Mound Volume Research Articles

Inequality in relational wealth within the upper societal segment: evidence from prehistoric Central Europe

While our understanding of long-term trends in material wealth inequality in prehistoric societies has expanded in recent decades, we know little about long-term trends in other dimensions of wealth and about social developments within particular societal segments. This paper provides the first evidence of inequality in relational wealth within the upper societal segment of a supra-regional network of communities in prehistoric Central Europe over the first four millennia BCE. To this end, we compiled a novel dataset of 5000 single-funeral burial mounds and employed burial mound volume as a proxy for the buried individual’s relational wealth. Our analysis reveals a consistently high level of inequality among the buried individuals, showing a wave-like pattern with an increasing trend over time. Additionally, our findings show temporal shifts in the size of the upper societal segment. Based on a review of archeological and paleo-environmental evidence, the temporal change in inequality may be explained by technological progress, climate and population dynamics, trade and social networks, and/or sociopolitical transformations.

Carbon dioxide and methane fluxes from mounds of African fungus-growing termites

Abstract. Termites play an essential role in decomposing dead plant material in tropical ecosystems and are thus major sources of gaseous C emissions in many environments. In African savannas, fungus-growing termites are among the ecologically most influential termite species. We studied the gas exchange from mounds of two closely related fungus-growing species (Macrotermes subhyalinus and M. michaelseni, respectively) in two habitats representing different vegetation types (grassland, bushland) together with soil fluxes around the mounds. The fluxes from active termite mounds varied from 120 to 2100 mg CO2–C m−2 h−1 for carbon dioxide (CO2) and from 0.06 to 3.7 mg CH4–C m−2 h−1 for methane (CH4) fluxes. Mound CO2 fluxes varied seasonally with a 64 % decrease and 41 % increase in the fluxes from the dry to wet season at the grassland and bushland sites, respectively. During the wet season, the CO2 fluxes were significantly correlated with termite mound volume. The diurnal measurements from two M. michaelseni mounds suggest that the gas fluxes peak during the daytime, possibly reflecting changes in mound internal air circulation. Soil fluxes of both CO2 and CH4 were enhanced at up to 2 m distance from the mounds compared to the local soil respiration, indicating that, in addition to mound ventilation structures, a small proportion of the metabolic gases produced also leave the nest via surrounding soils.

Mound architecture and season affect concentrations of CO2, CH4 and N2O in nests of African fungus‐growing termites

Abstract Termites are a significant natural source of greenhouse gases (GHGs), but quantifying emissions especially from large termite mounds is problematic as they rarely fit in measurement chambers. Predicting fluxes based on internal and atmospheric concentrations could provide an indirect way to assess mound emissions, but developing such models necessitates better understanding of the concentration levels and their variance. We used gas chromatography to measure carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) concentrations within nests of two co‐occurring species of fungus‐growing termites in both dry and wet seasons in Kenya, with termite Macrotermes michaelseni building mounds with a closed and Macrotermes subhyalinus with an open ventilation system. Gas concentrations were 3–100 times higher in mounds than the global averages in atmosphere, implying that termite mounds are sources of all three GHGs. Carbon dioxide concentrations were higher in closed than in open mounds. Methane concentrations remained constant in open mounds, whereas closed mounds exhibited considerable variation between nests and across seasons. Concentrations of both CH4 and N2O correlated positively with mound volume during the wet season, whereas interactions with mound size were not observed in CO2 concentrations or during the driest sampling period. These findings underline that among fungus‐growing termites, mound size, ventilation type and precipitation affect nest gas concentrations and with this likely the magnitude of mound GHG emissions. Potential reasons behind the observed relationships are discussed, including differences in population size, biomass of fungus gardens and CH4 oxidation.

Estimating mussel mound distribution and geometric properties in coastal salt marshes by using UAV-Lidar point clouds

The Atlantic ribbed mussel (Geukensia demissa) is common in southeastern US salt marshes, where they form dense aggregations (mounds), that occur in the highest densities and sizes on the marsh platform close to the tidal creeks' heads. Within these marshes, mussels help build marsh elevation via their biodeposition of organic and inorganic material, stimulate the growth of the dominant foundation species cordgrass (Spartina alterniflora), and create hotspots of invertebrate biodiversity, nutrient cycling, and drought resilience. Given their powerful role, there is rising interest in assessing natural variation in the distribution of mussel mounds and using such information to guide marsh conservation and restoration strategies. However, gathering such information is challenging, because the small dimension (∼1 m) of the mounds and the presence of overlying vegetation make it difficult to quantify mound distribution on the marsh. Therefore, this study presents a new procedure to compute the distribution, height, radius, volume, and distance of mounds in marsh environments using remote sensing. A high-resolution UAV-Lidar point cloud has been collected over a highly vegetated salt marsh in Georgia, USA, using a custom-built laser scanner system. An original detection algorithm, based on a Random Forest classifier, has been implemented to identify the mounds from the point cloud. The algorithm has been trained and tested on surveyed mounds and provides their location and geometric properties. Results indicate that the classifier can distinguish mussel mounds from non-mussel mound locations with an accuracy of 95 %. The classifier identified ∼8000 mounds, which occupy 10 % of the study domain, and a volume (shells+feces/pseudofeces) of 680 m3. The method is highly useful in efforts to monitor mussel mounds over time and scale up to assess mounds across sites, providing invaluable data for future studies related to the geomorphic evolution of marshes to sea level rise and siting marsh conservation and enhancement projects.

Effects of Secondary Current on the Local Erosion Induced by Circular Turbulent Wall Jets in Cross Flow

This paper presents the results of a series of laboratory experiments, by placing a turbulent wall jet in the upstream and downstream of a 90° channel bend, to investigate the effects of secondary flow on formation of local sediment erosion and deposition. The effects of jet and current flow intensities on the erosion pattern were characterized by the jet’s Reynolds number, Re, channel Froude number, Fr, and the ratio of water depth to nozzle diameter, h/do. The geometrical characteristics of local erosion such as jet trajectory, maximum scour depth, ds, and maximum mound height, hm, were measured. The area and volume of scours and mounds were calculated from measurements, and the results were correlated with the controlling parameters. Experimental observations indicated the existence of distinct scour patterns due to variations of channel Froude number. Two additional scour holes were identified due to the effect of stream interactions and formation of vortex regions immediately downstream of sediment mound. It was found that both channel and jet flows contributed to trajectory of the jet and the footprint of erosion. A threshold Froude number of Fr=0.091 was identified at which the current and jet flow were in equilibrium. The results showed that for a constant value of Fr, all scour parameters increased with increasing Reynolds number. However, Re did not have any effects on the jet’s deflection. Comparing the erosion profiles in the upstream and downstream bend indicated that the secondary current and turbulent redistribution altered the erosion and mound formation in the downstream of the bend in relatively high Reynolds (i.e., Re≥23,000), high channel Froude numbers (i.e., Fr>0.091) and high jet submergence (i.e., h/do>10.53).

Breast Lift Algorithm for the Treatment of Breast Implant Illness Requiring Implant Removal.

The recommendation of breast lift surgery in the setting of patients requiring breast implant removal is twofold. First, a breast lift is indicated for patients who present with breast mound or nipple-areolar complex ptosis. Second, a breast lift is indicated to accommodate the forecasted redundancy in skin and breast ptosis created by implant explantation. The most popular approaches to mastopexy include the inferior and superior pedicled breast lifts. We present a surgical algorithm with diagrams and cases clarifying mastopexy approaches for patients desiring breast implant removal in patients presenting with breast implant illness syndrome. An algorithm was developed to explain the process for selecting the ideal pedicle approach for mastopexy and implant removal surgeries. Three cases are presented to illustrate the application of each pedicle under different presentations and goals. Advantages of an inferior pedicle include the capacity for unlimited lifting of the nipple-areola complex and for preservation of maximal breast mound volume. Its disadvantages include the inability to remove the breast capsule simultaneously and contraindicated if the lower breast pole is contracted. The advantages of a superior pedicle include the ability to remove the entire capsule and to eliminate lower breast pole if it is contracted. Its disadvantages include limitations to how high the nipple-areola complex can be lifted and the inability to preserve maximal breast mound volume. With the current trend for the request of implant removal in patients presenting with breast implant illness syndrome, the algorithm presented may assist surgeons with selecting the ideal breast lift and implant removal approach. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Monument volumes and viewshed analysis at the Carson mounds site (22CO505), Coahoma County, Mississippi

Earthen mound construction is a cultural practice in the American Southeast that has over 5000 years of history. During this time, earthen mounds were variously associated with mortuary rituals, communal practices, social and political leadership, and/or cosmological structures of the universe. After CE 1200 in Mississippi’s Yazoo Basin, a floodplain of the Mississippi River stretching from Memphis to Vicksburg, numerous large, fortified and mounded towns were constructed. At these sites there is significant variation in numbers of mounds and mound volume. Blitz and Livingood and Payne stipulate in earlier studies that most earthen mounds were built slowly by kin groups for community integration and possibly flood relief. They also suggest that large mounds at large sites take on meanings of hierarchy and leadership. Using Peircean semiotics, Jerry Moore’s concept of relative scale, and with data compiled by Blitz and Livingood and Payne, this study evaluates mound volume and monumental viewsheds at the Carson site, a large Mississippian culture settlement that once had over 88 earthen mounds, some of which were small house mounds, and some of which were monumental.

放牧管理模式对高原鼢鼠(Eospalax baileyi)鼠丘形态特征的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 放牧管理模式对高原鼢鼠(Eospalax baileyi)鼠丘形态特征的影响 DOI: 10.5846/stxb202012253273 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（31760706）；甘肃省陇原青年创新创业人才项目（LYRC2018-02）和甘肃省科技计划项目（20JR10RA564） Effects of grazing management regimes on mound morphological characteristics of plateau zokors (Eospalax baileyi) Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为明晰放牧对高原鼢鼠（Eospalax baileyi）造丘活动的影响，于2019年5月、8月和10月分别对禁牧（No grazing，NG）、生长季休牧（Rest grazing in growing season，RG）、传统放牧（Traditional grazing，TG）和连续放牧（Continuous grazing，CG）4种放牧管理模式样地下高原鼢鼠的新鼠丘（2个月内形成）半径、高度、表面积和体积等进行测定，并分析其表面积、体积与土壤和植被生物量间的关系。结果发现：放牧管理模式显著影响了高原鼢鼠鼠丘形态特征，且具有季节性差异。NG下鼠丘的半径、表面积和体积最大，而CG下鼠丘的体积和表面积显著变小（P<0.05），在8月和10月，鼠丘半径在CG样地显著小于其他3种放牧模式样地（P<0.05）；8月TG下鼠丘高度最高，而5月和10月NG下鼠丘高度最高，鼠丘高度在CG样地显著小于NG样地（P<0.05）。冗余分析2个排序轴几乎全部解释了土壤因子及地下生物量与鼠丘特征之间的关系，但各放牧管理模式下影响因子不同，NG样地的土壤容重（P<0.05）、土壤紧实度（P<0.01）和莎草科植物的地上生物量（P<0.01），RG样地的地下生物量（P<0.01）、土壤紧实度（P<0.01）和豆科植物的地上生物量（P<0.01），TG样地的禾本科和豆科植物的地上生物量（P<0.01），CG样地的土壤水分、地下生生物量、土壤紧实度（P<0.05）和莎草科植物的地上生物量（P<0.01）均显著影响了鼠丘的形态特征。可见，放牧会影响高原鼢鼠的鼠丘形态特征，进而对草地的演替产生不同的影响。 Abstract:The rodent damage by plateau zokor in the process of alpine meadow grazing is a key problem in its utilization and management. Grazing is one of the most important ways to use grassland. Grazing management regimes, as a utilization system index to control grazing intensity, maintain livestock quantity and grassland ecosystem balance, which have different influences on grassland community structure, grassland productivity, soil structure, and nutrient properties. The plateau zokor (Eospalax baileyi) is a kind of underground rodent endemic to the Qinghai-Tibet Plateau, the embodiment of their different functions is the key to judge the "benefit and harm". Their continuous earthmoving and mound building is also one of the important manifestations of their harm,and the size of the mound building and the change of the excavated soil properties are the key factors affecting the grassland. Therefore, it is of great significance for rodent control and grassland management and utilization by elucidating the changes of mound characteristics in alpine meadow under different grazing management systems. In order to clarify the effect of grazing management regimes on the mound-building activity of plateau zokors, the radius, height, surface area and volumes of new mounds (formed within 2 months) under four kinds of grazing management regimes, namely no grazing (NG), rest grazing in the growing season (RG), traditional grazing (TG), and continuous grazing (CG) plots, were measured in May, August, and October 2019, and the relationship between surface area and volume and soil and vegetation biomass was analyzed. The results showed that the grazing management regimes significantly affected the morphological characteristics of mounds with seasonal differences. The radius, surface area and volume of mounds under no grazing regime were the largest, while the volume and surface area of mounds under continuous grazing regime decreased significantly (P<0.05), and the radius of mounds under the continuous grazing regime was significantly less than that of other three grazing regimes in August and October (P<0.05); the height of mounds under traditional grazing regime was the largest in August, while they were the largest under no grazing regime in May and October, and they were significantly less under continuous grazing regime than that under no grazing regime (P<0.05). The two sequencing axes of redundancy analysis almost entirely explained the relationship of mounds with environmental factors and underground biomass. However, the influencing factors were different under different grazing management regimes. There were great effects on the characteristics of zokor mounds from soil bulk density (P<0.05), soil compactness (P<0.01) and aboveground biomass of cyperaceae plants (P<0.01) under no grazing regimes. There were great effects on the characteristics of zokor mounds from underground biomass (P<0.01), soil compactness (P<0.01) and aboveground biomass of leguminosae plants(P<0.01) under rest grazing in growing season regime. There were great effects on the characteristics of zokor mounds from aboveground biomass of gramineae and leguminosae plants (P<0.01) under traditional grazing regimes, and there were great effects on the characteristics of zokor mounds from soil moisture, underground biomass, soil compactness (P<0.05) and aboveground biomass of cyperaceae plants(P<0.01) under continuous grazing regimes. Grazing can affect the mound-building activity of plateau zokors, and then had different effects on the succession of grassland. 参考文献 相似文献 引证文献

Predictive value of 3D imaging to guide implant selection in immediate breast reconstruction

SUMMARYBackgroundPre-operative estimation of breast mound volume for immediate breast reconstruction is necessary for operative planning, especially in direct-to-implant reconstruction. Our purpose was to investigate the relationship between pre-operative predictions of breast mound weight from 3D imaging and actual mastectomy weight and implant size.MethodsA retrospective chart review of all patients who had previously undergone nipple-sparing mastectomy (NSM) by a single surgeon was performed. Pre-operative 3D images were reviewed and calculations of breast mound weight were performed by three independent reviewers. Intra-operative mastectomy weight and final implant weight were collected from patient charts. A regression analysis between calculated and actual values was performed.ResultsThere were 59 reconstructed breasts included. Pre-operative 3D imaging-guided breast weight calculations were similar across reviewers (R=0.96). Pre-operative calculations of breast weight were 49.4g (SD=134.0) smaller than actual mastectomy specimens. Mastectomy specimens were 41.0g (SD=130.2) smaller than final implant sizes. Thereby, the relationship was as follows: Pre-operative calculated breast weight < actual Mastectomy weight < implant weight. Mastectomy weight and final implant size had linear relationships with pre-operative calculations of breast weight. Formulas for predicting mastectomy weight [mastectomy weight = 63.2 + 0.95 (pre-operative calculated weight)] and implant size [Implant weight = 209.7+ 0.56 (pre-operative calculated weight)] from pre-operative calculations of breast weight were generated.ConclusionsThree-dimensional scanning technologies may be a useful tool to predict implant sizes for direct-to-implant breast reconstruction. Final implant size was heavier than intra-operative mastectomy weight and pre-operative calculated breast mound weight.

Plant shade enhances thermoregulation of internal environments in Trinervitermes trinervoides mounds.

Microhabitats may be crucial in buffering organisms from temperature extremes, particularly given increases in maximum temperature associated with global climate change. For example, thermoregulation in termite mounds is influenced by prevailing ambient conditions, and plant canopies may reduce external temperatures, in turn lowering internal temperatures. This buffering may be crucial during heat waves. Whether this happens, and to what extent, remains equivocal, however. We tracked internal temperatures in eight inhabited and six uninhabited Trinervitermes trinervoides mounds, half of each group of which were shaded by vegetation. T. trinervoides seek to maintain internal mound temperatures at c. 20°C in winter and c. 30°C in summer. Temperatures were logged for 72h in winter, and again in summer. Internal temperatures of uninhabited mounds mirrored those of external temperatures, with temperatures varying by c. 15°C, although shading was associated with some buffering of internal temperatures. Internal temperatures within inhabited mounds were far less variable, varying by c. 6°C over the course of our study. In summer, exposed inhabited mounds maintained temperatures c. 29.5°C, whilst shaded inhabited mounds were c. 27.5°C. In winter, mean internal temperatures of exposed and shaded inhabited mounds were very similar, at 21.8 and 22.0°C, respectively. Internal mound temperature varied significantly with external (ambient) temperature, mound activity, temperature, shading, and to a small extent, mound volume. The buffering effect of shade was evident in summer (c. 2°C) but not in winter, suggesting that the benefit of such temperature modulation may be most important when ambient temperatures reach heat extremes, e.g. during heat waves.

Effects of human activity on the habitat utilization of Himalayan marmot (Marmota himalayana) in Zoige wetland.

Human activity is increasingly and persistently disturbing nature and wild animals. Affected wildlife adopts multiple strategies to deal with different human influences. To explore the effect of human activity on habitat utilization of Himalayan marmot (Marmota himalayana), habitat utilization patterns of three neighboring marmot populations in habitats affected differently by human activities were recorded and compared. We found that (a) distance between reproductive burrows (a represent of reproductive pairs) becomes shorter under the influence of human activities, and more burrows were dug as temporary shelters, resulting in shorter distance between those shelters and shorter distance flee to those shelters and, consequently, shorter flight initiation distance when threatened. More burrows that are closer to the disturbed habitats improve the ability to escape from threats. (b) Reproductive burrow site selection of the species is determined by the availability of mounds in the habitat, and breeding pairs selectively build reproductive (also the hibernation) burrows on mounds, potentially to improve surveillance when basking and the drainage of burrows. Human activities generally drive breeding pairs away from the road to dig their reproductive burrows likely to reduce disturbance from vehicles. However, even heavy human activity exerts no pressure on the distance of reproductive burrows from the road or the mound volume of the high disturbance population, potentially because mounds are the best burrowing site to reproduce and hibernate in the habitat. Marmots deal with disturbance by digging more burrows in the habitat to flee more effectively and building reproductive burrows on mounds to gain better vigilance and drainage efficiency.

Pedogeomorphology and paleoenvironmental implications of large termite mounds at the Brazilian semiarid landscape

Large termite mounds, regionally called Murundus, forming hillocks throughout the Brazilian territory, occur, with different names, across the entire tropical belt. Little is known about the genesis and age of these large biogenic structures in the semiarid zone, where termites have a limited range due to water deficit. We aimed to understand the process of mounds building on different types of soils at the ecotonal semiarid region of Minas Gerais state. In addition, we tested the hypothesis that these mounds have been produced by termites during the Holocene, and that the paleoenvironmental conditions during mound formation were different from today, helping to enhance the understanding of vegetation dynamics in the semiarid Caatinga Biome. For this, five mounds with and without living termites (M1, M2, M3, M4 and M5) and five adjacent soil profiles (P1, P2, P3, P4 and P5) were selected for morphological description, followed by physical, chemical, mineralogical and micromorphological analysis, as well as δ13C and 14C dating analysis. The occurrence of these large termite mounds in the semiarid landscape is unrelated to soils or parent material, and represent the products of cumulative termite activity in the edge of the semiarid domain. Mounds and adjacent soils formed after the mid Holocene (younger than 4000 years), based on 14C dating, and may be even older. The calculated rates of termite accretion (based on 14C dating) are consistent with previous reports of tropical soils, in the range of 0.027 to 0.066 cm soil/Ha/y. A comparative estimate based on mound volume and density was 0.188 cm soil/Ha/y, up to 3.5 times greater than the previous approach based on 14C dating. These figures suggest the production of a soil mantle in the range of 270–660 cm in 10,000 years, accounting for erosion. The mounds and adjacent soils have differences in micropedological features, notably related to bioturbation (excremental infillings), and contrasting textural variations with depth, with higher and more uniform clay and silt contents in mounds, and a kaolinitic/illitic mineralogical composition throughout. The chemical fertility of murundus depends on the type of underlying soil from which it was built, and does not increase in all cases. In the murundus studied, the microgranular structure typical of oxic materials is welded and massive, indicating that the natural compaction of soils dominated by kaolinite/illite under the semi-arid climate prevents the stability of loose aggregates formed by termite bioturbation, reorganizing the termitic microaggregate groundmass. This clearly shows the polycyclic (polyphasic) biogenic nature of mounds and adjacent soils, corroborated by carbon isotopes studies. Soils and mounds are younger than mid Holocene in the first 100 cm, and experienced alternations of dry and wet climate spells from the mid-Holocene onwards, resulting in apparent changes in vegetation at the ecotonal, southern limit of semi-arid Caatinga, over the last 5000 years. Since we did not reach the base of mounds, they should be even older; mounds represent fine proxies for Holocene paleoclimate reconstructions, if a more detailed pedostratigraphic study is carried out. A general model of termite mounds formation in relation to the interconnected pedological, geomorphological and vegetational evolution is presented, summarizing all present knowledge on these outstanding biogenic landforms.

Structure élémentaire de l’arganeraie Argania spinosa L. Skeels de Tindouf (Sahara occidental algérien) / Elementary structure of the argan forest Argania spinosa L. Skeels of Tindouf (Algerian western Sahara)

The argan tree is well adapted to drought conditions in Algerian western Sahara. The argan forest of Tindouf has a structure of coppice on stumps, characterized by an average height of 4.7m. Regeneration by dense resprouts represents 43% for 1,192 inventoried trees. The mother trees of Argania spinosa have a significant potential to resprout in coppice or suckers, thus forming crowns around mounds on beds of wadis. It should be noted that 21% of the trees are damaged by illegal cutting. The average spacing between the trees is around 13m. The argan tree retains a large volume of soil input with an average of 23.6 ± 36.3m3/ stump in the form of mounds. Linear regression analysis revealed an increasing relationship between mound volume and the number of stems per stump. Thanks to its powerful root system, the argan tree accumulates additional soil and contributes to the slow mechanism of sedimentation of micro-horizons, constituting mounds around the feet of trees.

Consequences of Climate Change-Induced Habitat Conversions on Red Wood Ants in a Central European Mountain: A Case Study.

Simple SummaryThe red wood ants are considered to be one of the main ecosystem engineers and keystone species of the habitats in which they exist. Most of the species from this species group inhabit coniferous forests, which, due to the consequences of anthropogenic climate change, are continuously cut down. Therefore, the main habitat of these important species is rapidly disappearing. We investigated the consequences of the absence of conifers (clear-cut area and deciduous forest) on one of the members of this species group, namely Formica polyctena. We have found that compared with the mixed-coniferous forest stand, the absence of coniferous species resulted in significant changes in the colony and nest structure of F. polyctena. In addition, the colony size was also smaller in these sites. These changes suggest that although F. polyctena is able to survive in suboptimal habitats, still their population decline is expected and urges conservation managers to apply necessary action plans for their protection.The consequences of anthropogenic climate change are one of the major concerns of conservation biology. A cascade of negative effects is expected to affect various ecosystems, one of which is Central European coniferous forests and their unique biota. These coniferous forests are the primary habitat of many forest specialist species such as red wood ants. Climate change-induced rising of temperature allows trees to skip winter hibernation, making them more vulnerable to storms that cause wind felling, and in turn, promotes bark beetle infestations that results in unscheduled clear-cuttings. Red wood ants can also be exposed to such habitat changes. We investigated the effects of bark beetle-induced clear-cutting and the absence of coniferous trees on colonies of Formica polyctena, including a mixed-coniferous forest as a reference. Our aim was to investigate how these habitat features affect the nest characteristics and nesting habits of F. polyctena. Our results indicate that, in the absence of conifers, F. polyctena tend to use different alternatives for nest material, colony structure, and food sources. However, the vitality of F. polyctena colonies significantly decreased (smaller nest mound volumes). Our study highlights the ecological flexibility of this forest specialist and its potential to survive under extreme conditions.

Abundance, population density and spatial ecology of mound-building termites in moist tropical deciduous forests of northern India

ABSTRACT Mound-building termites are ecosystem engineers whose abundance and spatial ecology are not adequately addressed in many forest ecosystems. We studied Odontotermes obesus mounds at two moist tropical deciduous forests (pure Sal and Sal-Teak mixed) in the Doon valley, northern India. Mound abundance, spatial pattern and termite population density were determined by direct count, nearest neighbour analyses and destructive sampling, respectively. Relations between mound attributes and stand characteristics such as woody vegetation diversity, density and tree stumps (representing food quality, quantity, open-space availability and disturbance) were tested at fine spatial scale using regression analyses. Active mounds were more abundant in the pure Sal stand (~8.0 mounds/ha) than in the mixed stand (~5.0 mounds/ha). Mean population density (both sites combined) was 2.01 × 105 individuals per mound. Population density was strongly correlated with mound volume. Predominance of young colonies was indicated by high occurrence (≥ = 65%) of small mounds (< 1.25 m3). Mounds were predominantly randomly distributed. However, the pure Sal stand showed a partial tendency towards aggregation. Our results revealed that woody species richness is an important, site-specific regulatory factor. Local-scale variations should be cautiously considered while up-scaling the contribution of O. obesus mounds to various ecosystem processes.

A Numerical Model for Offshore Mound Evolution

A numerical model was developed to simulate the evolution of a mound placed in the offshore (i.e., outside the zone of wave breaking), exposed to varying non-breaking waves and water levels. The net sediment transport rate is assumed to be mainly dominated by bed load transport, where wave asymmetry plays an important role. The net transport over a wave cycle is expressed with reference to an equilibrium profile, which ensures model reliability and robustness. In order to validate the model, data collected at two field sites, Cocoa Beach and Perdido Key Beach in Florida, USA, were employed. The numerical results show good agreement with the measured data from the two sites in terms of the profile evolution. It demonstrates that the model has the capability to simulate the evolution of mounds placed in the offshore. In addition, several scenarios with different mound volume and location designs were investigated to indicate potential uses for the model. The results illustrate how the mound evolution is influenced by the volume and location of the mound placement.

Termite mounds house a diversity of taxa in oil palm plantations irrespective of understory management

AbstractWe investigated the effects of oil palm understory vegetation management on termite mound activity and non‐termite inhabitants. We found a diversity of taxa, most of which were unaffected by understory management. Mound volume and termite activity had taxa‐specific effects on abundance. Preserving mounds in oil palm plantations will benefit biodiversity.Abstract in Indonesian is available with online material.

Upper Devonian (Frasnian) stromatactis-bearing mud mounds, western Alberta, Canada: reef framework dominated by peloidal microcrystalline calcite

ABSTRACT Two well-preserved mud mounds, approximately 50 m thick, in the Mount Hawk Formation (Upper Devonian, Frasnian) in western Alberta provide an unparalleled opportunity to study the microstructure of this reef type in detail for this time interval. This reveals that they are composed dominantly of peloidal sediments—more than a quarter of mud mound volume—along with dense micrite, particulate micrite, bioclasts, and stromatactis cavities. Five types of peloids are differentiated: bacterial, cyanobacterial, bioclastic, intraclastic, and pseudo-peloids. Bacterial peloids were generated by bacterial metabolic activities with possibly some contribution from organomineralization in areas within spicular networks. Three subtypes of cyanobacterial peloids are distinguished based on whether they are physically reworked calcified filaments, aggregates of calcified coccoids, or precipitated within stromatolite-forming cyanobacterial mats or biofilms. Bioclastic peloids are fully micritized fragments of skeletons and shells. Intraclastic peloids are eroded fragments of early-lithified matrix. Pseudo-peloids represent artifacts of poorly preserved sponge spicular networks reflecting the interplay between dissolution of spicules and organomineralization. The distribution of the various peloid types shows specificity in different microfacies. They prove to be valuable paleoecological indicators, and taken together suggest that the mud mounds accreted within the photic zone above storm wave base but below the fair-weather wave base, during deposition of a transgressive and perhaps highstand systems tracts. They are the products reflecting a dynamic balance between constructional versus destructive processes. Bacterial peloids combined with dense micrite constitute the framework, which in turn makes up close to 40% of the mud mounds. This indicates that microbial activities are responsible for the early-indurated framework. The onset of bacterial peloid formation in the bedded sediment immediately underlying the mud mounds further demonstrates that it may have been a necessary precursor to mud-mound initiation. Bacterial peloids appear to characterize most Paleozoic and Mesozoic reefal mud mounds as an essential framework element.

How much of the sediment in Gale crater's central mound was fluvially transported?

The origin of the sedimentary mound within Gale crater, the landing site for the Mars Science Laboratory rover Curiosity, remains enigmatic. Here we examine the total potential contribution of fluvial material by conducting a volume-based analysis. On the basis of these results, the mound can be divided into three zones: a lower, intermediate, and upper zone. The top boundary of the lowermost zone is defined by maximal contribution of water-lain sediments, which are ~13 to 20% of the total mound volume. The upper zone is defined by the elevation of the unbreached rim to the north (-2.46 km); sediments above this elevation cannot have been emplaced by flowing water. These volume balance calculations indicate that mechanisms other than flowing water are required to account for the overwhelming majority of the sediments transported into Gale crater. The most likely candidate process is settling from eolian suspension.

Multiattribute framework analysis for the identification of carbonate mounds in the Brazilian presalt zone

Carbonate mounds, as described herein, often present seismic characteristics such as low amplitude and a high density of faults and fractures, which can easily be oversampled and blur other rock features in simple geobody extraction processes. We have developed a workflow for combining geometric attributes and hybrid spectral decomposition (HSD) to efficiently identify good-quality reservoirs in carbonate mounds within the complex environment of the Brazilian presalt zone. To better identify these reservoirs within the seismic volume of carbonate mounds, we divide our methodology into four stages: seismic data acquisition and processing overview, preconditioning of seismic data using structural-oriented filtering and imaging enhancement, calculation of seismic attributes, and classification of seismic facies. Although coherence and curvature attributes are often used to identify high-density fault and fracture zones, representing one of the most important features of carbonate mounds, HSD is necessary to discriminate low-amplitude carbonate mounds (good reservoir quality) from low-amplitude clay zones (nonreservoir). Finally, we use a multiattribute facies classification to generate a geologically significant outcome and to guide a final geobody extraction that is calibrated by well data and that can be used as a spatial indicator of the distribution of good reservoir quality for static modeling.