Assessment of some heavy metals in various aquatic plants of Al-Hawizeh Marsh, southern of Iraq

Al-Abbawy DAH, Al-Thahaibawi BMH, Al-Mayaly IKA, Younis KH. 2021. Assessment of some heavy metals in various aquatic plants of Al-Hawizeh Marsh, southern of Iraq. Biodiversitas 22: 338-345. In order to describe the degree of contamination of aquatic environments in Iraq, heavy metals analysis (Fe, Ni, Cr, Cd, Pb, and Zn) was conducted for six aquatic macrophytes from different locations of Al-Hawizeh Marsh in southern Iraq. The six species were Azolla filiculoides (floating plant), Ceratophyllum demersum, Potamogeton pectinatus, Najas marina (submerged plants), Phragmites australis, and Typha domingensis (emergent plants). The results indicate that cadmium, chromium, and iron concentrations in aquatic plants were above the World Health Organization (WHO). In contrast, zinc, copper, and lead were within the allowable limits. C. demersum and N. marina showed higher concentrations of heavy metal accumulation than the other aquatic plants. The concentration of heavy metals in plant tissues during the summer months was higher than in the different seasons. C. demersum and N. marina showed higher concentrations of heavy metal accumulation than the other aquatic plants. Heavy metal bioconcentration (BCF) was calculated to assess heavy metals bioaccumulation in the aquatic plants.

Movement patterns, maximum distances traveled and microhabitat selection of spadefoot toad tadpoles in temporary ponds

Understanding the movement of individuals across natural habitats is important to determine fundamental aspects of their ecology, from dispersal patterns and habitat selection to interactions with predators, pathogens or conspecifics. Amphibian larvae are key to aquatic systems, playing fundamental roles as both consumers and prey, affecting nutrient cycling and even physico-chemical properties of the water bodies they occupy. Nevertheless, despite an extensive body of literature on most other aspects of their ecology, we know very little about spatial movements of amphibian larvae in their natural habitats, and the little information we have is restricted to lotic systems. Here we use a mark-and-recapture procedure using elastomers to determine movement patterns and microhabitat selection of western spadefoot toad tadpoles (Pelobates cultripes) in two large ponds in southwestern Spain. We observed maximum distances moved by these tadpoles of >67 m and >245 m, depending on the pond. These distances coincided with the maximum cross distance in each pond, suggesting that they could potentially move even farther in larger wetlands. Mean distances moved were 29.7 and 105 m in each pond. We sampled at two, four and nine days after release of tagged individuals, and we observed a stable, not expanding, movement pattern across sampling dates, suggesting that tadpoles resumed normal activity immediately after release. Tadpoles showed preference for deeper and more densely vegetated areas of the ponds, especially associated with plant species such as Ranunculus peltatus and Potamogeton pectinatus.

Ramichloridium endophyticum sp. nov., a novel species of endophytic fungus from Potamogeton pectinatus

During a survey of endophytic fungi in aquatic plants collected from Tibet, PR China, a novel species, Ramichloridium endophyticum, was isolated from Potamogeton pectinatus. This novel species differs from other species of the genus Ramichloridium by its finely verrucose, obovoid, ellipsoidal–obovoid and occasionally subglobose conidia. Phylogenetic analysis of the combined sequences of the internal transcribed spacers (ITS) and the translation elongation factor 1-alpha gene (tef1-α) confirmed that the isolated strain represents a member of the genus Ramichloridium. A full description, illustrations and a phylogenetic tree showing the position of R. endophyticum are provided.

Soil seed banks and restoration potential of tussock sedge meadows after farming in Changbai Mountain, China

Vast tracts of the wettest agricultural fields have been abandoned worldwide, hence knowledge of their restoration potential is becoming important. Soil seed banks can be important components of ecological restoration, particularly if the seeds of key structural dominants can survive periods of cultivation. In Changbai Mountain, China, we compared the seed banks and standing vegetation between natural sedge meadows and adjacent paddy fields under drained and flooded conditions. The tussock-forming sedge Carex schmidtii dominated plant communities in the natural sedge meadows. However, this key structural dominant species was not found in the paddy fields. Other important wetland species survived cultivation as seeds (e.g. Cyperus fuscus, Lythrum salicaria and Sagittaria trifolia). Species of various life history types require either drawdown (emergent; e.g. C. schmidtii) or flooding (e.g. Potamogeton pectinatus) for successful germination. This study indicates that the seed banks of farmed sedge meadows could contribute towards the establishment of new wetland vegetation assemblages. Active revegetation of sedge meadow, particularly the native tussock-forming Carex, and changes in environmental conditions are necessary to support the region’s biodiversity.

Accumulation of heavy metals in aquatic vegetation of the Barguzin River

This study is devoted to the analysis of the distribution of heavy metals in the aquatic system of the Barguzin River. This is one of the largest rivers of the Baikal lake system. The element composition of the aerial scion of Potamogeton pectinatus L. (syn. Stukenia pectinata (L.) Borner), Potamogeton perfoliatus L., Hippuris vulgaris L. and Nymphoides peltata (S.G. Gmelin) O. Kuntze of the Barguzin River is studied in this research. One of the main results of the study is the establishment of the following sequence of the accumulation of metals in aquatic plants: Mn > Fe > Сu (Zn) > Сr > Ni > Сo > Pb > Cd > Hg. Hippuris vulgaris L. contains the highest concentration of the studied metals. Thus, this research provides one of the important steps for the development of regional environmental standards and environmental risk assessments.

THE EFFECT OF CLIMATIC SHIFTS ON BIODIVERSITY OF PHYTOCENOSIS: LAKE ARAKHLEY (EASTERN SIBERIA, RUSSIA)

Lake Arakhley is located within the Lake Baikal basin in Eastern Siberia, Russia. The area is characterized by continental subarctic climate with considerate diurnal temperature range, long cold dry winters and short hot summers with more precipitation occurring during the latter half of the summer. Climatic shifts in high water years and low water years result in morphometric changes in the lake and in the chemical and physical parameters of the ecosystem. During low water years, concentrations of ammonium nitrogen and nitrite nitrogen are decreased, whereas nitrate concentration increases. High water years feature average concentrations of ammonium ions 1.5–2 times higher than the values of recent dry years. Redundancy analysis (RDA) of abiotic factors and biotic community indicated that the community structure shows the greatest correlation with physical and chemical parameters of water and biogenic elements (nitrites, ammonium, phosphates) along the first axis, and with the lake depth and transparency along the second axis. Changes in abiotic factors induce functioning and formation of characteristic communities of the primary producers in the trophic structure of the ecosystem. During low water years, with increased level of autochthonous organic matter, Lindavia comta dominance is observed, while during high water years, with increased allochthonous organic matter Asterionella formosa appeared as dominant. Currently, during low water years, the hydrophytes community is monodominant and composed of Ceratophyllum demersum. Meanwhile, such species indicating eutrophic conditions as Myriophyllum sibiricum, Potamogeton pectinatus are found in the lake vegetation.