Date of Award

6-2018

Document Type

Open Access

Degree Name

Bachelor of Science

Department

Biology

First Advisor

Jeffrey Corbin

Language

English

Keywords

biological soil crust, soil, crust, germination, seedling, cryptogamic crust, cyanobacteria, algae, lichen, moss

Abstract

Biological soil crusts (BSCs), otherwise known as cryptogamic soil crusts, biocrusts, or cyanobacterial crusts, are soil aggregations hosting diverse biotic communities. They are composed of cyanobacteria and algae, and generally have a covering of moss and/or lichen. BSCs are typically found in arid to semi-arid regions throughout the world, and are integral soil stabilizers, moisture retainers, and nitrogen fixers in these communities. Along with these factors, BSCs are able to impact germination and establishment of plants, either as an accompanying influence, or direct result of those listed above. BSCs have yet to be formally described in the inland northeastern United States, and yet they have been found in a variety of locations, including New York, New Hampshire, and Maine. This paper seeks to investigate the species composition of crusts and their effects on seedling germination in the Albany Pine Bush Preserve, an inland scrub-oak pine barren ecosystem in upstate New York. Crusted and non-crusted soil samples were taken from the Preserve and refrigerated at 4°C until use. Several of the crusted samples were sent off for analysis of their constituents, and the other eighty dishes (forty crust and forty sand) were used in the germination experiment. Three species of plants native to the Pine Bush (little bluestem (Schizachyrium scoparium), bush clover (Lespedeza capitata), and lupine (Lupinus perennis)) were scattered onto the soil conditions, with twenty seeds of one species in each dish. The results of this study supported our hypothesis that BSCs would inhibit the success of seedling germination, with bush clover and lupine germinating three and five times greater, respectively, on bare sand than crusted conditions. The crusts’ ability to influence the presence of plant species suggests a larger impact on the whole ecosystem, as those that succeed will affect other present biota. Crusts likely contribute to habitat heterogeneity, given their apparent influence on seeds and the crusts’ spatial variation throughout the environment. Further research into the impact of crusts in northeastern systems should be undertaken, as crusts’ impacts are significant and may be different than those described in arid and semi-arid systems.

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