DIVERSITY, DISTRIBUTION AND ABUNDANCE OF LICHEN IN SIMILIPAL BIOSPHERE RESERVE, ODISHA

Lichens are organized symbionts that have their importance due to a potential indicator of the forest ecosystem. The lichen diversity of Odisha is not well explored as compared to the other phytogeographical region of India. Though the earlier study reported the occurrence of 252 lichen species from different parts of the state, it was limited to the northeast part of the Similipal Biosphere Reserve (SBR). The objective of the present study was to survey some unexplored areas of SBR, which revealed the occurrence of 84 species of lichens belonging to 38 families and 18 genera. Most of the lichens were found growing as phorophytes on the matured bark of the trees. The western part of the SBR is rich in lichen diversity as compared to the eastern part. Species frequency was found to be highest in the southwest part of the SBR, while the density and abundance were more or less similar within all the study sites. The correlation between frequency and density was found to be significant and insignificant between frequency and abundance.

Preliminary Floristic Inventory of the Swamp Forest of Atan Ukwok Village in Ini L.G.A of Akwa Ibom State, Nigeria

The Floristic inventory of the swamp forest at Atan Ukwok was carried out using the Systematic and Transect Sampling Methods where the line transect was the main path of the forest and Sampling units were chosen along the path at a distance of 14m × 14m and 6 sampling plots were sampled. The frequency, density and abundance of the identified species were calculated using standard formulae. A total number of 61 species from 35 families were identified. The number of species recorded for the plant families were, Cyperaceae 5, Euphorbiaceae 4, Acanthaceae, Apocynaceae, Asteraceae, Aspidiaceae and Poaceae 3 each, Arecaceae, Caesalpiniaceae, Mimosaceae, Melastomataceae, Schizaceae, Thelypteridaceae and Verbanaceae 2 each and Athyriaceae, Costaceae, Dioscoreaceae, Dracaenaceae Gleicheniaceae Araceae, Davillianaceae, Malvaceae, Commelinaceae, Clusiaceae, Selaginellaceae, Combretaceae, Convolvulaceae, Colchicaceae, Fabaceae, Moraceae, Malvaceae, Lycopodiaceae and Rutaceae 1 each. The highest species frequency and density of 66.7% and 9.5% respectively was found in Setaria megaphylla and the highest abundance value of 50.0 was found in Dracaena arborea. The frequency percentage of the plant species showed that the forest is fast loosing vegetation due to the obvious encroachment of parts of it by the inhabitants of the community for the purpose of cultivation. This calls for concerted conservation measures in order to ensure the sustainable use of the floral diversity of the forest.

STRUKTUR KOMUNITAS DAN ZONASI VEGETASI MANGROVE DESA DARUNU KECAMATAN WORI KABUPATEN MINAHASA UTARA

Mangrove ecosystem is a collection of distinctive plant types that contained in tropical and subtropical coastal region. The purpose of research was to find out the community structure and mangrove zonation at Darunu Village, Wori District, North Minahasa Regency. The research was conducted by the quadrant transect line method. It was done by pulling a straight line, perpendicular from the outermost mangrove area to the land direction, along 100 m by determining three data retrieval Station. To determine the condition of mangrove then density, species frequency, species coverage, important value index, diversity index and equality types were analyzed. The result found 5 mangroves species, namely: Rhizophora apiculata, R. mucronata, Sonneratia alba, Bruguiera gymnorrhiza and Avicennia officinalis. The highest density value was R.apiculata, as well as species frequency, while the species coverage value found in S. alba. The diversity value found at Station 2. The zonation of mangrove vegetation in Darunu village respectively, at Station 1 and 2 in the front was overgrown by R.apiculata species with sandy mud substrate. The Station 3 was overgrown by S.alba species with sandy mud. Generalyl, this location substrate contains of sandy mud and mud.Keywords : Mangrove, community structure, zonation.

Strain Background, Species Frequency, and Environmental Conditions Are Important in Determining Pseudomonas aeruginosa and Staphylococcus aureus Population Dynamics and Species Coexistence

ABSTRACT Bacterial communities in the environment and in infections are typically diverse, yet we know little about the factors that determine interspecies interactions. Here, we apply concepts from ecological theory to understand how biotic and abiotic factors affect interaction patterns between the two opportunistic human pathogens Pseudomonas aeruginosa and Staphylococcus aureus, which often cooccur in polymicrobial infections. Specifically, we conducted a series of short- and long-term competition experiments between P. aeruginosa PAO1 (as our reference strain) and three different S. aureus strains (Cowan I, 6850, and JE2) at three starting frequencies and under three environmental (culturing) conditions. We found that the competitive ability of P. aeruginosa strongly depended on the strain background of S. aureus, whereby P. aeruginosa dominated against Cowan I and 6850 but not against JE2. In the latter case, both species could end up as winners depending on conditions. Specifically, we observed strong frequency-dependent fitness patterns, including positive frequency dependence, where P. aeruginosa could dominate JE2 only when common (not when rare). Finally, changes in environmental (culturing) conditions fundamentally altered the competitive balance between the two species in a way that P. aeruginosa dominance increased when moving from shaken to static environments. Altogether, our results highlight that ecological details can have profound effects on the competitive dynamics between coinfecting pathogens and determine whether two species can coexist or invade each others’ populations from a state of rare frequency. Moreover, our findings might parallel certain dynamics observed in chronic polymicrobial infections. IMPORTANCE Bacterial infections are frequently caused by more than one species, and such polymicrobial infections are often considered more virulent and more difficult to treat than the respective monospecies infections. Pseudomonas aeruginosa and Staphylococcus aureus are among the most important pathogens in polymicrobial infections, and their cooccurrence is linked to worse disease outcome. There is great interest in understanding how these two species interact and what the consequences for the host are. While previous studies have mainly looked at molecular mechanisms implicated in interactions between P. aeruginosa and S. aureus, here we show that ecological factors, such as strain background, species frequency, and environmental conditions, are important elements determining population dynamics and species coexistence patterns. We propose that the uncovered principles also play major roles in infections and, therefore, proclaim that an integrative approach combining molecular and ecological aspects is required to fully understand polymicrobial infections.

ANALISIS STRUKTUR KOMUNITAS MANGROVE DI KAWASAN SEKITAR PT. CONCH KABUPATEN BOLAANG MONGONDOW

This research was conducted for four months of April-July 2020. The purpose of this study was to determine species density, species relative density, species frequency, species relative frequency, species cover, species relative cover, index of the importance of mangrove species in the area around PT. Conch Lolak District, Bolaang Mongondow Regency, North Sulawesi Province. This research was conducted for four months of April-July 2020. The method used was a quadratic plot of 6 stations. Data collection at each station was made with a plot size of 10 × 10 m2 to measure the diameter of a tree at breast height (DBH), which has a minimum trunk circumference of 16 cm. The results showed that there were five types of mangroves, namely R. apiculata, R. mucronata, B. gymnorhiza, S. alba, and X. granatum. The highest relative density of species at station 2, namely R. mucronate 62.96%, while the lowest value at station 3, namely R. mucronata 8.77%, the highest relative frequency value at station 4, namely R. mucronata 33.33%, whereas the lowest value was at station 5, namely B. gymnorhiza 25.00%, the highest relative closure value was at station 5, namely R. mucronata 30.91%, while the lowest was at station 2, namely R. apiculata 12.88%, and the important value index the highest was at station 3, namely R. apiculata 138.09% and the lowest value was at station 5, namely X. granatum 35.05%.Kata Kunci: Mangrove, Structure in areas around PT. Conch. Conch, Rhizopora Abstrak Penelitian ini dilakukan selama 4 bulan April-Juli 2020. Tujuan penelitian ini adalah untuk mengetahui kerapatan jenis, kerapatan relatif jenis, frekuensi jenis, frekuensi relatif jenis, penutupan jenis, penutupan relatif jenis, indeks nilai penting jenis mangrove yang ada di kawasan sekitar PT. Conch Kecamatan Lolak, Kabupaten Bolaang Mongondow, Provinsi Sulawawesi Utara. Penelitian ini dilakukan selama 4 bulan April-Juli 2020. Metode yang dipakai adalah plot kuadrat sebanyak 6 stasiun. Pengambilan data pada setiap stasiun dibuat plot dengan ukuran 10 × 10 m2 untuk mengukur diameter pohon setinggi dada (DBH) yang memiliki lingkar batang minimal 16 cm. Hasil penelitian menunjukkan bahwa ada 5 jenis mangrove yaitu R. apiculata, R. mucronata, B. gymnorhiza, S. alba dan X. granatum. Kerapatan relatif jenis tertinggi pada stasiun 2, yaitu R. mucronata 62,96%, sedangkan nilai terendah pada stasiun 3, yaitu R. mucronata 8,77%, nilai Frekuensi relatif jenis tertingi pada stasiun 4, yaitu R. mucronata 33.33%, sedangkan nilai terendah pada stasiun 5, yaitu B. gymnorhiza 25.00%, nilai Penutupan relatif jenis tertinggi pada stasiun 5, yaitu R. mucronata 30,91%, sedangkan terendah pada stasiun 2, yaitu R. apiculata 12,88%, dan Indeks nilai penting tertinggi pada stasiun 3, yaitu R. apiculata 138,09% dan nilai terendah pada stasiun 5, yaitu X. granatum 35,05%.Kata Kunci: Mangrove, kawasan sekitar PT. Conch, Rhizopora

Structure and spatial distribution of the rotifer assemblages along a tropical reservoir

The construction of reservoirs is a common practice in the world. These systems modify the hydric landscape and alter the flow of rivers, becoming lotic environments in lentic. Here we investigated the structure and spatial distribution of rotifers along a tropical reservoir. We sampled four points in the Pedra do Cavalo Reservoir, Bahia, Brazil, bimonthly, between August 2014 and June 2015. We registered more than 70 taxa distributed in 17 families, with the majority of species belonging to the Lecanidae, Brachionidae and Trichocercidae families. The species rarefaction curve did not achieve a total asymptote, indicating that species richness in the reservoir is higher than what was registered. Based in the species frequency of occurrence, we identified 48 rare species, 16 common species, five constant species and one frequent species. The highest beta diversity values were registered in riverine P1 (0.513) and intermediate P2 (0.503), although there were no significant differences between the sampling points. Despite the high abundance values in P1, P2 and P3 no significant differences were found between the studied points. Thus, this study substantially increases the knowledge on the rotifer community in the Paraguaçu River and contributes to future studies that focus on biodiversity, ecology and conservation in the Brazilian reservoir ecosystems.

Strain background, species frequency and environmental conditions are important in determining population dynamics and species co-existence between Pseudomonas aeruginosa and Staphylococcus aureus

Bacterial communities in the environment and in infections are typically diverse, yet we know little about the factors that determine interspecies interactions. Here, we apply concepts from ecological theory to understand how biotic and abiotic factors affect interaction patterns between the two opportunistic human pathogens Pseudomonas aeruginosa and Staphyloccocus aureus, which often co-occur in polymicrobial infections. Specifically, we conducted a series of short- and long-term competition experiments between P. aeruginosa PAO1 (as our reference strain) and three different S. aureus strains (Cowan I, 6850, JE2) at three starting frequencies and under three environmental (culturing) conditions. We found that the competitive ability of P. aeruginosa strongly depended on the strain background of S. aureus, whereby P. aeruginosa dominated against Cowan I and 6850, but not against JE2. In the latter case, both species could end up as winners depending on conditions. Specifically, we observed strong frequency-dependent fitness patterns, including positive frequency dependence, where P. aeruginosa could dominate JE2 only when common, but not when rare. Finally, changes in environmental (culturing) conditions fundamentally altered the competitive balance between the two species, in a way that P. aeruginosa dominance increased when moving from shaken to static environments. Altogether, our results highlight that ecological details can have profound effects on the competitive dynamics between co-infecting pathogens, and determine whether two species can co-exist or invade each others’ populations from rare. Moreover, our findings might parallel certain dynamics observed in chronic polymicrobial infections.ImportanceBacterial infections are frequently caused by more than one species and such polymicrobial infections are often considered more virulent and more difficult to treat than the respective monospecies infections. Pseudomonas aeruginosa and Staphyloccocus aureus are among the most important pathogens in polymicrobial infections and their co-occurrence is linked to worse disease outcome. There is great interest in understanding how these two species interact with each other and what the consequences for the host are. While previous studies have mainly looked at molecular mechanisms implicated in interactions between P. aeruginosa and S. aureus, here we show that ecological factors such as strain background, species frequency and environmental conditions are important elements determining population dynamics and species co-existence patterns. We propose that the uncovered principles may also play major roles in infections, and therefore proclaim that an integrative approach combining molecular and ecological aspects is required to fully understand polymicrobial infections.