Exam 2 Flashcards
Decomposition is
the chemical breakdown of chemical bonds formed during the construction of plant and animal tissue
Decomposition involves
respiration
Respiration
the release of energy originally fixed by photosynthesis, carbon dioxide, and water and ultimately the conversion of organic compounds into inorganic nutrients
when does decomposition happen quickly
warm wet places
How are heterotrophs decomposers
as they digest food, heterotrophs break down organic matter, alter it structurally and chemically, and release it partially in the form of waste products
microflora
most organisms that decompose material are bacterial and fungi
what are the dominant decomposers of dead animal matter
bacteria
what are the dominant decomposers of plants material
fungi
microbivores
feeding on bacteria and fungi
act as regulators of decomposition
what make up microbivores
protozoans, springtails, nematodes, larval forms of beetles
nutrient immobilization
the incorporation of mineral nutrients into microbial biomass
stages of decomposition
- early stages involve leaching and fragmentation
- detritivores oxidate organic compounds, releasing energy through respiration
- they degrade them into smaller and simpler products
- the release of organically bound nutrients into a inorganic form available to plants is mineralization
Mineralization
the release of organically bound nutrients into an inorganic form available to plants
Aphodius
dung beetle genus that develops eggs, larvae, and pupae within dung
process of decomposition on leaves
A. microbial decomposition of plant leaves can begin while the green leaves are still on the plants
B. living plant leaves produce exudates that support an abundance of surface microflora
C. when the leaves become senescent, the tissues are invaded by both bacteria and fungi, and decomposition accelerates
D. the action of litter feeders as millipedes and earthworms can increase exposed lead area 15 fold
E. fecal material from the detritivores is colonized by other microbes
rhizosphere
the soil region immediately surrounding the roots of living plants
rhizoplane
root surface itself
what conditions reduce or inhibit microbial activity
Dry and cold conditions
what are the most complex compounds found in nature
Lignin
what is lignin
fold into complex 3D shapes and slowest tissue to decompose
what is not required in the breakdown of animal flesh
specialized enzymes needed to digest cellulose
biogeochemical cycles
The cycles that nutrients move through in an ecosystem
sources of a gaseous cycle
atmosphere, ocean
sedimentary cycles
main reservoirs of nutrients are the soil and rocks of earth’s crust