Pak J Biol Sci. 2020 Jan;23(8):1055-1059. doi: 10.3923/pjbs.2020.1055.1059.
Duckweeds are the world's smallest flowering plants. Its existence is affected by the water quality and availability. The increased water demand and water scarcity in most of the Mediterranean countries as Jordan have caused remarkable lowering in the water-table which reduced floods and disappearance of the seasonal lakes. Due to this, aquatic plants that grow on good quality of fresh water have disappeared totally. Therefore, this paper highlights the native growth and conservation of duckweed (Lemnaceae) in Jordan. It also focuses on the identification of water sources for duckweed's movement.
Field surveys were conducted to identify water source for water bodies that contain duckweeds. These surveys included visits to the Zarqa river, dams, irrigation ponds and Jordan valley. The source of water for duckweed movement and availability was determined. Water samples from the targeted areas were analyzed for selected parameters as pH, EC, NO3, PO4, BOD5, Zn, Pb, Cd and Cu.
The results showed that King Abdullah Canal and Zarqa river are the water sources that encourage the duckweeds growth. In Sukhnah, Jerash and Jordan valley areas, water analysis ranges (mg L-1) are: NO3 0.7-38, PO4 0.3-7.6 and BOD5 0-20. The pH range value is 7.1-8.1 and EC range value is 1.62-2.5 mS cm-1.The heavy metals values are, Zn is <0.02 mg L-1, Pb is <0.01 mg L-1, Cd is <0.002 mg L-1 and Cu is <0.01 mg L-1.
It can be concluded that mitigation measures are highly needed to overcome and altering the quality of the natural water flowing and participation of governmental institutions is also required for the success of applying mitigation measures to preserve the aquatic plants.
浮萍是世界上最小的开花植物。它的存在受水质和可获得性的影响。由于大多数地中海国家（如约旦）的用水量增加和水资源短缺，地下水位显著下降，减少了洪水的发生，季节性湖泊也消失了。由于这一原因，生长在优质淡水中的水生植物已经完全消失。因此，本文重点介绍了浮萍（浮萍科）在约旦的自然生长和保护情况。它还侧重于鉴定浮萍迁移的水源。
进行了实地调查，以确定含有浮萍的水体的水源。这些调查包括访问扎尔卡河、水坝、灌溉池塘和约旦河谷。确定了浮萍迁移和可用的水源。对目标区域的水样进行了选定参数分析，包括 pH 值、电导率、硝酸盐、磷酸盐、五日生化需氧量、锌、铅、镉和铜。
结果表明，阿卜杜拉国王运河和扎尔卡河是促进浮萍生长的水源。在 Sukhnah、杰拉什和约旦河谷地区，水质分析范围（mg L-1）为：硝酸盐 0.7-38、磷酸盐 0.3-7.6 和五日生化需氧量 0-20。pH 值范围为 7.1-8.1，电导率范围为 1.62-2.5 mS cm-1。重金属值为，锌<0.02 mg L-1、铅<0.01 mg L-1、镉<0.002 mg L-1 和铜<0.01 mg L-1。
可以得出结论，需要采取缓解措施来克服和改变自然水流的质量，需要政府机构参与，以成功实施缓解措施来保护水生植物。
