Crop type and altitude are the main drivers of species composition of arable weed vegetation in Tajikistan

Weed Research ◽  
2015 ◽  
Vol 55 (5) ◽  
pp. 525-536 ◽  
Author(s):  
A Nowak ◽  
S Nowak ◽  
M Nobis ◽  
A Nobis
Botany ◽  
2020 ◽  
Vol 98 (7) ◽  
pp. 381-392 ◽  
Author(s):  
Emanuele Fanfarillo ◽  
Sandrine Petit ◽  
Fabrice Dessaint ◽  
Leonardo Rosati ◽  
Giovanna Abbate

The interest in knowledge of the weed communities of arable land is growing worldwide. Italy is one of the countries in Europe that is the most biodiverse, geographically and environmentally heterogeneous, and rich in arable weed species. Thus, in this study, the geo-environmental factors influencing the floristic composition, the species richness, and the Shannon diversity of weed communities of Italian winter arable crops were investigated along a gradient across mainland Italy. Original data were collected in the spring of 2018 in 106 winter cereal and legume arable fields from one fixed area plot per field. Environmental and geographic data were retrieved for each plot, including latitude, longitude, elevation, soil texture, soil pH, continentality, temperature, and precipitation. The effect of crop type was also tested. Latitude was the main driver of floristic differentiation between the studied plant communities, followed by precipitation, temperature, continentality, elevation, and longitude. Soil features and crop type had no significant effects. Higher values of species richness and Shannon diversity were found in southern areas and at higher elevations. Significant explanatory variables accounted for 11.55% of the total variation in species composition of the surveyed communities. The results are discussed and compared with those of similar studies in other Eurasian countries.


2011 ◽  
Vol 15 (1) ◽  
pp. 136-144 ◽  
Author(s):  
Gyula Pinke ◽  
Péter Karácsony ◽  
Bálint Czúcz ◽  
Zoltán Botta-Dukát ◽  
Attila Lengyel

2019 ◽  
Vol 88 (4) ◽  
Author(s):  
Jana Májeková ◽  
Marica Zaliberová ◽  
Iveta Škodová

Arable fields are among the most widespread habitats in Slovakia, but recently, there have been no studies regarding species composition and structure of weed vegetation in these fields. Therefore, we studied the structure of arable weed vegetation and detected α- and β-diversity. The dataset of 507 phytosociological relevés in different crop types contains 407 plant taxa in 46 plant families. Native plants dominated over aliens, archaeophytes dominated over neophytes, and 14 plants belonged to invasive taxa. The most common species in the dataset were <em>Tripleurospermum perforatum</em>, <em>Cirsium arvense</em>, and <em>Viola arvensis</em>. Weeds were mostly therophytes, b- and a-euhemerobic, competitors, and ruderals, reproducing by seeds and pollinated by insects. The β-diversity of weed vegetation decreased with elevation and temperature and was higher in the Pannonicum than the Carpaticum region. The highest β-diversity was established in fodder+fallow fields, followed by that in cereals and root-crop fields, and the smallest diversity was found in stubble. Beta-diversity increased from spring to summer and slightly decreased again in fall. Detrended correspondence analysis indicated that the major compositional turnover of weed vegetation was related to light, temperature, moisture, and elevation. Weed vegetation constitutes an important habitat in the landscape that provides refuge to many threatened plants, and this vegetation has important functions in the agro-ecosystem food chain.


2017 ◽  
Vol 52 (6) ◽  
pp. 1279-1286
Author(s):  
G.P. Kononenko ◽  
◽  
E.A. Piryazeva ◽  
E.V. Zotova ◽  
A.A. Burkin ◽  
...  
Keyword(s):  

2014 ◽  
Vol 25 (3-4) ◽  
pp. 53-68
Author(s):  
I. V. Goncharenko ◽  
H. M. Holyk

Cenotic diversity and leading ecological factors of its floristic differentiation were studied on an example of two areas – Kyiv parks "Nivki" and "Teremki". It is shown that in megalopolis the Galeobdoloni-Carpinetum impatientosum parviflorae subassociation is formed under anthropogenic pressure on the typical ecotope of near-Dnieper hornbeam oak forests on fresh gray-forest soils. The degree of anthropogenic transformation of cenofloras can be estimated by the number of species of Robinietea and Galio-Urticetea classes, as well as neophytes and cultivars. Phytoindication for hemeroby index may be also used in calculation. We propose the modified index of biotic dispersion (normalized by alpha-diversity) for the estimation of ecophytocenotic range (beta-diversity) of releves series. We found that alpha-diversity initially increases (due to the invasion of antropophytes) at low level of antropogenic pressure, then it decreases (due to the loss of aboriginal species) secondarily with increasing of human impact. Also we found that beta-diversity (differential diversity) decreases, increasing homogeneity of plant cover, under the influence of anthropogenic factor. Vegetation classification was completed by a new original method of cluster analysis, designated as DRSA («distance-ranked sorting assembling»). The classification quality is suggested to be validated on the "seriation" diagram, which is а distance matrix between objects with gradient filling. Dark diagonal blocks confirm clusters’ density (intracluster compactness), uncolored off-diagonal blocks are evidence in favor of clusters’ isolation (intercluster distinctness). In addition, distinction of clusters (syntaxa) in ordination area suggests their independence. For phytoindication we propose to include only species with more than 10% constancy. Furthermore, for the description of syntaxonomic amplitude we suggest to use 25%-75% interquartile scope instead of mean and standard deviation. It is shown that comparative analysis of syntaxa for each ecofactor is convenient to carry out by using violin (bulb) plots. A new approach to the phytoindication of syntaxa, designated as R-phytoindication, was proposed for our study. In this case, the ecofactor values, calculated for individual releves, are not taken into account, however, the composition of cenoflora with species constancies is used that helps us to minimize for phytoindication the influence of non-typical species. We suggested a syntaxon’s amplitude to be described by more robust statistics: for the optimum of amplitude (central tendency) – by a median (instead of arithmetic mean), and for the range of tolerance – by an interquartile scope (instead of standard deviation). We assesses amplitudes of syntaxa by phytoindication method for moisture (Hd), acidity (Rc), soil nitrogen content (Nt), wetting variability (vHd), light regime (Lc), salt regime (Sl). We revealed no significant differences on these ecofactors among ecotopes of our syntaxa, that proved the variant syntaxonomic rank for all syntaxa. We found that the core of species composition of our phytocenoses consists of plants with moderate requirements for moisture, soil nitrogen, light and salt regime. We prove that the leading factor of syntaxonomic differentiation is hidden anthropogenic, which is not subject to direct measurement. But we detect that hidden factor of "human pressure" was correlated with phytoindication parameters (variables) that can be measured "directly" by species composition of plant communities. The most correlated factors were ecofactors of soil nitrogen, wetting variability, light regime and hemeroby. The last one is the most indicative empirically for the assessment of "human impact". We establish that there is a concept of «hemeroby of phytocenosis» (tolerance to human impact), which can be calculated approximately as the mean or the median of hemeroby scores of individual species which are present in it.


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