less than 50 % or more base saturation may also be Incepticsols
Alfisols*
well developed soils with a relatively fine-textured subsoil horizon that has a base saturation of 35 % or more
what are endomycorrhizae associated with
root cells and grasses and shrubs
what is the most important family of earthworms in enhancing agricultural soil
lumbricidae
what are anecic species
deep burrowing species of earthworm - permanent burrow systems
what are ectomycorrhizae associated with
trees and the surface
Gelosols
soils of cold climates influenced by permafrost
what do nitrifying bateria do?
change ammonium (NH4+) to nitrite (NO2-) then to Nitrate (NO3-)
Spodosols *
soils with a spodic horison (a dark-colored subhorizon with a mixture of organic matter and aluminum, with or with out iron)
what are shredders
chew up dead plant matter as they eat bateria and fungi
mollisols *
Soild with think (usually 10 inches or more), dark surfaces that have a base saturation of 50 % or more in the surface soil.
how many soil orders are found in florida
7
what are masses of Hyphae called?
rhizomorphs
what is the largest Protozoa
Ciliates
what do antropods do
shred organic material, stimulate microbial activity, mix microbes with food, mineralize plant nutrients, enhance soil aggregation , burrow , stimulate the succession of species, and control pests
