Vegetation reconstruction from soil phytoliths, Tongariro National Park, New Zealand

Abstract

Phytoliths are microscopic particles of opaline silica (SiO2.nH2O) formed by the accumulation and solidification of siliceous gel between and within the cells of many plants. Soil surface phytolith assemblages are assessed for their potential to accurately reconstruct the overlying vegetation community within the subalpine zone of Tongariro National Park, New Zealand. The results provide important new evidence that phytoliths are an under‐exploited tool for reconstructing past vegetation patterns. A new technique has been developed to quantitatively compare phytolith supply with accumulation. From four study sites, plants and soil were collected for phytolith extraction, and vegetation height and canopy cover were surveyed. The results indicate that at three of the four sites, source vegetation could be satsifactorily reconstructed at a broad community level from the dispersed soil phytolith record implying similar expectations for the application of this technique to the fossil phytolith record.

Key words:

• phytoliths
• palaeoecology
• biogenic silica
• New Zealand
• Tongariro National Park