Phytosociological survey of juniper wood vegetation in Tajikistan (Middle Asia)

Abstract

The paper presents the first syntaxonomic classification for juniper wood communities in Tajikistan with some remarks on their environmental gradients. A total of 119 relevés were sampled between 2015 and 2021 using the seven-degree Braun-Blanquet cover-abundance scale. They were classified by a modified TWINSPAN method. Diagnostic species were identified using phi coefficient as a fidelity measure. Detrended Correspondence Analysis (DCA) was used to determine relationships between samples, vegetation units and major gradients in species composition. Plant communities have been divided into two main groups. The first one is a west Irano-Turanian wood of Juniperus polycarpos var. seravschanica of the Pamir-Alai mountane belt. It occurs in two variants depending mainly on the aspect and precipitation. The second juniper wood type in Tajikistan is a stand of Juniperus pseudosabina. It prefers the northern slopes and north-eastern ranges of the Pamir-Alai and slightly lower elevations. Both juniper wood types are highly distinct in terms of species composition, especially in the moss layer, and have therefore been assigned to different classes: Pino-Juniperetea (Juniperetum seravschanicae) and Juniperetea pseudosabinae (Carici turkestanicae-Juniperetum pseudosabinae). The main factors determining the species composition of the studied associations are latitude, growing season precipitation, annual range of air temperature and precipitation of coldest quarter. Our study has shown that there are two very distinct vegetation types of the juniper wood groves in Tajikistan, which reflect the main phytogeographical division between the provinces of Turkestan and Central Asia.

Global Overview of the Application of the Braun-Blanquet Approach in Research

“…This study is based on extensive material, has an excellent design, and the research findings are perfectly illustrated. Based on the Braun-Blanquet approach, Nowak et al [147] carried out the first juniper classification of Tajikistan's forests. A group of authors developed a detailed classification of Palestine's vegetation [148].…”

Figure 2 from: Nowak A, Świerszcz S, Naqinezhad A, Nowak S, Nobis M (2024) The Pistacietea verae: a new class of open, deciduous woodlands in Middle and Southwestern Asia. Vegetation Classification and Survey 5: 109-126. https://doi.org/10.3897/VCS.104841

“…The data set included 110 relevés of pistachio open woodlands and xeric scrubs from Tajikistan (Nowak et al 2022b) and Iran (A. Naqinezhad unpubl. ), 352 of Carpino-Fagetea forests from Tajikistan (Nowak et al 2017a) and Iran, 119 of Pino-Juniperetea and Juniperetea pseudosabinae stands from Tajikistan (Nowak et al 2022a), 231 of Quercetea ilicis and Quercetea pubescentis forests from Italy and Greece (Tsiourlis et al 2007;Gianguzzi and Bazan 2019), 146 of Crataego-Prunetea shrubland from Tajikistan (šhiblyak; Nowak et al 2022b;Świerszcz et al 2022), 156 of Prangetea ulopterae tall-forb communities from Tajikistan (Nowak et al 2020) and 180 of Stipo-Trachynietea distachyae pseudosteppes from Tajikistan (Świerszcz et al 2020).…”

“…1,500-2,000 mm/yr; Assadi 1986;Safarov 2018;Nowak et al 2022a). Our recent phytosociological studies have shown that the woody vegetation of Tajikistan should be divided into thermophilous open woodlands (pistachio stands), mesophilous shrubland (šhiblyak as a seral vegetation to mesic broad-leaved forests or a thermophilous shrubland on edaphically extreme habitats), juniper stands (with two very different types) and xeric shrubland that develop on initial soils (Nowak et al 2022b(Nowak et al , 2022aŚwierszcz et al 2022). Pistacia woodlands are distributed in the Irano-Turanian and Eastern Mediterranean phytogeographical regions (e.g.…”

Distribution of graminoids in open habitats in Tajikistan and Kyrgyzstan

“…Similar results were obtained by Wagner (2009) in meadow-forb vegetation in the western Tian Shan, where non-graminoid species dominate while only 19 graminoid species were recorded. The low number and contribution of graminoids in tall-forb vegetation can be explained by their close relationship with juniper forests, xerophytic shrubs, or screes in which graminoids occur with low abundance (Nowak et al 2020b(Nowak et al , 2022aŚwierszcz et al 2022). Moreover, tall-forb communities are used as pastures, but grazing animals use sward selectively because the vegetation includes tasteless or even poisonous species (e.g.…”