植物生态学报 ›› 2016, Vol. 40 ›› Issue (2): 151-164.doi: 10.17521/cjpe.2015.0360

所属专题: 稳定同位素生态学

• 研究论文 • 上一篇    下一篇

华北低丘山区果药复合系统种间水分利用策略

何春霞1,2, 陈平1,3, 孟平1,2,,A;*(), 张劲松1,2,,A;*(), 杨洪国1,2   

  1. 1中国林业科学研究院林业研究所, 国家林业局林木培育重点实验室, 北京 100091
    2南京林业大学南方现代林业协同创新中心, 南京 210037
    3河北省水利水电勘测设计研究院, 天津 300250
  • 出版日期:2016-02-10 发布日期:2016-03-08
  • 通讯作者: 孟平,张劲松 E-mail:mengping@caf.ac.cn;zhangjs@caf.ac.cn

Interspecific water use strategies of a Juglans regia and Isatis tinctoria/Senna tora agroforestry

Chun-Xia HE1,2, Ping CHEN1,3, Ping MENG1,2,*(), Jin-Song ZHANG1,2,*(), Hong-Guo YANG1,2,*   

  1. 1Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China;

    2Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China;

    3Hebei Research Institute of Investigation Design of Water Conservancy Hydropower, Tianjin 300250,China
  • Online:2016-02-10 Published:2016-03-08

摘要:

了解林农复合系统的种间水分关系至关重要.该文通过稳定氘同位素研究了华北低丘山区核桃(Juglans regia)-菘蓝(Isatis tinctoria)/决明(Senna tora)复合系统各组分的水分来源, 试图明确该果药复合系统的种间水分利用策略, 为该区林农配置模式的选择提供理论依据.研究结果表明: 果药复合系统的土壤含水量明显高于单作菘蓝和单作决明地块, 在2012年,2013年上半年比单作菘蓝高26.74%和7.93%, 在下半年比单作决明高17.39%和13.65%.在果药复合系统内部, 土壤含水量以核桃树行中间位置的最低,树行北侧和树下最高.在各个土层深度, 单作系统的土壤水氢稳定同位素比率(δD值)均比复合系统的高.在菘蓝生长时期的春旱期, 复合系统中核桃的大部分水分来源于30-80 cm深层土壤水, 表明此时期核桃表层根系活性不高; 而决明生长时期正值雨季, 此时核桃优先利用雨水补充的0-30 cm浅层土壤水,表层根系活性增强.在任何生长时期, 菘蓝和决明85%以上的水分都来自浅层土壤水.在菘蓝苗期, 其根系尚未扎入深层土壤中, 单作菘蓝的水分完全来源于浅层土壤, 而在2012年间作菘蓝却有5.7%的水分来自于深层土壤, 在更为干旱的2013年该比例上升到9.7%, 该结果证实了核桃在旱季存在"水力提升"作用, 供浅根系作物吸收利用, 并且越干旱, 该水力提升作用越强.在华北低丘山区核桃-菘蓝/决明复合系统中, 深根性核桃改善了复合系统的土壤水分状况, 在旱季主要利用深层土壤水以避开与浅层作物的水分竞争,并能将深层土壤水提升至浅层土壤供菘蓝吸收利用, 核桃与两种药材表现为水分互利关系, 因而该模式适合在该地区发展.

关键词: 农林复合系统, 核桃, 菘蓝, 决明, 氢稳定同位素比率(&amp, #x003b4, D), 种间水分关系

Abstract:
Aims Understanding the interspecific water relations is important for designing agroforestry systems. The objective of this study was to determine the water use strategies of component species in a walnut (Juglans regia)-woad (Isatis tinctoria)/sicklepod (Senna tora) agroforestry system.Methods Water sources of component species in a walnut-woad/sicklepod agroforestry system were investigated with the technique of stable deuterium isotope tracing at a site of hilly area in Northern China during 2012-2013.Important findings Results showed that the soil water content in the agroforestry system was 26.74% and 7.93% greater than in the pure woad field in the first half year, and 17.39% and 13.65% greater than in the pure sicklepod field in the second half year (sicklepod growth period), in 2012 and 2013, respectively. The lowest water content was found in the middle of tree rows, and the highest water content was found in the northern side of tree rows or under the trees. In the soil layers measured, the pure woad and pure sicklepod systems had greater hydrogen stable isotope ratios (&#x003b4 D value) of soil water than in the agroforestry system. During the period of woad growth, more than half of the water absorbed by walnut was from the deeper soil layer (30-80 cm). In contrast, the walnut trees mainly utilized shallow layer (0-30 cm) soil water during the period of sicklepod growth. These findings suggest that walnut has a two-state root system: during the period of woad growth, shallow roots of walnut are not active when soil is dry whereas the sicklepod growth occur in rainy season, and the shallow roots of walnut are active and utilize more shallow soil water supplemented by rainwater. More than 85% of water used by both the woad and the sicklepod were from the shallow layer soil. At the seedling stage, the roots of woad, cannot grow into the deeper soil layer, and the absorbed water is completely from the shallow layer in the pure woad system. However, 5.7% of the water absorbed by the intercropped woad was from the deeper soil layer in 2012, and the proportion increased further (9.7%) in the following year when there was less precipitation. The results confirmed that hydraulic lift effect of walnut occurred on shallow layer crop in dry season, and this effect become greater under drier conditions. Therefore, deeper roots of walnut improved water condition in the walnut- woad/sicklepod agroforestry systems compared to pure crop systems. The walnut mainly utilized water from the deeper layer to avoid water competition with the shallow layer. In the dry season, crops benefited from the water provided by walnut roots through hydraulic lift. Walnut and intercropped plants exhibited water facilitation in the agroforestry systems, suggesting that this configuration is a suitable practice in this area.

Key words: agroforestry system, walnut (Juglans regia), woad (Isatis tinctoria), sicklepod (Senna tora), hydrogen stable isotope ratio (&amp, #x003b4, D), interspecific water relation