平茬高度对四合木生长及生理特性的影响

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 平茬高度对四合木生长及生理特性的影响 DOI: 10.5846/stxb201208051108 作者: 作者单位: 国际竹藤中心,内蒙古环境工程评估中心,国际竹藤中心,内蒙古西鄂尔多斯国家级自然保护区管理局,内蒙古鄂尔多斯市林业工作站,内蒙古西鄂尔多斯国家级自然保护区管理局,内蒙古鄂尔多斯市林业工作站,内蒙古鄂尔多斯市林业工作站 作者简介: 通讯作者: 中图分类号: 基金项目: 国家科技支撑计划资助项目（2011BAC07B02-03）；国家重点基础研究发展计划资助项目（2009CB825103）；鄂尔多斯市林业局资助项目 Effect of different stubble height treatments on the annual growth index and physiological characteristics of Tetraena mongolica in two growing seasons Author: Affiliation: International Centre for Bamboo and Rattan,,,,,,, Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为改善珍稀濒危植物四合木种群衰退现状，促进其更新复壮及可持续发展，对四合木老龄化植株进行了0、5、10、15 cm（即A、B、C、D）4种平茬高度处理，以未平茬老龄植株为对照（CK），跟踪测定各处理的生长指标和生理指标变化规律，结果表明：（1）平茬能够促进四合木老龄化植株更新复壮，平茬后第1生长季各处理组株高生长量极显著大于CK（P < 0.01），处理B、C、D冠幅年生长量极显著大于CK（P < 0.01），各处理组新生萌条数量大于CK、萌条基径和萌条枝长极显著大于CK（P < 0.01），其中处理B株高和冠幅生长量分别较对照组增加241.43%和417.21%，平均萌条数量为324枝分别大于处理A、C、D和CK的293枝、229枝、221枝和159枝；（2）对照植株净光合速率及蒸腾速率日变化均为双峰曲线，4种平茬处理植株平茬后第1个生长季7月份净光合速率和蒸腾速率为单峰曲线，而平茬后第2个生长季7月份变为双峰曲线；（3）平茬后前两个生长季7月份净光合速率日均值排序均为：处理B > D > C > A > CK，其中，处理B日均值分别为CK的2.07倍和1.94倍；（4）平茬处理改善了四合木植株水分状况，提高了四合木抵御干旱胁迫的能力，处理组蒸腾速率和水势均高于对照组；（5）平茬处理提高了四合木水分利用效率，其中，处理B提高程度最为明显，前两个生长季的水分利用效率分别是CK的1.38倍和1.42倍；（6）在平茬后前两个生长季内，5 cm平茬较其他高度平茬在生长和生理特性均有明显优势，但随平茬年限的增加其状况如何尚需进一步研究。 Abstract:Tetraena mongolica Maxim is an ancient relic plant distributed from Bayan Gele of western Inner Mongolia Autonomous Region to Shizui Mountain of eastern Ninxia Province. It is a narrowly monotypic genus of Zygophyllaceae and has a great value of plant genetic resources. In addition, T. mongolica play an important role in cropland windbreak construction, soil and water conservation and desert control in western China. However, due to environmental degradation caused by human activities during the past decades, its population declines rapidly and the plant community structure changes substantially. In order to gather information for promoting its regeneration and rejuvenation and restoring a healthy T. mongolica community, we conducted stump treatments on the plants. One transect was set up across the study area and a 20 m × 20 m sampling plot was marked at a interval of 20 m along the transect and a total of 5 plots were established. The plots included the treatments of stubble heights of 0, 5, 10, and 15 cm and a control. This study was conducted between March 2011 and July 2012 and we found that (1) Stumping can promote regeneration and rejuvenation of the plant T. mongolica during the first growing season after stumping. Both height growth and crown size increase of the plants at all stumping levels were significantly higher than the control (P < 0.01), with an increase of 241.4% of height and 417.2% of crown size under the stump treatment of 5 cm. Both basal diameter and branch length of the plants increased significantly comparing to the control (P < 0.01). The number of plant sprouts with the treatment of 5 cm was the largest (324), and the number of plant sprouts with treatments of 0, 10, and 15 cm and the control were 293, 229, 221 and 159 respectively; (2) The diurnal variation of net photosynthesis rate (Pn) and transpiration rate (Tr) of plants in the control fitted a bimodal curve. The diurnal variation of Pn and Tr of stumped plants fitted a single-peak curve in first growing season of July after stumping and then changed to a bimodal curve in the second growing season of July; (3) During the two growing seasons in July, both daily average values of plant Pn had the following order: 5 cm of stubble height > 15 cm > 10 cm > 0 cm > control. The values of Pn in 5 cm treatment in the first and the second growing seasons were 2.07 and 1.94 times the control; (4) Tr and water potential of plants with all the treatments had higher values than the control; and (5) Water use efficiency increased significantly in the two growing seasons after stumping, especially in the treatment of 5 cm which were 1.38 and 1.42 times the control. In our study, we found that the treatment of 5 cm stubble height was the best in term of improving plant growth, photosynthesis, water potential and other physiological indices. Higher Tr indicates that the stumped plants had higher resistance of drought and higher water potential of stumped plants indicates that the drought stress of T. mongolica could be lightened through stumping. 参考文献 相似文献 引证文献