Weed communities of root crops in the Pamir Alai Mts, Tajikistan (Middle Asia)

Abstract

<p>The paper presents the results of investigations of weed vegetation conducted on root crops in Tajikistan (Middle Asia), one of the world cradles of weed flora. The main research was conducted in the Zeravshanian, southern Tajikistan and Hissar-Darvasian geobotanical regions in 2011. The study was based on 107 phytosociological relevés obtained in various geobotanical regions of the country. The collected material probably presents the majority of variations among the weed communities of root cultivations in the Middle Asia. As a result of numerical analyses, 7 associations were distinguished: <em>Convolvulo arvensis-Cyperetum rotundi</em>, <em>Daturo stramonii-Hibiscetum trioni</em>, <em>Setario pumilae-Sorghetum halepensi</em>, <em>Galinsogo-Setarietum</em>, <em>Equiseto arvensi-Xanthietum italici</em>, <em>Portulacetum oleracei</em> and <em>Brassico campestris-Lamietum amplexicauli</em>. The last mentioned is new to science. Additionally, one subassociation has been proposed (<em>Convolvulo arvensis</em>-<em>Cyperetum rotundi kochietosum scopariae</em>). The main discrimination factor for the data set is the floristic structure of the associations. The study shows that root-crop plantations with segetal vegetation may harbor a relatively rich flora. Almost 200 species were found in vegetation plots, including some, which are rare and have not been recorded until now in this part of Middle Asia. However, most of the recorded species are widespread weeds typical for the Mediterranean and Irano-Turanian geobotanical provinces.</p>