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Influence Of Soil Acidity On The Occurrence Of Athiorhodaceae, Eville Gorham, Douglas C. Pratt Jan 1972

Influence Of Soil Acidity On The Occurrence Of Athiorhodaceae, Eville Gorham, Douglas C. Pratt

Journal of the Minnesota Academy of Science

Enrichment cultures from strongly acid Sphagnum bog peats and moderately acid to circumneutral fen peats revealed Athiorhodaceae to be present in almost all suitably wet samples above pH 5.3 and absent from almost all samples below pH 4.7. These bacteria were recorded in only one of fifty cultures from acid humus layers in a jack pine forest, and in none of thirty cultures from moderately acid humus layers in a mixed woodland. They were also absent from old-field surface soils, which often contained considerable amounts of organic litter.


Scirpus Validus And S. Acutus: A Question Of Distinctness, Marlyn Miller, E. O. Beal Jan 1972

Scirpus Validus And S. Acutus: A Question Of Distinctness, Marlyn Miller, E. O. Beal

Journal of the Minnesota Academy of Science

An analysis of 32 populations of bulrushes in the Scirpus validus-acutus complex growing in Itasca State Park and prairie ponds to the west indicates that most of the populations are referable to neither S. validus nor S. acutus but, rather, are intermediate in morphology. Further, the supposedly characteristic features by which the two nomenclatural species have been identified are erratically correlated.


A Computer Analysis Of Relationships Between Orders Of Chrysophyta, David P. Olds Jan 1972

A Computer Analysis Of Relationships Between Orders Of Chrysophyta, David P. Olds

Journal of the Minnesota Academy of Science

The division Chrysophyta has previously been formulated to include three diverse groups. A computer analysis was made of the individual orders within the division to determine the "naturalness" of this grouping and also to show how computer techniques may be used for this purpose. The computer methods are described, and a possible system of classification of the division based on the computer analysis is presented.


Size-Structure Correlation In Developing Roots Of Cissus And Syngonium, David L. Berquam Jan 1972

Size-Structure Correlation In Developing Roots Of Cissus And Syngonium, David L. Berquam

Journal of the Minnesota Academy of Science

The development of conducting tissues in relation to root size is examined in Cissus sicyoides L. and Syngonium podophyllum Engl. Evidence is presented that such relationships arise earlier in development than has hitherto been described. Their early appearance calls into question the hypothesis that such relationships reflect a solution to problems of water economy in mature tissues. While pattern determination in Syngonium is similar to that anticipated on the basis of published investigations, a new 'kind of size-structure correlation is identified in Cissus. In light of this fact, a need to broaden the philosophical bases for an interpretation of form …


Higher Fungi Of Minnesota, Ll., Margaret G. Weaver, Robert L. Shaffer Jan 1972

Higher Fungi Of Minnesota, Ll., Margaret G. Weaver, Robert L. Shaffer

Journal of the Minnesota Academy of Science

This paper, an annotated list of 240 species of Ascomycetes and Basidiomycetes of Minnesota, is the first published report of the occurrence of many of the species in the state and is the second report presented by the authors. These collections were made in nine Minnesota counties.


Deciduous Trees Of Minnesota: A Winter Key, Thomas Morley Jan 1972

Deciduous Trees Of Minnesota: A Winter Key, Thomas Morley

Journal of the Minnesota Academy of Science

Keys are provided for the identification in winter condition of Minnesota's native deciduous trees and also those commonly cultivated. A labelled plate of illustrations accompanies the keys, as does a brief selected reference list.


Pine Reproduction In Itasca State Park: Analysis In Moisture-Nutrient Coordinates, Vilis Kurmis, Henry L. Hansen Jan 1972

Pine Reproduction In Itasca State Park: Analysis In Moisture-Nutrient Coordinates, Vilis Kurmis, Henry L. Hansen

Journal of the Minnesota Academy of Science

Natural pine reproduction was studied in 36 forest communities representing the range of ecological variability of the upland forest in Itasca Park, Minnesota. The method of synecological coordinates was used to evaluate reproduction in relation to stand and site conditions. In the absence of fire, predominantly medium to nutrient-rich forest soils favor the growth of herbs, shrubs, and hardwoods under the open canopies of pine and aspen stands. There are very few red pine (Pinus resinosa Ait.) and jack pine (Pinus banksiana Lamb.) seedlings under these conditions, and growth of white pine (Pinus strobus L.) seedlings is severely restricted.


Effect Of Overstory Removal On Production Of Shrubs And Sedge In A Northern Minnesota Bog, James M. Brown Jan 1972

Effect Of Overstory Removal On Production Of Shrubs And Sedge In A Northern Minnesota Bog, James M. Brown

Journal of the Minnesota Academy of Science

A vegetation survey of a northern Minnesota bog three years after the removal of portions of the overstory showed a decrease in total coverage but an increase in frequency of ericaceous shrubs. Dry weight sedge production was approximately five-fold greater in clearcut areas than under the original black spruce canopy.


Sex Induction In Equisetum Arvense L., Stephen Davis Jan 1972

Sex Induction In Equisetum Arvense L., Stephen Davis

Journal of the Minnesota Academy of Science

Equisetum arvense was studied for sexual development. The effects of crowding and transplantation were observed to influence sexual maturity and growth patterns of the gametophytes. Regeneration experiments demonstrated that sexual development is environmentally induced.