摘要
橡胶林生态系统光合有效辐射(PAR)作为生态系统所有生命活动、有机物质合成和产量形成的最基本能量来源,是影响生态系统能量转化和物质生产的最重要生态因子,对其时空变异的研究,有助于理解系统内生理生态因子变化和光合行为,为充分开发利用林下资源提供理论依据。本研究分析2010年海南岛橡胶林生态系统PAR的时空分布格局及相互关系。结果表明,1)在日尺度上,橡胶林不同高度PAR日变化均呈现为相对比较规则的单峰型,最大值出现在正午前后;PAR从林冠顶层向下逐渐减弱,平均日总量全光照条件下(16m高度)最大,为28.89mol.m-2,到12、8、4m和2m处PAR平均日总量分别占85.22%、37.49%、17.48%和13.26%。2)在月尺度上,一年中橡胶林各层PAR月总量在7月达到最大值,在1月或者12月达到最小值。一年中PAR雨季高于旱季,但表现略有差异,橡胶林林冠顶层(16m)和林冠层(12m)白昼时段均表现为雨季高于旱季,而冠下3层(8、4m和2m)只有正午前后几小时雨季高于旱季,早晚时段则相反。3)橡胶林PAR年总量全光照条件下(16m)最大为10 543.75mol.m-2,往下逐渐减弱,12、8、4m和2m高度的光合有效辐射年总量分别为8 984.92、3 954.61、1 844.86mol.m-2和1 396.41mol.m-2,分别占到总量的85.21%、37.51%、17.50%和13.24%。4)橡胶林光合有效辐射透射率也因林冠等的遮挡,年内变化明显,各垂直高度也表现不同。
Photosynthetically active radiation（PAR） in rubber plantation ecosystem is the most basic energy source of all life activities,organic matter synthesis and yield formation.It is the most important ecological factor which affects the energy transforming and matter production in the ecosystem.It is helpful to understand the physiological and ecological characteristics and photosynthetic behavior of the ecosystem to study the temporal and spatial variation,and it will provide a theoretical basis for the full development and utilization of the under forest resources.In this paper,the temporal and spatial distribution pattern and interrelationships of PAR of rubber plantation ecosystem at Danzhou,Hainan Island in southern China in 2010 were analyzed.The results showed as follows.1） At daily scale,the PAR diurnal variation of different heights in rubber plantations showed a relatively regular single peak,and the maximum appeared around midday.The intensity of PAR decreased gradually from the top of canopy to the surface herbaceous layer,and the average daily total of full light condition（16 m height） was the maximum,28.89 mol·m^-2,those of 12,8,4 m and 2 m accounted for 85.22%,37.49%,17.48% and 13.26% of the full light condition,respectively.2） At monthly scale,the monthly total PAR in a year of each layer reached the maximum in July,the minimum in January or December.And the total PAR in the rainy season was higher than in the dry season while slight differences among different layers were observed： higher in rainy season than the dry season in top layer（16 m） and canopy layer（12 m） during the daytime,while in the other layers of 8,4 m and 2 m,PAR was higher in dry season in the morning and afternoon except for several hours around noon.3） The annual total PAR in rubber plantation reached the maximum at full illumination conditions（16 m height）,10 543.75 mol·m^-2.Those,decreasing gradually down forward,were 8 984.92,3 954.61,1 844.86 mol·m^-2 and 1 396.41 mol·m^-2 at 12,8,4 m and 2 m he
出处
《西北林学院学报》
CSCD
北大核心
2013年第3期13-21,共9页
Journal of Northwest Forestry University
基金
现代农业产业技术体系建设专项资金(CARS-34-GW5)
中国科学院战略性先导科技专项(XDA05050601-01-25)
中国热带农业科学院橡胶研究所基本科研业务费专项(1630022011013)
关键词
光合有效辐射
时空分布
橡胶林
海南岛
photosynthetically active radiation（PAR）
temporal and spatial distribution
rubber plantation forest
Hainan Island
