论文部分内容阅读
A trial of Avicennia officinalis L. with five different spacings was conducted in the newly accreted lands along the western coastline(Patuakhali district) of Bangladesh since 1993 to assess growth performance and the effect of spacing on tree growth. Data on tree density, height, diameter, bole height, crown diameter were recorded and analyzed when the stand was 19 years old. Mean height ranged from 12.89-13.52 m and diameter at breast height(dbh) from 26.57-32.16 cm in plots of different spacings. The mean annual height increment ranged from 0.67-0.71 m, mean annual diameter increment from 1.40-1.69 cm and wood volume from 6.02-10.04 m3·ha-1·a-1 in different treatments. Significantly greater diameter(32.16 cm) and wood volume(10.04 m3?ha-1?a-1) were obtained with wider(2.13 m × 2.13 m) spacing than with closer spacings. But tree growth was unaffected by other spacings. Growth data were also recorded from other A. officinalis plantations raised by Forest Department(FD) on different islands in Patuakhali and Bhola districts of Bangladesh. At these sites, mean annual height increment ranged from 0.33-0.62 m, mean annual diameter increment from 0.72-1.37 cm and wood volume from 1.55-5.73 m3?ha-1?a-1. The growth performance of A. officinalis indicated that the newly accreted lands along the western shoreline may be suitable for raising Avicennia plantations for the enrichment of coastal vegetation.
A trial of Avicennia officinalis L. with five different spacings was conducted in the newly accreted lands along the western coastline (Patuakhali district) of Bangladesh since 1993 to assess growth performance and the effect of spacing on tree growth. Data on tree density, height, diameter, bole height, crown diameter were recorded and analyzed when the stand was 19 years old. Mean height ranged from 12.89-13.52 m and diameter at breast height (dbh) from 26.57-32.16 cm in plots of different spacings. The mean annual height Increment ranged from 0.67-0.71 m, mean annual diameter increment from 1.40-1.69 cm and wood volume from 6.02-10.04 m3 · ha-1 · a-1 in different treatments. Significantly greater diameter (32.16 cm) and wood volume (10.04 m3 ? ha-1? a-1) were obtained with more spacings (2.13 m × 2.13 m) spacing than with closer spacings. But tree growth was unaffected by other spacings. Growth data were also recorded from other A. officinalis plantations raised by Forest Department (FD) on different islands in Patuakhali and Bhola districts of Bangladesh. At these sites, mean annual height increment ranged from 0.33-0.62 m, mean annual diameter increment from 0.72-1.37 cm and wood volume from 1.55-5.73 m3? ha-1? a-1. The growth performance of A. officinalis indicated that the newly accreted lands along the western shoreline may be suitable for raising Avicennia plantations for the enrichment of coastal vegetation.