Elizabeth Franklin

The Oribatid Mites

The occurrence of soil fauna populations increases nutrient release by fragmentation of litter, grazing of microflora and improvement of soil structure. In floodplain forests of Central Amazonia, Acari represent up to 64% of the arthropod fauna in the litter and upper soil layers (0–3.5 cm; Table 16.2) and up to 19% of the monthly catches on tree trunks (Chap. 14). The oribatid mites are often a numerically dominant group among the soil arthropods in all soil types. These animals inhabit a variety of habitats, such as soil, rotten wood, litter, mosses, and trees. In the Central Amazon lowlands, Beck (1969, 1971, 1972, 1976) and Adis and Ribeiro (1989) have reported on the ecological significance of oribatid mites in inundation forests. In this chapter we discuss their abundance, distribution, population dynamics and submersion resistance with respect to the flood pulse (Sect. 1.3; Junk et al. 1989) in the igapo of Taruma Mirim and in the varzea of Ilha de Marchantaria. Sampling sites are described in Chapter 2.

Limited effects of dominant ants on assemblage species richness in three Amazon forests

1. Ants are highly interactive organisms and dominant species are considered to be able to control the species richness of other ants via competitive exclusion. However, depending on the scale studied, inter‐specific competition may or may not structure biological assemblages. To date, ant dominance–richness relationships have only been studied in small sample units, where a few dominant colonies could plausibly control most of the sample unit.

Efficiency in inventories of ants in a forest reservein Central Amazonia

The objective of this work was to evaluate an inventory method efÞ ciency for ants. We used subsamples collected in 24 transects of 100 m, distributed in 6 plots of 600 ha each in primary forest, as part of a long-term project. Ten litter subsamples were extracted per transect using Winkler extractors. Ants were identiÞ ed to genus level, and Crematogaster, Gnamptogenys and Pachycondyla genera to species/morphospecies level. To evaluate the consequences of reduced sampling on the retention of ecological information, we estimated the lowest number of subsamples needed to detect the effects of environmental variables. Multidimensional scaling (MDS) was used to generate dissimilarity matrices, and Mantel correlations between each reduced-sampling effort and maximum effort were used as an index of how much information was maintained and could still be used in multivariate analyses. Lower p-values was observed on the effect of soil pH in the community of genera, and on the effect of the litter volume for the community of Crematogaster . The trend was still detectable in the analysis based on reduced-sampling. The number of subsamples can be reduced, and the cost-efÞ ciency of the protocol can be improved with little loss of information.

Combining Taxonomic and Functional Approaches to Unravel the Spatial Distribution of an Amazonian Butterfly Community

Abstract This study investigated the spatial distribution of an Amazonian fruit-feeding butterfly assemblage by linking species taxonomic and functional approaches.We hypothesized that: 1) vegetation richness (i.e., resources) and abundance of insectivorous birds (i.e., predators) should drive changes in butterfly taxonomic composition, 2) larval diet breadth should decrease with increase of plant species richness, 3) small-sized adults should be favored by higher abundance of birds, and 4) communities with eyespot markings should be able to exploit areas with higher predation pressure. Fruit-feeding butterflies were sampled with bait traps and insect nets across 25 km2 of an Amazonian ombrophilous forest in Brazil. We measured larval diet breadth, adult body size, and wing marking of all butterflies. Our results showed that plant species richness explainedmost of the variation in butterfly taxonomic turnover. Also, community average diet breadth decreased with increase of plant species richness, which supports our expectations. In contrast, community average body size increased with the abundance of birds, refuting our hypothesis.We detected no influence of environmental gradients on the occurrence of species with eyespot markings. The association between butterfly taxonomic and functional composition points to a mediator role of the functional traits in the environmental filtering of butterflies. The incorporation of the functional approach into the analyses allowed for the detection of relationships that were not observed using a strictly taxonomic perspective and provided an extra insight into comprehending the potential adaptive strategies of butterflies.

Mites (Arachnida, Acari) on Citrus sinensis L. Osbeck orange trees in the state of Amazonas, Northern Brazil

Despite the importance of citriculture in Brazil, very little is known about mite populations in citrus crops in the Northern Region. In the municipality of Manaus, 12 sprayed sweet orange orchards were surveyed every two weeks during seven months to record mite species amount, and to describe the abundance and distribution of the most important species. The size and age of the orchards varied from 3,360 to 88,080 m 2 and seven to 25 years, respectively. In the fourteen sampling period, leaves, twigs and fruits were collected from 12 trees, one per orchard. In total, 3,360 leaves, 672 twigs and 1,344 fruits were sampled from 168 trees. Mites were manually extracted from the fruits, and by the washing method on leaves and twigs. We identified pests with the potential to cause economic loss. Fourteen species of phytophagous and mycophagous mites from Eriophyidae, Tarsonemidae, Tenuipalpidae, and Tetranychidae were recorded. Brevipalpus phoenicis (Geijskes 1939) and Phyllocoptruta oleivora (Ashm., 1879), the two commonest phytophagous mites in other Brazilian regions were dominant, showing that local orchards are susceptible to their infestation. Eleven predatory mites were recorded, comprising 10% of the mite population, belonging to Phytoseiidae and Ascidae. Phytoseiidae was the richest family, with ten species. The results are discussed in relation to the temporal variation aspects and habitat use of the most important species. Long-term research encompassing chemical applications followed by evaluations of the mite community are necessary for a better management of the orchards, taking into consideration the seasonal phenology of key pests.

Attitudes Towards Scorpions and Frogs: A Survey Among Teachers and Students from Schools in the Vicinity of an Amazonian Protected Area

Abstract Many conservation and management policies adopted in countries with megadiverse forest remnants largely neglect local human communities living in areas surrounding preserves. We investigated the attitudes and knowledge of teachers and students towards scorpions and frogs in the limits between a tropical rainforest reserve and a large Amazonian city. We aimed to identify possible deficiencies in environmental education and the level of knowledge about these animals. Data were collected from 110 students of both genders, aging between eight and 16 years old, representing four different schools located at the periphery of Manaus City, Amazonas State, Brazil. Written responses concerning personal experiences, knowledge, and background about the animals were collected from students and teachers through open- and closed-ended questions. Hand drawn responses were also gathered from the students. Members of the studied population showed more negative than positive attitudes towards scorpions and frogs. We found that gender and sex held similar attitudes in relation to these animals. However, boys tended to be more interested than girls were in the biology of scorpions. In addition, attitudes towards scorpions became more negative as age increased. Most students pictured scorpions and frogs as dangerous, lethal, or aggressive. Such conceptions were also recorded among teachers. We detected a huge lacuna in the knowledge on the importance and about biological and ecological aspects of both groups. Educational activities focused on emotional affinity of students with animals should be associated with traditional lessons, which can enhance conservation strategies.

Soil oribatid mite (Acari: Oribatida) diversity and composition in semi- deciduous forest fragments in eastern Amazonia and comparison with the surrounding savanna matrix

We recorded species abundance and richness of oribatid mites along 16 plots established in semi-deciduous forest fragments in Amazonia. The results were compared with a published dataset consisting of an inventory carried out in 38 plots in the surrounding savanna. Totals of 143 and 91 species were recorded in the forest fragments and savanna, respectively. Sørensen similarity index between both environments was 0.44. Ordination of sites according to oribatid mite species composition showed a clear separation between forest fragments and savanna. Rostrozetes ovulum, Archegozetes longisetosus and Eohypochthonius (Eohypochthonius) becki were abundant and frequent in the forest fragments but exceedingly rare in the savanna. Neoppia (Neoppia) schauenbergi, Pseudoppia sp. C, Microppia sp. A and Cosmochthonius sp. A were limited to the savanna. This study also represents an early step toward knowing which groups of species are exclusive to one or another vegetation type or are sensitive to their inherent environmental conditions.

Multi-taxa Surveys: Integrating Ecosystem Processes and User Demands

Globally, natural resource management agencies are increasingly recognizing the importance of long-term ecological research (LTER) for monitoring biodiversity, ranging from relatively simple, known, local-level issues, such as managing tourist impacts in a conservation park, to more complex, multifaceted, pervasive, and far-reaching impacts, such as global climate change. Much previous literature has confused protocols for LTER projects to answer current research questions, with developing a system for long-term ecological monitoring. Contrary to perceptions that these LTER systems are not driven by well-defined objectives, we argue that LTER systems can be designed and implemented with the specific objective of providing a basis for both LTER projects and long-term monitoring. We present an overview of RAPELD, an LTER system developed in Brazil, with comparable infrastructure established in Australia and Nepal. The standardized biodiversity infrastructure and research platform provides a long-term basis for powerful multi-disciplinary, multi-scale analyses.

The scaling of colony size with nest volume in termites: a role in population dynamics?

Colony size is often attributed a key role in social insect population ecology. However, in nest‐building termites, colony size is a power function of nest volume, so that colonies of species with low scaling exponents tend to grow less as their nests are expanded. Thus, in such species, intercolonial differences in colony size may be less likely to develop, and changes in species total biomass may largely reflect those in colony numbers rather than colony sizes. The scaling of colony biomass with nest volume in three termite species, namely Anoplotermes banksiEmerson, Neocapritermes braziliensis Snyder and Labiotermes labralis Holmgren was determined. Then, their nests were counted and their total biomass in plots across an Amazonian rainforest landscape was estimated. Finally, whether the strength of the relationship between total biomass and number of nests reflected species scaling exponents was examined. Scaling exponents were 0.47 for N. braziliensis, 0.57 for A. banksi, and 0.83 for L. labralis. On the other hand, the strength of the relationship between total biomass and the number of nests (r2) followed the opposite trend: 0.93 for N. braziliensis, 0.92 for A. banksi, and 0.53 for L. labralis. It is suggested that the scaling of colony size with nest volume may mediate termite population dynamics: as the scaling exponent decreases across species, changes in total biomass would increasingly reflect changes in colony numbers, with an accompanying increase in the importance of colony births and deaths as opposed to colony growth.

What drives the dynamics of a soil mite population under seasonal flooding? A null model analysis

Floods can inflict high mortality on terrestrial organisms, but may also promote adaptive evolution. In seasonal floodplains, several taxa show flood-related traits that may be important for their long-term persistence, but the available evidence is conflicting. Here, we used a simulation approach to investigate the interplay between seasonal floods and submersion resistance in driving the population dynamics of the parthenogenetic soil mite Rostrozetes ovulum in an Amazonian blackwater floodplain. First, we gathered data from two flood cycles to estimate field survival rate. Next, we used further data from a submersion survival laboratory experiment and a historical flood record to build a null model for R. ovulum’s survival rate under seasonal flooding, and then tested it against field survival estimates. Floods caused marked density declines, but the two estimates of field survival rate were statistically equivalent, suggesting relatively constant survival across years. Submersion survival time varied tenfold among individuals, but its variability was within the range known for life history traits of other asexual invertebrates. Both field survival rates were consistent with the null model, supporting seasonal flooding as the main mortality factor. Surprisingly, though, average flood duration was actually larger than the average mite could survive, suggesting that population persistence relies on relatively rare, super-resistant phenotypes. Overall, the studied R. ovulum population appears to have a mainly density-independent dynamics across years, with its viability depending on mechanisms that buffer flood survival rate against temporal oscillations.