Establishing community-wide DNA barcode references for conserving mangrove forests in China

Background Mangrove ecosystems have been the focus of global attention for their crucial role in sheltering coastal communities and retarding global climate change by sequestering ‘blue carbon’. China is relatively rich in mangrove diversity, with one-third of the ca. 70 true mangrove species and a number of mangrove associate species occurring naturally along the country’s coasts. Mangrove ecosystems, however, are widely threatened by intensifying human disturbances and rising sea levels. DNA barcoding technology may help protect mangrove ecosystems by providing rapid species identification. Results To investigate this potential, 898 plant specimens were collected from 33 major mangrove sites in China. Based on the morphologic diagnosis, the specimens were assigned to 72 species, including all 28 true mangrove species and all 12 mangrove associate species recorded in China. Three chloroplast DNA markers rbcL, trnH-psbA, matK, and one nuclear marker ITS2 were chosen to investigate the utility of using barcoding to identify these species. According to the criteria of barcoding gaps in genetic distance, sequence similarity, and phylogenetic monophyly, we propose that a single marker, ITS2, is sufficient to barcode the species of mangroves and their associates in China. Furthermore, rbcL or trnH-psbA can also be used to gather supplement confirming data. In using these barcodes, we revealed a very low level of genetic variation among geographic locations in the mangrove species, which is an alert to their vulnerability to climate and anthropogenic disturbances. Conclusion We suggest using ITS2 to barcode mangrove species and terrestrial coastal plants in South China. The DNA barcode sequences we obtained would be valuable in monitoring biodiversity and the restoration of ecosystems, which are essential for mangrove conservation.

PHYTOREMEDIATION OF HEAVY METALS BY THE DOMINANT MANGROVE ASSOCIATE SPECIES OF INDIAN SUNDARBANS

The present study aims to investigate the phytoremediation potential of zinc (Zn), copper (Cu), and lead (Pb) by two dominant mangrove associate species, Suaeda maritima, and Salicornia brachiata, found in the high saline supralittoral zone of Indian Sundarbans in four stations of the Hooghly-Matla estuarine complex during the premonsoon season (May 2019). We found that concentrations of biologically available heavy metals (HMs) in the ambient soil and bioaccumulated HMs within the vegetative plant parts occurred as per the order: Sagar South > Bakkhali > Jharkhali > Bali Island. The order of biologically available and bioaccumulated HMs was Zn > Cu > Pb. Interestingly, the selected HMs display high organ-specificity for both species with the highest enrichment in roots, followed by stems and leaves. We propose that these halophytes could be used as agents of phytoremediation and their farming would be effective in the ecorestoration of this deltaic complex in context to conservative pollutants.

Metapopulation-level associations in mutualistic stream fishes

Positive biotic interactions are recognized as important factors determining species distributions. Although effects of positive interactions have often been observed at local scales, much less is known about consequences at larger spatial scales such as metapopulation dynamics. Here, we study nest associations of stream fishes - widespread reproductive mutualism between host (nest-builder) and beneficiary (nest associate) species in North America - as a model system to examine the role of positive interactions in determining the metapopulation-level association between host and beneficiary species. Using regional data of fish distribution in the Midwestern US, we found that watershed-level occupancy of host species (i.e., metapopulation occupancy) remarkably increased that of nest associates. Importantly, our results illustrated that the effects of positive biotic interactions at the metapopulation level were comparable or even stronger than environmental drivers, i.e., factors that have been studied most extensively in metapopulation studies. This study provides insightful evidence that positive biotic interactions have large-scale consequences for distributions of organisms than previously thought. Successful biodiversity conservation may need a broader framework that appreciates the role of positive biotic interactions at larger spatial scales.

New species of Asterina and Balladyna (black mildew fungi) from Mahabaleshwar, Maharashtra, India

Two new black mildew fungal species, Asterina rubiacearum sp. nov. and Balladyna canthiigena sp. nov., which infect the leaves of Canthium dicoccum var. umbellatum (Rubiaceae) are described from Mahabaleshwar, Maharashtra (India). Taxonomic descriptions, photomicrographs, line drawings and comparative account of close associate species are provided.

Learning in advance? Interspecific recognition ability in male Eurasian blackcaps

Interspecific aggression is common in bird communities. It is thought to be a consequence of learned behavior or misdirected intraspecific aggression. In the former case birds acquire the ability to identify individuals of other species by social learning of species-specific traits during interactions with heterospecifics in a shared habitat. I conducted a two-choice song playback experiment to investigate the role of associating signals from two sensory modalities, auditory and visual, in shaping the agonistic response of male Eurasian Blackcaps (Sylvia atricapilla) to simulated male Garden Warbler (S. borin) intruders. I measured focal males’ response to playbacks to the song of a Blackcap or a Garden Warbler while giving them a choice between stuffed male models of both species presented in their territories. The experiments were carried out in early spring, before the arrival of Garden Warblers from Africa. I found that male Blackcaps were able to associate species-specific songs with species-specific plumage types. The ability to associate signals characterized not only experienced after-second-year old males, but also second-year old males that had not had the opportunity to defend breeding territories against heterospecifics. This suggests that second-year old male Blackcaps acquire the ability to associate Garden Warbler song with plumage before they use this skill when defending territory during their first breeding episode. Male Blackcaps do not mistake male Garden Warblers for males of their species, but rather learn these associations during the first months of life. However, the possibility that these associations are innate cannot be excluded.

Thermodynamic assessment of the Sb–S and In–S binary systems

The Sb–S and In–S binary systems were assessed thermodynamically using the CALculation of PHase Diagrams (CAL-PHAD) approach based on the experiment data in the literature. Both phase diagrams revealed a congruent melting compound and liquid immiscibility. Therefore, associate species, Sb2S3 and In2S3, were introduced into the associate model to describe the liquid phase during optimization. The binary intermediate compounds, Sb2S3, InS(α, β), and In6S7, were treated as stoichiometric phases. Considering the wide composition range, In2S3(α, β, γ), were modeled using the sublattice model. A set of self-consistent thermodynamic parameters representing most of the reliable thermodynamic properties and phase diagram information were derived.

Local populations of Sorbus torminalis (L.) Crantz in forest plantings of natural origin in the South-Podolsk Forest-Steppe of Ukraine

The determination of factors that adversely affect the populations of rare plant species and development of measures to eliminate them are the important conditions for maintaining the rare component of natural flora. The article describes the study of forest phytocoenoses in the eastern territory of South-Podolsk Forest Steppe of Ukraine. The influence of natural conditions, morphological and physiological features of Sorbus torminalis (L.) Crantz on the distribution and population density in the studied region was analysed. The species is found in 80 quarters of different forestry districts with the population densities ranging from single to 300 individuals per hectare. The rare species has little prospect of natural seed restoration. The natural reforestation process of Sorbus torminalis is largely due to the specific conditions of phytocoenosis, age and vital structure of the forest stand. Most local populations have a low lifecycle. Very rare seed reproduction makes this species extremely vulnerable to the effects of any negative factors.In the oak-hornbeam plantations, the plants of reproductive age prevail, but with the die-back of old individuals, the influx of renewal has almost disappeared. According to the results of the studied region, the oak plantations with Sorbus torminalis are found to have better values of the species distribution in the protected area compared to the recreational and economic ones (Sorbus torminalis remains in any sanitary condition in the plantations and on clean felling). Artificial resettlement should be carried out in places with a small projective cover of the vegetation, and Sorbus torminalis should be introduced into Quercus robur cultures as an associate species. This territory is the northeast boundary of the natural growth of the species.

Remobilization of zinc in sediments by mangrove and its associated species in Blanakan River, West Java, Indonesia

Takarina ND. 2020. Remobilization of zinc in sediments by mangrove and its associated species in Blanakan River, West Java, Indonesia. Biodiversitas 21: 1743-1748. The biodiversity of mangrove and associated species have contribution to remove contaminants from aquatic environment, for example, river. This work aims to study the effects of mangrove and associated species in absorbing zinc (Zn) from water and sediment and remobilizing it into stems. The work was conducted by sampling mangroves, associated species, sediment and water along 9 stations in riparian of Blanakan River, West Java. The stems of mangrove and associated species, water and sediments were analyzed for Zn content using AAS. The biodiversity was evaluated using Shannon-Wiener index (H’). The bioremobilization potential was calculated using Bioconcentration Factor (BCF). There were 3 true mangrove species (i.e. Rhizophora mucronata, Avicennia marina, and Sonneratia caseolaris) and 3 mangrove associate species (i.e. Colocasia esculenta, Ipomoea aquatica, and Wedelia biflora). The H’ was ranging from 0.5 to 0.7. We found that the riparian with high species richness and biodiversity has less Zn contents both in water and sediments, while the riparian that has low species diversity has high Zn in water and sediments. All the mangrove and associated species have stored Zn in their stems with the most effective species in remobilizing Zn from water and sediment were C. esculenta, S. caseolaris, and R. mucronata. The contamination of Zn in aquatic ecosystem can be managed and reduced by increasing mangrove and associated species diversity and planting species that effective in remobilization of contaminants from environment.