Light environment characteristics of forest gap in deciduous broad-leaved forest and its effects on growth features of Gynostemma pentaphyllum in Jianghuai watershed
Wei, C.; Sun, Q.; Peng, Z.; Yan, D.
Ying Yong Sheng Tai Xue Bao 14(5): 665-670
2003
ISSN/ISBN: 1001-9332 PMID: 12924114 Document Number: 566673
The daily total light intensity, various wave band light intensities, spectrum composition, and the growth characteristics and total saponia content of Gynostemma pentaphyllum in forest gap and under forest were studied in deciduous forest (Liquidambar formosana) in Jianghuai watershed. The results showed that the intensities of full wavelength daily total light, blue light (400apprx510 nm), yellow-green light (510apprx610 nm), red-orange light (610apprx720 nm) and near-infrared light (720apprx1100 nm) in forest gap were higher than those under forest. The intensities and spectra compositions of blue light and red-orange light in forest gaps were significantly higher than those under forest. Additionally, the differences between those in forest gap and under forest varied seasonally. The relative intensity of blue light in April, July and October in forest gap was 8.32%apprx28.83%, 30.00%apprx579.17% and 6.70%apprx88.74% more than those under forest, respectively, and that of red-orange light in April, July and October in forest gap was 8.72%apprx28.83%, 30.19%apprx502.69%, 6.76%apprx91.57% more than those under forest, respectively. The spectrum composition of blue light in forest gap in these 3 months was 5.76%, 33.14% and 17.29% higher than those under forest, respectively, and that of red-orange light in forest gap in these 3 months was 5.04%, 53.34% and 10.23% higher than those under forest, respectively. The net photosynthetic rate, total dry-matter weight, and total saponia content of Gynostemma pentaphyllum growing in forest gap were higher than those under forest. Gynostemma pentaphyllum growing in forest gap had more dry-matter distributed in stem. The results could be available to utilize the light environment of deciduous broad-leaved forest and further building comprehensive management model of Gynostemma pentaphyllum in Jianghuai watershed zone.