363 research outputs found
Preliminary classification and evaluation of Engelmann spruce
No full textThis thesis is divided in to two parts:
In the first part - A Preliminary Classification of the Engelmann
Spruce - Alpine Fir Forests at Bolean Lake, B. C. - some ecological concept
are discussed. The forest association is defined as an ecological unit
that includes the characteristics of climate, soil, topography, flora and
fauna; and is recognized by its floristic structure. The area studied is
described. Data were collected from selected temporary plot. Soil profile
was described and samples collected. Forest mensurational data were
collected on tenth-acre plots. Two forest associations can be considered
established. They are:
1. Picea Engelmannii - Abies Lasiocarpa - Vaccinium membranaceum -
Rubus pedatus association. (Engelmann spruce - alpine fir - black
huckleberry - trailing Rubus association). Designated the VM
association.
2. Picea Engelmannii - Abies lasiocarpa - Vaccinium membranaceum -
Dryopteris Linnaeana association, (Engelmann spruce - alpine fir -
tall blueberry - oak fern association). Designated the VO association.
Four other forest associations were tentatively identified. They are
described because they are of interest to foresters.
In the second part - An Evaluation of Two Forest Associations in
the Engelmann Spruce - Alpine Fir Forests at Bolean Lake, B.C. - forest
mensurational data from the vegetational plots were compared and analysed
with data from permanent sample plots established independently.
Differences in average height of dominant and codominant trees, in height
of average dominant tree, and in volumes between the VO and VM associations were found. These results indicate that the VO forest
association has better site quality than the VM forest association.
Differences were also found to composition, number of trees per acre
and in the distribution of stem size, these differences indicate
that the VO and VM associations will probably give different responses
to silvicultural treatment.Forestry, Faculty ofGraduat
Letter from [author unknown] to John Muir, 1884 Apr 2
No full textDr. George Engelmann Born at Frankfurt on the Main, February 2nd, 1809 DIED, In the midst of his scientific labors at his more in St. Louis, on Monday, February 4th, 1884, in the seventy-fifth year of his age 3003 Locust Street, St. Louis March 10th, 1884https://scholarlycommons.pacific.edu/jmcl/44166/thumbnail.jp
Flora der nordwestdeutschen Tiefebene / [Hauptbd.]
No full textVorlage des Erscheinungsvermerks: Leipzig Verlag von Wilhelm Engelmann 189
Typification of Gnaphalium collinum var: monocephalum (Gnaphalieae: Asteraceae) and clarification of related material
No full textThe effects of climate on Engelmann spruce regeneration and vigor
No full text2017 Fall.Includes bibliographical references.Recent climate modeling suggests that drought will become more frequent in the southern Rocky Mountains over the next century. Understanding how tree species will respond and adapt to this changing climate is vital to guide future management decisions by land managers. Future increases in drought frequency and severity will likely have an impact on the composition of forests. Modeling studies have been used to predict the effect that increasing drought will have on Engelmann spruce in southwest Colorado, but little field data has been gathered to validate this modeling. This study uses empirical data to test whether drought conditions are related to decreases in seedling establishment and tree vigor. Annual regeneration data from 1990 to 2009 was collected from 24 sites with 30-year PRISM precipitation normals ranging from 531 mm to 924 mm to determine if dry and wet sites respond differently to drought. Elevations of our study sites ranged from 3100 m to 3500 m above sea level. Among these 24 sites, we found the number of seedlings per hectare varied between 1804 and 18975. We used a mixed effects model to identify climate variables important to annual seedling establishment density. A separate provenance study on the White River National Forest was analyzed to identify drought effects on tree vigor. Engelmann spruce bareroot seedlings from twenty sources ranging from British Columbia to New Mexico were planted in 1970 at an elevation of 2930 m north of Vail, Colorado. Annual precipitation normals of the 20 seed sources ranged from 423 – 1918 mm. We collected increment cores from six to eight trees from each of the 20 seed sources in 2016, and standardized the chronology of each tree using standard dendrochronological techniques. We then analyzed the annual radial growth response of each provenance to a period of severe drought from 2000-2004 using both RWI and a resistance/resilience framework. For both parts of our study, we found weather variability and drought did not impact regeneration or vigor as much as hypothesized, suggesting regeneration and vigor of spruce in these high elevation forests are not reduced by contemporary levels of drought
Scytophyllum waehneri (Stur) nov. comb., the correct name for Scytophyllum persicum (Schenk) Kilpper, 1975
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