Variation in nutrient content of forest trees is discussed using the
data from literature plus data collected by the authors. Sections are
included on sampling and methods of expression of nutrient content. The
emphasis is on possible causes of variation, which involves nutrient
variation between years, within the year, and...
Research activities in the post-IBP phase of the Biome program prior to July 1975 were reported in Internal Report 162. Summaries of research and synthesis activities from July 1975 to August 1976 are presented here. The reports are arranged in the following order: Analysis of individual terrestrial ecosystems, which has...
The specific objectives of the program are: (1) To understand the relative behavior of terrestrial and aquatic ecosystems in various environments in the biome. (2) To develop conceptual and computer simulation models that describe nutrient, carbon, and waterflows on a short-term basis (fewer than ten years) and which integrate research...
This report describes decomposition studies conducted in the H. J. Andrews
Forest, Oregon in 1973. Changes in weight loss and nutrient content of
leaves, cones, branches, and bark of Douglas-fir and leaves of big-leaf
maple, vine maple, Rhododendron, red alder, sword fern Oregon oak, and
Chinkapin were recorded in a...
The following report Introduces a documentation scheme for flow
oriented ecosystem models and shows its application to a carbon-water
model developed within the coniferous biome. This documentation scheme
has remained operative through revision of this model and expansion of
It to include nutrient flows. This model and subsequent versions are...
The food habits of yellow perch in Lake Washington were studied over a period
of nine months. Altogether, 549 yellow perch were examined for the stomach
contents. The food consisted mainly of cottids, mysid shrimp, and chironomid
pupae and larvae; the predominant food item being the mysid shrimp.
There was...
Macroinvertebrates were sampled on a regular basis from March to October
1973. A relationship between chironomid length and biomass was established.
Production equations to be used for these insects are reported. A similar
length/weight relationship is presently being explored for the oligochaetes.
A proposal is made for calculating their production...
A study of the phosphorus dynamics in castle Lake, California, is presented.
The approach is (1) to identify the important phosphorus parameters,
(2) to develop and apply methods measuring the parameters in the
field and (3) to develop a computer model of the phosphorus cycle. This
model will be used...
Nitrogen fixation rates were determined periodically by the acetylene
reduction technique at three depths in each of the lakes. Fixation began
in June in Lakes Washington and Sammamish and peaked during July and
August. Chester Morse and Findley Lakes did not exhibit acetylene
reduction activity until August and the rates...
Lakes Findley, Chester Morse and Sammamish, Washington, are characterized
by one major outburst of phytoplankton productivity and biomass (mainly
diatoms) with usually no or low fall activity. Vernal outbursts were
often delayed in the monomictic lakes by inadequate light because of
unfavorable climate and/or a lack of thermal stratification. Strong...
Zooplankton grazing rates and life history stage densities for secondary
production estimates were determined in three lakes in the Cedar River
watershed, Washington. Eight copepod species, seven cladoceran and nine
rotifer species were identified in the three lakes. No one species of
cladoceran or copepod occurred in all the lakes,...
A litter decomposition model was developed as part of :a watershed modeling effort. This model simulates weekly dry weight changes In woody and nonwoody litter (01), incorporated litter layer (02), and soil organic matter. Processes simulated by the model include: litterfall by component, root turnover, respiration, decomposition, and organic matter...
A convenient method of portraying functions of n dimensions to aid modeling
is needed. Unfortunately, visual representations are limited to only
two independent variables. ISO was written to partially meet the demands
of two-independent-variable graphics.
Much effort can be saved by having well-documented field notebooks and field sheets. ITABLE will produce notebook pages filling in the collector's name, dates, stations, and depths.
A steady-state phosphorus cycle was determined for the stratified period
May to November in Lake Sammamish, Washington. A steady-state. condition
for this period is considered at this time since data on some important
processes are only sufficient to estimate average values for the stratified
period. Nevertheless, such a cycle is...
Field reconnaissance, soil sampling, and laboratory analyses were
conducted to characterize the soils of the 50 by 50 meter forest community
reference stand plots in and near the H. J. Andrews Experimental
Forest. Soil descriptions, chemical and physical properties, soil classification,
and nutrient capital information for mineral soils are summarized....
Air temperatures at i m and soil temperatures at 2C cm are reported for
twenty-one forest stands in the central Western Cascader of Oregon. Records
began in 1970 for some stands, in 1971 or 1972 for most. Temperature Growth
Index for a stand, based on temperature effects on Douglas-fir seedling...
FLEX1 is a general model processor, patterned after Klir's
General Sequential System Paradigm (Figure 1). Specifically, the
processor is a discrete time flux oriented realization of the general
paradigm and can process non-linear, non-stationary, environmentally
controlled state variable system models with explicit memory. The
current version is restricted to not...