入侵植物的生理生态特性对碳积累的影响

随着国际贸易的发展和人们交往的增加以及全球环境的变化,生物种类在全球扩散的机会也大大增加,从而为生物入侵创造了机会。生物入侵不仅给农林牧生产造成损失,而且具有长期的生态学效应。外来种的成功入侵不是其自身某一个特性决定的,而是其特性与新的生境综合作用的结果。外来入侵种生理生态特性的研究对其预测和防治具有重要的意义。目前对入侵种生理生态特性的研究较少。已有的研究表明,与本地种相比入侵种可能通过提高光合能力、资源利用率、表型可塑性、化感作用,以及降低繁殖成本等增加植株碳积累,促进其入侵。但并不是所有的入侵种都同时具有这些特性。生境不同限制性资源不同,入侵机制就不同。成功的入侵种应该能够高效地利用生境中的限制性资源,并且能够较快地调节自身的生理特性以适应波动的资源环境。

The effects of ecophysiological traits on carbon gain in invasive plants

The spread of biological species is occurring at unprecedented rates as a result of human activities, international trade and global changes, which provides opportunity for biological invasion. Biological invasion badly affects productivity of agriculture, forestry and animal husbandry, and has long term ecological impacts on ecosystem. Research in invasion biology has tended to focus on the technology of invading organism control, rather than on attempting to understand why invasions succeed or fail, with the potential pay-off in the prevention of future invasion. Successful invasion of alien plant species depends not only on plant traits, but also on the comprehensive interactions between plant traits and new habitat being invaded. Studies on the ecophysiological traits of alien invasive species are more meaningful for prediction and prevention of plant invasion. Although there is now agreement on some morphological, demographic and life history attributes of invaders, ecophysiological traits are only beginning to be explored, despite the growing evidence that interspecific differences in growth rate have a combined ecophysiological and morphogenetic basis. The ecophysiological traits affecting carbon gain of invasive plants are reviewed in this report. The few studies on this aspect showed that, compared with native plants, invasive plants have a suite of traits, such as greater photosynthetic capacity, higher resource-use efficiency, larger phenotypic plasticity, and lower reproductive cost, and so on, which could improve their carbon gain. Furthermore, invasive plants can inhibit native plant growth through allelopathy. But not every invasive plant species has all of those traits. The mechanism of invasive plants invading different community with different limited resources might be different. Successful invasive plants must have the ability to use limited resources effectively, and to adjust their physiological traits to fluctuant resources.