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.

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.

Earthworms in the conversion of natural grasslands to agropastoral systems-a preliminary study in Vale Verde, Rio Grande do Sul, Brazil.

Soils, in addition to supporting agricultural production, are the source of a wide diversity of essential ecosystem functions and services performed by invertebrate organisms. Earthworms play a key role as ecosystem engineers, but little is known about the diversity of the state of Rio Grande do Sul, Brazil, and even less concerning land-use conversion scenarios. Earthworms were sampled using the TSBF method in natural grassland (NG1) in July 2018 and subsequently converted to soybean in an agropastoral system (AP) in December 2018 and July 2019. In July 2019 a nearby natural grassland (NG2) was also sampled and considered as a reference. The earthworms were identified to family, genus and/or species, and the total number of individuals and proportion of native and exotic species were calculated and presented. A total of 583 individuals were collected and seven species were identified: three native species-Kerriona sp.7, Kerriona sp.8, Eukerria rosea; and four exotic/peregrine species-Amynthas corticis, Dichogaster bolaui, Bimastos parvus, Pontoscolex corethrurus. The two native Kerriona species are new to science and were found after the conversion of the area. The other native species (Eukerria rosea), also found after the conversion, had a high number of individuals in the last sample. The results can be related to the availability and changing of resources, due to the conversion of the land use with a high rain preceding the winter season.

New Ocnerodrilidae genera, species and records from Brazil (Annelida: Crassiclitellata).

We describe three new species of Eukerria, six of Kerriona, one of Ocnerodrilus and two of Belladrilus (Clitellata: Ocnerodrilidae) from Brazil, mostly from wet habitats including bromeliad leaf axils, plus some from forest soils in Bahia state. We also provide new morphological and distribution data on Kerriona luederwaldti Michaelsen, 1924. We describe the new genus Pauqueba and its two new species, both from bromeliad leaf axils and forest floor litter in the state of Bahia. It has two pairs of calciferous glands, the balantine reduction of the male terminalia but spermathecae in ix, and no gizzard. The new genus Parabauba found in deeper (30 cm) soil layers is distinctive for the combination of two pairs of calciferous glands, a large gizzard in v, acanthodriline male terminalia, and no typholosole. The new genus Diplomoela from a mesic soil in Bahia is meronephric, unusually large for the Ocnerodrilidae, and has two well-developed gizzards.

Earthworms in natural grasslands and agropastoral systems in the Brazilian Pampa.

In this study, we sampled grazed natural grassland and agropastoral systems in two regions (Alegrete and Aceguá) in the highly diverse Brazilian Pampa region which is undergoing significant change in land use cover. By hand sorting the soil, a total of five species were found, belonging to the families Glossoscolecidae (Glossoscolex sp.50 and Glossoscolex sp.51), Ocnerodrilidae (Kerriona sp.6 and Eukerria sp.3), and Lumbricidae (Aporrectodea trapezoides). The former four were identified as native-new to science-and the latter as exotic. Differences were observed in both earthworm species richness and abundance between regions and land-use systems, likely due to environmental conditions and agricultural practices, respectively. Agropastoral systems had higher abundance and species richness than natural grasslands, though these differences varied by location. This suggests that conversion from natural grassland to agropastoral systems can maintain native earthworms and, possibly, enhance ecosystem services. However, an exotic species was found in high abundance at one agropastoral site. These results highlight the need for additional biodiversity studies on earthworms in the Brazilian Pampa and for research on the impacts of land use changes in this region.

Earthworm species in different land use systems in the state of Goiás and the Federal District of Brazil.

The state of Goiás and the Federal District together cover an area of about 346 thousand km2, including the diversified Cerrado vegetation, also known as the Brazilian Savanna, a biodiversity hotspot with many endangered and endemic species. Much of the Cerrado has been converted to agriculture, but little is known of its earthworms, and the impacts of land use management and agricultural practices on their density and diversity. In the present paper we review the known earthworm species in Goiás and the Federal District based on historical and museum records, and update information on their distribution and populations in different counties and land use systems with data from recent samplings. Five additional species are reported here for the first time, raising the total to 12 species currently known from Goiás, from the families Benhamiidae (1), Glossoscolecidae (1), Megascolecidae (3), Ocnerodrilidae (2) and Rhinodrilidae (5). In the Federal District, an additional 10 species are reported, bringing the total to 23 earthworm species, belonging to the families Benhamiidae (4), Eudrilidae (1), Glossoscolecidae (2), Ocnerodrilidae (1), Lumbricidae (2), Megascolecidae (1) and Rhinodrilidae (12). Native species in Goiás (6) were found in areas with lesser disturbance, such as in native forest and flooded areas/river banks, a phenomenon also observed in the Federal District. On the other hand, the exotic and peregrine species found in Goiás (6) and in the Federal District (9) dominated in disturbed sites, such as perennial crops, agroforestry, annual crops, urban areas, secondary forests, pastures and agropastoral systems, among others. Given the many new species found and the extension of Goiás and the Federal District, further effort is needed to adequately characterize the earthworm fauna of the region, from where many other species are expected.

Earthworms from natural and managed ecosystems in Southern Bahia, Brazil.

The earthworms (Crassiclitellata) of the Northern Atlantic Forest region are poorly known, and many new species are expected to be found in the region. Hence, quantitative and qualitative samples were taken in the Atlantic Forest region of southern Bahia State, Brazil, at eight sites to assess species presence and abundance in different land uses (forests, pastures, plantations). Earthworms were also qualitatively collected at an additional eight sites. Only one to two species per site were found in quantitative samples, while qualitative samples generally resulted in higher species recoveries, with highest richness observed at the native Atlantic Forest of Veracel in Porto Seguro. Pontoscolex corethrurus (Müller, 1857) was the dominant species at all sites and in most land use systems, probably favored by human migration and agricultural activities; it was only absent in one primary forest site where native Ocnerodrilidae species predominated. In total at least 14 species were found of which eight were new, belonging to the genus Rhinodrilus and three new genera in the Ocnerodrilidae family (Pauqueba, Parabauba and Diplomoela). Contrary to sites in Southern and Southeastern Brazil, where many native species belong to the Glossoscolecidae family, in southern Bahia, Ocnerodrilidae species tend to be more prevalent, occupying various habitats. More intensive sampling of these habitats, including surface litter, in and under fallen logs and dead tree trunks, under rocks, in bromeliad leaf tanks and deeper soil layers is essential in order to properly characterize earthworm communities in Brazilian Atlantic Forests.

Earthworm richness in no-tillage farming systems and riparian forests in Southern and Southeastern Brazil.

No-tillage (NT) is a soil conservation management practice that can sustain important earthworm populations due the maintenance of soil cover and absence of soil disturbance. Sites with NT can also support native earthworm species, but few studies have identified the earthworms collected under NT. Therefore, the present study evaluated earthworm diversity in 14 sites under NT and seven with riparian forest (RF) in Atlantic Forest located in Rolândia, Cambé, Toledo (Paraná), Coxilha, Sarandi (Rio Grande do Sul) and Itaí (São Paulo). The earthworms were collected by handsorting using quantitative and qualitative methods. The 1471 individuals collected were classified into 23 species belonging to five families: Glossoscolex sp.71, sp.72, sp.73 and sp.74, Fimoscolex sp.23 sp.24 and sp.25 (Glossoscolecidae); Pontoscolex corethrurus, Urobenus brasiliensis (Rhinodrilidae); Haplodrilus sp.1 and sp.2, Ocnerodrilidae sp.1, sp.15, sp.16, sp.48, sp.49 and sp.50 (Ocnerodrilidae); Amynthas gracilis, Metaphire californica (Megascolecidae); Dichogaster affinis, D. gracilis, D. bolaui and D. saliens (Benhamiidae). Of the total, 15 were native and eight were exotic species. In general NT sites had higher species richness than the forest sites (except at Itaí), mainly due to the invasion of NT fields by exotic species, particularly Ocnerodrilidae sp.1 and Dichogaster spp. Six of the seven forests had native species, but only four NT fields had native earthworms, and these were generally found in low abundance.

Urban green areas as earthworm species maintainers in Curitiba, Paraná, Brazil.

Urban green areas can have a high impact on soil fauna due the environmental changes caused by human activities. This work aimed to assess earthworm populations in urban sites in the city of Curitiba, Paraná, Brazil. Earthworms were sampled in two urban sites: the Campus Ecoville of the Universidade Positivo and the Casa Verde space and in two land use systems (Grass Lawn and Native Vegetation), in the summer of 2018 and 2019 and winter of 2019. A total of 1052 individuals were found, belonging to five families and 12 species were identified, of which five are native: Glossoscolex sp.55, Fimoscolex sp.36, Fimoscolex sp.37 (Glossoscolecidae), Andiorrhinus duseni (Rhinodrilidae) and Ocnerodrilidae sp.43 (Ocnerodrilidae) and seven are exotic species: Amynthas corticis, Amynthas morrisi, Metaphire californica, Metaphire schmardae (Megascolecidae), Dendrodrilus rubidus (Lumbricidae) and Pontoscolex corethrurus (Rhinodrilidae). Of the five native species found, four are new species and will be described in the future and the specie A. duseni belongs to the group known as giant earthworms (minhocuçu) with specimens larger than 30cm. Despite the predominance of exotic species (n=932) compared to native species (n=114), the presence of new species may indicate that the managed environments can preserve native species. Moreover, the difference in the total number (native vs. exotic) can be attributed to the ability of the exotic species to survive human disturbances.

Earthworms in various agricultural and forest ecosystems in São Carlos-SP, Brazil.

Integrated agricultural systems have been greatly expanding in Brazil and currently cover over 30 million hectares. Although these land use systems help soil and environmental quality, little is known of their impacts on earthworm communities. In the present study we evaluated earthworm abundance, biomass and species richness in various integrated and conventional agricultural production systems (pasture, crops), as well as native forest and Eucalyptus plantations. The research was carried out at Fazenda Canchim (Embrapa Livestock Southeast) and at the neighboring campus of the University de São Carlos (UFSCar), in São Carlos municipality in São Paulo state, Brazil. Two earthworm sampling methods, i.e., quantitative (25 x 25 x 20 cm deep monoliths) and qualitative (holes of similar size and niche sampling), were used in three integrated production systems, three conventional systems and two forest systems, totaling 232 quantitative samples and over 160 qualitative samples. Earthworms were counted and identified using available keys. Eight earthworm species of five families (Rhinodrilidae, Ocnerodrilidae, Megascolecidae, Benhamiidae and Glossoscolecidae) were found, with most of the 2,145 individuals being exotic or peregrine species, particularly Pontoscolex corethrurus (88% of total) and various Dichogaster spp. (8% of total). Two native species were encountered in low abundance (55 individuals), both of which are new to science (Fimoscolex n.sp.7 and Glossoscolex n.sp.9) and must still be formally described. The new species were found in the agricultural systems, but not in the native forest and the Eucalyptus plantation, where P. corethrurus and Megascolecids predominated. One unidentified Ocnerodrilid sp. was found only in the intensive pasture. Species richness was highest in the intensive pasture (7 spp.), followed by the agrosilvopastoral and agropastoral systems, highlighting the importance of integrated and pastoral systems in preserving earthworm richness and native species.

Earthworm communities in long-term no-tillage systems and secondary forest fragments in Paraná, Southern Brazil.

The area destined for agricultural production in Paraná state in Brazil is ~6 million hectares, of which 79% are under no-tillage systems (NTS) that can positively affect earthworm populations. Furthermore, earthworm abundance and richness can be valuable soil quality. This study assessed earthworm communities in long-term no-tillage sites (NTS) and nearby secondary Atlantic Forest (SF) fragments. Sampling was performed in June 2018 and May 2019 using the quantitative Tropical Soil Biology and Fertility handsorting method (ISO-TSBF), complemented by qualitative sampling in three municipalities: Faxinal, Mauá da Serra and Palmeira, in NTS and SF. Eleven earthworm species, belonging to five families (Benhamiidae, Glossoscolecidae, Megascolecidae, Ocnerodrilidae, and Rhinodrilidae) were found along with seven native species (Glossoscolex sp.22, Glossoscolex sp.23, Fimoscolex sp.21, Fimoscolex sp.24, Fimoscolex sp.42, Andiorrhinus duseni and Urobenus brasiliensis) and four exotic or cosmopolitan species (Dichogaster gracilis, Amynthas gracilis, Metaphire californica and Pontoscolex corethrurus). The cosmopolitan P. corethrurus dominated Faxinal and Mauá da Serra, while in Palmeira Fimoscolex and Glossoscolex were the most abundant. Six species belonging to Glossoscolex and Fimoscolex were new to science and must be described. Overall, 239 individuals were found. In 2018 126 individuals were found (76 in NTS and 50 in SF) and in 2019, only 112 individuals were found (45 in NTS and 67 in SF). The highest earthworm abundance was in Faxinal (123 individuals), with 76 individuals in NTS and 47 in SF. In Mauá da Serra the same pattern was observed (SF>NTS), while in Palmeira in overall, fewer individuals (38) were collected (24 in NTS and 14 in SF). The NTS at Faxinal and SF Mauá da Serra in 2019 had only/more exotic/cosmopolitan species, while at the other dates and sites >50% of the specimens sampled were native species. Overall, forests had more native species than exotics: in 2018, natives represented > 75% of all specimens, but in 2019 both Faxinal and Mauá da Serra had more exotic species (> 65%), while at Palmeira, they represented 50% of the individuals. Earthworm total biomass for forest sites was higher in Faxinal (3.2 g) and NTS in Mauá da Serra (1.7 g) in 2019. Overall, the total biomass was higher in SF sites than NTS. Using a classification available for earthworm populations in no-tillage systems, all three sites were considered to have poor quality in terms of abundance (ind m-2), while for species richness, they were considered to have moderate (Faxinal and Mauá da Serra) and good quality (Palmeira).

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.

Global data on earthworm abundance, biomass, diversity and corresponding environmental properties.

Earthworms are an important soil taxon as ecosystem engineers, providing a variety of crucial ecosystem functions and services. Little is known about their diversity and distribution at large spatial scales, despite the availability of considerable amounts of local-scale data. Earthworm diversity data, obtained from the primary literature or provided directly by authors, were collated with information on site locations, including coordinates, habitat cover, and soil properties. Datasets were required, at a minimum, to include abundance or biomass of earthworms at a site. Where possible, site-level species lists were included, as well as the abundance and biomass of individual species and ecological groups. This global dataset contains 10,840 sites, with 184 species, from 60 countries and all continents except Antarctica. The data were obtained from 182 published articles, published between 1973 and 2017, and 17 unpublished datasets. Amalgamating data into a single global database will assist researchers in investigating and answering a wide variety of pressing questions, for example, jointly assessing aboveground and belowground biodiversity distributions and drivers of biodiversity change.

Towards an integrative understanding of soil biodiversity.

Soil is one of the most biodiverse terrestrial habitats. Yet, we lack an integrative conceptual framework for understanding the patterns and mechanisms driving soil biodiversity. One of the underlying reasons for our poor understanding of soil biodiversity patterns relates to whether key biodiversity theories (historically developed for aboveground and aquatic organisms) are applicable to patterns of soil biodiversity. Here, we present a systematic literature review to investigate whether and how key biodiversity theories (species-energy relationship, theory of island biogeography, metacommunity theory, niche theory and neutral theory) can explain observed patterns of soil biodiversity. We then discuss two spatial compartments nested within soil at which biodiversity theories can be applied to acknowledge the scale-dependent nature of soil biodiversity.

A neotype for Pontoscolex corethrurus (Müller, 1857) (Clitellata).

Following many decades of work on the taxonomy, biology and ecology of the globally-distributed tropical earthworm Pontoscolex corethrurus (Müller, 1857), morphological and molecular data have shown that the stability and effectiveness of nomenclature depends on the designation of a neotype from the type locality. We do that, with all the required justifications, and provide sufficient information to permit the correct identification of this species.

Global distribution of earthworm diversity.

Soil organisms, including earthworms, are a key component of terrestrial ecosystems. However, little is known about their diversity, their distribution, and the threats affecting them. We compiled a global dataset of sampled earthworm communities from 6928 sites in 57 countries as a basis for predicting patterns in earthworm diversity, abundance, and biomass. We found that local species richness and abundance typically peaked at higher latitudes, displaying patterns opposite to those observed in aboveground organisms. However, high species dissimilarity across tropical locations may cause diversity across the entirety of the tropics to be higher than elsewhere. Climate variables were found to be more important in shaping earthworm communities than soil properties or habitat cover. These findings suggest that climate change may have serious implications for earthworm communities and for the functions they provide.

New species-group taxa of Glossoscolex (Clitellata: Glossoscolecidae) from Rio Grande do Sul, Brazil.

Five new species-group taxa of Clitellata of the genus Glossoscolex from Rio Grande do Sul State, Brazil are described in this paper: Glossoscolex (Glossoscolex) riograndensis n. sp. has three subspecies, G. (G.) riograndensis riograndensis, G. (G.) riograndensis pollulus n. ssp., G. (G.) riograndensis nativus n. ssp. The two other new species are named G. (G.) pastivus n. sp., and G. (G.) pampas n. sp. All new species are part of the truncatus species group within the subgenus, characterized by the presence of male pores in segment xvii. A single unnamed specimen, also described here, is deemed to belong to a sixth new species-group taxon of the truncatus group. A tabular character comparison of the new taxa and known and morphologically similar species is given. Information on the habitat, such as vegetation cover and soil characteristics, is given as well. G. (G.) r. riograndensis and G. (G.) r. pollulus had an unusual storage of sperm in the nephridia. Histological sections were performed to verify it.

Earthworm species in various land use systems in the Campos Gerais region of Lapa, Paraná, Brazil.

The Campos Gerais region of Paraná are on an ancient plateau of sandstone origin and are covered with a diverse vegetation including mainly grasslands and various types of Atlantic Forest (particularly Araucaria forest). The region represents an important natural capital for biodiversity conservation as well as for agricultural and forestry production. However, little is known of the species richness and diversity of soil macroinvertebrates in this region. In the present study we evaluated earthworm species occurrence and richness in five land use systems (LUS) in the southern part of the Campos Gerais in Lapa county. Earthworms were handsorted from up to 18 soil monoliths on five occasions over three years (Feb. 2014, Feb., Mar., Nov. 2015, Jul. 2016) in the following LUS: old native forest, native grassland, young regenerating forest and grass lawn in the Uru Reserve and annual crop fields (soybean) in neighboring private farms (not all systems were sampled on all occasions). Nine earthworm species belonging to four families and five genera were found, of which six were native and three exotic species (Dichogaster gracilis, Amynthas gracilis, A. corticis). Of the native species, Urobenus brasiliensis and Andiorrhinus duseni (a large bodied-worm) are already well known from S and SE Brazil, while the remaining four were new species that require further description (Fimoscolex n.sp.1 and n.sp.2, Glossoscolex n.sp.1 and n.sp.2). In general, more species were found in February (summer) than March and November. The cropping system (soybean) had the lowest abundance and species richness in relation to other sites, although in the young and old forests no earthworms were found on some sample dates. Given the several new species found in this small reserve, and the relatively few sites studied thus far in the Campos Gerais, further efforts are needed to adequately characterize the earthworm fauna of the region, from which many other species are expected.