海南儋州橡胶林土壤水分变化及其对气象因子的响应特征

Soil Moisture Variation of Rubber Plantations in Danzhou, Hainan and Its Response to Meteorological Factors

通过分析气象环境要素对海南岛西部橡胶人工林土壤水分的影响,了解土壤水分动态变化的特征以及与气象因子的关系,揭示人工橡胶林土壤水分变化规律,为热带生态环境保护及农业产业经营提供理论数据参考。基于2017年1月至2018年12月两年间对海南西部儋州橡胶林的土壤水分及局部气象因子的连续定位观测,收集土壤水分以及相关气象数据,针对海南岛西部气候特点探讨土壤水分变化规律以及气象因子对土壤水分的影响。结果表明:该地区橡胶林的土壤水分动态变化呈现出明显的季节性,7~9月土壤含水量较高,5月、10月至翌年1月次之,2~4月最低。不同土层深度的水分年尺度内变化趋势基本一致,但表层土壤波动程度更加剧烈。土壤含水量与气象因子的相关分析表明,土壤水分主要受风速、地表温度、降水、土壤热通量、净辐射的影响,相关系数达到极显著水平(p<0.01)。旱季时(11月至翌年4月)土壤水分主要受到风速的影响,雨季时(5~10月)地表温度和土壤热通量对土壤水分的影响较大。土壤含水量随着土层深度增加而增高,表层土壤的波动频率和幅度都较深层的变化更为剧烈。橡胶人工林的土壤水分具有储量大、流失快等特点,可以通过经营丛林式胶园等方式,以涵养土壤水分和营养物质,有利于保护橡胶林水文环境,提高生态价值。

The effects of meteorological environmental factors on soil moisture in rubber plantations in western Hainan Island were analyzed systematically to understand the characteristics of soil water dynamics and the relationship of soil water with meteorological factors,and reveal the changes of soil moisture in rubber plantations,which provide a theoretic reference for protection of tropical ecological environment and management of agriculture industry.Continuous localized observation of soil moisture and local meteorological factors in rubber plantations was made in western Hainan from January 2017 to December 2018,and data on soil moisture and meteorological factors were collected to analyze the changes of soil moisture in the rubber plantations and the effects of meteorological factors on the soil moisture.The results showed that the soil moisture in rubber plantations in this area had an obvious seasonal dynamic change.The soil moisture content was higher from July to September,followed by May and October-January,and lowest in February-April.The change in the soil moisture content in different soil depths is basically the same at an annual scale,but the fluctuation of the surface soil water is more severe.Correlation analysis between the soil water content and the meteorological factors showed that the soil moisture was mainly affected by wind speed,surface temperature,precipitation,soil heat flux and net radiation,with its correlation coefficient being at a highly significant level(P<0.01).During the dry season(November-April)the soil moisture was mainly affected by wind speed.During the rainy season(May-October),the surface temperature and soil heat flux had a greater impact on the soil moisture.The soil water content increased with the depth of the soil layer,and the fluctuation frequency and amplitude of the soil water content were more severe in the surface soil than in the deep layer.The soil moisture content in rubber plantations was characteristic of large reserves and fast loss.The rubber plantations can be managed in a jungle way or other ways to conserve soil moisture and nutrients and protect the hydrological and ecological environment of the rubber plantations.