Source: UNIV OF CALIFORNIA submitted to
NUTRIENT RELEASE AND ORGANIC DECOMPOSITION IN FOREST SOILS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
Reporting Frequency
Annual
Accession No.
0175723
Grant No.
(N/A)
Project No.
CA-B*-ECO-6331-H
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Oct 1, 2002
Project End Date
Sep 30, 2007
Grant Year
(N/A)
Project Director
McColl, J. G.
Recipient Organization
UNIV OF CALIFORNIA
(N/A)
BERKELEY,CA 94720
Performing Department
ECOSYSTEM SCIENCES
Non Technical Summary
What are the controls of different forms of phosphorus in decomposing forest litter? This project examines the roles of climate, forest community and other factors in determining phosphorus dynamics of decomposing forest litter.
Animal Health Component
(N/A)
Research Effort Categories
Basic
100%
Applied
(N/A)
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1020110206150%
1020612206150%
Goals / Objectives
1. To characterize phosphorus (and other nutrients) and carbon forms, and the linkages between them, in forest litter and soils from two different climates under different forest tree species. 2. To determine what controls the anticipated differences in the decomposition dynamics of phosphorus (and other nutrients) and carbon forms at the contrasting study sites. In particular, is the controlling factor climate, tree species, or something else?
Project Methods
I plan to extend my interests in the release of nutrient elements (especially phosphorus, P) from decomposing forest litter and organic matter. I have established a comparative field study in California and Washington forests to examine differences in the pathways of the decomposition processes that are largely dictated by different climates where either oxidizing or reducing conditions predominate, and where different forest communities exist. Prior work suggests that the litter/soils in these two locations contain different forms of P, but a comparative study using identical methods of P and C analyses, has not been done until now. Nuclear Magnetic Resonance techniques will be used.

Progress 10/01/02 to 09/30/07

Outputs
This project examines the roles of climate, forest community and other factors in determining phosphorus dynamics of decomposing forest litter. Forest soils and litter from different regions may contain different P forms. Climate may control soil P forms, because more complex P forms have been seen in forests from regions with higher her rainfall and cooler temperatures. The role of climate and decomposition on phosphorus cycling was studied in forests of two climatic regimes: the Sierra Nevada, California, with warm, dry, oxidizing conditions; and the Olympic Peninsula, Washington, with cooler, moister, reducing conditions. Small-diameter branch samples of California red fir decomposed on the forest floor over a 17 year period showed that total dry mass of bark decreased by 62%, bark Carbon(C)/Nitrogen(N) ratio decreased from 72 to 48, and bark concentrations of Nitrogen and Manganese(Mn) increased, but bark Phosphorous(P) concentration decreased. For the wood portion of the samples total dry mass decreased by 37%, wood C/N ratio decreased from 217 to 177, concentrations of N and Mn increased, and P concentration decreased. Thinning and N-fertilizer treatments did not affect decomposition after 17 years. White rot fungi require Mn to decompose lignin and maintain high levels of Mn in decomposing bark and wood. The temporal separation of warm and moist conditions in California limited microbial activity during the periods of summer drought, thereby reducing decomposition rates. The results suggest that climate may not be the most important factor controlling phosphorus forms; tree species and possibly mycorrhizae may also be important. In a paired-litter bag study, Douglas fir litter type material had changed nutrient concentrations that resembled those of destination sites. In contrast, for the cedar litter type material, the concentrations of nutrients remained unchanged after two years, and resembled those of the source material more than the destination material, both for California-to-Washington and Washington-to-California transplants.

Impacts
Nutrient cycling through litter decomposition is largely controlled by the litter microenvironment of the Douglas fir litter type, but much more controlled by 'litter quality' in the case of the cedar litter types. Woody debris in the form of wood and bark returns nutrients to the soil. In the environment of California red fir, with cold winters and dry summers, decomposition can be quite slow. Silvicultural treatments did not affect decomposition after 17 years. Some nutrients are retained or even accumulated in the woody material during decomposition, especially Mn which is requied by white-rot fungi.

Publications

  • No publications reported this period


Progress 01/01/04 to 12/31/04

Outputs
This project examines the roles of climate, forest community and other factors in determining phosphorus dynamics of decomposing forest litter. Forest soils and litter from different regions may contain different P forms. Climate may control soil P forms, because more complex P forms have been seen in forests from regions with higher her rainfall and cooler temperatures. The role of climate and decomposition on phosphorus cycling was studied in forests of two climatic regimes: the Sierra Nevada, California, with warm, dry, oxidizing conditions; and the Olympic Peninsula, Washington, with cooler, moister, reducing conditions. Small-diameter branch samples of California red fir decomposed on the forest floor over a 17 year period showed that total dry mass of bark decreased by 62%, bark Carbon(C)/Nitrogen(N) ratio decreased from 72 to 48, and bark concentrations of Nitrogen and Manganese(Mn) increased, but bark Phosphorous(P) concentration decreased. For the wood portion of the samples total dry mass decreased by 37%, wood C/N ratio decreased from 217 to 177, concentrations of N and Mn increased, and P concentration decreased. Thinning and N-fertilizer treatments did not affect decomposition after 17 years. White rot fungi require Mn to decompose lignin and maintain high levels of Mn in decomposing bark and wood. The temporal separation of warm and moist conditions in California limited microbial activity during the periods of summer drought, thereby reducing decomposition rates. The results suggest that climate may not be the most important factor controlling phosphorus forms; tree species and possibly mycorrhizae may also be important. In a paired-litter bag study, Douglas fir litter type material had changed nutrient concentrations that resembled those of destination sites. In contrast, for the cedar litter type material, the concentrations of nutrients remained unchanged after two years, and resembled those of the source material more than the destination material, both for California-to-Washington and Washington-to-California transplants.

Impacts
Nutrient cycling through litter decomposition is largely controlled by the litter microenvironment of the Douglas fir litter type, but much more controlled by 'litter quality' in the case of the cedar litter types. Woody debris in the form of wood and bark returns nutrients to the soil. In the environment of California red fir, with cold winters and dry summers, decomposition can be quite slow. Silvicultural treatments did not affect decomposition after 17 years. Some nutrients are retained or even accumulated in the woody material during decomposition, especially Mn which is requied by white-rot fungi.

Publications

  • No publications reported this period


Progress 01/01/03 to 12/31/03

Outputs
After two years (in a paired-litter bag study) Douglas fir litter type material had changed nutrient concentrations that resembled those of destination sites. In contrast, for the cedar litter type material, the concentrations of nutrients remained unchanged after two years, and resembled those of the source material more than the destination material, both for California-to-Washington and Washington-to-California transplants.

Impacts
Results indicate that nutrient cycling through litter decomposition is largely controlled by the litter microenvironment of the Douglas fir litter type, but much more controlled by 'litter quality' in the case of the cedar litter types.

Publications

  • Cade-Menun, B.J., McColl, J.G., Moghaddas, E.E.Y., and Edmonds, R.L. 2003. The role of climate in the forms of P in forest floor samples: a paired-litterbag study. Soil Science Society of America Abstracts. Annual Meeting, Denver CO.


Progress 01/01/02 to 12/31/02

Outputs
Small-diameter branch samples of Califronia red fir decomposed on the forest floor over a 17 year period showed the following:total dry mass of bark decreased by 62%, bark Carbon(C)/Nitrogen(N) ratio decreased from 72 to 48, and bark concentrations of Nitrogen and Manganese(Mn) increased, but bark Phosphorous(P) concentration decreased. For the wood portion of the samples: total dry mass decreased by 37%, wood C/N ratio decreased from 217 to 177, concentrations of N and Mn increased, and P concentration decreased.Thinning and N-fertilizer treatments did not affect decomposition after 17 years. White rot fungi require Mn to decompose lignin and maintain high levels of Mn in decomposing bark and wood.

Impacts
Woody debris in the form of wood and bark returns nutrients to the soil. In the environment of California red fir, with cold winters and dry summers, decomposition can be quite slow. Silvicultural treatments did not affect decomposition after 17 years. Some nutrients are retained or even accumulated in the woody material during decomposition, especially Mn which is requied by white-rot fungi.

Publications

  • McColl, J.G., and R.F. Powers. 2003. Decomposition of small woody debris of California red fir: mass loss and elemental content over 17 years. Soil Science Society of America Journal. (In press).
  • Waldrop, M.P., J.G. McColl and R.F. Powers. 2003. The effects of forest post-harvest management practices in enzyme activities in decomposing litter. Soil Science Society of America Journal. (In press).


Progress 01/01/01 to 12/31/01

Outputs
Nuclear magnetic resonance spectroscopy techniques were tried for soil organic phosphorus; the effect of extractants on delay times and peak saturation were examined. Two samples (forest litter and mineral soil) and three extractants (sodium hydroxide, sodium hydroxide plus chelex, sodium hydroxide plus EDTA) were used to determine differences in phosphorus concentration and cations solubilized by each extractant, and the spin lattice relaxation times of phosphorus peaks in each extract. For the litter sample, relaxation times were short for all extractants due to high iron concentration remaining after extraction. For the soil sample, there were noticeable differences among the extractants. Results suggest that nuclear magnetic resonance techniques for litter and soil phosphorus must include careful selection of an extractant, measurement of paramagnetic ions extracted with phosphorus, using appropriate delay times and the minimum number of scans, and measurement of relaxation times whenever possible.

Impacts
In nuclear magnetic resonance analyses for phosphorus in litter and soil, attention should be given to selection of appropriate extractants, measurement of paramagnetic ions extracted with phosphorus, use of appropriate delay times and the minimum number of scans, and measurement of relaxation times.

Publications

  • No publications reported this period


Progress 01/01/00 to 12/31/00

Outputs
Relative rates of decomposition, measured as mass loss of decomposing birch sticks, were greater in the temperate rainforests of western Washington than the Mediterranean-type forests in the Sierra Nevada of northern California. The temporal separation of warm and moist conditions in California limited microbial activity during the periods of summer drought, thereby reducing decomposition rates. Ninety-two to 93 percent of the variance in mass loss within each state could be explained by the concentration of nitrogen in the residual material. Although total nitrogen is not a direct measure of nitrogen availability to microbial populations, it is a strong predictor of decay dynamics. The net amounts of nitrogen, phosphorus, potassium, calcium and magnesium in the birch sticks increased both by mass and concentration. Potassium, magnesium and calcium (in Washington only) were initially released prior to increases in content. The efficiency of substrate utilization was greater in Washington than in California. The availability and/or accessibility of nutrient pools may be greater in the Washington forests. Despite differences in decomposition rates and nutrient dynamics in forests of California and Washington, patterns of nutrient mobility in decomposing birch sticks were very similar. In both states, the mobility of the elements measured, from greatest to least was: carbon, potassium, magnesium, nitrogen, phosphorus. Only the relative mobility of calcium differed between these two climatic regions. Although mass loss under cedar was consistently greater than under Douglas-fir, the differences were not statistically significant. No significant differences in the efficiency of substrate utilization were observed between the cedar and Douglas-fir stands. The only species effect on nutrient mass dynamics was measured for potassium after six months of decomposition. Although climate may in fact control decomposition processes in these forests, two points must be well considered before dismissing species effects as inconsequential. First, the cedar species differed between California and Washington. While incense cedar and western redcedar share similar growth requirements, inherent differences between the two species, such as nutrient cycling and retention, stand longevity and architecture, and associated microorganisms, may confound analyses in which these differences are disregarded. Secondly, although each study site was dominated by the species for which it was chosen (Douglas-fir or cedar), the presence of other tree species produced unmeasured effects on decomposition processes.

Impacts
(N/A)

Publications

  • Greinke, E.E.K., McColl, J.G., Edmonds, R.L., and Cade-Menun, B.J., 1999. Relative Sci. decomposition rates in California and Washington forests. Agron. Abstr., p. 305., Soil Soc. Am., Madison, WI.
  • Cade-Menun, B.J., C.W.Liu, R. Nunlist, and J.G.McColl. 2000. Soil and litter 31P-NMR: extractants, metals and P relaxation times. J. Environ. Qual. (in press).
  • Greinke, E.E.Y. 2000. Wood decomposition and nutrient dynamics in California and Washington forests. M.S. thesis. University of California, Berkeley, California. 111 p.


Progress 01/01/99 to 12/31/99

Outputs
The role of climate and decomposition on phosphorus cycling was studied in forests of two climatic regimes: the Sierra Nevada, California, with warm, dry, oxidizing conditions; and the Olympic Peninsula, Washington, with cooler, moister, reducing conditions. Seasonal samples of litter and soil were collected from stands of ectomycorrhizal cedar and arbuscular mycorrhizal cedar (incense cedar in California and western red cedar in Washington). These were analyzed for phosphorus, carbon and related chemical parameters, using classical analytical techniques and also nuclear magnetic resonance spectroscopy for phosphorus. The results suggest that climate may not be the most important factor controlling phosphorus forms; tree species and possibly mycorrhizae may also be important. The Washington sites had higher moisture, narrower temperature extremes and lower pH than the California sites. There were no differences in carbon, nitrogen or the carbon:nitrogen ratio. The main difference between species was for organic phosphorus: in Washington, cedar had eighty percent of total phosphorus in the organic form at 20-cm depth, and Douglas-fir had thirty percent. In California, the differences were smaller.

Impacts
(N/A)

Publications

  • CADE-MENUN, B. J., McCOLL, J. G., EDMONDS R. L., and GREINKE. E. 1999. Is soil phosphorus different under cedar than under Dougals-fir? Ann. Mgt. Soil Sci. Soc. Am., Oct. 31- Nov. 4. Salt Lake City, UT. Agron. Abstr., p.301.
  • CADE-MENUN, B. J., McCOLL, J. G., GREINKE, E., and EDMONDS, R. L. 1999. Relative decomposition rates in California and Washington forests. Ann. Mgt. Soil Sci. Soc. Am., Oct. 31- Nov. 4. Salt Lake City, UT. Agron. Abstr., p.305.


Progress 01/01/98 to 12/01/98

Outputs
Forest soils and litter from different regions may contain different P forms. Climate may control soil P forms, because more complex P forms have been seen in forests from regions with higher her rainfall and cooler temperatures. In this work, part of a larger study examining the role of decomposition in P cycling, forests from two climatic regimes were used: the Sierra Nevada, CA, with warm, dry, oxidizing conditions; and the Olympic Peninsula, WA, with cooler, moister, reducing conditions. At each location, seasonal samples of litter and soil were collected from stands of: ectomycorrhizal Douglas-fir, which grows in both places; and arbuscular mycorrhizal cedar (incense cedar in California and western red cedar in Washington). These were analyzed for P, C and related soil chemical parameters, using classical analytical techniques and 31P-NMR spectroscopy. The WA sites had higher moisture and lower pH than CA. In WA, cedar had more total P as organic P than Douglas-fir; in CA there were no differences. These results suggest that climate may not be the most important factor controlling soil P forms: tree species, and possibly mycorrhizae, may also be important.

Impacts
(N/A)

Publications

  • CADE-MENUN, B. J., MCCOLL, J. G., EDMONDS, R. L., and GREINKE, E. 1998. The P regime of soils and litter supporting two forest types in California and Washington. Agronomy Abstracts, p.298, Annual Meeting, Soil Science Society of America,.
  • NORTHUP, R. R., DAHLGREN, R. A., and MCCOLL, J. G. 1998. Polyphenols as regulators of plant-litter-soil interactions in northern California's pygmy forest: a positive feedback. Biogeochemistry.
  • WINSOME, T., and MCCOLL, J. G. 1998. Changes in chemistry and aggregation of a California forest soil worked by the earthworm Argilophilus papillifer Eisen (Megascolecidae). Soil Biology and


Progress 10/01/97 to 12/01/97

Outputs
A comparative study in two different climatic regimes has been initiated in forests of Douglas-fir and cedar in the Olympic Peninsula, Washington, and in northern California, to examine forms of phosphorus released as forest litter decomposes. Preliminary results indicate soil moisture and pH differences between climatic regimes and species, and the possibility of different pathways of decomposition that may dictate release of different forms of phosphorus over time.

Impacts
(N/A)

Publications

  • CADE-MENUN, B. J., MCCOLL, J. G., and EDMONDS, R. L. 1997. Processes linking P and C in forest soils in two climatic regimes. Agronomy Abstracts, p.283, Annual Meeting, Soil Science Society of America,