Soil macrofauna communities in Brazilian land-use systems.

Background: Soil animal communities include more than 40 higher-order taxa, representing over 23% of all described species. These animals have a wide range of feeding sources and contribute to several important soil functions and ecosystem services. Although many studies have assessed macroinvertebrate communities in Brazil, few of them have been published in journals and even fewer have made the data openly available for consultation and further use. As part of ongoing efforts to synthesise the global soil macrofauna communities and to increase the amount of openly-accessible data in GBIF and other repositories related to soil biodiversity, the present paper provides links to 29 soil macroinvertebrate datasets covering 42 soil fauna taxa, collected in various land-use systems in Brazil. A total of 83,085 georeferenced occurrences of these taxa are presented, based on quantitative estimates performed using a standardised sampling method commonly adopted worldwide to collect soil macrofauna populations, i.e. the TSBF (Tropical Soil Biology and Fertility Programme) protocol. This consists of digging soil monoliths of 25 x 25 cm area, with handsorting of the macroinvertebrates visible to the naked eye from the surface litter and from within the soil, typically in the upper 0-20 cm layer (but sometimes shallower, i.e. top 0-10 cm or deeper to 0-40 cm, depending on the site). The land-use systems included anthropogenic sites managed with agricultural systems (e.g. pastures, annual and perennial crops, agroforestry), as well as planted forests and native vegetation located mostly in the southern Brazilian State of Paraná (96 sites), with a few additional sites in the neighbouring states of São Paulo (21 sites) and Santa Catarina (five sites). Important metadata on soil properties, particularly soil chemical parameters (mainly pH, C, P, Ca, K, Mg, Al contents, exchangeable acidity, Cation Exchange Capacity, Base Saturation and, infrequently, total N), particle size distribution (mainly % sand, silt and clay) and, infrequently, soil moisture and bulk density, as well as on human management practices (land use and vegetation cover) are provided. These data will be particularly useful for those interested in estimating land-use change impacts on soil biodiversity and its implications for below-ground foodwebs, ecosystem functioning and ecosystem service delivery. New information: Quantitative estimates are provided for 42 soil animal taxa, for two biodiversity hotspots: the Brazilian Atlantic Forest and Cerrado biomes. Data are provided at the individual monolith level, representing sampling events ranging from February 2001 up to September 2016 in 122 sampling sites and over 1800 samples, for a total of 83,085 ocurrences.

Amazonian earthworm biodiversity is heavily impacted by ancient and recent human disturbance.

Despite the importance of earthworms for soil formation, more is needed to know about how Pre-Columbian modifications to soils and the landscape. Gaining a deeper understanding is essential for comprehending the historical drivers of earthworm communities and the development of effective conservation strategies in the Amazon rainforest. Human disturbance can significantly impact earthworm diversity, especially in rainforest soils, and in the particular case of the Amazonian rainforest, both recent and ancient anthropic practices may be important. Amazonian Dark Earths (ADEs) are fertile soils found throughout the Amazon Basin, created by sedentary habits and intensification patterns of pre-Colombian societies primarily developed in the second part of the Holocene period. We have sampled earthworm communities in three Brazilian Amazonian (ADEs) and adjacent reference soils (REF) under old and young forests and monocultures. To better assess taxonomic richness, we used morphology and the barcode region of the COI gene to identify juveniles and cocoons and delimit Molecular Operational Taxonomic Units (MOTUs). Here we suggest using Integrated Operational Taxonomical units (IOTUs) which combine both morphological and molecular data and provide a more comprehensive assessment of diversity, while MOTUs only rely on molecular data. A total of 970 individuals were collected, resulting in 51 taxonomic units (IOTUs, MOTUs, and morphospecies combined). From this total, 24 taxonomic units were unique to REF soils, 17 to ADEs, and ten were shared between both soils. The highest richness was found in old forest sites for ADEs (12 taxonomic units) and REFs (21 taxonomic units). The beta-diversity calculations reveal a high species turnover between ADEs and REF soils, providing evidence that ADEs and REFs possess distinct soil biota. Furthermore, results suggest that ADE sites, formed by Pre-Columbian human activities, conserve a high number of native species in the landscape and maintain a high abundance, despite their long-term nature.

New species and records of earthworms (Annelida, Oligochaeta: Crassiclitellata) in small holder farming systems in the Peruvian Amazon.

We examined external characters and internal anatomy, after dorsal dissection, of 11 species of Oligochaeta from the Peruvian Amazonia Loreto department. Four new species of families Glossoscolecidae and Rhinodrilidae and genera Righiodrilus and Martiodrilus are described here. Righiodrilus omagua, sp. nov., differs from other Righiodrilus by the presence of tubercula pubertatis in segments ½15, 15- ½18, 18; male pores located in intersegment 16/17; large seminal vesicles in segment 12 that extend until segment 24. Martiodrilus (Maipure) yurimaguensis, sp. nov., has a saddle-shaped clitellum in 14-1/4 25 and tubercula pubertatis between segments 1/318 -1/2 25. Martiodrilus (Maipure) tapiai, sp. nov., is differentiated from the others by the position of the tubercula pubertatis in 19-24, and the shape and size of spermathecae, common setae, ornamentation of genital setae and the location of male pores in intersegment 18/19. Martiodrilus (Martiodrilus) alegrei sp. nov., differs from other species of the genus by extension of tubercula pubertatis from 21 to 26, the number and shape of spermathecae. It is the only species of the genus that presents a single pair of spermathecae in segment 6. Additional records for the Peruvian Republic and the Amazonian region are also reported for Martiodrilus (Maipure) pano, Periscolex yuya, Pontoscolex (Pontoscolex) corethrurus, Rhinodrilus lavellei, Rhinodrilus pahanasii, Dichogaster (Diplothecodrilus) modiglianii and Ocnerodrilus occidentalis. With these new records, the earthworm fauna of Perú recorded so far increases to 36 species (21 native and 15 exotic), including eight native from Peruvian Amazonia Region. Many more species are still expected to be found.

A "Dirty" Footprint: Macroinvertebrate diversity in Amazonian Anthropic Soils.

Amazonian rainforests, once thought to be pristine wilderness, are increasingly known to have been widely inhabited, modified, and managed prior to European arrival, by human populations with diverse cultural backgrounds. Amazonian Dark Earths (ADEs) are fertile soils found throughout the Amazon Basin, created by pre-Columbian societies with sedentary habits. Much is known about the chemistry of these soils, yet their zoology has been neglected. Hence, we characterized soil fertility, macroinvertebrate communities, and their activity at nine archeological sites in three Amazonian regions in ADEs and adjacent reference soils under native forest (young and old) and agricultural systems. We found 673 morphospecies and, despite similar richness in ADEs (385 spp.) and reference soils (399 spp.), we identified a tenacious pre-Columbian footprint, with 49% of morphospecies found exclusively in ADEs. Termite and total macroinvertebrate abundance were higher in reference soils, while soil fertility and macroinvertebrate activity were higher in the ADEs, and associated with larger earthworm quantities and biomass. We show that ADE habitats have a unique pool of species, but that modern land use of ADEs decreases their populations, diversity, and contributions to soil functioning. These findings support the idea that humans created and sustained high-fertility ecosystems that persist today, altering biodiversity patterns in Amazonia.

Unveiling the age and origin of biogenic aggregates produced by earthworm species with their NIRS fingerprint in a subalpine meadow of Central Pyrenees.

In this study the near-infrared reflectance (NIR) spectra signals (750-2,500 nm) of soil samples was compared with the NIR signals of the biogenic aggregates produced in the lab by three earthworm species, i.e., Aporrectodea rosea (Savigny 1826), Lumbricus friendi Cognetti, 1904 and Prosellodrilus pyrenaicus (Cognetti, 1904) from subalpine meadows in the Central Pyrenees. NIR spectral signatures of biogenic aggregates, root-aggregates, and non-aggregated soil were obtained together with soil carbon (C), nitrogen (N), [Formula: see text] and [Formula: see text] determinations. The concentrations of C, N and C:N ratio in the three types of soil aggregates identified were not statistically significant (ANOVA, p>0.05) although non-macroaggregated soil had slightly higher C concentrations (66.3 g kg-1 dry soil) than biogenic aggregates (earthworm- and root-aggregates, 64.9 and 63.5 g kg-1 dry soil, respectively), while concentrations of [Formula: see text] and [Formula: see text] were highest in the root-attached aggregates (3.3 and 0.31 mg kg dry soil-1). Total earthworm density and biomass in the sampled area was 137.6 ind. m-2, and 55.2 g fresh weight m-2, respectively. The biomass of aggregates attached to roots and non-macroaggregated soil was 122.3 and 134.8 g m-2, respectively, while biomass of free (particulate) organic matter and invertebrate biogenic aggregates was 62.9 and 41.7 g m-2, respectively. Multivariate analysis of NIR spectra signals of field aggregates separated root aggregates with high concentrations of [Formula: see text] and [Formula: see text] (41.5% of explained variance, axis I) from those biogenic aggregates, including root aggregates, with large concentrations of C and high C:N ratio (21.6% of total variability, axis II). Partial Least Square (PLS) regressions were used to compare NIR spectral signals of samples (casts and soil) and develop calibration equations relating these spectral data to those data obtained for chemical variables in the lab. After a derivatization process, the NIR spectra of field aggregates were projected onto the PLS factorial plane of the NIR spectra from the lab incubation. The projection of the NIR spectral signals onto the PLSR models for C, N, [Formula: see text] and [Formula: see text] from casts produced and incubated in the lab allowed us to identify the species and the age of the field biogenic aggregates. Our hypothesis was to test whether field aggregates would match or be in the vicinity of the NIR signals that corresponded to a certain species and the age of the depositions produced in the lab. A NIRS biogenic background noise (BBN) is present in the soil as a result of earthworm activity. This study provides insights on how to analyse the role of these organisms in important ecological processes of soil macro-aggregation and associated organic matter dynamics by means of analyzing the BBN in the soil matrix.

Biodiversity loss along a gradient of deforestation in Amazonian agricultural landscapes.

Assessing how much management of agricultural landscapes, in addition to protected areas, can offset biodiversity erosion in the tropics is a central issue for conservation that still requires cross-taxonomic and landscape-scale studies. We measured the effects of Amazonia deforestation and subsequent land-use intensification in 6 agricultural areas (landscape scale), where we sampled plants and 4 animal groups (birds, earthworms, fruit flies, and moths). We assessed land-use intensification with a synthetic index based on landscape metrics (total area and relative percentages of land uses, edge density, mean patch density and diversity, and fractal structures at 5 dates from 1990 to 2007). Species richness decreased consistently as agricultural intensification increased despite slight differences in the responses of sampled groups. Globally, in moderately deforested landscapes species richness was relatively stable, and there was a clear threshold in biodiversity loss midway along the intensification gradient, mainly linked to a drop in forest cover and quality. Our results suggest anthropogenic landscapes with high-quality forest covering >40 % of the surface area may prevent biodiversity loss in Amazonia.

Dissecting the multi-scale spatial relationship of earthworm assemblages with soil environmental variability.

BACKGROUND: Studying the drivers and determinants of species, population and community spatial patterns is central to ecology. The observed structure of community assemblages is the result of deterministic abiotic (environmental constraints) and biotic factors (positive and negative species interactions), as well as stochastic colonization events (historical contingency). We analyzed the role of multi-scale spatial component of soil environmental variability in structuring earthworm assemblages in a gallery forest from the Colombian "Llanos". We aimed to disentangle the spatial scales at which species assemblages are structured and determine whether these scales matched those expressed by soil environmental variables. We also tested the hypothesis of the "single tree effect" by exploring the spatial relationships between root-related variables and soil nutrient and physical variables in structuring earthworm assemblages. Multivariate ordination techniques and spatially explicit tools were used, namely cross-correlograms, Principal Coordinates of Neighbor Matrices (PCNM) and variation partitioning analyses. RESULTS: The relationship between the spatial organization of earthworm assemblages and soil environmental parameters revealed explicitly multi-scale responses. The soil environmental variables that explained nested population structures across the multi-spatial scale gradient differed for earthworms and assemblages at the very-fine- (<10 m) to medium-scale (10-20 m). The root traits were correlated with areas of high soil nutrient contents at a depth of 0-5 cm. Information on the scales of PCNM variables was obtained using variogram modeling. Based on the size of the plot, the PCNM variables were arbitrarily allocated to medium (>30 m), fine (10-20 m) and very fine scales (<10 m). Variation partitioning analysis revealed that the soil environmental variability explained from less than 1% to as much as 48% of the observed earthworm spatial variation. CONCLUSIONS: A large proportion of the spatial variation did not depend on the soil environmental variability for certain species. This finding could indicate the influence of contagious biotic interactions, stochastic factors, or unmeasured relevant soil environmental variables.

Characterization of cattle farms and adoption of agroforestry systems as a proposal for soil management in Caquetá, Colombia / Caracterización de fincas ganaderas y adopción de sistemas agroforestales como propuesta de manejo de suelos en Caquetá, Colombia / Caracterização das fazendas de gado e adoção de sistemas agroflorestais como uma proposta de manejo do solo no Caquetá, Colômbia

Objective: to promote the adoption of agroforestry systems for the recovery and reorientation of land use of traditional farming systems in the Colombian Amazon. Methods: participatory techniques were used to assess the current state of local farming systems and to exchange experiences with farmers regarding environmentally-friendly technologies. The first stage involved the application of a structured survey in 134 farms, which included variables related to livelihood and production systems. In a second stage, agroforestry ''protein bank'' plots were evaluated in two farms associated with bio-organic fertilization (FBO). Descriptive statistics and a ''t'' test for mean differences using the SPSS package were used for the analysis. Results: the group of farmers engaged in traditional farming using large areas produced 1.6 liters of milk/cow/day with large money investments. A second group that established silvopastoral systems such as fodder banks, diversified production with annual crops. A third group that engaged in agroforestry manage of small farms kept a few cattle basing production on perennial crops, and received higher income than the other two groups due to higher profits per area. Agroforestry systems with Tithonia diversifolia plots associated with FBO were higher than treatments without FBO (p<0.001). Green forage production with FBO was 4.3 kg/plant in Farm 1, and 5.8 kg in Farm 2 during 195 days since its establishment. Conclusions: a farm diversification process is under development in the Colombian Amazon with the establishment of silvopastoral and agroforestry systems, showing interesting preliminary results.

Objetivo: propiciar la adopción de sistemas agroforestales como propuesta para la recuperación y reorientación del uso tradicional del suelo en sistemas agropecuarios tradicionales en la Amazonia colombiana. Métodos: se emplearon técnicas de desarrollo rural participativo para reconocer el estado actual de los sistemas agropecuarios locales e intercambiar experiencias con agricultores y generar tecnologías apropiadas al entorno. Una primera etapa incluyó la aplicación de una encuesta estructurada en 134 fincas, que incluía variables referentes a medios de vida y sistemas de producción. En una segunda etapa, en dos fincas se evaluaron sistemas agroforestales de bancos de proteína asociados a la técnica de fertilización bio-orgánica (FBO) de suelos. Para el análisis de resultados se utilizó un análisis estadístico descriptivo y una prueba ''t'' para diferencias de medias usando el paquete SPSS. Resultados: los resultados muestran un grupo de agricultores dedicados a la ganadería con manejo tradicional, que utiliza grandes áreas, produciendo 1.6 litros de leche/vaca/día y con grandes inversiones en patrimonio. Un segundo grupo estableció sistemas silvopastoriles como bancos de forraje, diversificando la producción con cultivos anuales. Un tercer grupo dedicado a la agroforestería maneja pequeñas fincas, mantienen poco ganado y fundamentan su producción en cultivos perennes, reciben ingresos más altos que los otros dos grupos al generar mayor ganancia por área utilizada. En la evaluación de forraje de sistemas agroforestales con bancos de proteína de Tithonia diversifolia asociados a la técnica FBO se encontraron mayores resultados para los tratamientos con FBO en comparación con los tratamientos sin FBO (p<0.001). La producción de forraje verde con FBO fue de 4.3 kg/planta en la finca 1 y de 5.8 kg para la 2 durante 195 días desde su establecimiento. Conclusiones: se está gestando un proceso de diversificación de fincas en la Amazonia Colombiana, tendiente al establecimiento de sistemas silvopastoriles y agroforestales, que presentan resultados preliminares interesantes.

Objetivo: propiciar a adoção de sistemas agroflorestais como proposta para a recuperação e reorientação do uso tradicional do solo em sistemas agropecuários tradicionais na Amazônia Colombiana. Métodos: foram empregadas técnicas de desenvolvimento rural participativo para reconhecer o estado atual dos sistemas agropecuários locais e intercambiar experiências com agricultores e gerar tecnologias apropriadas ao entorno. Uma primeira etapa incluiu a aplicação de uma enquete estruturada em 134 fazendas, com variáveis referentes a os meios de vida e sistemas de produção. Em uma segunda etapa, em duas fazendas foram avaliados sistemas agroflorestais de bancos de proteína associados à técnica de fertilização bio-orgânica (FBO) de solos. Para a análise de resultados foi utilizada a estatística descritiva e o teste ''t'' para diferenças de médias usando o pacote SPSS. Resultados: os resultados mostraram um grupo de agricultores dedicados à criação de gado com manejo tradicional, utilizando grandes áreas e produzindo 1.6 litros de leite/vaca/dia, com grandes investimentos em patrimônio. Um segundo grupo estabeleceu sistemas silvopastoris como bancos de forragem, diversificando a produção com cultivos anuais. Um terceiro grupo dedicado à agrossilvicultura maneja pequenas fazendas, mantém pouco gado e fundamentam a sua produção em culturas perenes, recebem ingressos mais altos do que os outros dois grupos ao gerar maior lucro por área utilizada. Na avaliação da forragem de sistemas agroflorestais com bancos de proteína de Tithonia diversifolia asociados ou nao à técnica FBO, obtiveram-se melhores resultados para os tratamentos sem FBO (p<0.001). A produção de forragem verde com FBO foi de 4.3 kg/ planta na fazenda 1 e de 5.8 kg para a fazenda 2 durante 195 dias desde o seu estabelecimento. Conclusões: Está se gestando um processo de diversificação nas fazendas da Amazonia colombiana, com tendência ao estabelecimento de sistemas silvopastoris e agroflorestais, que apresentam resultados preliminares interessantes.