Abstract:

The vertical distribution and seasonal change of leaf area were studied in intensive and extensive culture poplar plantations. The result showed that the cumulative leaf area index(CLAI)of intensive culture trees was obviously higher than that of extensive culture trees during the growing season. According to the sample trees, the weighted mean of leaf area index in two stands was 3.0362 m²/m² and 2.1786 m²/m² respectively. Seen from the seasonal dynamic of leaf area, the intensive ones showed relative longer growing season than extensive ones. The higher leaf area and longer growing season contributed to the higher productivity in the former. The vertical distribution of CLAI in two plantations can be accurately simulated by the relative models according to the observing data. Even in the uniform plantation where the difference of leaf area in different individuals obviously existed, the leaf area appeared positive relation with its diameter at breast height(DBH).

Key words: Poplar plantation, Leaf area index, Extensive culture, Intensive culture