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Full-Text Articles in Physical Sciences and Mathematics
Effects Of Bifenox, Dcpa, And Napropamide On Ectomycorrhizal Development Of Conifer Seedlings In Central And Northern Rocky Mountain Nurseries, United States Department Of Agriculture, Forest Service
Effects Of Bifenox, Dcpa, And Napropamide On Ectomycorrhizal Development Of Conifer Seedlings In Central And Northern Rocky Mountain Nurseries, United States Department Of Agriculture, Forest Service
Forestry
Postseeding and postgermination treatments with three weed control herbicides (Bifenox, DCPA, Napropamide) at two rates of application caused little reduction of ectomycorrhizal development on 1- and 2-year-old conifer seedlings in Central or Northern Rocky Mountain nurseries. In many cases, herbicide treatment increased ectomycorrhizal development, particularly with DCPA. In general, herbicide treatment effects on ectomycorrhizal development were species and nursery specific.
Histological Differentiation Among Abiotic Causes Of Conifer Needle Necrosis, United States Department Of Agriculture, Forest Service
Histological Differentiation Among Abiotic Causes Of Conifer Needle Necrosis, United States Department Of Agriculture, Forest Service
Forestry
Symptoms induced by phytotoxic gases within conifer needles can be differentiated histologically from those caused by other abiotic agents including winter drying, drought, and salt. However, it is not possible to differentiate among symptoms caused by hydrogen fluoride, sulfur dioxide, ethyl mercaptan, and hydrogen sulfide. Phytotoxic gases cause hypertrophy and hyperplasia of vascular parenchyma, endodermis collapse, and intense vascular staining. The other abiotic agents induce mesophyll collapse with little or no observable effects on vascular tissues. Histological analyses should be useful in diagnosis of air pollution-induced injury and damage in coniferous forests.
A Hydrologic Model Of Aspen-Conifer Succession In The Western United States, United States Department Of Agriculture, Forest Service
A Hydrologic Model Of Aspen-Conifer Succession In The Western United States, United States Department Of Agriculture, Forest Service
Forestry
Hydrologic impacts of grass-forb to aspen to conifer succession in the Rocky Mountain area are simulated by means of a fundamental model. Model algorithms representing hydrologic processes are sensitive to vegetational changes within the subalpine vegetation zone. Reductions in water yield are predicted as the vegetation on a small Utah watershed proceeds from a grass-forb type to aspen to conifers. Streamflow changes are largely attributable to an interaction between seasonal consumption for each vegetation type and the influence of vegetation type on snowpack. The model synthesizes present understanding and provides a framework for future watershed research.