Author

Jaime Barrett

Date of Award

8-2013

Document Type

Thesis

Department

Environmental and Forest Biology

Thesis Advisor

Robin W. Kimmerer

Abstract

Bryophyte species often live in very specific habitats based on a complex relationship between water and nutrient requirements and tolerance of environmental conditions. The objective of this study was to further define some of the conditions under which Orthotrichum anomalum will colonize a site. Since the study site was the anthropogenic habitat of gravestones within a city cemetery, the goal was to determine if colonization preference, substrate specificity in particular, for this moss would change within a manmade system. This study focused on the distribution of Orthotrichum anomalum as it relates to rock type (granite, limestone or marble), microtopographic complexity and stone age based on percent moss cover. Stones (n=99) from study sites (n=3) within Oakwood Cemetery were randomly selected to be sampled vertically via transect for percent cover of: the total stone, each aspect and each microtopographic class (vertical, horizontal, slant and curve). Stones were scored for microtopographic complexity and age was approximated from the death dates engraved on the stone. Statistical analyses were done to determine if there were significant differences in percent moss cover for: each rock type, the level of microtopography and the approximated age. These tests included: one-way ANOVA tests for rock type, microtopographic class and aspect: and linear regressions for microtopographic complexity and age. There was a significant difference (pOrthotrichum (p>0.1). Differences in microtopographic class preference were significant (p0.9). My study supports preferential colonization of O. anomalum on calcareous rocks as reported by Crum ( 2004) further supporting the substrate specificity found in other studies (Gabriel and Bates 2005; Cleavitt 2001: Cleavitt 2002: Pharo and Beattie 2002). Though microtopographic complexity did not have a linear relationship with percent moss cover, that there were differences for microtopographic class brings up interesting questions about preferential positioning of moss species on substrates with and without competition. Percent moss cover variation over time could reflect clearing and/or stochastic dispersal events. That O. anomalum has similar colonization patterns on gravestones which are analogous to its natural rock habitats implies that substrate specificity is unaffected by human manipulation of the substrate.

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