The mechanisms governing short- and long-term belowground carbon dynamics need to be understood. As part of a larger project developed to assess the effect of quantity and quality of litter inputs on the rate of soil organic matter (SOM) formation, I examined SOM in the H. J. Andrews Detritus Input...
Few studies have directly compared denitrifying community composition and activities in soils by coupling molecular-genetic techniques and traditional measures of denitnfication. I investigated communities of denitrifying bacteria from adjacent meadow and forest soils in the Cascade Mountains, Oregon. A key gene in the denitrification pathway, N₂O reductase (nosZ), served as...
Silviculture systems that involve commercial thinning may provide higher quality wildlife habitat than traditional clearcut systems, yet such systems have not been vigorously tested. This prospective study examined forest floor animal abundance and habitat relationships under three different silviculture conditions: clearcuts, commercial thins, and uncuts. Eighteen stands, six per treatment,...
The primary purpose of this study was to (1) develop methods for the analysis of and (2) provide information on the chemical nature of reducing ends in typical cellulose substrates used for the study of cellulolytic enzymes. The studies were designed such that values obtained for cellulose substrates were compared...
This two-part study attempts to find appropriate mass dimension and terminal velocity relationships that,
when considered together with particle size distributions (PSD), agree with coincident measurements of ice
water content (IWC), and with variables related to higher moments such as the mean mass-weighted fall
speed. Reliable relationships are required for...
A continuous flow diffusion chamber (CFDC) was used to measure ice formation by
cloud particle residuals during the Cirrus Regional Study of Tropical Anvils and Cirrus
Layers-Florida Area Cirrus Experiment. These measurements were directed toward
determining the relative contributions of homogeneous nucleation, heterogeneous
nucleation, and secondary ice formation processes to...
At low latitudes, cirrus are ubiquitous and can be in
excess of 100°C colder than the surface, limiting the
amount of sunlight absorbed by the earth’s atmosphere and
surface, and reducing its loss of heat. Here we present
aircraft measurements within cirrus over southern Florida
indicating that ice crystals have...
This paper presents a detailed study of a single thunderstorm anvil cirrus cloud measured on 21 July 2002
near southern Florida during the Cirrus Regional Study of Tropical Anvils and Cirrus Layers–Florida Area
Cirrus Experiment (CRYSTAL-FACE). NASA WB-57F and University of North Dakota Citation aircraft
tracked the microphysical and radiative...
Fire-history reconstructions are based on tree-ring records that span the last few centuries and charcoal data
from lake-sediment cores that extend back several thousand years. The two approaches have unique strengths and
weaknesses in their ability to depict past fire events and fire regimes, and most comparisons of these datasets...