Impacts of edge proximity on bryophyte growth and soil quality in Nova Scotia farmlands

Abstract

1 online resource (31 pages) : colour illustrations, maps, graphsIncludes abstract.Includes bibliographical references (pages 25-31).Agricultural practices reduce biodiversity and degrade soil quality on farms. Millions of dollars are spent yearly on the upkeep of the carbon content, bulk density and texture of agricultural soils. These qualities are all associated with the presence of biological soil crusts in natural dryland habitats. Biological soil crusts on Nova Scotia farmland are comprised mostly of bryophytes, which represent a unique and diverse set of species. Non-crop life in agricultural fields is often dependent on the field margin. Analysing the patterns of agricultural bryophytes can give us insight into their effects on soil health and biodiversity. Our aim was to examine the relationship between bryophyte abundance and distance from the field margin on Nova Scotia farmland, and to determine whether a pattern in abundance is the result of challenges to bryophyte propagule spread or because of environmental conditions preventing germination. We gathered bryophyte abundance data from eight Nova Scotia farm fields at increasing distances from the field edge. In each plot, we tested the soil quality and germinated propagules from the top 2 cm of soil in laboratory conditions to test for the presence of bryophyte propagules. Bryophyte abundance and the abundance of bryophyte propagules decreased with distance from the field edge, although the relationship was much stronger in the abundance of bryophytes compared to propagules. Bryophyte abundance was not related to any of the soil conditions examined. Therefore, we concluded that the decrease in bryophyte abundance from the field edge to the center was largely because of environmental conditions maintained by the field margin