Diversity of bacterium communities in saline-alkali soil in arid regions of Northwest China

Background The saline-alkali soil area accounts for over 1/4-1/5 of the land area in Gansu Province of China, which are mainly distributed in the north of Hexi corridor and Jingtai basin. The unique ecological environment contains unique and diverse microbial resources. The investigation of microbial diversity in saline environment is vital to comprehend the biological mechanisms of saline adaption, develop and utilize microbial resources. Results The Illumina MiSeq sequencing method was practiced to investigate the bacterial diversity and composition in the 5 subtypes and 13 genera of saline-alkali soil in Gansu Province, China. The results from this study show that Proteobacteria, Bacteroidetes, Actinobacteria, Firmicutes, and Gemmatimonadetes were the dominant bacterial groups in 13 saline soil. Proteobacteria had the greatest abundance in sulfate-type meadow solonchaks and orthic solonchaks, chloride-type orthic solonchaks and bog solonchaks, sulfate-chloride-type, chloride-sulfate-type, and sulfate-type dry solonchaks. Halobacteria was the dominant bacterial class in soil samples except for sulfate-type meadow solonchaks and orthic solonchaks, chloride-type orthic solonchaks and bog solonchaks. The richness estimators of Ace and Chao 1 and the diversity indices of Shannon and Simpson revealed the least diversity in bacterial community in sulfate-chloride-type orthic solonchaks. Conclusions The sulfate anion was the most important driving force for bacterial composition (17.7%), and the second most influencing factor was pH value (11.7%).

Species Richness, Diversity, and Packing

Methods to measure species richness and α‎-, β‎-, and γ‎-diversity are reviewed. A useful classification is α‎-diversity, the diversity of species within a community or habitat, β‎-diversity, a measure of the rate and extent of change in species along a gradient from one habitat to others, and γ‎-diversity, the richness in species of a range of habitats in a geographical area. Species inventories are frequently required for conservation management. Because a complete census is rarely feasible, the community must be sampled, and methods are needed to estimate via sampling the total taxa number present. A wide range of species richness estimators are described and their applicability reviewed. Models for species abundance, including geometric, log-normal, and broken stick are presented. Rarefaction techniques to compare species richness in communities sampled with differing effort are described. Methods to compare α‎-diversity between samples are described. Techniques to study community structure are introduced, and measures of niche size and overlap are presented. Similarity, indices are reviewed, and R code to measure niche overlap is presented.

The species composition of rotifers in three hydroelectric reservoirs of western highlands, Central Vietnam

The rotifer fauna in three hydroelectric reservoirs of western highlands, central Vietnam were studied. Among a total of 63 identified species and subspecies, beloging to 23 genera in 15 families, Brachionidae was the most diverse family with 15 taxa recorded (23.81%) followed by Lecanidae (14 taxa, 22.22%), and Synchaetidae (8 taxa, 12.7%). Species accumulation curve and species richness estimators suggested a relatively high level of biodiversity of rotifera assemblages in the studied area. Besides, results on species composition of rotifera community in this study were compared to those of other freshwater bodies in Vietnam using Jaccard similarity index. In particular, the highest similarity was found between reservoirs in western highlands and Phu Ninh lake, Quang Nam Province while the largest difference in species composition was observed between western highlands and Bau Thiem lake, Thua Thien Hue Province.

ICHTHYOFAUNA OF TRIBUTARY STREAMS OF THE CINZAS RIVER BASIN, PARANAPANEMA RIVER, BRAZIL

Streams are environments that are very affected by human activities such as pollution, deforestation of riparian forests and introduction of exotic species. In this context, it is important to know its biodiversity for monitoring and conservation. The present study inventoried the fish fauna of three tributary streams of the Jacarezinho River (Cinzas River basin, Paranapanema River) with different environmental characteristics: Água dos Anjos, Monjolinho and Ubá streams. Quarterly collections were performed in the period between October 2012 and July 2013 at the headwaters, in the middle and at the mouth of each stream, using electrofishing. We analyzed the parameters of species richness, total abundance, relative abundance, capture constancy, rarefaction curves of Coleman, and richness estimators ACE and ICE. We captured a total of 7102 individuals, distributed in six orders, 12 families and 33 species. The most abundant order was Characiformes (76.15 %), while the most abundant species were: Bryconamericus iheringii (39.5 %), Astyanax bockmanni (19.36 %), and Geophagus brasiliensis (7.52 %). The highest species richness was found in Água dos Anjos stream (26), followed by Monjolinho stream (25), and the Ubá stream (15). We recorded the occurrence of four non-native species (Bryconamericus exodon, Gymnotus inaequilabiatus, Poecilia reticulata and Oreochromis niloticus), which represent a risk to the biodiversity of the studied streams. The Ubá stream was considered the most conserved, but the presence of P. reticulata shows that it has also suffered from anthropic impacts. This non-native species is constantly associated to degraded environments, mainly when it occurs in high abundance. Our results suggest that the fish assemblages studied present different structures, probably due to the interaction among historical, abiotic, biotic, and anthropic factors. This study has been carried out for the first time in the Cinzas River basin and can help provide theoretical input for the elaboration of monitoring and conservation plans.

Anurofauna of a remnant of Atlantic Forest in northeast Brazil

Studies on spatial occupation are fundamental to understand amphibian communities. The aim of this study was to record information on the spatial distribution of anurans in the Tejipió forest, state of Pernambuco, Northeastern Brazil. Fieldwork was carried out weekly between October 2011 and April 2012, with daytime and night-time excursions for time-constrained active searching, in forested and open areas, military construction area and water bodies. Pitfall traps and accidental sightings were also used as alternative collection methods. Data were used to calculate richness, rarefaction curves and richness estimators. A total of 21 species were recorded, distributed in six families: Bufonidae (2 spp.); Craugastoridae (1 sp.); Hylidae (8 spp.); Leptodactylidae (8 spp.); Microhylidae (1 sp.) and Phyllomedusidae (1 sp.). Only the species Rhinella jimi was found occupying all sampled habitats in the research area. Adenomera hylaedactyla and Pristimantis ramagii deserve special care in the area because they are specialists, occupying a smaller number of habitats and microhabitats. The community of anurans of the Tejipió forest is similar to those recorded in other areas of the Atlantic Forest at the Pernambuco State, and its knowledge is essential as a basis for conservation of the area. The gradual recovery of this Atlantic Forest remnant would favor the recolonization of fauna and flora and the conservation of local biodiversity.

Effect of crop residue management on damage by Diatraea saccharalis (Lepidoptera: Crambidae), its egg parasitoids and the ants associated with sugarcane

In the American continent, the sugarcane borer Diatraea saccharalis (F.) is the main pest in sugarcane producing areas. The objective of this study was to assess the effect of crop residue management on damage by D. saccharalis, its egg parasitoids and the ants associated with sugarcane. The study was carried out during 2011–2012, 2012–2013 and 2013–2014 crop cycles, in three commercial fields located in different regions of Tucumán state, Argentina. Two types of crop residue management (= treatments) were compared: conservation of trash at the soil surface (CT) and trash burning (TB). In ‘trash conservation’ treatment, crop residue was allowed to remain over the soil surface during the whole sugarcane growing season, while the second treatment consisted of complete burning of trash blanket approximately 2 weeks after harvest. The injury level was measured by recording the number of stalks bored and internodes bored. Parasitism was estimated by counting the total number of eggs and number of black eggs (which indicates the occurrence of egg parasitoids). Ants (Formicidae) richness was calculated by two estimators; abundance-based coverage estimator and incidence-based coverage estimator, using the non-parametric richness estimators: Chao 2 and Jackknife. Finally, the indicator value was estimated through the measurement of specificity and fidelity. In all the parameters studied no significant difference was found between TB and CT treatments.

At the edge of extinction: a first herpetological assessment of the proposed Serra do Pingano Rainforest National Park in Uíge Province, northern Angola

We systematically assess the herpetofaunal diversity of the Serra do Pingano Forest Ecosystem (SPFE) and additional localities throughout the northern Angolan province of Uíge during four independent Rapid Assessment (RA) field campaigns held between 2013 and 2019. These assessments represent the first systematic surveys of amphibians and reptiles from the province, and thus we provide the first province-wide species list. We collected data on the status and current threats to amphibians and reptiles in the proposed Serra do Pingano Rainforest National Park and were able to document 33 species of reptiles from Uíge province. Of the 33 species recorded from the province, 10 species are exclusively found in the SPFE. Amphibian surveys yielded 47 amphibian species from the province. These include 14 new country records and additional records that may represent undescribed species. This raises the amphibian count for Angola to at least 133 species, which includes 18 species exclusively found within the SPFE. Species-richness estimators indicate that more species should be detected if survey efforts are intensified. The species composition in the SPFE is unique and consists of a high proportion of forest specialists with restricted ranges and species found nowhere else in the country. This emphasizes today’s paramount importance of the SPFE, which is threatened by increasing agricultural encroachment and uncontrolled timber extraction and charcoal production. These principal factors need to be controlled and/or abandoned in already impacted areas. Conservation strategies should particularly consider the strict protection of remaining intact forests and both lentic and lotic aquatic systems. They are not only crucial for safeguarding a significant number of species that depend on these habitats for reproduction; they also provide key ecosystem services to the local population. Angola, and Uíge province in particular, is at a crossroads concerning decisions and trade-offs among utilization, conservation, and preservation of its forests and, thus, substantial parts of the country’s biodiversity. The establishment of a National Protected Area in the Serra do Pingano Ecosystem is therefore a necessary and urgently needed first step towards protecting Angola’s national biodiversity heritage.

Mollusk bycatch in trawl fisheries targeting the Atlantic seabob shrimp Xiphopenaeus kroyeri on the coast of Sergipe, northeastern Brazil

The malacofauna bycatch of sea-bob shrimp Xiphopenaeus kroyeri (Heller, 1862) trawl fisheries on the coast of Sergipe was studied for 5 years. The malacofauna bycatch considered was obtained in nine oceanographic sampling campaigns carried out between May 1999 and June 2003 in 18 stations distributed in six transects along depths of 10, 20 and 30 m. A total of 2,669 individuals of mollusk belonging to 54 species were captured on the 18 sea-bob shrimp trawl stations carried out along the coast of Sergipe. The considerable richness of mollusks was composed by 19 families and 31 species of gastropods, 12 families and 19 species of bivalves and 2 families and 4 species of cephalopods. The highest abundance were observed at stations 13 (373 individuals) and 16 (685 individuals) that represents the lowest depth (10 m) and the richness was higher at stations 15 and 12 (17 and 11 species, respectively) both located at the highest depth (30 m). Cephalopods had high frequency of occurrence being collected in all the stations and by far the most abundant group with a total of 2,488 individuals captured. On the other hand, gastropods (with 142 individuals found in 83.3% of stations) and bivalves (about 1% of the individuals collected) contribute with a much smaller percentage of individuals captured. Lolliguncula brevis (Blainville, 1823) was most representative cephalopod in number and frequency of occurrence. Arcidae, Conidae, Muricidae and Strombidae were the families with the higher number of species in the trawl-fishery. Among bivalves, Pitar arestus (Dall & Simpson, 1901) and Spathochlamys benedicti (Verrill & Bush [in Verrill], 1897) were the species with higher frequency of occurrence. Although the considerable sample effort and a number of mollusks captured as bycath, the richness estimators indicated that the species richness could increase with additional sampling effort in the study area. The present study expands the taxonomic alpha knowledge on the mollusk bycatch of sea-bob shrimp trawl fisheries on the northeastern coast of Brazil. However, it is of crucial importance to assess urgently the negative impacts of the sea-bob shrimp trawl fisheries on the benthic community of the entire coast of Brazil.

Composition and structure of the frugivorous butterfly community (Lepidoptera: Nymphalidae) at the Serra Azul State Park (PESA), Mato Grosso, Brazil

Due to the important ecological role of Nymphalidae as consumers of fermented fruits, excrement, exudates of decomposed plants and animals, as well as bioindicators of environmental quality that attract the interest of the general public, this study aimed to characterize the fauna of frugivorous butterflies at the Serra Azul State Park – PESA (Mato Grosso, Brazil) with regards to composition, taxonomic richness and spatial distribution. Collections were carried out in 2014 from six 250 m plots in a RAPELD module (5x5 km). We defined five sampling points in each plot and placed a Van Someren-Rydon trap (VSR), with a bait made from banana fermented in cane juice, positioned 1 m above the ground for 24 hours. We collected 204 specimens of Nymphalidae from five subfamilies, 22 genera, and 40 species. Satyrinae was the most abundant and species-rich subfamily. The community structure varied spatially, with the gallery forest presenting the greatest richness, diversity, and equitability, while ‘cerrado ralo’ presented higher abundance and less diversity and equitability. Therefore, according to the pattern of abundance in the PESA, species were best adapted to the log series model. Yphthimoidesrenata (Stoll, 1780) (Satyrinae), Hamadryasferonia (Linnaeus, 1758), and Callicoresorana (Godart, 1824) (Biblidinae) were the most abundant species, 19 species were singletons, and eight were doubletons. Richness estimators showed that 63% of all species were sampled. Our results indicate that the frugivorous butterfly community is structured according to phytophysiognomies, and the dominance of species that are tolerant to disturbances indicates landscape fragmentation within the PESA, which interferes with species substitution pattern and their abundances in different environments of the park.