Cattle Pastures Research Articles

Isotopically constrained soil carbon and nitrogen budgets in a soybean field chronosequence in the Brazilian Amazon region

AbstractThe impacts of large‐scale conversion of cattle pastures to cropland on soil carbon (C) and nitrogen (N) stocks are poorly understood in the Amazon region. The objective of this research was to determine whether soybean cultivation on a previously deforested and pastured soil has changed C and N stocks and dynamics. We sampled a chronosequence of soybean fields in 2009 and again in 2013. We hypothesized that detecting statistically significant changes in total soil C and N stocks would be difficult but that fluxes of C and N through the soil would be sufficiently large to significantly decrease the stable isotope ratios of soil organic matter. We observed statistically significant decreases in the 13C and 15N enrichments and C:N ratio. When combined with estimates of crop biomass production, harvest yield, and biological nitrogen fixation, these measurements provided sufficient constraints for C and N budgets to infer modest rates of net change in soil N (+15 to +27 kg N ha−1 yr−1) and soil C (−0.15 to −0.30 Mg C ha−1 yr−1) in the top 10 cm of soil. These results indicate that this intensive soybean cropping system is having minimal impacts on N loss to the environment but likely is a small net source of C to the atmosphere.

THE SOIL AND VEGETATIVE COMPONENT OF THE NATURAL ENVIRONMENT IN THE PROBLEM OF THE KUIALNYK LIMAN DESICCATION

Purpose. The aim of the article assessment of the agroecological status and hydrological role of soils as well as the soils and vegetation cover (SVC) of the left bank of the Kuialnyk liman (Kl) and the Kuialnyk-Khadzhybei inter-liman lands.Data & Methods. In the article used sources which contained characteristics of the natural and economic conditions of the Kl basin, as well as its SVC and hydrology, starting from the second half of the XIX century. Also used materials of the 2015 field research on contemporary soil formation processes, as well as on the chemical composition and properties of the soils of the focus area. The methodological solidity of the latter research is ensured by the field expeditions and laboratory analysis.Results. The article confirms that the natural and ecological environment of the Kl basin was affected and continues to be affected by the strong anthropogenic influence which resides in the high degree of the territory under cultivation (up to 75%), cattle pasturing on the slopes of liman and nearby rivers, deforestation, and frequent forest fires in the summer and autumn months. Under the conditions of anthropogenic pressure, global warming, and erosion, the last decades have witnessed intensification of the processes of dehumification, structural destruction, and compaction of soils, which lose their moisture capacity and water permeability; this results in the declining role of the SVC in the formation of the hydrological regime of the territory. To improve the environmental and ecological conditions of soils, lands, and the SVC of the Kl basin, as well as to increase their role in the formation of the hydrological regime of the territory, it is required to decrease the degree of the cultivated watershed lands with particular attention given to the near-watershed slopes, increase the density of the vegetation, shrub, and wood cover, and – finally – perform periodical thinning of the black soils under cultivation. In the structure of crop rotation it is appropriate to increase the area under the broadcast seeded crops and sorghum, as well as to increase the share of the perennial herbs to 25-35%.

No touching, please

Disease Ecology![Figure][1] European badgers avoid cattle in pastures, reducing bovine tuberculosis transmission routes. PHOTO: ROBERTHARDING/ALAMY STOCK PHOTO European badgers have been blamed for the transmission of bovine tuberculosis in the United Kingdom and, despite much evidence to the contrary, have endured regular and repeated culling efforts based on the assumption that their lethal removal decreases the spread of the disease. Woodroffe et al. used GPS and contact collars to record the degree to which badgers and cattle actually come into contact. Despite finding that badgers prefer to spend their time in pastures, they recorded no direct contact between the two species, with badgers tending to say at least 50 m from cattle. Thus, any transmission between these two species seems to be environmentally mediated, a result that could be instrumental in targeting nonlethal ways to prevent the spread of the disease. Ecol. Lett. 10.1111/ele.12654 (2016). [1]: pending:yes

Predicting bull mounting behavior using classification algorithms

Data from multiple-sire beef cattle pastures have shown variability exists among the number of calves sired per bull. The reason(s) for the variability is unknown. Successful investigation of possible reasons requires accurate recording and evaluation of bull behavior. The purpose of this study was to assess the accuracy of classifying bull mounting events in a multiple-sire pasture using accelerometer data and classification algorithms.

Livestock Performance in Warm‐Climate Silvopastures Using Tree Legumes

Tree legumes are a viable option to increase ecosystem services provided by warm‐climate grasslands. Benefits of using tree legumes in silvopasture systems (SPS) include the provision of shade for livestock, biological N2 fixation, and C sequestration. This study assessed cattle performance and pasture characteristics in signalgrass (Brachiaria decumbens Stapf.) pastures in monoculture or in SPS. The following treatments were assessed: (i) signalgrass/sabiá (Mimosa caesalpiniifolia Benth.), (ii) signalgrass/gliricidia [Gliricidia sepium (Jacq.) Kunth ex Walp.], and (iii) signalgrass monoculture. Crossbred steers were managed under continuous stocking and variable stocking rates. Response variables included herbage mass, herbage allowance, stocking rate, average daily gain (ADG), gain per area (GPA), in vitro dry matter digestibility (IVDMD), and crude protein (CP). Total signalgrass herbage mass in monoculture (5091 kg DM ha−1) was greater (P ≤ 0.05) compared with SPS (3964 kg DM ha−1). Green signalgrass herbage mass, however, was greater (P ≤ 0.05) for SPS (2237 kg DM ha−1) compared with monoculture (1934 kg DM ha−1). Herbage allowance, IVDMD, CP, stocking rate, ADG, and GPA did not differ among treatments, with average values of 2.9 kg−1 green herbage mass (DM) kg−1 live weight; 633 g kg−1, 55 g kg−1, 1.9 animal units (AU) ha−1 (1 AU = 450 kg live weight); 0.57 kg−1 AU−1 d−1; and 30 kg ha−1 28 d−1, respectively. During the establishment phase (3 yr), SPS with tree legumes can produce as much livestock gain as signalgrass in monoculture, providing other ecosystem services and marketable products, increasing land use efficiency.Core Ideas Livestock production was similar in silvopasture systems and signalgrass monoculture. Silvopasture systems provided additional ecosystem services compared with grass monoculture. The use of tree legumes adds biologically fixed N2 and provide other ecosystem services. Trees compete with herbaceous vegetation and might reduce livestock production in the long term.

Model testing for nitrous oxide (N2O) fluxes from Amazonian cattle pastures

Process-oriented models have become important tools in terms of quantification of environmental changes, for filling measurement gaps, and building of future scenarios. It is especially important to couple model application directly with measurements for remote areas, such as Southern Amazonia, where direct measurements are difficult to perform continuously throughout the year. Processes and resulting matter fluxes may show combinations of steady and sudden reactions to external changes. The potent greenhouse gas nitrous oxide (N2O) is known for its sensitivity to e.g. precipitation events, resulting in intense but short-term peak events (hot moments). These peaks have to be captured for sound balancing. However, prediction of the effect of rainfall events on N2O peaks is not trivial, even for areas under distinct wet and dry seasons. In this study, we used process-oriented models in both a pre-and post-measurement manner in order to (a) determine important periods for N2O-N emissions under Amazonian conditions and (b) calibrate the models to Brazilian pastures based on measured data of environment conditions (soil moisture and Corg) and measured N2O-N fluxes. During the measurement period (early wet season), observed emissions from three cattle pastures did not react to precipitation events, as proposed by the models. Here both process understanding and models have to be improved by long-term data in high resolution in order to prove or disprove a lacking of N2O-N peaks. We strongly recommend the application of models as planning tools for field campaigns, but we still suggest model combinations and simultaneous usage.

Badgers prefer cattle pasture but avoid cattle: implications for bovine tuberculosis control.

Effective management of infectious disease relies upon understanding mechanisms of pathogen transmission. In particular, while models of disease dynamics usually assume transmission through direct contact, transmission through environmental contamination can cause different dynamics. We used Global Positioning System (GPS) collars and proximity-sensing contact-collars to explore opportunities for transmission of Mycobacterium bovis [causal agent of bovine tuberculosis] between cattle and badgers (Meles meles). Cattle pasture was badgers' most preferred habitat. Nevertheless, although collared cattle spent 2914 collar-nights in the home ranges of contact-collared badgers, and 5380 collar-nights in the home ranges of GPS-collared badgers, we detected no direct contacts between the two species. Simultaneous GPS-tracking revealed that badgers preferred land >50m from cattle. Very infrequent direct contact indicates that badger-to-cattle and cattle-to-badger M.bovis transmission may typically occur through contamination of the two species' shared environment. This information should help to inform tuberculosis control by guiding both modelling and farm management.

Tamaño poblacional y patrón de conducta de Grus canadensis nesiotes (Aves: Gruidae) en dos localidades de Cuba

The availability of information on species abundance in the Neotropic is insufficient, and this prevents the execution of precise analysis and the definition of adequate conservation strategies for endemic and threatened species. This study aimed to analyze the population size of the endemic and threatened subspecies Grus canadensis nesiotes. For this, a simultaneous census was undertaken in 24 count stations in Isla de la Juventud (IJ) and 32 stations in Ciego de Ávila (CA), Cuba, during two consecutive days between 2008 and 2010. Abundance and behavior pattern (instantaneous method) were analyzed by habitat type, to help understand how cranes modify their behavioral pattern when the natural habitat is changed. Flocks in IJ had three individuals, and between 1.9 ± 1.5 and 2.8 ± 1.5 in CA. Population size in IJ was 164 individuals, and in CA of 137, 141 and 168 individuals for the 2008-2010 period, respectively. The counting efficacy was high (IJ: 91 %; CA: 81-87 %) and the numerical concordance was intermediate (IJ: 45.4 %; CA: 72 %). When comparing the habitat type, the abundance was higher in natural savannahs (83), followed by coastal flats (59), pines (23) and cattle pastures (7) in IJ; while in CA, marsh grasslands hosted the greatest abundance for the three years period (130; 120; 112), followed by grassland with palms (2; 17; 51) and cattle pastures (5; 4; 5). The cranes were fed more in cattle pastures and were more alert in natural savannas and marsh grasslands. The frequency of feeding and alert behaviors was different from the natural savannah/coastal flats and natural savannah/cattle pastures combinations in IJ. For CA, differences were found between marsh grasslands and marsh grasslands with palms. The population size increased by management strategies adopted in CA; nevertheless, might be affected by habitat loss associated with invasive alien plants in IJ. We propose the maintenance of prescribed fire in marsh grasslands under protection regime, as a strategy for long-term management to contribute with population growth.

Mobility and toxicity of heavy metal(loid)s arising from contaminated wood ash application to a pasture grassland soil

Heavy metal(loid) rich ash (≤10,000 mg kg−1 total As, Cr, Cu and Zn) originating from the combustion of contaminated wood was subjected to several experimental procedures involving its incorporation into an upland pasture soil. Ash was added to soil that had been prior amended with local cattle manure, replicating practices employed at the farm scale. Metal(loid) concentrations were measured in soil pore water and ryegrass grown on soil/manure plus ash mixtures (0.1–3.0% vol. ash) in a pot experiment; toxicity evaluation was performed on the same pore water samples by means of a bacterial luminescence biosensor assay. Thereafter a sequential extraction procedure was carried out on selected soil, manure and ash mixtures to elucidate the geochemical association of ash derived metal(loid)s with soil constituents. Predictive modelling was applied to selected data from the pot experiment to determine the risk of transfer of As to meat and milk products in cattle grazing pasture amended with ash.The inclusion of manure to soils receiving ash reduced phyto-toxicity and increased ryegrass biomass yields, compared to soil with ash, but without manure. Elevated As and Cu concentrations in pore water and ryegrass tissue resulting from ash additions were reduced furthest by the inclusion of manure due to an increase in their geochemical association with organic matter. Zinc was the only measured metal(loid) to remain uniformly soluble and bioavailable regardless of the addition of ash and manure. Risk modelling on pot experimental data highlighted that an ash addition of >1% (vol.) to this pasture soil could result in As concentrations in milk and meat products exceeding acceptable limits.The results of this study therefore suggest that even singular low doses of ash applied to soil increase the risk of leaching of metal(loid)s and intensify the risk of As transfer in the food chain.

PENGENDALIAN THELAZIASIS PADA TERNAK SAPI DENGAN MENGGUNAKAN REBUSAN DAUN SIRIH DI DESA OEFAFI

 Oefafi village located in East Kupang district, there are two groups of animals: Tun Feu consisting of 5 people and Aim HIF Nao consisted of 6 people. Each member has a tail with 3-5 cattle pasture ± 5 hectares. Endemic disease that infects cattle: Septicemia epizootika and Thelaziasis. Supporting factors: the limited knowledge of farmers on the management of animal health, such as vaccination, sanitation cage. Rotational grazing, cattle feces processing into organic fertilizer and the eradication of the flies as mechanical vectors Thelaziasis not been implemented. Target outcomes: skilled workers formed 50% of the total number of members, in the areas of: vaccination, manufacture neem extract, betel leaf decoction manufacture, processing feces. The presence of a pilot cage every group. Specific target, the target group is expected to be an example for cattle farmers in the province of NTT. Based on observations and information, since the vaccination SE until December 2015 is clinically undiscovered Septicemia epizootika and generated 7 vaccinators. Fly population can be controlled as has been done cage sanitation, rotation grazing, available ± 11 liter extract of neem production (exterminating flies) and the resulting 5 person skilled workers. Thelaziasis incidence decreases gradually because there is a skilled labor 9 in control using betel leaf decoction. There Demplot cage, fertilizer bokasi each group of skilled labor and 4 of the planned target 5 people.        Keywords : Vaccination , Herbs, Bali Cattle

Dung removal by dung beetles (Coleoptera: Scarabaeidae) and macrocyclic lactone use on cattle ranches of Yucatan, Mexico.

The expanded use of macrocyclic lactones (ML) to treat endo- and ectoparasites in cattle in tropical regions, can reduce dung beetle populations, and thus interrupt the dung removal process in cattle pasture ecosystems. During the reproductive period (the rainy season) of two functional groups of dung beetles (paracoprid and telocoprid Scarabaeinae), we compared dung removal amount in ranches where ML are and are not used in Yucatan, Mexico, through exclusion traps baited with 500 g of ML-free cow dung. On each ranch, two transects (separated by 500 m) with six traps each, were set up for 24 hours. After this time, all the dung remnants in each trap were obtained and weighed in order to record the dung removal. Results showed that dung removal amounts were similar in ranches with and without ML use. Dung beetles removed 40.1 % of all cow dung weighed. Paracoprids removed 87.46 % and telocoprids 12.54 % of all the dung that was removed. Our results indicated that the ecological function of dung beetles in the pastures studied, does not seem to be affected by the ML use, and that paracoprid species removed most of the dung. For both types of ranch, further studies that take into account the population dynamics and movement of the most important dung beetle species in the region are required, coupled with laboratory studies evaluating the effect of ML on their reproductive success. This could give some light on the effect of ML on the ecological function of this important insect group in the sustainability of cattle production systems.

Agricultural land-use diversity and forest regeneration potential in human- modified tropical landscapes

A major challenge in tropical human-modified landscapes (HMLs) is meeting the ever-growing demand for agricultural products while conserving biodiversity and ecosystem services provided by forest ecosystems. Within this challenge, a major issue is the understanding of the forest potential to naturally regenerate in abandoned agricultural fields. To assess such potential, it is necessary to know the diversity of agricultural land uses in the landscape, quantify the ecological disturbance inflicted by such uses, and evaluate forest regeneration as a function of disturbance both at the field and landscape levels. Our previous work has shown that in abandoned fields the abundance and species diversity of regenerating rain forest trees decline as disturbance level increases. Here we aimed to achieve the following: 1) to quantify the diversity of agricultural land uses in HMLs; 2) to assess ecological disturbance regimes caused by different agricultural land uses, at the field and landscape scales; and 3) to identify groups of agricultural land uses with contrasting effects for forest regeneration at the landscape level. We approach these issues by using a case study of HMLs in a southeastern region of Mexico, which are representative of landscapes in the agricultural frontier in the Neotropics. We interviewed 68 landowners to gather information on agricultural land uses and management of 156 fields. Based on this information, we quantified an ecological disturbance regime associated with each field considering the following: field size (in hectares), duration of agricultural use (in years), and land-use disturbance severity (i.e. frequency or magnitude of fire, agrochemicals, machinery, grazing or removal of tree cover). By integrating disturbance inflicted by different land uses and the proportion of the landscape covered by each land use, we constructed a landscape ecological disturbance index. Finally, by using this index and data gathered from nine landscapes (3×3km each), we tested the hypothesis that structural attributes (abundance, biomass, and species diversity of trees) of regenerating forests decrease as agriculture disturbances increase in the landscape. There was a high inequality in the proportion of land allocated to the 13 recorded agricultural land uses, with cattle pastures representing ca. 90% of total agricultural land. There was a wide disturbance gradient, ranging from land uses with high (e.g. cattle pastures) to low disturbance (e.g. coffee and cocoa plantations). Three major groups of land uses with contrasting disturbance regimes were detected: 1) agroforestry systems, characterized by small size, low to intermediate duration, and low disturbance severity; 2) monocultures, typically small size, long duration, and medium to high disturbance severity; and 3) extensive farming, large size, short to intermediate duration, and high disturbance severity. Biomass and species diversity of regenerating forests consistently reduced with increasing levels of agriculture disturbance in the landscape. We conclude that positive balances between biodiversity conservation and agricultural production in HMLs will depend on establishing agricultural land uses that inflict low disturbance regimes (such as agroforestry systems) embedded in a matrix of old-growth forest and long-lasting second-growth forests. Our results may inform farmers, policy makers and land managers about HMLs where agricultural production and conservation of biodiversity and ecosystem services can be conciliated.

Dung beetle (Coleoptera: Scarabaeinae) persistence in Amazonian forest fragments and adjacent pastures: biogeographic implications for alpha and beta diversity

The aim of this study is to analyze the effects of habitat loss and forest replacement by cattle pasture on the alpha and beta diversity, abundance, biomass and species composition of dung beetles with different dispersal ability. Dung beetles were captured in 19 forest fragments and neighbouring pastures. Forest fragment area ranged from 3.7 to 4825 ha and in this study were grouped into four categories: small, medium, large and control forest. A total of 35,048 dung beetles representing 101 species were collected. Forest fragments had the highest richness with 81 species, followed by pasture with 58 species. Replacement of forest by pasture reduced species richness; however, due to the proximity and connectivity of these areas with Cerrado patches, pastures also had high species richness, but species composition was independent of adjacent fragments. Small fragments had lower abundance and species richness than our other habitat categories, even pastures. Our results highlight that proximity and connectivity with Cerrado areas influenced the patterns of alpha and beta diversity of dung beetles in fragments and pastures. We highlight that the ability to cross the pasture matrix is a strong adaptive trait for species living in human-modified landscapes. Consequently, species with these abilities are less susceptible to the effects of forest fragmentation and local extinction. Our results reinforce the importance of considering the biogeographic location and distribution pattern of species in forest fragmentation studies.

Transition from traditional to modern forest management shaped the spatial extent of cattle pasturing in Białowieża Primeval Forest in the nineteenth and twentieth centuries.

Pasturing of livestock in forests has had profound consequences for Europe’s landscapes. In Białowieża Primeval Forest (BPF), cattle pasturing was a part of traditional forest use that ceased only in the second half of the twentieth century. We collected information on the institutional changes governing forest cattle pasturing and the changes in spatial extent of cattle presence in BPF in last two centuries and information on cattle numbers and their impact on forest regeneration. The spatial extent of cattle pasturing was highly variable, with the distribution of grazing areas frequently changing. Forest near villages (constituting less than 10 % of the area) was most often used for cattle grazing during continued longer time periods. Historical data showed that cattle have had a clear impact on forest regeneration. However, the frequent changes that occurred in the extent of cattle grazing indicate that their impact occurred locally, was smaller in other less intensively used areas, and in the forest as a whole.

A New Species ofPristimantis(Amphibia: Strabomantidae) from the Cloud Forest of Sangay National Park, Ecuador

Abstract We describe Pristimantis tinguichaca sp. nov., a member of the Pristimantis unistrigatus species group, from the cloud forests of Sangay National Park located on the eastern slopes of the Andes in southeastern Ecuador. The new species was collected in cloud forests and cattle pastures at 2,750–2,830 m elevation. It differs from other members of the P. unistrigatus group by the presence of small conical tubercles on the upper eyelids and heels, as well as by its reddish-colored iris. It is further distinguished by its small conical ulnar and tarsal tubercles. A single sharp metallic note composed of a modulated frequency characterizes the call. Stomach content analysis revealed a diet composed principally of beetles (51.7%).

Linking dominant Hawaiian tree species to understory development in recovering pastures via impacts on soils and litter

AbstractLarge areas of tropical forest have been cleared and planted with exotic grass species for use as cattle pasture. These often remain persistent grasslands after grazer removal, which is problematic for restoring native forest communities. It is often hoped that remnant and/or planted trees can jump‐start forest succession; however, there is little mechanistic information on how different canopy species affect community trajectories. To investigate this, I surveyed understory communities, exotic grass biomass, standing litter pools, and soil properties under two dominant canopy trees—Metrosideros polymorpha (‘ōhi‘a) and Acacia koa (koa)—in recovering Hawaiian forests. I then used structural equation models (SEMs) to elucidate direct and indirect effects of trees on native understory. Native understory communities developed under ‘ōhi‘a, which had larger standing litter pools, lower soil nitrogen, and lower exotic grass biomass than koa. This pattern was variable, potentially due to historical site differences and/or distance to intact forest. Koa, in contrast, showed little understory development. Instead, data suggest that increased soil nitrogen under koa leads to high grass biomass that stalls native recruitment. SEMs suggested that indirect effects of trees via litter and soils were as or more important than direct effects for determining native cover. It is suggested that diverse plantings which incorporate species that have high carbon to nitrogen ratios may help ameliorate the negative indirect effects of koa on natural understory regeneration.

Quantifying carbon and amphibian co‐benefits from secondary forest regeneration in the Tropical Andes

AbstractTropical land‐use change is a key driver of global declines in biodiversity and a major source of anthropogenic carbon emissions, yet there is a substantial shortfall in the funding available to tackle these issues. We urgently need mechanisms that can simultaneously tackle both biodiversity and carbon losses, with carbon‐based payments for ecosystem services (e.g. REDD+) of particular interest. A critical question is whether such payments offer strong carbon–biodiversity co‐benefits via the regrowth of forests on abandoned farmlands (carbon enhancements) for amphibians, which are the most threatened vertebrate group and reach the greatest richness of threatened and small‐ranged species in the montane tropics (>1000 m a.s.l.). Here, we study changes in amphibian communities across a typical Andean habitat transition from cattle pasture through secondary forests (8–35 years) to primary forest. As secondary forests mature, they recovered the abundance, species richness, species composition and Red‐listed (near threatened and threatened) species typically found in primary forest. By contrast, cattle pasture contained much lower richness of Red‐listed species and a different species composition compared to forest. We then reveal positive relationships between carbon stocks and amphibian species richness and abundance, Red‐listed species richness and abundance and the similarity of communities to primary forests, confirming significant carbon–biodiversity co‐benefits. Our results underscore the high conservation value of secondary forests and the strong potential for carbon and biodiversity recovery. Using carbon‐based funding initiatives to support the regrowth of forests on marginal agricultural land is therefore likely to conserve threatened biodiversity in the Tropical Andes.

Methane emissions from lactating and non-lactating dairy cows and growing cattle fed fresh pasture

Currently, a fixed methane (CH4) emission factor is used for calculating total CH4 emissions from cattle in the national greenhouse gas inventory of New Zealand, independent of diet composition, cattle class (beef, dairy) or physiological state (growing, lactating, non-lactating). The objectives of this study were to determine CH4 emissions from lactating and non-lactating dairy cows (118 dairy cows; 81 lactating and 37 non-lactating, over 10 periods) and growing dairy heifers (12 measured twice) fed 100% fresh pasture forage in respiration chambers, which in combination with the published data of beef cattle (36 measured twice) fed fresh pasture were used to determine the relationship between CH4 emissions and dry matter intake (DMI), feed quality, cattle class (dairy vs beef) and physiological state (lactating, non-lactating and growing). Before regression analysis the dominant variables (DMI, CH4) needed to be transformed using natural logarithms (Ln) to make the variation in CH4 emissions more homogeneous across the range of data (i.e. stabilise the variance). Over all periods, average DMI ranged from 3.1 to 13.9 kg/day, average CH4 production from 64 to 325 g/day and average CH4 yield from 21.4 to 26.5 g/kg DMI. The DMI alone explained 90.8% of the variation in CH4 production (LnCH4 (g/day) = 3.250 + 0.9487 × LnDMI). Regression was improved to a minor extent (<3%, with associated increased prediction error) by including physiological status, cattle class or dietary composition in the model, in addition to LnDMI, on LnCH4 production. In conclusion, DMI alone was the strongest predictor for CH4 emissions from cattle fed fresh pasture with minor but irrelevant improvements in the prediction when considering pasture quality, cattle class or physiological status.

Got Dung? Resource Selection by Dung Beetles in Neotropical Forest Fragments and Cattle Pastures.

Both the impact of habitat modification on the food preferences of species and its impact on ecosystem functioning are poorly understood. In this study, we analyzed food selection by dung beetles in 80 tropical forest fragments and their adjacent cattle pastures in the Los Tuxtlas Biosphere Reserve, Mexico. Ten pitfall traps were placed at each site, half baited with human dung and the other half with fish carrion. We assessed dung beetle food selection and classified any specialization in resource use quantitatively using a multinomial classification model. We collected 15,445 beetles belonging to 42 species, 8747 beetles (38 species) in forest fragments and 6698 beetles (29 species) in cattle pastures. Twenty-five species were present in both habitats. Of all the beetles captured, 76% were caught in dung traps (11,727 individuals) and 24% in carrion traps (3718 individuals). We found 21 species of dung specialists, 7 carrion specialists, 8 generalists, and 6 species too rare to classify. The bait most frequently selected by beetles in this study was dung in both forests and pastures. Specialists tended to remain specialists in both habitats, while generalists tended to change their selection of bait type depending on the habitat. In summary, our results show that replacing forests with cattle pastures modifies the patterns of resource selection by dung beetles and this could affect ecosystem functioning.

Patterns and processes of pasture to crop conversion in Brazil: Evidence from Mato Grosso State

The rate and location of cropland expansion onto cattle pastures in Brazil could affect global food security, climate change, and economic growth. We combined mapping, statistical modeling, and qualitative methods to investigate patterns and processes of pasture to crop conversion (P2C) in Mato Grosso State (MT), Brazil, a globally important center of agricultural production. P2C land constituted 49% of cropland expansion from 2000 to 2013. For a random sample of ̃250m pixels in MT, we estimated a regression model skilled at predicting P2C land in the rest of the state as a function of cattle ranching suitability, cropping suitability, and P2C conversion costs. Surprisingly, just 1/7 of pasture agronomically suitable for cultivation had undergone P2C. Hedonic regressions revealed that agronomic characteristics of land were associated with less than 20% of the variation in cropland suitability. Instead, the majority of the variation stemmed from a combination of proximity to agricultural infrastructure, characteristics of neighboring lands, and time fixed effects. The weak relationship between agronomic characteristics of land and P2C location suggests a less certain future for P2C than projections made with agronomic models. Consequentially, complications may arise for greenhouse gas mitigation policies in Brazil predicated on widespread expansion of cropland on pasture vs. natural areas. Our follow-up qualitative research shows that because P2C has often involved land rentals or sales, poorly functioning land institutions may have constrained P2C. Locally poor land quality, omitted from agronomic P2C predictions, can either catalyze or constrain P2C by limiting returns to ranching, farming, or both. Interventions to control rates and locations of P2C should take these insights into account.