Burrowing herbivores alter soil carbon and nitrogen dynamics in a semi-arid ecosystem, Argentina

Activities of burrowing herbivores, including movement of soil and litter and deposition of waste material, can alter the distribution of labile carbon (C) and nitrogen (N) in soil, affecting spatial patterning of nutrient dynamics in ecosystems where they are abundant. Their role in ecosystem processes in surface soil has been studied extensively, but effects of burrowing species on processes in subsurface soil remain poorly known. We investigated the effects of burrowing and grazing by plains vizcachas (Lagostomus maximus, Chinchilidae), a large colonial burrowing rodent native to South America, on the distribution and dynamics of C and N in soil of a semi-arid scrub ecosystem in central Argentina. In situ N mineralization (Nmin), potential Nmin and CO2 emissions were measured in surface soil (0-10 cm) and soil at the mean depth of burrows (65 ± 10 cm; mean ± 1 SD) in five colonial burrow systems and adjacent grazed and ungrazed zones. Decomposition and N dynamics of vizcacha feces on the soil surface and in burrow soil was assessed using litterbags. Total C and N in soil in burrows were 1.6 and 5.5 times greater than in undisturbed soil at similar depths, and similar to amounts in surface soil. Inorganic N, particularly NO3-, was consistently highest in burrows, intermediate in surface soil on burrow systems, and relatively low in all other zones. Despite high C and N content in all burrows, in situ net Nmin was highly variable in burrow soil. Feces decomposed and released N more rapidly in burrow soil. Laboratory incubations indicated that soil moisture limited Nmin under conditions that typically characterize burrow microclimate, and that rates increased dramatically at soil moisture contents \u3e25% field capacity, which likely occurs during pulsed rainfall events. Thus, the high and seasonally stable NO3- content in burrow soil likely originated from the accumulation of pulsed mineralization events over time. Burrowing and waste deposition by vizcachas produced “resource islands” at the landscape scale. At a measured density of 0.3 burrow systems per hectare, colonial burrow soil contained an amount of inorganic N equal to 21% and 30% of plant-available N in surface soil and subsurface soil, respectively, in an area that represented only 0.35% of the landscape. Our study indicates that burrowing and deposition of waste results in a highly active subsurface layer in which C and N dynamics function much like surface soil when soil moisture is not limiting

Folk Medicine Of Alter Do Chão, Pará, Brazil

A total of 192 medicinal plants were collected in Alter do Chão, Pará. Reliable informants living in the area described 394 medicinal preparations made from these plants and used for various sicknesses, as showm in Table 1. More than 52% of the medicinal species are collected from the native forests and many are also used as food sources.Foram coletadas em Alter do Chão, Pará, um total de 192 plantas de uso medicinal e que segundo informações de pessoas idôneas residentes na região são aplicadas para diversas doenças em 394 remédios, conforme mostra a Tab. 1. Mais de 52% das espécies medicinais são, porém, trazidas da mata pelos moradores e, muitas delas são também utilizadas na alimentação

QUANTIFYING DAMAGE POTENTIAL OF THREE RODENT SPECIES ON SUGARCANE

ABSTRACT Cotton rats, roof rats, and rice rats collectively inflict significant damage to sugarcane crops in the Everglades Agricultural Area; however, the relative damage inflicted by each species is unknown. A feeding trial experiment showed that some differences existed in the grams of sugarcane consumed per gram of body mass among species (male cotton rats: 0.39 ± 0.03g; female cotton rats: 0.34 ± 0.03g; male roof rats: 0.25 ± 0.04g; female roof rats: 0.26 ± 0.04g; male rice rats: 0.49 ± 0.08g; female rice rats: 0.20 ± 0.06g); however, because mean body mass differed for each species (male cotton rats: 120.5 ± 4.5g; female cotton rats: 111.4 ± 5.3g; male roof rats: 182.3 ± 6.9g; female roof rats: 157.1 ± 5.5g; male rice rats: 81.8 ± 3.8g; female rice rats: 58.1 ± 1.9g), the projected amount of sugarcane consumed will be approximately the same for all rodents. Therefore, overall abundance of rodents in sugarcane fields is an adequate predictor of rodent damage and knowledge of relative abundance of different species is not necessary. Periodic estimates of within field rodent abundance may be used to prioritize locations for rodent control. Integrated pest management that incorporates ecologically friendly methods, such as the elimination of rodent refugia habitat, may reduce the need for chemical rodenticides while maintaining or enhancing the effectiveness of rodent control

Data from: Response of pumas (Puma concolor) to migration of their primary prey in Patagonia

Large-scale ungulate migrations result in changes in prey availability for top predators and, as a consequence, can alter predator behavior. Migration may include entire populations of prey species, but often prey populations exhibit partial migration with some individuals remaining resident and others migrating. Interactions of migratory prey and predators have been documented in North America and some other parts of the world, but are poorly studied in South America. We examined the response of pumas (Puma concolor) to seasonal migration of guanacos (Lama guanicoe) in La Payunia Reserve in northern Patagonia Argentina, which is the site of the longest known ungulate migration in South America. More than 15,000 guanacos migrate seasonally in this landscape, and some guanacos also are resident year-round. We hypothesized that pumas would respond to the guanaco migration by consuming more alternative prey rather than migrating with guanacos because of the territoriality of pumas and availability of alternative prey throughout the year at this site. To determine whether pumas moved seasonally with the guanacos, we conducted camera trapping in the summer and winter range of guanacos across both seasons and estimated density of pumas with spatial mark–resight (SMR) models. Also, we analyzed puma scats to assess changes in prey consumption in response to guanaco migration. Density estimates of pumas did not change significantly in the winter and summer range of guanacos when guanacos migrated to and from these areas, indicating that pumas do not follow the migration of guanacos. Pumas also did not consume more alternative native prey or livestock when guanaco availability was lower, but rather fed primarily on guanacos and some alternative prey during all seasons. Alternative prey were most common in the diet during summer when guanacos also were abundant on the summer range. The response of pumas to the migration of guanacos differs from sites in the western North America where entire prey populations migrate and pumas migrate with their prey or switch to more abundant prey when their primary prey migrates

smr.pumas.traps.north

Location data for cameras in North gri

smr.pumas.captures.NOID

Camera trapping data for pumas that could not be individually identified. Occasion refers to the trapping occasion. SiteID lists the grid and camera number

smr.pumas.traps.south

Location of cameras in south gri