Dung Types Research Articles

The association between pasture systems, dung removal and colonization by a local Australian temperate dung beetle assemblage

Abstract Herbivore dung quality (physical and chemical parameters) varies between animal species and animal diet which is influenced by seasonal fluctuations and farm management practices. Subsequently, this influences the reproductive success of dung beetles. In Australian pasture systems, how the introduced dung beetle assemblage interacts in the field with cattle dung derived from different resources is unknown. This study quantifies the colonization by dung beetles (abundance, species richness and evenness) and removal of cattle dung derived from three common temperate pasture systems (improved native, forage oat and rye/clover pasture, henceforth dung type) over 24 h for 12 months. From the three dung types, 13 species of dung beetle were captured. Abundance and species richness were influenced by month and transect, with weak evidence for differences between dung types influencing overall abundance: Onthophagus binodis (49.7%), Aphodius fimetarius (24.4%) and Labarrus lividus (17.1%) were the most abundant species. Dung removal (organic matter) was influenced by month and dung type, with more dung buried in improved native (23.9 g) and rye/clover (24.7 g) derived dung compared with forage oat (12.3 g) dung. Dung beetle abundance was positively correlated with removal of all dung types, with O. binodis biomass significantly influencing dung removal. This study showed that diet of bovine animals weakly influences the abundance of a local dung beetle assemblage, warranting further investigation on the influence of other dung types in different regions. Improvements to reporting of pasture species and growth stage is recommended for comparisons between dung derived sources.

Male Reproductive Traits Display Increased Phenotypic Variation in Response to Resource Quality and Parental Provisioning in a Tropical Rainforest Dung Beetle, Onthophagus c.f. babirussa.

Reproductive traits that mediate differential fitness associated with mate acquisition and fertilisation success are often strongly linked to the overall condition. We investigated the effects of resource quality and parental provisioning in the phenotypic expression of sexual and non-sexual traits in a rainforest dung beetle, Onthophagus c.f. babirussa (Eschscholtz, 1822) from Singapore. F1 individuals were reared from wild-caught beetles and paired up to produce offspring (F2), and F2 larvae from the same F1 parents were reared on two dung substrates (herbivore and omnivore) in a full-sib design. Sexual traits displayed greater phenotypic variation in response to dung resource quality, with the precopulatory trait (horn length) responding more than the postcopulatory trait (testes weight). Notably, genotype-by-environment interactions between parental lines (genotype) and dung type (environment) affected male body size and horn length only, suggesting sex-specific variance in plasticity associated with sexually selected precopulatory traits. Dung type had significant effects on all measured traits. Offspring that were provisioned higher quality resource (omnivore dung) had larger absolute and relative trait values. Parental lines only significantly affected female body size but none of the male traits, suggesting an important role of environment and resource partitioning in determining precopulatory success of male offspring. Parental provisioning of larval resource varied with resource quality and brood sequence. Parents provisioned more dung when herbivore dung was presented than when they were given omnivore dung and provisioned more dung for their earlier broods when using herbivore dung but not omnivore dung. This suggests a trade-off between early offspring fitness and resource quality. We tested directly for genotype-by-environment (G × E) interactions in the expression of several morphological traits relevant to dung beetle fitness and documented that offspring with similar phenotypes may result from completely different parental resource allocation strategies. We discuss the importance of studying parental investment on trait variation and its implications on dung beetle ecology.

Alpha and beta‐diversity and community structure of dung beetle assemblages in an East African protected savannah

AbstractFew studies have examined how dung beetle species composition changes across several mammalian dung types. Species composition and abundance of dung beetles were studied in dung samples of seven African mammals along animal trails and using 14 baited‐pitfall traps in both the park and the buffer zone resulting in a combined data set of 113 samples. Both the number of species (18) and the number of individual dung beetles (600) encountered were low for an area close to the Equator. Few species (2) and herbivores (13) tunnellers (9) dominated the dung beetles community, feeding and guild structure respectively. Alpha diversity was moderate 2.06 (1 < H′ ≤ 3). Beta diversity ranged from low 0.8 (high similarity) to high (zero, no similarity). Dung beetle species composition varied with dung type with the degree of pairwise similarity between two dung types in 19 of the total (21) dung beetle communities comparisons showing low similarity (0.4) to no similarity (zero). The observed discrepancies may be attributed to dung size, composition and consistency as well as to the low number of dung of the different animal species sampled. Furthermore, further research is needed as rarefaction curves suggest that sampling was incomplete.

Indication of coprophilous fungal spores for monitoring grazing intensity in the Horqin Sandy Land, Northern China

Coprophilous fungal spores are an emerging and potential proxies for indicating the long-term pastoral history. However, the indication of coprophilous fungal spores for dung and grazing intensity remains uncertain. In this study, in Horqin Sandy Land, 27 livestock dung samples and 33 surface soil samples were collected, and the indication of coprophilous fungal spores was discussed for the first time. The results showed that a total of 38 fungal spore types were recognized in the modern samples from the Horqin Sandy Land, including seven coprophilous fungal spore types. The coprophilous fungi assemblages vary in different dung types and may enable the diagnosis of specific livestock taxa. Coprophilous fungal spores, especially Sporormiella and Podospora are the most reliable dung indicators and can indicate the presence of herbivores. Moreover, some fungal spores, including Helminthosporium, Apiosordaria, HdV-104, and Glomus A were also potential indicators of grazing activities in the Horqin Sandy Land. On this basis, the concentration of coprophilous fungal spores may have the potential to be a quantitative indicator of grazing intensity. This study clarifies the indication of coprophilous fungal spores on dung and grazing intensity in the Horqin Sandy Land and provides a theoretical reference for further research on pastoral history in the region.

Mammal dung-dung beetle trophic networks: an improved method based on gut-content DNA.

Dung beetles provide many important ecosystem services, including dung decomposition, pathogen control, soil aeration, and secondary seed dispersal. Yet, the biology of most dung beetles remains unknown. Natural diets are poorly studied, partly because previous research has focused on choice or attraction experiments using few, easily accessible dung types from zoo animals, farm animals, or humans. This way, many links within natural food webs have certainly been missed. In this work, we aimed to establish a protocol to analyze the natural diets of dung beetles using DNA gut barcoding. First, the feasibility of gut-content DNA extraction and amplification of 12s rDNA from six different mammal dung types was tested in the laboratory. We then applied the method to beetles caught in pitfall traps in Ecuador and Germany by using 12s rDNA primers. For a subset of the dung beetles caught in the Ecuador sampling, we also used 16s rDNA primers to see if these would improve the number of species we could identify. We predicted the likelihood of amplifying DNA using gut fullness, DNA concentration, PCR primer, collection method, and beetle species as predictor variables in a dominance analysis. Based on the gut barcodes, we generated a dung beetle-mammal network for both field sites (Ecuador and Germany) and analyzed the levels of network specificity. We successfully amplified mammal DNA from dung beetle gut contents for 128 specimens, which included such prominent species as Panthera onca (jaguar) and Puma concolor (puma). The overall success rate of DNA amplification was 53%. The best predictors for amplification success were gut fullness and DNA concentration, suggesting the success rate can be increased by focusing on beetles with a full gut. The mammal dung-dung beetle networks differed from purely random network models and showed a moderate degree of network specialization (H2': Ecuador = 0.49; Germany = 0.41). We here present a reliable method of extracting and amplifying gut-content DNA from dung beetles. Identifying mammal dung via DNA reference libraries, we created mammal dung-dung beetle trophic networks. This has benefits over previous methods because we inventoried the natural mammal dung resources of dung beetles instead of using artificial mammal baits. Our results revealed higher levels of specialization than expected and more rodent DNA than expected in Germany, suggesting that the presented method provides more detailed insights into mammal dung-dung beetle networks. In addition, the method could have applications for mammal monitoring in many ecosystems.

Microbial community composition in the dung of five sympatric European herbivore species.

The dung microbiome is a complex system that is highly influenced by species and diet. This study characterized the dung bacterial and fungal communities of five herbivore species inhabiting the National Park Zuid-Kennemerland, the Netherlands. The five selected herbivore species were rabbit (Oryctolagus cuniculus L.), cow (Bos taurus L.), horse (Equus ferus caballus L.), fallow deer (Dama dama L.), and European bison (Bison bonasus L.). We explored the effects of distinct digestive physiology (ruminants vs. non-ruminants) and diverse dietary preferences on the microbial community composition of herbivore dung. Firmicutes and Bacteroidetes were dominant bacterial phyla in the dung of all five herbivore species, and Ascomycota was the predominant fungal phylum. Verrucomicrobiota and Mucoromycota were more present in horse dung and Proteobacteria were more abundant in rabbit dung than the three ruminant dung types. There were few significant differences in the microbial community structure among the three ruminant dung types. The alpha and beta diversity of dung microbial communities significantly differed between ruminants and non-ruminants, especially in bacterial communities. Based on MetaCyc pathways, we found that the primary functions of bacteria in herbivore dung were focused on biosynthesis, various super pathways, and degradation, with a few differences between ruminant and non-ruminant dung. FUNGuild analysis showed that horse dung had more saprotrophic fungi, while the fungi in fallow deer dung had more symbiotrophic properties, with the fungal functions of bison, cow, and rabbit dung somewhere in between. There was also a correlation between microbial community and nutrient composition of the substrate in herbivore dung. Understanding the dung microbial community composition of these herbivore species can enrich the database of mammalian gut microbiomes for studying the mechanisms of microbial community variation while preparing for exploring a new perspective to study the impact of herbivores on ecosystems through dung deposition.

ANAEROBIC CO-DIGESTION OF DIFFERENT TYPES OF COW DUNG WITH FOOD WASTE

The value of manure as a source of clean energy can be increased through the conversion of animal waste into energy, which can also reduce the negative effects that animal waste disposal has on the environment. Anaerobic digestion (AD) is a potential bioprocess for the utilisation of waste biomass and the conservation of energy. It is also an alternative method of energy recovery and waste treatment that produces biogas, which can be used to generate either electricity or heat and is a byproduct of the digestion process. In this study, different types of cow dung in terms of nutritional processes (grass: bran); 100 % grass, 95 % grass: 5 % bran, and 80 % grass: 20 % bran were taken for anaerobic co-digestion with food waste. The purpose of this study is to investigate the production of biogas as well as the properties of anaerobic co-digestion using different types of cow dung under mesophilic temperature (37°C). Biogas production was measured by the water displacement method. The pH value, Organic Matter (OM) content, C/N ratio, and Volatile Acid (VA) were recorded throughout the experiment. Samples of 100 % grass accumulated the highest biogas production (1250 ml) followed by samples of 80 % grass: 20 % bran (1080 ml) and samples of 95 % grass: 5% bran (780 ml) between the 20th and 23rd days. This shows the sample of 100 % grass-feeding has a better performance on biogas production among the samples.

Are yellow dung flies domesticated cow dung specialists?

The theory of niche differentiation implies some extent of specialization of species with regard to key resources, notably food. Coprophagous (dung-eating) insect larvae play a critical role in the decomposition of livestock dung in modern and traditional agricultural grasslands. The yellow dung fly (Scathophaga stercoraria L.; Diptera: Scathophagidae) is one of the largest, most common and abundant dung decomposers on pastures in cold-temperate regions across the entire northern hemisphere. As this fly is often associated with domesticated cattle or dairy cows, which are commonly kept for human nutrition worldwide (beef, milk, cheese, etc.), it is sometimes suspected to be a cow dung specialist. However, yellow dung flies are regularly active on and around other dung types, and must have reproduced on dung of wild vertebrates before the domestication of cattle. We therefore experimentally studied the performance of yellow dung fly larvae on dung of various large domestic vs. wild mammals (cow, horse, wild boar, red deer) in the laboratory in Switzerland. Larval performance in terms of juvenile survival, egg-to-adult development time, growth rate, and final adult body size, the major life history indicators of individual reproductive success, did not vary greatly among the various dung types tested. Thus, yellow dung flies can successfully reproduce on multiple types of mammal (vertebrate) dung, wild and domestic, and are therefore dung generalists rather than specialists. We conclude that yellow dung flies are common in European low- and highlands because they could plastically shift to dung of common herbivorous livestock after their domestication without losing the ability to reproduce on dung of common wild mammals.

Choose Local: Dung Addition from Native Herbivores Can Produce Substantial Positive Effects on the Growth of Native Grasses Compared to Livestock Dung

Livestock grazing and dung deposition can increase soil nutrients, contributing to the dominance of exotic species. Recent research suggests that native herbivore grazing has positive effects on native vegetation and soil health. However, little is known about the effects of native herbivore dung on plant growth and its potential implications for the restoration of degraded grasslands. This study examined the effects of dung addition from a native herbivore, kangaroo (Macropus giganteus), and ruminant livestock, sheep (Ovis aries), on biomass production and nutrient uptake of the native perennial wallaby grass (Rytidosperma auriculatum) and the annual exotic wild oat (Avena barbata), two of the most abundant grasses from the temperate grasslands of southern Australia. We conducted a glasshouse experiment, adding each type of dung to each plant species grown without competition in pots containing soil with a nutrient composition similar to that of old fields. Kangaroo dung produced higher wallaby grass aboveground biomass than other treatments and less wild oat aboveground biomass than the control. Kangaroo dung affected nutrient uptake but not nutrient concentration. Sheep dung had no effect. We demonstrated that native herbivores and livestock dung can have different effects on the biomass of native and invasive grasses. The higher nutrient uptake in wallaby grass appeared to be a consequence of the higher biomass production, suggesting that the effects produced by kangaroo dung could be related to its chemical and biological characteristics rather than its nutrient composition. Incorporating native herbivores’ dung or facilitating their presence can improve restoration outcomes in degraded grasslands.

Evolution of Expending Extra Effort in Making a Dung Mass before Making a Brood Ball in the Nesting Behavior of the Female Dung Beetle Copris acutidens (Coleoptera; Scarabaeoidea)

Nutrient limitations have often caused the evolution of mechanisms for efficient nutrient acquisition. The mouthparts of adult dung beetles efficiently acquire nutrients from a fiber-rich diet. Conversely, primitive mouthparts force larvae to survive on a low-quality diet despite experiencing the most demanding growth stages. In this study, we investigated the nutritional conditions and microbial community of the larval diet through the nesting behavior of the dung beetle Copris acutidens. We revealed that diet quality (C/N ratio) increased during the process of making the brood ball, irrespective of dung type. The sequencing of the bacterial community based on a partial 16S rRNA gene and the fungal community that targeted ITS2 region revealed that the fungal community in the female gut was the closest to the larval diet, whereas the bacterial community was not. The proportion of fungal Trichosporonaceae tended to increase with a decreasing C/N ratio irrespective of dung type and was alive in the larval gut. We suggest that Trichosporonaceae is a gut symbiont of both the adult female and larvae of C. acutidens, which is transmitted to the dung mass and then to larval gut through the brood ball, and that females have evolved the extra effort processes in their nesting behavior to compensate for larval diet quality, which is likely associated with symbiont fungi within the family Trichosporonaceae.

The influence of manure-based organic fertilisers on the oviposition behaviour of Anopheles arabiensis

The rice agroecosystem provides suitable breeding habitat for many malaria vector species, and rice-adjacent communities are consequently exposed to a greater malaria transmission risk than non-rice-associated communities. As part of efforts to expand rice production in Africa, sustainable and climate-adapted practices such as the System of Rice Intensification (SRI) are being promoted. SRI encourages the use of organic fertilisers (OFs) such as cow and chicken dung, as opposed to inorganic industrially produced fertilisers, due to their lower resource cost, apparent benefit to the rice agroecosystem and as a means to reduce the greenhouse gas emissions associated with the production of industrial fertilisers. However, the impact of OFs on mosquito fauna is not well documented and may have knock-on consequences on malaria transmission risk. Here, we demonstrate, using dual choice egg count assays, that both cow and chicken dung modulate the oviposition behaviour of Anopheles arabiensis, a major malaria vector in Sub-Saharan Africa. A significantly reduced proportion of eggs were laid in water treated with either cow or chicken dung compared to untreated water, with higher dung concentrations resulting in further reduced proportions. When presented in competition, significantly fewer eggs were laid in water treated with chicken dung than with cow dung. Moreover, there was no evidence of egg retention in any experiment, including in no-choice experiments where only dung-containing dishes were available. These results suggest both cow and chicken dung may act as oviposition deterrents to malaria vector species and that the application of manure-based OFs in rice agriculture may modulate the oviposition behaviour of An. gambiae s.l. within agroecosystems. Quantification of the ammonia present in dung-infused water showed higher concentrations were present in the chicken dung infusion, which may be one contributing factor to the difference in observed deterrence between the two dung types. Deterrence of mosquito oviposition in OF-treated farms may potentially affect the overall production of malaria vectors within rice fields and their contribution to local malaria transmission.

Endozoochorous Seed Dispersal by Yak and Tibetan Sheep on Alpine Meadow and Shrubland

The presence of seeds in livestock dung can alter the composition of aboveground vegetation. However, there have been few studies of the composition of the dung seed bank of Tibetan livestock on different vegetation types on the Qinghai-Tibet Plateau. The aims of this study were to identify the differences of endozoochorous seed dispersal in dung type and vegetation type and determine the relationships between the dung seed bank and aboveground vegetation in meadow and shrubland. We conducted experiments to assess the density and plant diversity of the seed bank of yak and sheep dung in meadow and shrubland. The dung seed density in Tibetan sheep dung from meadow sites was the highest (239.3 ± 13.8 seeds kg−1), and the number of species in yak dung from meadow sites was the highest. Among seasons, the livestock dung seed density was highest in November and the lowest in April. The species richness of the dung seed bank was higher in meadows than shrubland and higher in yak dung than that in Tibetan sheep dung only for shrubland. The dispersal of dung seeds has a greater impact on vegetation changes in meadows than shrubland, and the dispersal of seed in yak dung has a greater effect on vegetation changes than does dispersal in Tibetan sheep dung in shrubland. There were more monocotyledons in yak dung of shrubland (42%), whereas there were more dicotyledons in Tibetan sheep dung of meadow (45%). This suggests that yak and Tibetan sheep are complementing each other in their seed dispersal potential. Therefore, we recommend grazing more Tibetan sheep in the meadow and more yak in the shrubland on the Qinghai-Tibet Plateau.

Variation in Dung Removal Rates by Dung Beetles (Coleoptera: Scarabaeoidea) in a Temperate, Dry Steppe Ecosystem

During their feeding process, dung beetles perform a series of ecosystem functions that provide valuable ecosystem services, such as soil fertilization, improvement of soil properties, plant growth enhancement, and biological pest control. However, in the grasslands of the Central Asian dry steppe, the effects of dung beetles on dung removal remain almost unstudied. Here, we examined dung removal by different dung beetle species (Colobterus erraticus (Linnaeus, 1758), Onthophagus bivertex Heyden, 1887, Onthophagus gibbulus (Pallas, 1781), Gymnopleurus mopsus (Pallas, 1781), Cheironitis eumenes Motschulsky, 1859, and Geotrupes koltzei Reitter, 1892), and compared the impacts with control treatments (without beetles) under natural pasture conditions and in the laboratory. We examined the influence of different variables on dung removal rates, such as dung type and dung beetle traits (nesting strategies, abundance, body size, and biomass). We found higher dung removal rates during the initial 48 h in field and laboratory conditions. Among nesting strategies, tunnellers demonstrated significantly higher dung removal rates than dweller and roller species. The highest amount of dung removal was estimated for C. eumenes (6.5 g/day by seven individuals). We found no significant relationship between dung removal rates and dung beetle body size or biomass, but we observed a strong negative correlation between dung beetle abundance and dung removal rates. Our findings highlight the importance of dung type and age, nesting strategies and abundances of dung beetles, and experimental conditions, which are the main factors driving the process of dung removal.

Co-digestion of food waste with cow dung by anaerobic digestion for biogas production.

Food waste is categorized under household waste which were produce in large amount every day and it can be a good potential to generate biogas production via anaerobic digestion. In this research, the characteristics of co-digestion process are measured to determine the biogas production between food waste and cow dung. The food waste is co-digest with two different type of cow dung are collected depends on their food consuming (grass:bran); 100% grass and 95% grass : 5% bran. The digester is maintained at 35°C of temperature for mesophilic condition. pH values and C/N ratio are noted until 35 days. The biogas production is analysed by using biogas analyzer. The highest biogas production in this study is 67.2% which are co-digest between food waste and cow dung (100%) compared cow dung (95%) is 53.9% on day 26. This shows that the cow dung (100%) produces more biogas than cow dung (95%). Anaerobic digestion process will best suits for biogas production and for the best utilization of food waste.

Podospora anserina.

Podospora anserina is a coprophilous ascomycete fungus that has been used as a model organism since the 1930s. It has been reported from numerous types of herbivore dung globally, but recent genetic analyses have determined that P. anserina is a member of a species complex. It is an obligate sexual species capable of self-fertilization, completing its lifecycle in ∼10 days under laboratory conditions. It has served as the basis for numerous discoveries, including new types of selfish genetic elements (Spoks and Starships), senescence plasmids, and prions.

Dung-visiting beetle diversity is mainly affected by land use, while community specialization is driven by climate.

Dung beetles are important actors in the self‐regulation of ecosystems by driving nutrient cycling, bioturbation, and pest suppression. Urbanization and the sprawl of agricultural areas, however, destroy natural habitats and may threaten dung beetle diversity. In addition, climate change may cause shifts in geographical distribution and community composition. We used a space‐for‐time approach to test the effects of land use and climate on α‐diversity, local community specialization (H 2′) on dung resources, and γ‐diversity of dung‐visiting beetles. For this, we used pitfall traps baited with four different dung types at 115 study sites, distributed over a spatial extent of 300 km × 300 km and 1000 m in elevation. Study sites were established in four local land‐use types: forests, grasslands, arable sites, and settlements, embedded in near‐natural, agricultural, or urban landscapes. Our results show that abundance and species density of dung‐visiting beetles were negatively affected by agricultural land use at both spatial scales, whereas γ‐diversity at the local scale was negatively affected by settlements and on a landscape scale equally by agricultural and urban land use. Increasing precipitation diminished dung‐visiting beetle abundance, and higher temperatures reduced community specialization on dung types and γ‐diversity. These results indicate that intensive land use and high temperatures may cause a loss in dung‐visiting beetle diversity and alter community networks. A decrease in dung‐visiting beetle diversity may disturb decomposition processes at both local and landscape scales and alter ecosystem functioning, which may lead to drastic ecological and economic damage.

Links Between Feeding Preferences and Electroantennogram Response Profiles in Dung Beetles: The Importance of Dung Odor Bouquets

The detection of dung odors is a crucial step in the food-searching behavior of dung beetles (Coleoptera: Scarabaeoidea). Yet, whether certain compounds characteristic of a given dung type contribute to a ‘choosy generalism’ behavior proposed for this taxonomic group is unknown. To address this, we analyzed the chemical composition of three types of dung (cow, horse, and rabbit) and conducted behavioral and electroantennogram (EAG) bioassays on 15 species of dung beetles using 19 volatile organic compounds representing the three dung samples. Chemical analyses revealed substantial qualitative and quantitative differences among dung types. When offered these food options in an olfactometer, 14 species exhibited a feeding preference. Surprisingly, all 19 compounds used in the EAG assays elicited antennal responses, with species displaying different olfactory profiles. The relationship between behavioral preferences and electrophysiological profiles highlighted that species with different food preferences had differences in antennal responses. Moreover, a specific set of EAG-active compounds (nonanal, sabinene, acetophenone, ρ-cresol, 2-heptanone, 1H-indole, and 6-methyl-5-hepten-2-one) were the strongest drivers in the distinct sensory profiles of the trophic preference groups. Our results point to the importance of the whole bouquet of dung-emanating compounds in driving food-searching behavior, but specific volatiles could aid in determining highly marked trophic preferences in certain species.

Contrasting Volatilomes of Livestock Dung Drive Preference of the Dung Beetle Bubas bison (Coleoptera: Scarabaeidae).

Volatile cues can play a significant role in the location and discrimination of food resources by insects. Dung beetles have been reported to discriminate among dung types produced by different species, thereby exhibiting behavioral preferences. However, the role of volatile organic compounds (VOCs) in dung localization and preference remains largely unexplored in dung beetles. Here we performed several studies: firstly, cage olfactometer bioassays were performed to evaluate the behavioral responses of Bubas bison (Coleoptera: Scarabaeidae) to VOCs emanating from fresh horse, sheep, and cattle dung; secondly, concurrent volatilome analysis was performed to characterize volatilomes of these dung types. Bubas bison adults exhibited greater attraction to horse dung and less attraction to cattle dung, and they preferred dung from horses fed a pasture-based diet over dung from those fed lucerne hay. Volatilomes of the corresponding dung samples from each livestock species contained a diverse group of alkanes, alkenes, alkynes, alcohols, aldehydes, ketones, esters, phenols, and sulfurous compounds, but the composition and abundance of annotated VOCs varied with dung type and livestock diet. The volatilome of horse dung was the most chemically diverse. Results from a third study evaluating electroantennogram response and supplementary olfactometry provided strong evidence that indole, butyric acid, butanone, p-cresol, skatole, and phenol, as well as toluene, are involved in the attraction of B. bison to dung, with a mixture of these components significantly more attractive than individual constituents.

Diverse Effects of Climate, Land Use, and Insects on Dung and Carrion Decomposition

Land-use intensification and climate change threaten ecosystem functions. A fundamental, yet often overlooked, function is decomposition of necromass. The direct and indirect anthropogenic effects on decomposition, however, are poorly understood. We measured decomposition of two contrasting types of necromass, rat carrion and bison dung, on 179 study sites in Central Europe across an elevational climate gradient of 168–1122 m a.s.l. and within both local and regional land uses. Local land-use types included forest, grassland, arable fields, and settlements and were embedded in three regional land-use types (near-natural, agricultural, and urban). The effects of insects on decomposition were quantified by experimental exclusion, while controlling for removal by vertebrates. We used generalized additive mixed models to evaluate dung weight loss and carrion decay rate along elevation and across regional and local land-use types. We observed a unimodal relationship of dung decomposition with elevation, where greatest weight loss occurred between 600 and 700 m, but no effects of local temperature, land use, or insects. In contrast to dung, carrion decomposition was continuously faster with both increasing elevation and local temperature. Carrion reached the final decomposition stage six days earlier when insect access was allowed, and this did not depend on land-use effect. Our experiment identified different major drivers of decomposition on each necromass form. The results show that dung and carrion decomposition are rather robust to local and regional land use, but future climate change and decline of insects could alter decomposition processes and the self-regulation of ecosystems.

Agronomic Yield Performance of Rape and Assessment of Discrimination of Soil Fertilizer Amendments on Genotypic Responses

Aim: The objectives of the study were to (i) assess agronomic performance of rape (Brassica napus L.) genotypes under different soil amendments and seasons and (ii) identify the most discriminating soil fertilizer amendment on genotypic responses of rape.
 Study Design: The experiment was laid as a split plot design with 3 replications in each season.
 Place and Duration of Study: The study was undertaken in Monze district, southern province, Zambia in winter and summer periods of 2020/2021 cropping season.
 Methodology: The soil fertilizer amendment combinations were the main plots and rape varieties (English Giant [ENG], Hobson [HOB] and Rampart [RAM]) were laid as subplots. Giving a total of 54 experimental units per season. The amendments constituted combinations of raw dung type and artificial fertilizer. The quantitative data, on biomass, breadth, height and leaf count were measured at six weeks after transplanting.
 Results: Across seasons, soil amendment and genotypic main effects exhibited significantly responses with regards to biomass and leaf count (P = 0.05). Furthermore, the agronomic genotypic performance showed that RAM was the worst performer. The genotypic response to measured agronomic parameters was better in Raw Cow-Dung plus Cow- Dung Ash (RCD + CDA) soil fertilizer amendment than others. Interestingly RCD + CDA was the common discriminating amendment in summer and winter trials.
 Conclusion: Rape genotypes performed relatively better in summer than in winter season. The genotype English giant rape and Hobson were better performers across seasons and soil fertilizer amendments. The combination of RCD + CDA was the common discriminating amendment in both summer and winter trials.