scholarly journals Contribution to the knowledge of Crataego-Prunetea Tüxen 1962 class in Bulgaria

Hacquetia ◽  
2020 ◽  
Vol 19 (1) ◽  
pp. 81-97
Author(s):  
Kiril Vassilev ◽  
Momchil Nazarov ◽  
Nikolay Velev

AbstractMantle vegetation includes plant communities dominated mostly by shrubs and occurs in habitats where the typical tree layers meet difficulties to evolve. This study was conducted in three areas of Bulgaria – Western Balkan Range, Western Sredna Gora Mt. and the Fore-Balkan. Numerical classification and ordination were performed by PC-ORD and JUICE software packages. Diagnostic species were determined by calculating the Phi-coefficient. Two associations and one plant community of the Berberidion alliance were recognized – Corno-Ligustretum Horvat ex Trinajstić ---amp--- Z. Pavletić 1991, Pruno spinosae-Ligustretum vulgaris Tüxen 1952 and Elytrigia repens-Crataegus monogyna community. The latter considered as a successional stage of shrub encroachment into the grasslands. Its species composition is very close to that of the ass. Corno-Ligustretum. The species composition of ass. Pruno-Ligustretum represents a mixture of species characteristic for dry and mesic grasslands, fringe and forest vegetation. The Crataego-Prunetea class is still poorly studied in Bulgaria and much more data from all regions in the country have to be collected.

2022 ◽  
Vol 81 (1) ◽  
Author(s):  
Kiril Vassilev ◽  
Momchil Nazarov ◽  
Constantin Mardari ◽  
Borislav Grigorov ◽  
Stoyan Georgiev ◽  
...  

Class Polygono-Poetea annuae Rivas-Mart. 1975 includes therophyte-rich vegetation on trampled habitats. The study presents the first analysis of the syntaxonomy of this class and its ecology in Bulgaria. One hundred seventy-five relevés from this class were collected and stored in the Balkan Vegetation Database during 2017–2020. Numerical classification (hierarchical divisive) and ordination were performed by JUICE and CANOCO software packages. Diagnostic species were determined by calculating the Phi-coefficient. Four associations, Sclerochloo durae-Polygonetum arenastri, Polygonetum arenastri, Lolio-Polygonetum arenastri and Poëtum annuae, were recognized. Their floristic composition has been shaped mainly by climatic and soil conditions. Sclerochloo durae-Polygonetum arenastri association has been found at lower altitudes, occurring in fully lighted habitats with high radiation, whereas Poëtum annuae has been found at higher altitudes in wetter and cooler areas. On the other hand, stands of Polygonetum arenastri have been found on nutrient-rich soils, whereas communities of Lolio-Polygonetum arenastri were distributed in warmer and nutrient-poor areas. The Polygono-Poetea annuae class is still poorly studied in Bulgaria and much more information from all regions of the country needs to be collected and analyzed.


1995 ◽  
Vol 14 (2) ◽  
pp. 48-54 ◽  
Author(s):  
W. J. Myburgh

The vegetation of the wetlands in the Grootvlei-Villiers area was investigated phytosociologically to distinguish plant communities. The results of a numerical classification (TWINSPAN) of 44 relevés, refined by Braun-Blanquet procedures, revealed ten plant communities which are classified hierarchically and which are presented in a phytosociological table. Although individual wetlands are poor in plant species, considerable variation in species composition exists among the different wetlands.


Koedoe ◽  
2001 ◽  
Vol 44 (1) ◽  
Author(s):  
J. De Klerk ◽  
L.R. Brown ◽  
H. Bezuidenhout ◽  
G. Castley

The application of fire as a management tool is often used to change the species composition of the vegetation and its cover to maintain plant communities in a specific successional stage. This study investigates the influence of two fire treatments (a head and a back fire) on the plateau grassland communities in the Mountain Zebra National Park (MZNP). The production of herbage yield on grazed areas and areas protected from grazing which were subjected to two fire treatments, were compared with that of an unburnt control area subjected to grazing in the same homogenous grassland over two growing seasons. No differences were found in herbage production between the two fire treatment areas. After the burn the grazing exclosures achieved the same herbage yield as the control area within two growing seasons. In comparison, the grazed areas could after the burn only achieve a herbage yield equal to 55.7 of that of the control area. The results indicate that fire stimulates active vegetation growth on the plateau grasslands in MZNP leading to a higher production rate and better utilisation by game.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Mesfin Belete Hailemariam ◽  
Tamru Demsis Temam

Vegetation-environment relationships are usually studied along elevational gradient. The patterns of plant community distribution in Gole forest, Ethiopia, were studied along elevational gradient and disturbances. Disturbances were recorded following the elevational gradient. For vegetation data collection, 62 sample plots of size 20 × 20 m were established along an elevational gradient (2728–3480 m.a.s.l). Data on species composition and environmental variables were measured and recorded in each plot. The elevation of each sample plot was measured using Garmin GPS. Anthropogenic disturbances in each plot were estimated using the following scales: 0 = no disturbance, 1 = slightly disturbed, 2 = moderately disturbed, and 3 = highly disturbed. R statistical package was used for cluster and ordination analysis. Boxplots and analysis of variance were used to assess the relationships between plant communities and environmental variables. Sorensen’s similarity coefficient was used to detect similarities and dissimilarities among communities. A total of 114 plant species belonging to 57 families and 94 genera were identified. Five plant community types were identified using agglomerative hierarchical cluster analysis. Every plant community had differences in composition and environmental variables. The variation in plant community distributions was significantly related to elevation and disturbance. Plant community distribution was negatively correlated with elevation ( P < 0.05 ) and also with disturbance ( P < 0.05 ). Sorensen’s similarity index showed that there was a difference in the distribution of plant species composition among the communities. The difference in plant community distribution of Gole forest was significantly related to elevation. Disturbances also have a considerable influence on the plant communities and mitigation of disturbance should be the main measure that needs to be taken into account in conservation planning in the study area.


Author(s):  
Merdas Saifi ◽  
Yacine Kouba ◽  
Tewfik Mostephaoui ◽  
Yassine Farhi ◽  
Haroun Chenchouni

Despite many studies explored the effect of livestock grazing on plant communities the response of species composition and diversity to livestock grazing in arid rangelands remain ambiguous. This study examined the effects of livestock grazing vs grazing exclusion on plant communities in arid steppe rangelands of North Africa. Plant diversity of annual species perennial species and all species combined was measured and compared between grazed and grazing-excluded areas. We also verified whether the difference in plant community composition between the two management types was due to species spatial turnover or community nestedness. Besides the effects of livestock grazing on beta diversity at local among transects and landscape among sites scales were examined using the multiplicative diversity partitioning. Results revealed that livestock grazing significantly decreased the alpha diversity of all species combined and the diversity of annual plants. Livestock grazing induced a shift in plant community composition where the most of species composition variation ~74% was due to infrequent species replacement between the two management types rather than community sub setting ~26%. The analysis of beta diversity at different spatial scales revealed that livestock grazing significantly increased beta diversity at the local scale but decreased it at the landscape scale. Our findings suggest that livestock grazing in arid steppe rangelands increases the variation of plant composition at local spatial scale and engenders vegetation homogeneity at coarse spatial scale. Therefore, the implementation of appropriate management practices such as short-term grazing exclusion is mandatory to prevent these ecosystems from large scale biotic homogenization.


2020 ◽  
Author(s):  
Katharina Ramskogler ◽  
Svenja Müller ◽  
Bettina Knoflach ◽  
Johann Stötter ◽  
Clemens Geitner ◽  
...  

&lt;p&gt;Glacier forelands are perfect for analysing the development of plant communities from zero onward. According to Matthews (1992), the chronosequence can act as a spatial representation of the temporal sequence. Therefore, it is ideal to analyse changes in landscape and land cover in time slices. Development of plant communities does not only depend on the age of the deposits, but also on topography, microclimate, soil development, and geomorphological processes as well as on biotic interactions. In the long term, permanent plots represent an adequate method to follow the colonisation on differently aged terrain throughout time.&lt;/p&gt;&lt;p&gt;The main research question of the study is: Do cryospheric changes influence plant community development in time and space? During the first study year we were focused on the following questions: i) How fast does a plant community evolve? ii) How many species do occur on different moraine stages? iii) How do soil parameters correlate with primary succession stages?&lt;/p&gt;&lt;p&gt;The study site is located in the southern part of the Central European Alps, Martell Valley (South Tyrol, Italy). We established 12 permanent plot clusters of 2 x 5 m on areas deglaciated between 1985 and 2018, two per retreat area. In each square meter of these clusters, species composition, cover, and number of individuals were sampled. On the ground moraines of the glacier stages 1911 and approximately 1850 we recorded species composition and cover on 10 x 10 m plots (four plots in total). In all plot clusters and plots on the old moraines, soil temperature and soil water potential as well as relevant soil parameters were measured.&lt;/p&gt;&lt;p&gt;We found up to two vascular plant species per square meter on areas ice free for one year and up to 16 vascular plant species per square meter on areas ice free since 1985.&lt;/p&gt;&lt;p&gt;On the moraines of 1911 were up to 39 vascular plant species per plot with a mean cover of 52.5 %. On the moraines of 1850 we found up to 43 vascular plant species with a mean cover of 40 %.&lt;/p&gt;&lt;p&gt;In the next step we will analyse the effects of pioneer, early and late successional species on morphodynamic processes and their response to these processes using functional traits.&lt;/p&gt;&lt;p&gt;Matthews, J.A. (1992): The ecology of recently-deglaciated terrain: a geoecological approach to glacier forelands and primary succession. Cambridge University Press, Cambridge.&lt;/p&gt;


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7833 ◽  
Author(s):  
Chiaki Otsu ◽  
Hayato Iijima ◽  
Takuo Nagaike

Exclosures that exclude large herbivores are effective tools for the protection and restoration of grazed plant communities. However, previous studies have shown that the installation of an exclosure does not ensure plant community recovery. Our study aimed to determine the effects of the domination of unpalatable plants and the timing of exclosure installation on the plant community recovery process in montane grassland overgrazed by sika deer (Cervus nippon) in Japan. In this study we compared plant species composition and their cover with inside and outside exclosures installed at different times. Furthermore, we also compared them with those in 1981, when density of sika deer was very low. We used quadrats inside and outside fenced areas established in 2010 and 2011 to record both the cover and the height of species in each quadrat between 2011 and 2015. Plant cover, with the exception of graminoid species, increased in later years in all treatments. Non-metric multidimensional scaling (NMDS) plots showed significantly differentiated treatment trends. The species composition within the 2010 fenced area gradually shifted to greater similarity with the species composition reported in 1981. The plant community in the 2011 fenced area was slower to recover. Compositions of plant communities outside the fenced areas hardly changed from 2011 to 2015. Chao’s dissimilarity index decreased over time between the plant community surveyed between 2011 and 2015 and the past plant community in 1981 within the exclosures, and was higher in the 2011 fenced area than in the 2010 fenced area. In conclusion, we show that the reduction of graminoids and the time after exclosure installation were important for plant community recovery from deer grazing damage. A delay in exclosure installation of one year could result in a delay in plant community recovery of more than one year.


2019 ◽  
Author(s):  
Coline Deveautour ◽  
Sally Power ◽  
Kirk Barnett ◽  
Raul Ochoa-Hueso ◽  
Suzanne Donn ◽  
...  

Climate models project overall a reduction in rainfall amounts and shifts in the timing of rainfall events in mid-latitudes and sub-tropical dry regions, which threatens the productivity and diversity of grasslands. Arbuscular mycorrhizal fungi may help plants to cope with expected changes but may also be impacted by changing rainfall, either via the direct effects of low soil moisture on survival and function or indirectly via changes in the plant community. In an Australian mesic grassland (former pasture) system, we characterised plant and arbuscular mycorrhizal (AM) fungal communities every six months for nearly four years to two altered rainfall regimes: i) ambient, ii) rainfall reduced by 50% relative to ambient over the entire year and iii) total summer rainfall exclusion. Using Illumina sequencing, we assessed the response of AM fungal communities sampled from contrasting rainfall treatments and evaluated whether variation in AM fungal communities was associated with variation in plant community richness and composition. We found that rainfall reduction influenced the fungal communities, with the nature of the response depending on the type of manipulation, but that consistent results were only observed after more than two years of rainfall manipulation. We observed significant co-associations between plant and AM fungal communities on multiple dates. Predictive co-correspondence analyses indicated more support for the hypothesis that fungal community composition influenced plant community composition than vice versa. However, we found no evidence that altered rainfall regimes were leading to distinct co-associations between plants and AM fungi. Overall, our results provide evidence that grassland plant communities are intricately tied to variation in AM fungal communities. However, in this system, plant responses to climate change may not be directly related to impacts of altered rainfall regimes on AM fungal communities. Our study shows that AM fungal communities respond to changes in rainfall but that this effect was not immediate. The AM fungal community may influence the composition of the plant community. However, our results suggest that plant responses to altered rainfall regimes at our site may not be resulting via changes in the AM fungal communities.


2003 ◽  
pp. 28-40 ◽  
Author(s):  
L. L. Zanokha

The 2 new associations, Carici stantis—Salicetum reptantis and Salico-Polemonietum acutiflori, are described within the all. Caricionstantis of the class Scheuchzerio-Caricetea fuscae R. Tx. 1937 for the northern belt of the typical tundra subzone of Taymyr. The diagnostic species group of the first syntaxon includes plants typical of sites with excessive watering. The ass. Carici stantis—Salicetum reptantis is restricted to bottoms or lower parts of the watershed and moun­tain terrace slopes. The ecological regime of these sites is subject to slight variations reflected in presence/ absence of certain species. Due to floristic differences, the association is subdivided into several subassociations which form a topographic-ecological series along the humidity gradient: epilobietosum palustris→ptilidietosum ciliaris→typicum→petasitetosum frigidi. The ass. Carici stantis—Salicetum reptantis is referred to the all. Caricionstantis which also includes the associations Meesiotriquetris—Caricetumstantis and Pooarcticae—Dupontietumfisheri (also described from the Ragozinka R. basin); the latter occur in the wet depres­sions between sloping hills and the flowing valleys, respectively. If compared to these two, the ass. Carici stantis—Salicetum reptantis is shown to hold an intermediate position between them. The ass. Salico-Polemonietum acutiflori with the 2 variants, Salix lanata and S. reptans, represents various variants of mire vegetation which have under­gone zoogenic transformation (by lemmings). The stands size 1—1.5 m2 in space. The diagnostic species group comprises plants common of the wet mossy stream banks. The association is referred to the all. Caricion stantis, although many diagnostic species of the alliance are not present in its composition. When the new data are available, the association is probable to be separated into an independent alliance.


2012 ◽  
pp. 66-77 ◽  
Author(s):  
I. A. Lavrinenko ◽  
O. V. Lavrinenko ◽  
D. V. Dobrynin

The satellite images show that the area of marshes in the Kolokolkova bay was notstable during the period from 1973 up to 2011. Until 2010 it varied from 357 to 636 ha. After a severe storm happened on July 24–25, 2010 the total area of marshes was reduced up to 43–50 ha. The mean value of NDVI for studied marshes, reflecting the green biomass, varied from 0.13 to 0.32 before the storm in 2010, after the storm the NDVI decreased to 0.10, in 2011 — 0.03. A comparative analysis of species composition and structure of plant communities described in 2002 and 2011, allowed to evaluate the vegetation changes of marshes of the different topographic levels. They are fol­lowing: a total destruction of plant communities of the ass. Puccinellietum phryganodis and ass. Caricetum subspathaceae on low and middle marches; increasing role of halophytic species in plant communities of the ass. Caricetum glareosae vic. Calamagrostis deschampsioides subass. typicum on middle marches; some changes in species composition and structure of plant communities of the ass. Caricetum glareosae vic. Calamagrostis deschampsioides subass. festucetosum rubrae on high marches and ass. Parnassio palustris–Salicetum reptantis in transition zone between marches and tundra without changes of their syntaxonomy; a death of moss cover in plant communities of the ass. Caricetum mackenziei var. Warnstorfia exannulata on brackish coastal bogs. The possible reasons of dramatic vegetation dynamics are discussed. The dating of the storm makes it possible to observe the directions and rates of the succession of marches vegetation.


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