| Phytoliths are silica bodies that farm inside some plant cells. They are formed by a wide variety of plants and have many distinctive shapes. Although there has been considerable interest in using phytoliths as paleoenvironmental indicators, efforts to do so have met with only limited success. This is primarily because of the difficulties in identifying individual species of plants from their phytolith component. In this paper I will present a new method of using phytoliths to reconstruct paleo-environments without relying on individual species identification.; Many of the dominant species of plants on the island of Martha's Vineyard, MA produce phytoliths. The soils of Martha's Vineyard preserve phytoliths creating the potential for their use in reconstructing the environmental history on the island. While individual species cannot be distinguished the suites of phytoliths characteristic of higher taxa are distinctive. Hence different island ecosystems may be distinguished by their phytolith assemblages in soil profiles, making it possible to identify the past distribution of these ecosystems.; Soil cores were taken at 56 sites on the island. At each site the plant community was defined by the percent of cover of different vegetation types. The four principle ecosystems were pine woods, hardwood forest (dominated by oak in almost every case), sand-plain grassland, and heath (usually dominated by ericaceous brush). There were, of course, gradations among these ecosystems. From each core, phytoliths were extracted by ashing the leaf litter and humus layer at 450{dollar}spcirc{dollar}C, and by heavy liquid (bromoform) separation from 4 cm core segments of the soil layers.; Cluster analyses show that hardwood forest, heath, and sand-plain grassland are clearly identifiable communities based on phytoliths. The presence of phytoliths in the B horizon of island soils along with historical documentary evidence suggests that the percolation of phytoliths through the soils is significant. Historical records from some sites indicate that the phytolith record provides a good record of local ecosystem change for a period of as much as the past 150-200 years. Analysis of the soil cores reveals patterns of environmental change over this time period. |
