Rhinodrilus priscilae and Andiorrhinus (Amazonidrilus) caxiuana (Crassiclitellata, Rcrilidae) two new species from Caxiuanã National Forest.

The amazon forest is the habitat of a high species diversity of invertebrates and unfortunately the real richness had been underestimated. Earthworms' inventories had been poor because difficult to describe new species. This study adds new records to eastern amazon of two new species belong Rhinodrilus and Andiorrhinus genera. R. priscilae n. sp. is another rare specimen of the genre having two pair of prostatoid glands. A. (Amazonidrilus) caxiuana differ of other species in size, the intestinal origin is in XXVIII and also has only one glandular mass associated to spermatheca.

An annotated checklist and distribution of earthworms from Venezuela (Megadrili: Crassiclitellata).

An earthworm checklist has produced 78 nominal taxa (species/subspecies) of earthworm reported to date in Venezuela. The list of nominal taxa was obtained through literature review and the distribution maps were plotted by ecoregion. The 78 species/subspecies are divided into 24 genera and 6 families. Native earthworm species were more widely distributed than peregrine and exotic and are more associated with the conserved areas. Exotic species had been collected mainly in the north of the country in areas with at least some disturbance history. The peregrine species P. corethrurus is also widely distributed but with a preference for disturbed areas or related to its native natural grassland condition near the Guayana's shield. This is the first accurate assessment of Venezuela's earthworm species and subspecies in the last 14 years.

Additions to earthworms (Annelida, Crassiclitellata) from Aragua and Miranda states, Venezuela.

Two new species of the earthworm genus Pontoscolex found in San Casimiro County, northern Venezuela are described. Because of some morphological variability, and to improve the previous description, we redescribe Onychochaeta windlei and Rhinodrilus fuenzalidae collected at La Cortada settlement, Miranda state. Pontoscolex (Mesoscolex) juanae sp. n. and Pontoscolex (Nulloscolex) hugoi subgen. n., sp. n have three pairs of tiny calciferous glands in 7th to 9th segments, with a simple tubular structure similar to that of the genus Onychochaeta; however, testes and funnels are enclosed in sacs in the 11th segment similar to the Pontoscolex. We also report the occurrences of Pontoscolex (Pontoscolex) corethrurus Müller, 1857, Metaphire houlleti (Perrier, 1872), Perionyx excavatus Perrier, 1872, Dichogaster bolaui (Michaelsen, 1891), and Eisenia fetida (Savigny, 1826).

Microbiome resilience of Amazonian forests: Agroforest divergence to bacteria and secondary forest succession convergence to fungi.

An alarming and increasing deforestation rate threatens Amazon tropical ecosystems and subsequent degradation due to frequent fires. Agroforestry systems (AFS) may offer a sustainable alternative, reportedly mimicking the plant-soil interactions of the natural mature forest (MF). However, the role of microbial community in tropical AFS remains largely unknown. This knowledge is crucial for evaluating the sustainability of AFS and practices given the key role of microbes in the aboveground-belowground interactions. The current study, by comparing different AFS and successions of secondary and MFs, showed that AFS fostered distinct groups of bacterial community, diverging from the MFs, likely a result of management practices while secondary forests converged to the same soil microbiome found in the MF, by favoring the same groups of fungi. Model simulations reveal that AFS would require profound changes in aboveground biomass and in soil factors to reach the same microbiome found in MFs. In summary, AFS practices did not result in ecosystems mimicking natural forest plant-soil interactions but rather reshaped the ecosystem to a completely different relation between aboveground biomass, soil abiotic properties, and the soil microbiome.

Fast recovery of soil macrofauna in regenerating forests of the Amazon.

The emergence of secondary forests in deforested tropical regions represents an opportunity to mitigate biodiversity loss and climate change, but there is still debate on how fast and to which level these forests can recover biodiversity. Recent studies have shown that the recovery of plant and vertebrate species richness is relatively fast, but the pace of recovery for other groups remains unclear. Soil macroinvertebrates play critical roles on litter decomposition and seed dispersal, therefore the pace of their recovery has consequences for the entire forest ecosystem. We investigated how fast broad taxonomic groups of soil macrofauna recover in the first 30 years of forest regeneration using forests older than 50 years as reference. We surveyed the number, diversity and abundance of 19 broad taxonomic groups of soil macrofauna in 85 sites located in Brazilian Amazon, covering forests of different ages and clearing frequencies. Forest age and clearing frequency were obtained accurately from Landsat images in forests up to 30 years old. We used regression analysis to determine (a) the effects forest age and clearing frequency on macrofauna groups in secondary forests up to 30 years old; and (b) the changes in macrofauna groups between young forests (up to 10 years old), median age forests (between 10 and 30 years old) and forests older than 50 years. We found that the number and diversity of macrofauna groups recover rapidly in the first 10 years of forest regrowth, but show slower change among older forests. This rapid recovery was also observed in the abundance of several taxonomic groups and for predators and detritivores as functional groups. Forest clearing frequency had no effect on the number or the diversity of macrofauna groups, but the abundance of ants increased as forest was cleared more often. Our results for soil macrofauna align with those in plant and vertebrate studies showing that secondary forests quickly recover a large part of their biodiversity and ecological functions. Therefore, global-scale conservation strategies are needed to ensure the opportunity for secondary forests to grow. ​.

A new earthworm species of the genus Rhinodrilus (Rhinodrilidae, Clitellata) and new records of earthworms species from the Amazon-Cerrado-Caatinga transition in the State of Maranhão, Brazil.

We describe a new species of the genus Rhinodrilus from the transition between the Amazon, Cerrado and Caatinga biomes in the State of Maranhão, Brazil. The region is currently being converted to large-scale agriculture, which may cause severe losses in the local fauna and flora diversity yet very poorly studied. Rhinodrilus antonioi sp. nov. has irregular setae in the posterior region of the body, spermathecae without diverticula, tubercula pubertatis in the form of band extended in the line BC in XXI-XXV and clitellum from XIV-XXVII. Five new records are reported for the region, Dichogaster bolaui, Liodrilus mendesi, Pontoscolex (Pontoscolex) corethrurus, Urobenus brasiliensis and Urobenus petrerei.

A new species of Pontoscolex earthworm (Rhinodrilidae, Clitellata) from the Gurupi Biological Reserve, along with records of earthworm species from the Amazon region of Maranhão, Brazil.

We describe a new species of the genus Pontoscolex from the Amazon region of Maranhão State in Brazil. The region is the most deforested and degraded in the biome, with only 25% of the original forest cover left. Pontoscolex awa sp. nov. has regular setae, very small spermathecae, and tubercula pubertatis band-shaped extending to AB line in XIX-XII. Common and genital setae are of similar length and without ornamentations; these features are new in the genus, although unknown in several species. The Gurupi Biological Reserve where the new species was found is the only integral protection area within the Belém Endemism Area and therefore of crucial importance for conservation of earthworms and other endemic organisms.

¿Refleja Formicidae el impacto de la degradación de los bosques ribereños en la Amazonía Oriental?

La creciente presión antropogénica sobre la Amazonia Oriental hace imperativo el diagnóstico de la degradación forestal y, particularmente, su efecto sobre las comunidades clave dentro de los ecosistemas ribereños, unos de los últimos bosques amazónicos remantes en el estado de Maranhão. La familia de hormigas Formicidae juega un papel fundamental en el suelo, refleja los cambios en el uso de la tierra y es un grupo abundante en los bosques estudiados. Este trabajo tuvo como objetivo determinar el efecto del gradiente sucesional en la riqueza, frecuencia y composición de esta familia. El muestreo fue realizado durante los periodos seco y lluvioso con el método TSBF. Los organismos recolectados se identificaron a nivel de morfoespecies y se crearon curvas de acumulación de especies. Fueron utilizados modelos lineales mixtos para evaluar los efectos del periodo de recolecta local y estado de sucesión en la riqueza y la frecuencia de las hormigas. Por otro lado, se utilizaron regresiones polinómicas para investigar la relación entre la riqueza y la frecuencia de los formícidos según la cobertura del dosel y la altura de la vegetación. La composición de especies fue representada a través del índice de similitud de Jaccard. En total, 1 940 individuos fueron separados en 86 morfoespecies. Se obtuvo más del 80 % de la riqueza de especies probables. La frecuencia y riqueza de hormigas aumentó significativamente siguiendo la sucesión con valores bajos en las áreas abiertas durante la estación seca. Asimismo, durante esta estación, la cobertura del dosel y la altura de la vegetación tuvieron un efecto parcial en la riqueza y frecuencia de Formicidae. Por su parte, las áreas de sucesión intermedia y avanzada presentaron una composición similar con 50 especies compartidas, seguidas de las áreas de sucesión temprana con 43 y el uso antrópico con 34. Concluimos que la eliminación de los bosques ribereños tiene un efecto considerable sobre la riqueza y frecuencia de Formicidae, con valores mínimos en áreas degradadas durante la estación seca. Por otro lado, las áreas de bosques transformadas en sistemas agrícolas sufrieron pérdidas de 41 y 56% en la riqueza y frecuencia respectivamente. Con la sucesión, se restauran la estructura y las funciones del bosque favoreciendo la recolonización de las especies de hormigas. Finalmente, estos himenópteros son un grupo clave en los programas de monitoreo para la conservación/restauración de los bosques ribereños locales.

The increasing anthropogenic pressure on Eastern Amazon makes imperative the diagnosis of forest degradation, particularly the effect on key communities within the riparian ecosystems, one of the last remaining Amazonian forests in Maranhão State. The ant family Formicidae is an abundant group in these types of forests plays a fundamental role on the soil and also reflects the land use changes. Therefore, this study aimed to determine the impact of riparian forest successional stages on the Formicidae richness, frequency, and composition. Sampling was performed during both dry and wet seasons using the TSBF method. Collected organisms were identified as morphospecies. Also, species-accumulation curves were created. Linear mixed models were used to evaluate the effects of seasonal, local, and successional stage on ant richness and frequency. Polynomial regression models were applied to investigate the relationship between ant richness and frequency with canopy cover and vegetation height. Lastly, the species composition was represented by the Jaccard similarity index. In total, we observed 1 940 individuals grouped into 86 morphospecies. We obtained more than 80 % of the probable species richness. Ant frequency and richness increased significantly, following the successional stage, with low values in the open areas, especially during the dry season. Canopy cover and vegetation height seemed to affect partially both Formicidae richness and frequency during the dry season. Intermediate and advanced successional areas presented similar composition (50) shared species, followed by the areas of early succession (43) and anthropic use (34). We concluded that the elimination of riparian forests produces a considerable effect on the richness and frequency of the Formicidae family, minimally affecting them in open areas during the dry season, but resulting in losses of 41 % in richness and 56 % in frequency in forest areas when they are transformed into agricultural systems. Nevertheless, succession restores forest structure and functions, thus favoring re-colonization of ant species. Formicidae reflects forest degradation and is a key group in monitoring programs for the conservation/restoration of local riparian forests.

Efecto de la riqueza de especies y estructura de la vegetación en el almacenamiento de carbono en sistemas agroforestales de la Amazonía, Bolivia / Effect of species richness and vegetation structure on carbon storage in agroforestry systems in the Southern Amazon of Bolivia

Resumen Los sistemas agroforestales diversos concilian la producción de alimentos, la conservación de la biodiversidad y la provisión de servicios ecosistémicos como el secuestro de carbono atmosférico. Sin embargo, el papel de la riqueza florística sobre la producción de carbono en la biomasa de estos sistemas no está claro. Este estudio evaluó el efecto de la riqueza de especies y la estructura de la vegetación sobre el carbono en la biomasa de diferentes sistemas agroforestales, en la Amazonía Sur de Bolivia. Para eso, fueron estudiados 25 sistemas agroforestales y 4 bosques secundarios, en los departamentos de Santa Cruz y Beni. En cada sistema se instalaron parcelas circulares de 1 963 m2, donde la vegetación (árboles, arbustos y herbáceas) y necromasa (hojarasca, ramas y árboles muertos) fueron muestreados. Se utilizó funciones lineales y logarítmicas para evaluar el efecto de la riqueza y estructura de la vegetación sobre el carbono; y la partición de la varianza para examinar el efecto puro y compartido de las variables riqueza y estructura. Las regresiones mostraron una relación positiva fuerte de la riqueza de especies sobre el carbono de la biomasa (r2 = 0.74; P < 0.001). En la partición de la varianza, el 85.7 % de la variabilidad del carbono fue explicada por la riqueza, estructura y variación de la estructura. De forma aislada, la riqueza explicó el 12.7 %, la estructura el 8.8 % y la variación de la estructura el 4.8 %. Estos resultados confirman que el carbono en la biomasa sobre el suelo aumenta con la riqueza de especies y la variación estructural de la vegetación. Por lo tanto, sistemas agroforestales más biodiversos y estratificados son más eficientes en el uso de los recursos y pueden contribuir con la mitigación del cambio climático.(AU)

Abstract Diverse agroforestry systems conciliate food production, biodiversity conservation, and the provision of ecosystem services as atmospheric carbon sequestration. However, the role of floristic richness in the production of biomass in these systems is not clear. This study evaluated the effect of species richness and vegetation structure on aboveground biomass carbon in different agroforestry systems in the Southern Amazon of Bolivia. For that, 25 agroforestry systems and 4 secondary forests were studied in the departments of Santa Cruz and Beni. In each system, a 1 963 m2 circular plot was installed, where the vegetation (trees, shrubs and herbaceous) and necromass (leaf litter, branches and dead trees) were sampled. Linear and logarithmic functions were used to evaluate the effect of vegetation richness and structure on carbon, and the variance partition was used to examine the pure and shared effect of the richness and vegetation structure variables on carbon. Regressions showed a positive strong relationship between species richness and carbon (r2 = 0.74; P < 0.001). The partition of carbon variance showed that richness, structure and variation of the structure explained 85.7 %. Alone the richness explained 12.7 %, the structure 8.8 % and the variation of the structure 4.8 %. These results confirm that carbon in the aboveground biomass increases with species richness and structural variation of the vegetation. Therefore, more biodiverse and stratified agroforestry systems are more efficient in the use of resources and can contribute to climate change mitigation.(AU)

Brasilisia n. gen. and Arraia n. gen., two new genera of Ocnerodrilidae (Annelida, Clitellata, Oligochaeta) from Eastern Amazonia, Brazil.

We describe two new species from two new genera of Ocnerodrilidae from Alcântara and Rosário counties of Maranhão, Brazil. They were collected in very sandy soil in the transition between the Amazonia and Cerrado biomes. One of the species, Brasilisia punki n. sp., is the first report of earthworms of this family with an unusual pattern of genital markings and a gizzard in segment five. The other species Arraia nelmae n. sp. has a gizzard in segment six and a pair of calciferous glands in nine. We also provide an updated key for all genera of Ocnerodrilidae.

Three new species of Holoscolex (Clitellata, Glossoscolecidae) from the Gurupi Biological Reserve, last forest remnant of the Belém Endemism Area, Eastern Amazon.

We describe three new species of the earthworm genus Holoscolex from the Gurupi Biological Reserve in Maranhão state, Brazil. The Reserve, with the Indigenous Territories Awá, Caru, Alto Turiaçu and Alto Rio Guamá represent the last continuous forest remnants of the Belém Endemism Area, the most deforested and threatened area of Brazilian Amazonia. Holoscolex dossantosi sp. nov. has tubercula pubertatis looking like double bands, Holoscolex alatus sp. nov. presents alate tubercula pubertatis, and Holoscolex fernandoi sp. nov. has testis sacs and several intraclitellar atrial glands associated with genital markings between XIX and XXII. The presence of these unusual characters in Holoscolex fernandoi sp. nov. suggests that this species could be an evolutionary transitional stage linking Eudrilidae and more recent Glossoscolecidae genera.

Additions to Andiorrhinus (Turedrilus) (Rhinodrilidae, Clitellata) from Eastern Amazonia.

Two new species of the earthworm family Rhinodrilidae (Clitellata), from Maranhão state, Brazil, were studied by dissection. Andiorrhinus (Turedrilus) miricuri n. sp. is the first record of a big earthworm for this region with three pairs of large spermathecae in segments 7-9 and one pair of tubercula pubertatis bands lateral to b line in XX-XXV. Andiorrhinus (Turedrilus) barrosoi n. sp. lacks spermathecae and has one pair of tubercula pubertatis bands lateral to b line in XX-(1/3) XXIV. The earthworms described are from the most threatened region of Amazonia where 75% of forest cover is already lost. More information is urgently necessary to assess their ecology and vulnerability status.

New earthworm species of Righiodrilus (Clitellata, Glossoscolecidae) from eastern Amazonia.

Three new species of the glossoscolecid earthworm genus Righiodrilus are described from material collected in northern Pará and Maranhão States, Brazil. Rhigiodrilus gurupi n. sp. is characterized by four pairs of post-testicular spermathecae in xiv-xvii. Rhigiodrilus viseuensis n. sp. is distinguished by tubercula pubertatis in xix-xxiii and clitellum in xvi-xxiii. Rhigiodrilus moju n. sp. is the only species in the genus that lacks tubercula pubertatis. We provide an updated key and a distribution map for all species of Righiodrilus.

Macrofauna do solo em uma cronosequência de capoeiras, florestas e pastos no Centro de Endemismo Belém, Amazônia Oriental / Soil macrofauna in a chronosequence of fallows, old-growth forests and pastures in the Belém Endemism Center, Eastern Amazon

The Belém Endemism Center (CEB; the biogeographic region located between the Tocantins and Pindaré rivers) is the most deforested area of the Amazon. To study the soil biota of the remaining old-growth and second-growth forests is essential to promote more sustainable farming practices, and provide orientation for degraded land restoration. The aim of this study was to identify the main determinants of the composition and diversity of major taxa of soil macrofauna (current soil use, geographic centers, soil use history, fire frequency) in a chronosequence of fallows and forests in the CEB. Macrofauna was sampled in eight sites of young secondary forests (4-7 y), six sites of medium secondary forests (11-15 y), seven sites of "old" secondary forests (20-40 y), eight sites of old-growth forest remnants and three sites of pastures. Its composition and diversity were analysed through Principal Component and Between-class Analyses. A total of 9.225 individuals from 29 major taxa (orders or families) were collected in the 32 plots. Soil macrofauna composition was very sensitive to soil use history and identified different communities among geographic centers. The intensity of soil use decreased the abundance and richness of predators, indicating long-lasting impacts of soil degradation on macrofauna composition and diversity, and therefore on soil ecological functions.

O Centro de Endemismo Belém (CEB) -região biogeográfica localizada entre os rios Tocantins e Pindaré- é a área mais desmatada da Amazônia. Estudar a biota do solo dos remanescentes florestais e de áreas em regeneração (capoeiras) do CEB é fundamental para promover práticas agrícolas mais sustentáveis e orientar ações de restauração de áreas degradadas. Dessa forma, o objetivo desse estudo foi identificar os principais determinantes da composição e da diversidade dos grandes táxons de macrofauna do solo (uso atual do solo, núcleos geográficos, histórico de uso, freqüência de fogo) em uma cronoseqüência de capoeiras e florestas no CEB. A macrofauna foi amostrada em oito áreas de capoeiras baixas (4-7 anos), seis áreas de capoeiras médias (11-15 anos), sete áreas de capoeiras altas (20-40 anos), oito áreas de remanescentes de florestas e três áreas de pastagem. Sua composição e diversidade foi estudada através de Análises de Componentes Principais e Entre-classes. Um total de 9.225 indivíduos pertencentes a 29 grandes taxóns (ordens ou famílias) foram coletados nas 32 parcelas amostradas. A composição da macrofauna se mostrou sensível ao efeito do histórico de uso do solo e identificou comunidades significativamente distintas entre as micro-regiões, havendo nessa escala efeito da cronosequência de capoeiras e florestas. A intensidade do uso do solo levou a redução da abundância e da riqueza de predadores, indicando alterações significativas no funcionamento do solo. Esses resultados mostram um efeito duradouro da degradação sobre a macrofauna do solo e conseqüentemente sobre suas funções ecológicas.

Perceptions of environmental change and use of traditional knowledge to plan riparian forest restoration with relocated communities in Alcântara, Eastern Amazon.

BACKGROUND: Riparian forests provide ecosystem services that are essential for human well-being. The Pepital River is the main water supply for Alcântara (Brazil) and its forests are disappearing. This is affecting water volume and distribution in the region. Promoting forest restoration is imperative. In deprived regions, restoration success depends on the integration of ecology, livelihoods and traditional knowledge (TEK). In this study, an interdisciplinary research framework is proposed to design riparian forest restoration strategies based on ecological data, TEK and social needs. METHODS: This study takes place in a region presenting a complex history of human relocation and land tenure. Local populations from seven villages were surveyed to document livelihood (including 'free-listing' of agricultural crops and homegarden tree species). Additionally, their perceptions toward environmental changes were explored through semi-structured interviews (n = 79). Ethnobotanical information on forest species and their uses were assessed by local-specialists (n = 19). Remnants of conserved forests were surveyed to access ecological information on tree species (three plots of 1,000 m2). Results included descriptive statistics, frequency and Smith's index of salience of the free-list results. RESULTS: The local population depends primarily on slash-and-burn subsistence agriculture to meet their needs. Interviewees showed a strong empirical knowledge about the environmental problems of the river, and of their causes, consequences and potential solutions. Twenty-four tree species (dbh > 10 cm) were found at the reference sites. Tree density averaged 510 individuals per hectare (stdv = 91.6); and 12 species were considered the most abundant (density > 10ind/ha). There was a strong consensus among plant-specialists about the most important trees. The species lists from reference sites and plant-specialists presented an important convergence. CONCLUSIONS: Slash-and-burn agriculture is the main source of livelihood but also the main driver of forest degradation. Effective restoration approaches must transform problems into solutions by empowering local people. Successional agroforestry combining annual crops and trees may be a suitable transitional phase for restoration. The model must be designed collectively and include species of ecological, cultural, and socioeconomic value. In deprived communities of the Amazon, forest restoration must be a process that combines environmental and social gains.