低热喀斯特河谷顶坛花椒生态需水及抗旱机理研究——以花江峡谷为例

Study on Water Balance and Drought-resistant Mechanism of Dominant Plant in Hot-low Karst Valley

贵州典型的低热河谷区——花江峡谷由于大气降水时空分布严重失衡,长期干旱缺水,人畜用水困难,生态环境恶劣,但近几年顶坛花椒的种植在农业发展及生态建设两方面取得了重大突破。本文针对这一实际情况,通过建立雨水资源的利用率和作物需水系数,重点分析了雨水资源供应的时空分布与主要优势经济作物的需水规律间的差异性,并找出其水分胁迫条件下成功抗旱的机理。结果表明:(1)花江峡谷区全年雨水资源时空分布极不平衡,存在严重缺水危机;(2)林地全年蒸腾与蒸发需水总量大,水资源压力较大;(3)水资源供需矛盾突出,平稳状态难以维持;(4)顶坛花椒通过增加根系、角质层及栅栏组织保护、植株自身调节及Ca2+的保护等作用能较好地缓解水分不足所产生的不良影响。

Because of serious unbalanced distribution of rainfall and long-term lacks of water in Huajiang valley of Guizhou, it is difficult for human and livestock to use water and the vegetation taking a extreme bad look and the ecological environment was destructed seriously. But in recent years, Zanthaxylum planispinum vat. dinatnensis planting actually has obtained the significant breakthrough in agricultural developing and ecology recovering. Aiming at this actual situation, the article mainly analyzed the difference between the rain water resources distribution and the water-demand of main crop and finally discovered the drought-resistant mechanism under the bad condition. The result indicated that： 1） distribution of rainfall is not balanced in a whole year and latent crisis of water lacks are big; 2） The water resources pressure is big in forest because of big evapotranspiration; 3） The deference of demand and supply is so prominent that it is difficult to maintain the balance; 4） Zanthaxylum planispinum vat. dinatnensis can alleviate the effect of insufficient moisture content through shortening themselves and increasing roots and the protection of cuticle and stockade organization and Ca^2＋.