scholarly journals Long-term changes in the flora and vegetation of Lake Mikołajskie (Poland) as a result of its eutrophication

2014 ◽  
Vol 70 (4) ◽  
pp. 323-334 ◽  
Author(s):  
Barbara Solińska-Górnicka ◽  
Ewa Symonides

Changes in littoral flora as well as aquatic and swamp vegetation were analysed with increasing eutrophication of the mesotrophic Lake Mikołajskie. Over 30 years the habitat conditions of the lake deteriorated and the phy-tolittoral was reduced from a zone 6 metres wide to one of only 2 metres. In addition, the number of submerged macrophyte species decreased by 50% and the frequency of most of the remaining species declined severalfold. No new species were encountered. Species retreating from the lake littoral included all <em>Chara</em> species, <em>Potamogeton obtusifolius</em>, <em>P. natans</em> and <em>Hydrocharis morsus-ranae</em>. A significant lowering of the phytosociological diversity and species richness of aquatic and swamp communities was observed. By 1994, six of the 12 associations identified in 1964 and representing the submerged and floating-leaved vegetation (e.g. <em>Nitellopsidetum ubtusae</em>, <em>Charetum asperae</em> and <em>Potamogetonetum compressi</em>) were no longer present. In turn, 6 swamp communities from among the original 14 identified in the lake were lacking (e.g. <em>Typhetum angustifoliae</em>, <em>Sugittario-Sparganietum emersi</em> and <em>Eleocharitetum palustris</em>). At the same time, two new aquatic and swamp communities appeared (<em>Ranunculetum circinuti</em>, <em>Myriophylletum spicati</em>, <em>Caricetum acutiformis</em> and <em>Caricetum distichae</em>). In contrast there was an increase in the species richness of reedswamp communities due to an influx of marshland species. While the 1990s witnessed a distinct decrease in concentrations of nutrients in Lake Mikołajskie, the consequent increase in water transparency was not associated with an increase in the area of submerged macrophytes, or the species richness of aquatic vegetation.

2012 ◽  
Vol 18 (2) ◽  
pp. 154-163 ◽  
Author(s):  
Jūratė Karosienė ◽  
Jūratė Kasperovičienė

Abstract Karosienė J., Kasperovičienė J., 2012: Peculiarities of epiphyton algal communities formation on different macrophyte species [Skirtingų makrofitų rūšių epifitono dumblių bendrijų formavimosi ypatumai]. - Bot. Lith., 18(2): 154-163. The epiphyton on different aquatic vegetation represented by emerged macrophytes (Phragmites australis, Equisetum fluviatile, Schoenoplectus lacustris), floating-leaved plants (Nuphar luteum) and submerged macrophytes (Potamogeton perfoliatus, Chara rudis) was studied in two meso- and mesoeutrophic lakes. The morphological characteristics, physiological and synecological peculiarities of plant host had more effect on epiphyton algae abundance and biomass than species richness. The highest densities of algae were associated with helophytes Phragmites australis, Equisetum fluviatile, the lowest was recorded on Schoenoplectus lacustris and laminae of Nuphar luteum. Loosely attached diatoms prevailed on helophytes, adnate species on Nuphar luteum laminae. Cyanobacteria and green algae were more abundant on Nuphar luteum laminae and Potamogeton perfoliatus.


Author(s):  
Katherine C Kral-O’Brien ◽  
Adrienne K Antonsen ◽  
Torre J Hovick ◽  
Ryan F Limb ◽  
Jason P Harmon

Abstract Many methods are used to survey butterfly populations, with line transect and area surveys being prominent. Observers are typically limited to search within 5 or 10 m from the line, while observers are unrestricted in larger specified search regions in area surveys. Although methods differ slightly, the selection is often based on producing defendable data for conservation, maximizing data quality, and minimizing effort. To guide method selection, we compared butterfly surveys using 1) line versus area methods and 2) varying width transects (5 m, 10 m, or unrestricted) using count data from surveys in North Dakota from 2015 to 2018. Between line and area surveys, we detected more individuals with area surveys, even when accounting for effort. However, both methods accumulated new species at similar rates. When comparing transect methodology, we detected nearly 60% more individuals and nine more species when transect width increased from 5 m to unrestricted, despite similar effort across methodology. Overall, we found line surveys slightly less efficient at detecting individuals, but they collected similar species richness to area surveys when accounting for effort. Additionally, line surveys allow the use of unrestricted-width transects with distance sampling procedures, which were more effective at detecting species and individuals while providing a means to correct count data over the same transect length. Methods that reduce effort and accurately depict communities are especially important for conservation when long-term datasets are unavailable.


Author(s):  
Wojciech Ejankowski ◽  
Tomasz Lenard

<p>The physicochemical parameters of water, the concentration of chlorophyll-<em>a</em> and the submerged aquatic vegetation (SAV) were studied to evaluate the effects of different winter seasons on the biomass of macrophytes in shallow eutrophic lakes. We hypothesised that a lack of ice cover or early ice-out can influence the physicochemical parameters of water and thus change the conditions for the development of phytoplankton and SAV. The studies were conducted in four lakes of the Western Polesie region in mid-eastern Poland after mild winters with early ice-out (MW, 2011 and 2014) and after cold winters with late ice-out (CW, 2010, 2012 and 2013). The concentrations of soluble and total nitrogen, chlorophyll-<em>a</em> and the TN:TP ratio in the lakes were considerably higher, whereas the concentration of soluble and total phosphorus and water transparency were significantly lower after the MW compared with after the CW. No differences were found in water temperature, reaction and electrolytic conductivity. Low water turbidity linked with low concentration of chlorophyll-<em>a</em> after the CW resulted in increased water transparency and the total biomass of the SAV. The negative effect of the MW on the macrophyte species was stronger on more sensitive species (<em>Myriophyllum spicatum</em>,<em> Stratiotes aloides</em>) compared with shade tolerant <em>Ceratophyllum demersum</em>. Our findings show that the ice cover phenology affected by climate warming can change the balance between phytoplankton and benthic vegetation in shallow eutrophic lakes, acting as a shift between clear and turbid water states. We speculate that various responses of macrophyte species to changes in the water quality after two winter seasons (CW and MW) could cause alterations in the vegetation biomass, particularly the expansion of shade tolerance and the decline of light-demanding species after a series of mild winters.</p>


Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1218
Author(s):  
Katarína Mikulová ◽  
Ivan Jarolímek ◽  
Jozef Šibík ◽  
Tomáš Bacigál ◽  
Mária Šibíková

Objectives: We followed the long-term changes of softwood floodplain forests strongly altered by water regime changes and examine the behaviour of neophytes in this environment. Here we ask: (1) How did the composition of neophyte and native species change? (2) How did the presence of species that prefer wetter conditions change? (3) What traditionally distinguished type of softwood floodplain forests (a wetter one or a more mesophilous one) do neophytes prefer? (4) What environmental factors affect the native species richness and the occurrence and cover of neophytes? Materials and Methods: Historical and recent phytosociological relevés of the association Salicetum albae of the Slovak part of the inland delta of the Danube River were used (177 plots together). For each plot, the number and cover of neophytes and number of native species were measured, and the Shannon-Wiener diversity index, the stand structure (cover of tree, shrub and herb layer) and the mean of Ellenberg indicator values were calculated and compared among time periods. Temporal trends of the soil moisture characterized by indicator values calculated for each plot were determined using a Linear Model. The synoptic table of traditional vegetation types was done to show preferences of neophytes for particular softwood forest types. The effect of site conditions on native species richness and occurrence of neophytes was determined using the Generalized Linear Model. Results: The relative number and cover of neophyte species increased and the absolute number of native species decreased over time; the vegetation of the area has changed from variable hygrophilous and mesophilous to homogenised mesophilous; most non-native species prefer the mesophilous vegetation of the floodplain forests; the wetter parts of the floodplain more successfully resisted invasions. Conclusions: The vegetation of the researched area has considerably changed over time to become less diverse and less hygrophilous, and has more invasive species. To preserve floodplain forests, natural hydrological and connectivity patterns should be adequately protected.


Hydrobiologia ◽  
2003 ◽  
Vol 506-509 (1-3) ◽  
pp. 625-634 ◽  
Author(s):  
Sergiu Cristofor ◽  
Angheluta Vadineanu ◽  
Anca Sarbu ◽  
Carmen Postolache ◽  
Roxana Dobre ◽  
...  

2009 ◽  
Vol 57 (7) ◽  
pp. 533 ◽  
Author(s):  
Trent D. Penman ◽  
D. L. Binns ◽  
T. E. Brassil ◽  
R. J. Shiels ◽  
Ruth M. Allen

Wildfire has shaped historic and contemporary vegetation assemblages in Australia. Ecological research has generally focussed on the effects of frequent fire on plant assemblages, with less attention given to the changes that occur in the absence of wildfire. Here we examine changes in understorey assemblages in dry sclerophyll forest catchments where wildfires have not occurred since 1973 and 1979 to determine if the initial floristics model applies. Understorey species (<2 m height) richness peaked approximately 5 years after fire with an average of 22.7 ± 0.4 (s.e.) species per 10 m2. These values declined throughout the study period resulting in an average of 13.4 ± 0.5 (s.e.) species per 10 m2 33 years after fire. Similarly, significant shifts in the understorey community composition were seen with increasing time since wildfire. These changes were attributed to a decrease in 40 species (24 resprouters, 16 obligate seeders) and an increase in 11 species (10 resprouters, 1 obligate seeder). Large shrub species richness (>2 m height) and stem density increased steadily until 10–15 years post-wildfire at which point they remained stable at ~3.2 species per 100 m2. In the absence of wildfire, these forests undergo significant changes in understorey/large shrub communities consistent with the initial floristics model.


2006 ◽  
Vol 29 (3) ◽  
pp. 1167-1173 ◽  
Author(s):  
Seppo Hellsten ◽  
Antton Keto ◽  
Maria Suoraniemi ◽  
Sari Partanen

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