Edaphic Controls Over Succession In Former Oak Savanna, Willamette Valley, Oregon
Datum
2008-06
Autor:innen
Zeitschriftentitel
ISSN der Zeitschrift
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Verlag
University of Oregon
Zusammenfassung
Oak savanna was a dominant ecosystem of Oregon's Willamette Valley prior to
Euro-American settlement but has declined precipitously due to urbanization, agriculture,
and reduced fire regimes. Some areas have retained their savanna structure while others
have succeeded into woodland or forest. I investigated the relationships of current
community type to edaphic (bulk density, texture, carbon, nitrogen, depth, and pH) and
topographic (slope and heatload) factors at seven sites using analysis of variance and
principal components analysis. Results indicate that edaphic and topographic conditions
strongly influence successional pathways in former oak savanna, but the specific effects
depend on site location. Soil moisture was also measured seasonally at three of the sites
in community types representing the current successional stages. Results indicate that dry conditions restrict succession to dense forest, and that soil depth is an important
control over soil moisture within the soil profile.
Beschreibung
xii, 87 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.