Detrital microbial community development and phosphorus dynamics in a stream ecosystem

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1985

OSTI ID:6640506

Perkins, R E

Detrital microbial community development and phosphorus dynamics in a lotic system were investigated in non-recirculating laboratory streams containing leaf detritus. Temporal patterns of microbial colonization, as determined by scanning electron microscopy, indicate leaf species dependency and that bacteria were the first colonizers followed by fungi. An extensive glycocalyx layer developed. Phosphorus incorporation rates of both the whole community and intracellular components were determined by time-course measurements of /sup 33/PO/sub 4/ or /sup 32/PO/sub 4/. Phosphorus turnover rates were determined by a sequential double-labeling procedure using /sup 33/PO/sub 4/ and /sup 32/PO/sub 4/, in which the microbiota were labeled with /sup 33/P until in isotopic equilibrium, then /sup 32/P was added. The turnover rates was determined by time-course measurements of the ratio /sup 32/P to /sup 33/P. The turnover rate for the maple community was 0.319% h/sup -1/ and ranged from 0.379% h/sup -1/ to 0.577% h/sup -1/ for the intracellular components. The turnover rates for the ungrazed and graved oak microbiota were 0.126% h/sup -1/ and 0.131% h/sup -1/. Snail grazing resulted in an increase in phosphorus metabolism per unit microbial biomass; however, per unit area of leaf surface no increase was observed. Grazing also caused a two-fold reduction in microbial biomass. The results of this investigation indicate that microbiota associated with decomposing leaves slowly recycle phosphorus, are slowly growing, and have a low metabolic activity. The spiraling length is shortened by microbiota on a short-term basis; however, it may increase on a long-term basis due to hydrological transport of detritus downstream.

• Research Organization: Tennessee Univ., Knoxville (USA)
• OSTI ID: 6640506
• Country of Publication: United States
• Language: English

Related Subjects

520300* -- Environment
Aquatic-- Radioactive Materials Monitoring & Transport-- (1989)
54 ENVIRONMENTAL SCIENCES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
DAYS LIVING RADIOISOTOPES
DETRITUS
ELECTRON MICROSCOPY
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
LEAVES
LIGHT NUCLEI
MAPLES
MICROSCOPY
MINERAL CYCLING
NUCLEI
OAKS
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
PHOSPHORUS 32
PHOSPHORUS 33
PHOSPHORUS ISOTOPES
PLANTS
RADIOISOTOPES
STREAMS
SURFACE WATERS
TRACER TECHNIQUES
TREES