Butterfly Diversity and Abundance in the Middle Afromontane Area of Northwestern Ethiopia

Butterflies are good indicators of environmental health, and they play a critical role in the food chain. Butterfly diversity and abundance were studied for the first time at three forests and their surrounding habitats in northwestern Ethiopia, a borderline ecosystem between the subtropical savannah and the Ethiopian highlands (Afromontane). Butterfly species richness and abundance were assessed using transects between October 2018 and June 2019. Data were analyzed using analysis of variance, correlation and regression analysis, diversity indices, ordination analysis, cluster analysis, and rarefaction curves. A total of 27,568 butterflies were recorded that belonged to three families, five subfamilies, and eight genera. The forest habitat had more butterfly taxa (abundance and diversity) than other habitats. Belenois spp. and Mylothris agathina were the most abundant in all three study locations. Species common to all study areas include Belenois aurota, Belenois raffrayi, Mylothris agathina, Eronia leda, Junonia terea elgiva, and Phalanta eurytis neuritis. Forest edge and woody forest habitats were the richest in terms of both number of species and number of individuals. Equitability (Pielou's index) showed equal distribution of the species, i.e., 0.8 to 0.9, except at the open grassland at Tara Gedam (0.3). Margalef's index varied between habitats and locations showing differences in species richness (from 0.25 at the woody forest of Mount Bezawit to 0.86 at the forest edge of Tara Gedam). Ordination analyses also showed that associations existed between habitats, locations, and dates of sampling. Rarefaction curves rose quickly at the forest edge and woody forest habitats compared to other forests. The cluster analysis discriminated the different habitats. Populations declined during the dry season (December to April). In conclusion, butterfly species diversity and abundance varied with respect to habitat and sampling date (season), although less diverse than other regions in the country where natural forests still widely exist. Butterfly species must be regularly monitored, and their habitats must be preserved for the health of the entire ecosystem.

Diversity and microhabitat use of benthic invertebrates in an urban forest stream (Southeastern Brazil)

ABSTRACT This work aimed to assess the diversity and microhabitat use of benthic invertebrates in an urban forest stream in southeastern Brazilian region. The invertebrates were sampled in a headwater stream, located at the Tijuca Forest, Rio de Janeiro. Three types of microhabitats were sampled (litter, sand and stone) using a Surber sampler. Specimens were identified to the family-level and rarefaction curves were constructed for the total sampling and for each type of microhabitat. Community structure indices (abundance, taxonomic richness, diversity, and dominance) were calculated for each microhabitat. Differences among indices were tested through a repeated measure ANOVA, and differences among microhabitatsʼ composition through a PerMANOVA. A total of 9,800 specimens were registered in which Chironomidae was the most abundant. The rarefaction curves did not reach the asymptote. Community structure indices exhibited differences (RM ANOVA; p < 0.001), as well as microhabitats’ composition (PerMANOVA; p < 0.001). Abundance and taxonomic richness were the highest in litter, diversity was higher both in litter and stone, and sand had the highest dominance. Results highlighted that the variety of microhabitats may enhance local diversity and that the differences in resources availability of each type of microhabitat determine the distribution of these invertebrates.

Microbial Diversity Assessment in Milkfish Culture Ponds

Aims: To determine bacterial diversity in milkfish culture ponds that contain different life-cycle stages of the milkfish (pond A: fry, pond B: juveniles and pond C: adults) by DNA sequence analysis of organisms and compare that microbial diversity to organisms found in soil adjacent to the ponds. Study Design: Comparative metagenomic study of aquatic and terrestrial biodiversity based on DNA sequence analysis of water and soil DNA. Place and Duration of Study: SEADEC milkfish ponds in Tingnauan, Iloilo. Philippines. All water and soil samples were collected over a three-day period. Methodology: DNA sequence analysis of nucleic acids extracted from water samples collected from the three types of milkfish ponds along with soil adjacent to the ponds. DNA was extracted and PCR was performed using the 11F-1492R primer pair to amplify 16S rRNA gene. Purified 16S rDNA amplicons were cloned in using the TOPO-TA cloning kit for DNA sequencing. 16s rRNA gene sequences were analyzed with the use of software tools at the National Center for Biotechnology Information website and imported into the ARB phylogenetic analysis software. Distance matrices were exported using the neighbor-joining algorithm in ARB, in the form of PHYLIP-formatted lower triangular matrices. The distance matrices were then used to calculate Shannon-Weaver and Simpson diversity indices to evaluate the richness and evenness of the sampled populations. Rarefaction curves were determined to evaluate sampling efficiency. Results: Rarefaction curves indicated that the sampling effort was sufficient to reveal the majority of phyla present in the sample. Shannon-Weaver and Simpson indices suggested that the diversities of all the groups were statistically different from each other. It was observed that pond A was least diverse, followed by pond C and pond B. The soil was most diverse. DNA sequence analysis identified the various species of bacteria in soil and water. Conclusion: All three pond communities were significantly different in diversity. This study did not identify any significant human pathogens such as Vibrios, Salmonella or Shigella. Bacterial diversity of sites decreased in the following order: soil > fry pond > fingerling pond > adult pond.

Evaluation of bait use for mammal richness

In this study, we aimed to evaluate the effectiveness of baits as a tool for estimating species richness for medium and large mammals. To this end, we installed 15 cameras in the Ecological Station of Jataí, São Paulo, Brazil (21°30′S – 47°40′W and 21°40′S/47°50′W). The cameras were placed in a grid with a distance of 1 km between each station. We randomly placed cameras with baits and those without baits and made observations for 4 weeks. Then, after a week’s break, the treatments were inverted and continued for another 4 weeks. We estimated species richness based on the presence or absence of species using the Jackknife1 estimator in the EstimateS program and compared the treatments using the paired Wilcoxon test. Species composition and estimated richness did not differ between treatments with baits (SJack1 = 20.97 ± 1.96) and those without baits (SJack1 = 20.95 ± 1.95; W = 30 p = 0.15). The rarefaction curves between the treatments were similar, suggesting that the use of baits did not increase or reduce the number of species recorded. In addition, the use of baits did not significantly increase capture rates. Analysis of the costs of the different treatments showed that the use of baits increased the project costs by more than 4 times. The findings of this study suggest that, for species surveys, camera traps do not need to be baited.

Scaling of species distribution explains the vast potential marine prokaryote diversity

Global ocean expeditions have provided minimum estimates of ocean’s prokaryote diversity, supported by apparent asymptotes in the number of prokaryotes with sampling effort, of about 40,000 species, representing <1% of the species cataloged in the Earth Microbiome Project, despite being the largest habitat in the biosphere. Here we demonstrate that the abundance of prokaryote OTUs follows a scaling that can be represented by a power-law distribution, and as a consequence, we demonstrate, mathematically and through simulations, that the asymptote of rarefaction curves is an apparent one, which is only reached with sample sizes approaching the entire ecosystem. We experimentally confirm these findings using exhaustive repeated sampling of a prokaryote community in the Red Sea and the exploration of global assessments of prokaryote diversity in the ocean. Our findings indicate that, far from having achieved a thorough sampling of prokaryote species abundance in the ocean, global expeditions provide just a start for this quest as the richness in the global ocean is much larger than estimated.

How Much is Enough? Improving Participatory Mapping Using Area Rarefaction Curves

Participatory mapping is a valuable approach for documenting the influence of human activities on species, ecosystems, and ecosystem services, as well as the variability of human activities over space and time. This method is particularly valuable in data-poor systems; however, there has never been a systematic approach for identifying the total number of respondents necessary to map the entire spatial extent of a particular human activity. Here, we develop a new technique for identifying sufficient respondent sample sizes for participatory mapping by adapting species rarefaction curves. With a case study from a heavily fished marine ecosystem in the central Philippines, we analyze participatory maps depicting locations of individuals’ fishing grounds across six decades. Within a specified area, we assessed how different sample sizes (i.e. small vs. large numbers of respondents) would influence the estimated extent of fishing for a specified area. The estimated extent of fishing demonstrated asymptotic behavior as after interviewing a sufficiently large number of individuals, additional respondents did not increase the estimated extent. We determined that 120 fishers were necessary to capture 90% of the maximum spatial extent of fishing within our study area from 1990 to 2010, equivalent to 1.1% of male fishers in the region. However, a higher number of elder fishers need to be interviewed to accurately map fishing extent in 1960 to 1980. Participatory maps can provide context for current ecosystem conditions and can support guidelines for management and conservation. Their utility is strengthened by better consideration of the impacts of respondent sample sizes and how this can vary over time for historical assessments.

Amphibian diversity in Serranía de Majé, an isolated mountain range in eastern Panamá

Eastern Panamá is within the Mesoamerican biodiversity hotspot and supports an understudied amphibian fauna. Here we characterize the amphibian diversity across an elevational gradient in one of the least studied mountain ranges in eastern Panamá, Serranía de Majé. A total of 38 species were found, which represent 17% of all species reported for Panamá. Based on expected richness function and individual-based rarefaction curves, it is estimated that this is an underestimate and that at least 44 amphibian species occur in this area. Members of all three amphibian orders were encountered, represented by ten families and 22 genera, including five species endemic to Central America. Estimated species richness decreased with elevation, and the mid-elevation site supported both lowland and highland species. Our study provides a baseline for understanding the distribution pattern of amphibians in Panamá, for conservation efforts, and for determining disease-induced changes in amphibian communities.

A framework for disentangling ecological mechanisms underlying the island species-area relationship

The relationship between an island’s size and the number of species on that island—the island species-area relationship (ISAR)—is one of the most well-known patterns in biogeography, and forms the basis for understanding biodiversity loss in response to habitat loss and fragmentation. Nevertheless, there is contention about exactly how to estimate the ISAR, and the influence of the three primary ecological mechanisms—random sampling, disproportionate effects, and heterogeneity— that drive it. Key to this contention is that estimates of the ISAR are often confounded by sampling and estimates of measures (i.e., island-level species richness) that are not diagnostic of potential mechanisms. Here, we advocate a sampling-explicit approach for disentangling the possible ecological mechanisms underlying the ISAR using parameters derived from individual-based rarefaction curves estimated across spatial scales. If the parameters derived from rarefaction curves at each spatial scale show no relationship with island area, we cannot reject the hypothesis that ISARs result only from random sampling. However, if the derived metrics change with island area, we can reject random sampling as the only operating mechanism, and infer that effects beyond sampling (i.e., disproportionate effects and/or heterogeneity) are also operating. Finally, if parameters indicative of within-island spatial variation in species composition (i.e., β-diversity) increase with island area, we can conclude that intra-island compositional heterogeneity plays a role in driving the ISAR. We illustrate this approach using representative case studies, including oceanic islands, natural island-like patches, and habitat fragments from formerly continuous habitat, illustrating several combinations of underlying mechanisms. This approach will offer insight into the role of sampling and other processes that underpin the ISAR, providing a more complete understanding of how, and some indication of why, patterns of biodiversity respond to gradients in island area.