摘要
在林窗、林缘、林下3种自然光环境下,对千岛湖次生林优势种马尾松、苦槠、石栎和青冈栎在不同季节的光合作用日变化、光响应、CO2响应和叶绿素荧光参数进行比较,探讨优势种对光环境的适应及响应的差异,以期了解群落演替的内在机制.结果表明:在3种光环境下,马尾松、苦槠的日均净光合速率(Pn)为夏季最高,石栎、青冈栎为秋季最高.在林窗、林缘中,年均最大净光合速率(Amax)、光饱和点(LSP)、光补偿点(LCP)、暗呼吸速率(Rd)均为马尾松最高,苦槠次之,青冈栎和石栎最低;林下生境中,青冈栎的年均Amax、表观量子效率(AQY)最高,其次是石栎和苦槠,马尾松最低.3种生境中,马尾松的年均最大羧化速率(Vc max)、最大电子传递速率(Jmax)和磷酸丙糖利用率(TPU)均显著高于其他3种优势种.马尾松、苦槠4个季节的PSII最大光化学效率(Fv/Fm)均为林窗最高,石栎、青冈栎为林下最高;马尾松、苦槠的Fv/Fm最大值出现在夏季,石栎、青冈栎出现在秋季.马尾松、苦槠更适合生长于林窗等高光强生境中,而石栎、青冈栎在林下等低光强生境中生长较好.随着演替的进程,群落郁闭度增大,石栎和青冈栎将取代马尾松和苦槠成为群落演替顶极阶段的优势种.
To understand the mechanisms driving community succession in the secondary forest sur- rounding Qiandao Lake, Zhejiang, China, we investigated seasonal dynamics of the diurnal varia- tions of net photosynthetic rates, their responses to both light and CO2, and chlorophyll fluorescence parameters of four dominant plant species, i. e. , Pinus massoniana, Castanopsis sclerophyUa, Lith- ocarpus glaber and Cyclobalanopsis glauca in three natural light habitats, i. e. , gap, edge and un- derstory. In the three different light regimes, the daily mean values of the net photosynthetic rate （Pn） of P. massoniana and C. sclerophylla were significantly higher in summer than in the other seasons, while P, of L. glaber and C. glauca was significantly higher in autumn than in the other seasons. In the forest gap and edge habitats, the annual mean values of the maximum net photosyn- thetic rate （Amax ） , the light saturation point （LSP）, light compensation point （LCP） and dark res- piration rate （Ra ） of P. massoniana were the highest, followed by C. sclerophylla, and those of L. glaber and C. glauca were the lowest. In the understory habitat, the annual mean values of Amax and the apparent quantum yield （AQY） of C. glauca were the highest, followed by L. glaber and C. sclerophylla, and those of P. massoniana were the lowest. The annual mean values of the maximumrate of carboxylation （ Vcmax）, maximum rate of electron transport （ Jmax ） and triose phosphate use rate （TPU） of P. massoniana were significantly higher than those of the other three plant species in the three different light regimes. During the four seasons, the photochemical maximum efficiency of PSII （Fv/Fm） of P. massoniana and C. sclerophylla in the forest gap habitat was significantly high- er, while those of L. glaber and C. glauca in the understory habitat were significantly higher than in the other light regimes. The maximum values of Fv/Fm of P. massoniana and C. sclerophyUa were the highest in summer, and those of L. g
出处
《应用生态学报》
CAS
CSCD
北大核心
2014年第6期1615-1622,共8页
Chinese Journal of Applied Ecology
基金
浙江省自然科学基金项目(Y507660)
台州学院培育基金项目(2013PY21)资助
关键词
千岛湖
光合特性
优势种
光环境
林窗
Qiandao Lake
photosynthesis trait
dominant species
light regime
canopy gap.
