RESUMEN
Brazil is considered a megadiverse country, but the soil fauna is still very poorly known. The aim of this study was to report, for the first time, the abundance and genus composition of terrestrial enchytraeids (Enchytraeidae, Oligochaeta) in Savanna Tall Woodland (Cerradão) and a pasture in Cerrado Biome and in Upper Montane Atlantic Forest and a grassland in Atlantic Forest Biome. The enchytraeid density in Pasture and Cerradao was 2,036 and 18,844 (204 and 2,094, on average) individuals per square meter, respectively. At the Atlantic forest and Grassland, density was 9,666 and 12,242 individuals per square meter (1,075 and 1,471 on average). About genus composition for the studied areas, Enchytraeus and Hemienchytraeus were found in the four ecosystems evaluated, while Tupidrilus and Fridericia were found only in Cerradão and Atlantic Forest, respectively. Achaeta was absent in Upper Montane Atlantic Forest, but dominant in pasture, while Guaranidrilus was absent in Pasture, but predominant in the other ecosystems.
Asunto(s)
Oligoquetos , Animales , Brasil , Ecosistema , Bosques , Pradera , Humanos , SueloRESUMEN
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.
RESUMEN
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.
Asunto(s)
Oligoquetos , Animales , Agricultura , Biodiversidad , Brasil , BosquesRESUMEN
Wildfire is very common in Brazilian savannas, and its effects on water, soil and aquatic/soil organisms are poorly understood. In this study, we observed the effects of fire, especially of ashes, on surface soil and subsurface water in a typical Brazilian savanna (Cerrado sensu strictu) for one year. Soil analyses (pH, organic matter content, potential acidity, K, Ca, Mg and P) and subsurface water analyses (NO3-, PO43- Mg2+, Ca2+ and K+) were assessed. We evaluated the ecotoxicological effects of ashes on three different endpoints and species, in fish Danio rerio (embryonic development), aquatic snail Biomphalaria glabrata (reproduction) and a soil species Enchytraeus sp. (reproduction). We found a higher amount of exchangeable cations and organic matter content in short-term fire effects on soil, but the higher availability of nutrients did not affect the soil pH in field plots. The effects of ashes on soil and subsurface water did not persist for one-year post-fire, except for organic matter content in burned areas. No toxic effects were observed on hatching success and incidences of developmental abnormalities in D. rerio embryos. However, ash input had adverse effects on reproduction in snails and enchytraeids. We reported a statistically significant decrease in snail eggs exposed to the 50g.L-1 and 100g.L-1 of ashes after four weeks (p<0.05, Dunnett's test and Tukey test). Enchytraeus sp. reproduction was negatively influenced by the natural soil, which presents high acidity, and also when exposed directly to the ashes from burned area, suggesting that pH and other ash compounds may limit the growth of enchytraeids. More studies in burned areas are strongly encouraged, addressing the potential important routes of exposure to ashes in order to understand the impact of intense fires on soil and aquatic biota in tropical savannas.