Enclosure Area Research Articles

Enclosure area expansion and reduction mechanism for artificial mastication device

Enclosure area expansion and reduction mechanism for artificial mastication device

Welfare of ducks, geese and quail on farm.

This Scientific Opinion concerns the welfare of Domestic ducks (Anas platyrhynchos domesticus), Muscovy ducks (Cairina moschata domesticus) and their hybrids (Mule ducks), Domestic geese (Anser anser f. domesticus) and Japanese quail (Coturnix japonica) in relation to the rearing of breeders, birds for meat, Muscovy and Mule ducks and Domestic geese for foie gras and layer Japanese quail for egg production. The most common husbandry systems (HSs) in the European Union are described for each animal species and category. The following welfare consequences are described and assessed for each species: restriction of movement, injuries (bone lesions including fractures and dislocations, soft tissue lesions and integument damage and locomotory disorders including lameness), group stress, inability to perform comfort behaviour, inability to perform exploratory or foraging behaviour and inability to express maternal behaviour (related to prelaying and nesting behaviours). Animal-based measures relevant for the assessment of these welfare consequences were identified and described. The relevant hazards leading to the welfare consequences in the different HSs were identified. Specific factors such as space allowance (including minimum enclosure area and height) per bird, group size, floor quality, characteristics of nesting facilities and enrichment provided (including access to water to fulfil biological needs) were assessed in relation to the welfare consequences and, recommendations on how to prevent the welfare consequences were provided in a quantitative or qualitative way.

Potamogeton crispus restoration increased the epiphytic microbial diversity and improved water quality in a micro-polluted urban river

Special characterization and assembly of epiphytic microbial communities remain unclear in micro-polluted water column during submersed macrophytes restoration. In this study, an in-situ enclosure area sowing with turions of Potamogeton crispus (P. crispus) was conducted in a micro-polluted urban river to investigate the characterization of P. crispus and epiphytic microbial communities and their response to water environment under different water depths. Turions completely germinated in water column with <90 cm water depth and the germination speed decreased with increasing water depth within 18 days. There were obvious differences in morphological characteristics of P. crispus between deep and shallow water layers. P. crispus restoration decreased by 12–32%, 13–36%, 9–43% and 5–36% of COD, NH4+-N, TN and TP concentration, respectively, in enclosed overlying water compared to the river (P < 0.05) during 5 months of experiment. Illumina sequencing was employed to explore the epiphytic bacterial and microeukayotic communities at water depth 25–35 cm (shallow area) and 80–90 cm (deep area). A total of 9 bacterial and 12 microeukayotic dominant phyla were obtained in eight samples. It should be noted that the algae abundances were higher in shallow area than deep area but a reverse trend was observed for methanotrophs. Null model analysis revealed that dispersal limitation and undominated process was the most important assembly process, whereas stochastic processes gained more importance in shallow area than deep one. According to cooccurrence analysis (|r| > 0.6, P < 0.05), there were more strongly correlated edges in shallow area (456 edges) than deep area (340 edges). These results highlight that submerged macrophytes restoration can increase microbial diversity and improve water quality, and provide a “summer disease cured in winter” way by using could-resistant P. crispus for water purification in micro-polluted rivers in low-temperature season.

A stable and quantitative method for dimensionality reduction of aortic centerline.

Aortic dissection (AD) is a fatal aortic disease with high mortality. Assessing the morphology of the aorta is critical for diagnostic and surgical decisions. Aortic centerline projection methods have been used to evaluate the morphology of the aorta. However, there is a big difference between the current model of primary plane projection (PPP) and the actual shape of individuals, which is not conducive to morphological statistical analysis. Finding a method to compress the three-dimensional information of the aorta into two dimensions is helpful to clinical decision-making. In this paper, the evaluation parameters, including contour length (CL), enclosure area, and the sum of absolute residuals (SAR), were introduced to objectively evaluate the optimal projection plane rather than artificial subjective judgment. Our results showed that the optimal projection plane could be objectively characterized by the three evaluation parameters. As the morphological criterion, SAR is optimal among the three parameters. Compared to the optimal projection plane selected by traditional PPP, our method has better AD discrimination in the analysis of aortic tortuosity, and is conducive to the clinical operation of AD. Thus, it has application prospects for the preprocessing techniques for the geometric morphology analysis of AD.

Prevalence Patterns for Enteric Parasites of Chickens Managed in Open Environments of the Western United States.

Growing demand for poultry meat and eggs labeled as organic, cage free, or pasture raised has increased the number of producers that manage chickens outdoors. In these open environments, there are likely diverse enteric parasites sustained by fecal-oral transmission or passage through intermediate invertebrate hosts (e.g., worms and insects) that chickens consume. Enteric parasites can reduce chicken health and productivity, but there are few published data describing the identities or prevalence of these parasites on farms that use open environments in the United States. We surveyed 27 poultry farms with open environments that were situated across a wide geographic range, including California, Oregon, Idaho, and Washington. These farms did not use anticoccidial drugs, coccidia vaccines, or parasiticides. Flock size, enclosure area, flock density, flock rotation frequency, and average flock age were highly correlated for all the farms in this study. We analyzed how enclosure size and flock rotations per year (which represented two axes of variation in management) correlated with prevalence of five observed parasite taxa at the farm level. Across all flocks, we detected by fecal flotation Eimeria spp. (95% flocks), Ascaridia galli (69%), Heterakis gallinarum (52%), Capillaria spp. (39%), Strongyloides avium (13%), tapeworm species (29%), Cryptosporidium spp. (3%), and Dispharynx nasuta (1%). Eighty-five percent of samples were coinfected with two or more parasite taxa. Sixty-seven percent of farms raised only layer chicken breeds, 4% raised only broiler breeds, and 30% raised both layer and broiler breeds. The average age of the broiler flocks was 11.0 wk (±1.1 SE), and flocks were moved 54.7 (±17.9) times annually to new locations in pastures (hereafter, "rotation"). Layer flocks averaged 84.9 (±7.67) wk of age and were moved less often on farms being rotated 20.0 (±6.05) times per year. Generalized linear mixed models indicated that for every 1 m2 increase in enclosure size, the odds of detecting Eimeria spp. increased by 0.03%. Furthermore, for every additional rotation per year, the odds of detecting A. galli decreased by 1.3%. For every additional rotation per year, the odds of detecting tapeworm species increased by 2.2%. We found no evidence that flock spatial management affected prevalence of the other parasites observed on the farms. Farming practices and parasite responses in these systems are highly varied, which makes it difficult to identify potential management interventions for reducing these infections.

An Explicit Fourth-Order Compact Numerical Scheme for Heat Transfer of Boundary Layer Flow

The main contribution of this article is to propose a compact explicit scheme for solving time-dependent partial differential equations (PDEs). The proposed explicit scheme has an advantage over the corresponding implicit compact scheme to find solutions of nonlinear and linear convection–diffusion type equations because the implicit existing compact scheme fails to obtain the solution. In addition, the present scheme provides fourth-order accuracy in space and second-order accuracy in time, and is constructed on three grid points and three time levels. It is a compact multistep scheme and conditionally stable, while the existing multistep scheme developed on three time levels is unconditionally unstable for parabolic and considered a type of equations. The mathematical model of the heat transfer in a mixed convective radiative fluid flow over a flat plate is also given. The convergence conditions of dimensionless forms of these equations are given, and also the proposed scheme solves equations, and results are compared with two existing schemes. It is hoped that the results in the current report are a helpful source for future fluid-flow studies in an industrial environment in an enclosure area.

Grassland community structure in Permanent Preservation Areas associated with forestry and livestock in the Pampa biome, Southern Brazil

The Pampa biome comprises a high species richness, but has been transformed by various human activities, threatening its inherent diversity. One of the mechanisms that contributes to conservation is the Permanent Preservation Areas (PPA); however, studies related to the vegetation of these areas are scarce, especially regarding the herbaceous stratum, creating a gap in the evaluation of the conservation of the Pampa biome's grassland formations. The objective of this study was to characterize the structure of fragments of grasslands in PPA, with and without cattle grazing, inserted in a plantation of Eucalyptus saligna Sm. in the Pampa biome. The survey was conducted on 40 systematically distributed sample units in six grassland areas, three of which were occasionally exposed to grazing and three fenced off with no grazing. Cover and frequency values ​​(absolute and relative) and importance value index (IVI) were estimated for species, exposed soil and dry plant material. The difference between the areas was evaluated by the Principal Coordinate Analysis (PCoA) and ANOSIM, complemented by SIMPER. Richness, dry plant material and exposed soil were evaluated using the Kruskall-Wallis test. A total of 210 species were registered, with the Poaceae family being the most numerous, followed by Asteraceae (41), Cyperaceae (19), Fabaceae (12) and Rubiaceae (9). The areas differed in relation to richness, with grazing showing more diversity. Enclosure Area 3 did not differ from open areas 2 and 3, possibly due to the greater proximity and low cattle interference. The exposed soil did not vary according to the enclosure; however, the dry plant material was higher in the enclosed areas. The distribution of species, as well as their cover and frequency were regulated according to grazing. The presence of animals in PPA has modified the dynamics and botanical composition of the areas, in which richness was promoted.

Ecological effects on enclosure culture demolition of Lake Hongze

为研究湖泊网围养殖对湖泊生态系统的影响，2018年全年3次于洪泽湖养殖网围及主要出入湖河道开展调查，通过对比洪泽湖不同区域（河口、湖心、网围区、外围区和拆除区）水质及水生生物的空间分布特征，分析养殖网围拆除后湖泊生态系统的响应机制.结果表明，洪泽湖不同区域的水质及水生生物群落结构存在明显差异，其中养殖区水体总氮、总磷及悬浮颗粒物浓度明显低于河口和湖心，但浮游动植物密度及生物量则整体高于河口和湖心，且养殖区蓝藻、轮虫所占比重较高，这种分布差异很大程度上受外源输入及水动力条件影响.与之相对，养殖区内网围区、拆除区和外围区的水质及水生生物群落结构差异并不明显，表明养殖网围拆除后的短期时间内水质并未明显改善，且高藻类密度、低透明度的水体环境也不利于沉水植物的萌发生长与群丛恢复，有必要进一步采取合理有效的生态修复措施促进养殖迹地生态系统的恢复.;In order to investigate the ecological effects of enclosure culture on the lake ecosystem, the investigation was carried out three times in the enclosure culture of Lake Hongze and its inlets and outlets during 2018. The response mechanism of the lake ecosystem after enclosure culture demolition was analyzed based on the data accumulated by comparing the spatial distribution characteristics of water quality parameters, the phytoplankton, zooplankton, and benthos communities in different areas of Lake Hongze (estuary, lake center, enclosure area, peripheral area, and demolition area). The results show that there are obvious differences between water quality and aquatic organisms in different lake regions. The concentrations of total nitrogen, total phosphorus, and suspended particulate matter in the samples collected within the culture areas are slightly higher than samples collected in the estuary and lake center, but both density and biomass of the phytoplankton are lower in the culture areas than those in the estuary and lake center. The proportion of Cyanophyta and rotifers in the culture areas is higher than that in the estuary and lake center. This distribution difference is largely affected by external input and hydrodynamic conditions. On the contrary, the differences in water quality and aquatic organisms between various areas of the enclosure culture are not considerable, indicating that the water quality has not improved significantly in the short period after the enclosure culture is removed. And the water quality with high algae density and low transparency will be detrimental to submerged plant growth and community recovery. Therefore, it's necessary to take further rational and effective ecological restoration measures to promote the restoration of the enclosure culture ecosystems.

Tree planting indices and their effects on summer park thermal environment: A case study of a subtropical satellite city, China

Urban residents are suffering from serious thermal stress resulting from urban heat island and global warming. Investigators have explored several methods to address this issue. Vegetation, especially trees, were found to play a vital part in urban environments. It produces a cooling effect by reducing temperature and radiation levels. To find thermal performances of trees in detail, this study physically measured two urban parks during August 2019 in a satellite city of China regarding their thermal environments relevant to tree planting indices. There were three planting indices used, sky view factor, leaf area index and enclosure area. Through associating them with thermal indicators by linear regression, all of the indices were confirmed to have significant thermal effects. Every 0.1 increase in sky view factor resulted in an increase of 1°C air temperature, 0.16 m/s air velocity, 40 W/m2 solar radiation level and 1.6°C mean radiant temperature. Same effects were found in nearly 0.4 leaf area index decrease and approximately 20 m2 enclosure area increase. These results provide very optimistic directions for future urban forestry planning and landscaping.

Exploration of Plasmodium vivax merozoite surface proteins 1 and 7 genetic diversity in Brazilian Amazon and Rio de Janeiro Atlantic Forest.

Plasmodium vivax merozoite surface proteins (PvMSP) 1 and 7 are considered vaccine targets. Genetic diversity knowledge is crucial to assess their potential as immunogens and to provide insights about population structure in different epidemiological contexts. Here, we investigate the variability of pvmsp-142, pvmsp-7E, and pvmsp-7F genes in 227 samples from the Brazilian Amazon (BA) and Rio de Janeiro Atlantic Forest (AF). pvmsp-142 has 63 polymorphisms - 57 nonsynonymous - generating a nucleotide diversity of π=0.009 in AF, and π=0.018 in BA. In pvmsp-7E, 134 polymorphisms - 103 nonsynonymous - generate the nucleotide diversity of π=0.027 in AF, and π=0.042 in BA. The pvmsp-7F has only two SNPs - A610G and A1054T -, with nucleotide diversity of π=0.0004 in AF, and π=0.0007 in BA. The haplotype diversity of pvmsp-142, pvmsp-7E, and pvmsp-7F genes is 0.997, 1.00, and 0.649, respectively. None of the pvmsp-142 or pvmsp-7E sequences are identical to the Salvador 1 strain's sequence. Conversely, most of pvmsp-7F sequences (94/48%) are identical to Sal-1. We evaluated eight B-cell epitopes in pvmsp-7E, four of them showed higher nucleotide diversity compared to pvmsp-7E's epitopes. Positive selection was detected in pvmsp-142, pvmsp-7E central region, and pvmsp-7F with Tajima's D. In pvmsp-7E, the significant nucleotide and haplotype diversities with low genetic differentiation, could be indicative of balancing selection. The genetic differentiation of pvmsp-142 (0.315) and pvmsp-7F (0.354) genes between AF and BA regions is significant, which is not the case for pvmsp-7E (0.193). We conclude that pvmsp-142 and pvmsp-7E have great genetic diversity even in AF region, an enclosure area with deficient transmission levels of P. vivax zoonotic malaria. In both Brazilian regions, pvmsp-119, pvmsp-7E, and pvmsp-7F are conserved, most likely due to their roles in parasite survival, and could be considered potential targets for a "blood-stage vaccine".

Investigating Habitat Suitability and Conservation Issues of Re-introduced Wild Water Buffalo in Chitwan National Park, Nepal

With an ever present threat of extinction aggravated mostly by inbreeding, genetic introgression and flooding stress, translocation of wild water buffalo (Bubalus arnee) to another suitable habitat was a must since decades. Habitat suitability analysis for wild water buffalo has been done by using binary model in ArcGIS 10.2.2 and slope, elevation, distance to water bodies and land cover criteria were used to prepare habitat suitability map of Chitwan National Park. Vegetation compositions were assessed in the grassland of Old Padampur area in sample plots (n = 36) each of size 1m x 1m for grasses and 10m x 10m for trees by using random sampling strategy. Conservation issues were identified through key-informant interviews and on-site observation of enclosure area, where re-introduced wild water buffalo were soft released. 127.13 km2 of the park area was identified as suitable habitat for wild water buffalo with around 79% of Old Padampur area. Importance Value Index (IVI) indicated that Saccharum spontaneum was found to be the most dominant grass species (IVI = 100.43) followed by Imperata cylindrica (IVI = 56.70) in Old Padampur area. Old Padampur area lies in the lap of Rapti River with many streams and marshes in the area which contributes to its suitability. The grassland of Old Padampur area is the largest in the park. At present, the wild water buffalo is facing some conservation issues mainly due to improper execution of soft release strategy and few uncontrolled natural events, such as floods and predators attacks. Therefore, to maintain the viable population of wild water buffalo in Chitwan National Park in the long-run, it is crucial to regulate and enhance effective soft release strategy and more advance techno-based modality in close coordination with conservation partners and relevant stakeholders.

Estimates of catchment area of pitfall traps for carabids

Relationships between beetle abundance in the field and data collected from pitfall traps has generated much interest from several generations of carabidologists. Despite the argument and controversy about this relationship, pitfall data remain the main source of knowledge about carabid populations and assemblages in nature. In order to estimate the relationship between pitfall catches of carabids and catchment area in a homogenous deciduous forest, we constructed circular field enclosures of three sizes (radii: 2.5m, 5m and 10m) and sampled carabids using single pitfall traps located in the centre of each enclosure over 3 seasons (2014-2016). We found that overall beetle catches increased linearly with enclosure area during all three years, and the linear models were nearly identical for the two years (2014 and 2016) in which the data were comparable. We then extrapolated the relationship to predict the catchment area using unenclosed traps run simultaneously. For data from both 2014 and 2016, the catchment area for the assemblage is predicted to be 620-640 m2, representing a radius of c. 14.3 m. Interestingly, this value is consistent with the published inter-trap distance required for independence of trap captures at the same site. Unfortunately, but as expected, calibration of pitfall data at the species level is challenging because the best linear model fits vary considerably among species. Trap catchment area also increased during breeding season. Clearly, pitfall traps need to be set at least c. 30 meters apart to ensure independence of samples in mixedwood boreal forest.

English

This research aims to assess the driving factors hindering the effectiveness of these protected areas implemented to counter land degradation and evaluate the services provided by these ecosystems in the North West of China. With Ningxia province, Yanchi County chosen as experimental research area, preferential sampling technique was used with 50 plots of (quadrat) laid for plant community characteristics survey combined with species and biomass measures mainly in three different areas, along with unit price system of evaluating ecosystem services values based on Costanza’s evaluation model also used to quantify the V_ei (Ecosystem Service Value). The results showed both up and down trends of vegetation characteristics in protected areas including E, E1 and E2 year-round enclosure, seasonal and un-enclosed area respectively where anthropogenic disturbance has been prohibited for natural restoration. Moreover, compared to 1999, the total ecosystem service values of the year 2004 increased by 6.75% and those for 2010, 2015 increased by 7.28 and 5.55% respectively, indicating some positive effects of the protected on the total value of the grassland ecosystem service. In addition, regulatory and support services occupied the largest proportions: 52.08 and 32.69% respectively, followed by supply and cultural services 8 and 7% respectively. These results prove that the protected areas are improving the grasslands by reducing the soil loss and increasing their ecosystem services provision. Thus, sustainability and guarantee of the ability of the arid ecosystem to continue to provide the ecological services is important in the management taking into account the limiting factors. Key words: Land degradation, limiting factors, sustainable management, Ecosystem Service Value

Husbandry and enclosure influences on penguin behavior and conservation breeding

Multi-zoo comparisons of animal welfare are rare, and yet vital for ensuring continued improvement of zoo enclosures and husbandry. Methods are not standardized for the development of zoo enclosures based on multiple indicators, and case study species are required. This study compares behavior and breeding success to various enclosure and husbandry parameters for the Humboldt penguin, Spheniscus humboldti, for the development of improved enclosure design. Behavioral sampling was completed at Flamingo Land over a period of 8 months. Further data on behavior, enclosure design, and breeding success were collected via questionnaires, visits to zoos, and literature review. Breeding success was primarily influenced by colony age and number of breeding pairs, suggesting an important social influence on reproduction. Across zoos, there was also significant variation in behavior. The proportion of time spent in water varied between zoos (2-23%) and was used as an indicator of physical activity and natural behavior. Regression models revealed that water-use was best predicted by total enclosure area per penguin, followed by land area, with some evidence for positive influence of pool surface area per penguin. Predominantly linear/curvilinear increases in our biological indicators with enclosure parameters suggest that optimal conditions for S. humboldti were not met among the selected zoos. We propose revised minimum conditions for S. humboldti enclosure design, which exceed those in the existing husbandry guidelines. We present a framework for the evaluation of zoo enclosures and suggest that a rigorous scientific protocol be established for the design of new enclosures, based on multivariate methods. Zoo Biol. 35:385-397, 2016. © Wiley Periodicals, Inc.

Impact of Enclosure on Plant Species Composition and Biomass Production in Ewa Woreda of Afar Region State, Ethiopia

This study was conducted to know the impact of enclosure on plant covers dynamics and biomass production in Ewa district. A total of 13 species of grasses, 2 species of legumes, and 4 species of other herbaceous plants were identified in both grazing areas. Of the grass species, 15.3%, 30.8%, 38.6% and 15.3% were highly desirable, desirable, less desirable and undesirable respectively. The grass species dominant in communal grazing areas were Chryspogon plumolosus (22.1%) and Tragus beteronianus (20.6%) whereas Cenchrus ciliaris (21.2%) was dominant in the enclosure area. A higher (P<0.05) total grass biomass production and total herbaceous biomass production were obtained in the enclosure areas than in communal grazing areas while in case of non-grass biomass production, there was no any significant different (P<0.05) between the two grazing areas. In general, the result showed that in species composition and biomass production communal grazing areas have deteriorated which may need an immediate intervention, while the enclosure areas need a sustainable conservation of their present condition by considering alternative management that allows selectively and carefully timed utilization.

Effects of Configuration and Headspace Mixing on the Accuracy of Closed Chambers for DairyFarm Gas Emission Measurement

<abstract><title><italic>Abstract. </italic></title> This study was aimed at evaluating the influence of chamber configuration (enclosure area and height), the use of a mixing fan and the wind speed induced by the fan at the emitting surface (head space mixing) on the accuracy for the closed chamber in gas emission measurement at low emission rates (≤3000 g SF₆ m^-2 h^-1). A calibration system was designed to generate a reference flux, and SF₆ was used as the target gas. Accuracy or chamber performance was defined based on the agreement between the calculated reference and chamber fluxes, which were not affected by chamber configuration. Four unvented closed chambers with two floor diameters (300 and 400 mm) and three different heights (200, 300, and 400 mm) were tested at seven different emission rates (from 684 ±72 to 2958 ±144 g m^-2 h^-1). Chamber configuration was correlated with the reference flux of sulfur hexafluoride (SF₆), and the tested chambers underestimated the reference fluxes by 21.5% ±13.6% (average ±SD). Chamber enclosure area did not affect the chamber performance while the height significantly impacted measurement accuracy. A chamber height of 300 mm was recommended to measure low gas emission rates. The positive air pressure induced by the mixing fan in the headspace increased with the fan speed, but the chamber performance was not affected by the mixing fan at lower emission rates. For our tested conditions, a mixing fan was not necessary and a vent opening balancing the air pressure inside and outside a chamber was not recommended.

An Oral Clinician?s Perspective towards Peutz Jegher?s Syndrome ? A Case Report

Ethiopia is one of the African countries facing problems of environmental degradation. In particular, the problem is severe in the Tigray region of Northern Ethiopia highlands where, environmental degradation is threatening many parts of the region. Efforts to contain this problem and facilitate natural rehabilitation have been made at several levels. The establishment of area enclosures, and soil and water conservation works are two of the main strategies promoted to contain land degradation and restore the natural vegetation. This study investigates the effect of area enclosures on regenerating the degraded vegetation. A comparative analysis was performed by investigating two sites: enclosed and unprotected sites. A temporal vegetation change analysis and a vegetation index differencing technique were applied to investigate the change in vegetation that has occurred in the two study sites. Multitemporal SPOT NDVI images for the period 2001 to 2009 were used for this purpose. The findings of the remote sensing analysis indicated that a consistent positive improvement in vegetation regeneration was observed in the enclosure area. This is indicative of the role of area closure, exclusion of livestock grazing and human interference from selected areas, as an important policy instrument to allow the recovery degraded vegetation provided that they are properly protected and managed.

Using LiDAR data to locate a Middle Woodland enclosure and associated mounds, Louisa County, Iowa

LiDAR data is used to locate an enclosure reported at the McKinney site (13LA1) as well as destroyed mounds associated with the Toolesboro mound group National Historic Landmark (13LA29). Using various geo-visualization and interpolation techniques, one of us (Riley) located the earthwork enclosure, eight mounds, and possibly a ninth or an excavation spoil pile. An anomaly north of 13LA1 and within the detected enclosure area were also identified. There is no modern survey relating to these two anomalies. Our results support historic accounts regarding the location and shape of the McKinney enclosure and its relationship to the Toolesboro mound group. All features found by LiDAR will be ground truthed in the future.

An Analysis of Factors Affecting Available Safe Escape Time

This paper deals with some of the parameters that affect the available safe evacuation time (ASET), including fire growth rate, enclosure area, and thermal properties of the bounding construction. Although the available safe escape time is a crucial design parameter, it is, or has to be, often generalised to cover a range of scenarios; this is also the case of design codes. It is therefore necessary to be aware in which aspects such generalisation is possible. A set of computer model cases, carried out in CFAST, is analysed and the effect of individual variables quantified. As real fires usually grow exponentially with time, the t2-fire model was used, employing the standard fire growth rates. By analysing the computer model scenarios, it was found that increasing the size of the enclosure does not bring proportional growth of available safe escape time. It is the rate of fire growth that is the primary factor affecting the safe available escape time. Two different smoke layer height tenability criteria – 0.9m and 1.5m – are also compared; the first derived from literature and the latter represent a more conservative estimate.

Snow evens fragmentation effects and food determines overwintering success in ground‐dwelling voles

AbstractClimate instability strongly affects overwintering conditions in organisms living in a strongly seasonal environment and consequently their survival and population dynamics. Food, predation and density effects are also strong during winter, but the effect of fragmentation of ground vegetation on ground‐dwelling small mammals is unknown. Here, we report the results of a winter experiment on the effects of habitat fragmentation and food on experimental overwintering populations of bank voles Myodes glareolus. The study was conducted in large outdoor enclosures containing one large, two medium‐sized or four small habitat patches or the total enclosure area covered with protective tall‐grass habitat. During the stable snow cover of midwinter, only food affected the overwintering success, body condition, trappability and earlier onset of breeding in bank voles. However, after the snow thaw in spring, habitat fragmentation gained importance again, and breeding activities increased the movements of voles in the most fragmented habitat. The use of an open, risky matrix area increased along the habitat fragmentation. Our experiment showed that long‐lasting stable snow cover protects overwintering individuals in otherwise exposed and risky ground habitats. We conclude that a stable winter climate and snow cover should even out habitat fragmentation effects on small mammals. However, along prolonged snow‐free early winter and in an earlier spring thaw, this means loss of protection by snow cover both in terms of thermoregulation and predation. Thus, habitat cover is important for the survival of small ground‐dwelling boreal mammals also during the non‐breeding season.