Abstract:

Aims Our objective is to study the change rules of the main phytolith morphotypes in Phragmites australis from June to October.
Methods We selected similarly sized leaves of P. australis in 12 sampling sites and extracted phytoliths with the wet-ashing method.
Important findings The main phytolith morphotypes in P. australis could be classified into five categories. There is little change about the phytolith assemblages in P. australis during different growth periods and different combination of temperature and humidity. This implies that phytolith morphotypes of the same plant species are stable and therefore can be used to effectively reconstruct paleo-vegetation. The maximum value of the saddle percentage appears in July and then slightly decreases. While the maximum value of the percentage and concentration of the bulliform appears in August or September, with its minimum value in July. This indicates that the saddle formation may be more controlled by plant photosynthesis and transpiration, while the bulliform formation may be closely associated with the support of bulliform cells. The result also shows that the phytolith concentration in P. australis does not gradually accumulate from June to October. Its maximum value appears in August and its minimum value in September, so the change rules of the phytolith concentration may be concordant with the need of silicon for plants in different growth periods. Furthermore, the maximum value of the saddle concentration in P. australis also appears in August, with its minimum value in September. This trend is similar to changes of the phytolith concentration in P. australis.

Key words: change character, growth period, Northeast China, Phragmites australis, phytolith