A survey of natural regeneration of Doug1as-fir and associated species was made on 15 staggered-setting cuttings four and five years after logging. These areas were on the H. J. Andrews Experimental Forest which is located in the McKenzie River area of western Oregon. Five types of cuttings were represented: (1)...
The fleshy carpophores of fungi fruiling, on soil and litter were collected from watersheds 2, 3, and 10, IBP sites located in the H.J. Andrews Experimental Forest near Blue River, Oregon (122° W, 44° N). No effort was made to systematize collections: all
carpophores in fresh condition seen were taken....
Litter nutrient dynamics contribute significantly to biogeochemical cycling in
forest ecosystems. These dynamics may be influenced by site attributes, litter nutrient concentrations, and soil nutrient availability either independently or synergistically. Litter nutrient dynamics were examined in two decomposition studies in temperate coniferous forests of Oregon. I used ¹⁵N-labelled litter of...
The objectives of this thesis were to evaluate the responses of soil microbial communities to physical and chemical disturbances, and associate these responses with soil functional stability and changes in soil quality. The first study consisted of application of heat shocks (HS) to soils with contrasting land use history to...
Prior to 2005, ammonia oxidation, the first step of nitrification, was thought mediated mainly by ammonia-oxidizing bacteria (AOB). However, the discovery of Thaumarchaeota carrying the genes coding for the ammonia monooxygenase (AMO) enzyme led to the discovery that ammonia-oxidizing archaea (AOA) also contribute to nitrification. Despite the uptick in studies...
Trees that survive disturbances can form a prominent legacy which may influence
post-disturbance successional pathways. The effects of biological legacies on community
dynamics is a critical question in ecology. In the present study, I examined two mapped
stands in which old-growth remnant trees, survivors of partial fires, emerge above a...
In the Coniferous Forest Biome, many of the understory as well as
dominant plants are evergreen and thus water uptake is a year around
process. The flow of water from the soil through plants to the atmosphere
affects the entire forest ecosystem. As water is evaporated, it absorbs
heat and...