Center of Excellence

Botany Research Sub-Group

Projects - Environmental changes

Using indicator plants in the GBY assemblage, we have obtained preliminary evidence for environmental changes over the time represented by the succession of layers (Melamed, 2003). Two phases in the lifespan of GBY (layer 14 is the transitional layer) have been reconstructed. The earlier phase was wetter, with much of the valley being covered by water, and marshes prevailing in immediately surrounding areas. The later phase was drier, the lake level dropped and rivers flowed through the marsh-covered valley. This marshland was wet during the rainy season and exposed during the dry season. For example, plants such as papyrus (Cyperus papyrus) and water fern (Azolla sp.) indicate a warm climate, and water chestnut (Trapa natans) and fen pondweed (Potamogeton coloratus) indicate a colder, dryer climate. By observing the increase or decrease in these two groups of plants, we can estimate in which direction the climate is progressing.