Minimum Area Requirements Research Articles

Taxonomic, phylogenetic, and functional nestedness of mammal assemblages in the Zhoushan Archipelago, China

Abstract Nestedness is an important part of the theoretical framework of island biogeography and community ecology. However, most previous studies focused on taxonomic dimension and overlooked functional and phylogenetic nestedness. Here, we simultaneously investigated taxonomic, functional, and phylogenetic nestedness of terrestrial mammals on 39 land-bridge islands in the Zhoushan Archipelago, China. As mammals’ response to the environment may depend on their body size, we performed analyses for three mammal assemblages separately: overall species, large and medium-sized species, and small species. The taxonomic nestedness was quantified by organizing the species incidence matrix, while the functional and phylogenetic nestedness were estimated by combining the similarity of their ecological traits and phylogeny. Island characteristics (island area, three isolation indices, land use intensity, and habitat diversity) and species traits (body size, litter size, habitat specificity, geographic range size, and minimum area requirement) were used as predictors of nestedness. Overall and small species were significantly nested in 3 facets of nestedness, and results supported the selective extinction, selective colonization, and habitat nestedness hypotheses. Large and medium-sized species were functionally and phylogenetically nested when matrices were ordered by increasing distance to mainland, supporting the selective colonization hypothesis. Overall, differences in nestedness and its underlying mechanisms were detected not only in 3 facets of nestedness but also in the 3 mammal assemblages. Therefore, frameworks that incorporate taxonomic, phylogenetic, and functional nestedness can contribute to a more comprehensive understanding of nestedness processes. Additionally, it also improves our ability to understand the divergent responses of mammal assemblages to the insular environment.

Gaps in mammal conservation in China: An analysis with a framework based on minimum area requirements.

Climate change, habitat loss, and human disturbance are major threats to biodiversity. Protecting habitats plays a pivotal role in biodiversity conservation, and there is a global imperative to establish an effective system of protected areas (PAs) to implement habitat conservation and halt biodiversity decline. However, the protected patch size of habitat for a species is just as important for biodiversity conservation as the expansion of areas already under protection. In China, conservation management is often carried out based on administrative divisions. Therefore, here, an analytical conservation management framework was developed based on administrative divisions to assess whether the current network of PAs can effectively meet species' conservation needs using the minimum area requirements (MARs) of species as criteria for medium and large-sized mammals in China. This study found that the MAR of medium and large-sized mammals was larger in the northwest and smaller in the southeast, while taking the Hu line as the dividing line. Precipitation seasonality, elevation, annual mean temperature, and annual precipitation are the main environmental factors driving the distribution of a species MAR. Compared with MAR for each species, the maximum protected patch size of habitat is severely undersized in most provinces where those species primarily distribute, and this is particularly true for large carnivores and threatened species. The densely populated provinces of eastern China are particularly affected by this. The present study's framework can identify the provinces needing to expand PAs or implement other effective area-based conservation measures and habitat restoration. This analytical framework is also relevant for biodiversity conservation in different taxa and regions around the globe.

Woodpeckers in the city: Abundances are highest in large green spaces with complex understories

Abstract We documented occurrence and relative abundance (henceforth abundance) of five woodpecker species in 36 forested green spaces in Portland, Oregon (USA), to estimate minimum area requirements (MAR; 0.5 probability of occurrence) and to test for potential influences of green space area and type (heavily treed manicured green spaces vs. undeveloped natural forests), habitat features, and landscape composition on the abundance of woodpeckers. Abundances of all species increased with green space area. Manicured and natural green spaces did not differ in canopy cover or total basal area, but woodpecker abundances were greater in natural than manicured green spaces for all species except Northern Flickers (Colaptes auratus). Flickers and Downy Woodpeckers (Picoides pubescens) were most abundant, MAR of both were under 1.5 ha, and both were found in essentially all green spaces. Hairy (P. villosus) and Pileated (Dryocopus pileatus) woodpeckers were least abundant, and with MAR of 34 and 51 ha, respectively, exhibited pronounced area sensitivity. Red-breasted Sapsuckers (Sphyrapicus ruber) were intermediate in abundance and MAR to the 2 former and 2 latter species. The most important habitat variables associated with variation in abundance among green spaces were the contribution of deciduous trees to the canopy (Downy Woodpecker [+], Pileated Woodpecker [+], and Northern Flicker [–]), canopy cover (Hairy Woodpecker [+] and Northern Flicker [+]), and log density (Hairy Woodpecker [+], Red-breasted Sapsucker [–]). At the landscape level, lower woodpecker abundance was associated with increased urbanization (Red-breasted Sapsucker and Northern Flicker), while increasing forest cover influenced abundance of Northern Flicker (–) and Pileated Woodpecker (+). Highest woodpecker abundances were thus found in large green spaces with complex understories that were embedded in relatively undeveloped treed landscapes. Management of forested urban green spaces should prioritize needs of the area-sensitive species because ensuring their continued presence benefits the entire avian community.

Urban Green Space Policy Reform in Indonesia: Breathing in the Middle of Development

Rapid population growth and limited land availability have resulted in a decline in environmental space utilization, including green open spaces, which are crucial for oxygen production and supporting biodiversity. Land conversion driven by increased land demand exacerbates this issue. This research focuses on two main problems: the adherence of the Salatiga City Local Government in Indonesia to the minimum area requirement for green open spaces mandated by Law No. 26 of 2007, and the forms and utilization of green open spaces within the city. This research reveals deficiencies and obstacles in implementing the policy, leading to a failure in meeting the minimum area target. Factors such as idealistic policy pursuit, delegation of authority issues, and excessive emphasis on perfection rather than practical relevance contribute to these challenges. The Salatiga City Regional Spatial Plan, outlined in Regional Regulation Number 4 of 2011, designates green open spaces as protected areas, encompassing city parks, cemeteries, urban forests, border rivers, and green belts. However, obstacles arise from small area sizes, incorrect initial land use practices, and inadequate resolution of land ownership issues. Despite these challenges, the City of Salatiga has partially maintained the functionality of these spaces, prioritizing their overarching purpose over specific land use. In conclusion, this research highlights the shortcomings in implementing Green Open Space policies in Salatiga. It emphasizes the importance of addressing land-related issues and ensuring proper management of green spaces. Resolving these challenges is crucial for enhancing environmental sustainability and benefiting both the community and the environment.

Selective extinction and habitat nestedness are the main drivers of lizard nestedness in the Zhoushan Archipelago.

Nested subset pattern (nestedness) is an important part of the theoretical framework of island biogeography and community ecology. However, most previous studies often used nestedness metrics or randomization algorithms that are vulnerable to type I error. In this study, we investigated the nestedness of lizard assemblages on 37 islands in the Zhoushan Archipelago, China. We used the line-transect method to survey species occurrence, abundance, and habitat types of lizards on 37 islands during 2 breeding seasons in 2021 and 2022. We applied the nested metric WNODF and the conservative rc null model to control for type I error and quantify the significance of nestedness. Spearman rank correlations were used to evaluate the role of 4 habitat variables (island area, 2 isolation indices, and habitat diversity) and 4 ecological traits (body size, geographic range size, clutch size, and minimum area requirement) in generating nestedness. The results of WNODF analyses showed that lizard assemblages were significantly nested. The habitat-by-site matrix estimated by the program NODF was also significantly nested, supporting the habitat nestedness hypothesis. The nestedness of lizard assemblages were significantly correlated with island area, habitat diversity, clutch size, and minimum area requirement. Overall, our results suggest that selective extinction and habitat nestedness were the main drivers of lizard nestedness in our system. In contrast, the nestedness of lizard assemblages was not due to passive sampling or selective colonization. To maximize the number of species preserved, our results indicate that we should protect both large islands with diverse habitats and species with large area requirement and clutch size.

The Critically Endangered El Rincon stream frog: Population viability and management actions in Patagonia, Argentina

Abstract The El Rincon stream frog (Pleurodema somuncurense) is a microendemic species currently restricted to the thermal headwaters of the Valcheta Stream in the Somuncura Plateau, Northern Patagonia, Argentina. This species is listed as Critically Endangered on the IUCN Red List. The critical status of the El Rincon stream frog requires urgent management actions. Population viability analysis is one of the most effective tools to predict extinction risk and assess the potential effect of management actions. It is also helpful in knowing the minimum viable population (MVP) and minimum area requirements (MAR). However, this tool is rarely used to model viability in endangered amphibians. This work aimed to: (i) estimate the extinction risk of each local population of El Rincon stream frogs; (ii) estimate the MVP and MAR; and (iii) model reintroduction and supplementation of the population as management strategies for this species. Practical management actions are also suggested for each relict population. Population viability analyses were developed in Vortex 10.3.5.0 to estimate each local population's extinction risk, MVP and MAR. Supplementation and reinforcement of individuals were also modelled for local populations that are below the MVP. The estimated MVP was 430 individuals, while MAR reached 683 m2. Modelling of reintroducing individuals showed that a single reintroduction of at least 50 adults, 140 juveniles, or 1,000 tadpoles would be needed to achieve a viable population. Local populations below the MVP would benefit from supplementation of a pair of adult frogs every 17 to 20 years. This study provides a fundamental basis for assessing and improving current management and planning future conservation strategies within the framework of the El Rincon stream frog action plan.

A generic sizing methodology for thermal management system in fuel cell vehicles using pinch analysis

The escalating transport demand over the past decade has intensified the need to replace internal combustion (IC) engines with better alternatives like fuel cells that can simultaneously provide superior performance and diminished emissions. The radiators that are used in fuel cell-based electric vehicles are at least twice the size of IC engine radiators. This leads to vehicle overloading and an increase in fuel consumption. The undertaken study proposes a reduction in radiator size by storing thermal energy in phase change materials. This paper presents a generalized sizing method for the recommended thermal management system, using a simple mathematical approach based on Pinch Analysis. The optimization studies show the possibility to bring down the minimum radiator area requirement in a fuel cell vehicle like the 2022 Toyota Mirai by 5.5 times by using around 13 kg of Paraffin Wax along with it. The proposed methodology is realized by analyzing a few representative parameters like ambient temperature, drag area and curb weight of the vehicle, maximum allowable temperature rise in fuel cells, etc. In addition, the study also estimates the minimum required radiator areas for a few commercial fuel cell vehicles in the Indian environment.

What Matters Most for Neighborhood Greenspace Usability and Satisfaction in Riyadh: Size or Distance to Home?

Much research work has been carried out on larger urban parks. Smaller neighborhood greenspaces have not received as much academic attention, particularly in sprawling large cities of the developing world. This paper examines the frequency of use and user satisfaction with smaller urban greenspaces within the residential neighborhoods of Riyadh metropolitan city, Saudi Arabia. To measure use frequency and satisfaction level differentials among neighborhood residents, gap analysis using paired samples t-test was performed to assess the differences between mean score ratings of expected (pre-use) and experienced (post-use) feelings of user satisfaction with local greenspace features. A five-point Likert scale questionnaire was used to measure user satisfaction. Pearson r correlation coefficient, chi-square test and F-test were also used to examine the relationships between dependent (usability and satisfaction) and independent variables. The findings show that smaller size, close-to-home neighborhood greenspaces in Riyadh fell short of drawing many users or meeting user expectations. Larger local greenspaces however, managed to attract much more users even from relatively far-away neighborhoods. Size rather than closeness to home is a much stronger determinant affecting use frequency and user satisfaction with local neighborhood green spaces. It is therefore recommended to amend the city’s planning codes and regulations that require the provision of local greens based on service or catchment areas of 500–800 m. They should insist instead on the need for a minimum area requirement of such facilities if their usability and user satisfaction are to be enhanced.

Modeling Alternative Approaches to the Biodiversity Offsetting of Urban Expansion in the Grenoble Area (France): What Is the Role of Spatial Scales in ‘No Net Loss’ of Wetland Area and Function?

It is increasingly common for developers to be asked to manage the impacts of their projects on biodiversity by restoring other degraded habitats that are ecologically equivalent to those that are impacted. These measures, called biodiversity offsets, generally aim to achieve ‘no net loss’ (NNL) of biodiversity. Using spatially-explicit modeling, different options were compared in terms of their performance in offsetting the impacts on wetlands of the planned urban expansion around Grenoble (France). Two implementation models for offsetting were tested: (a) the widespread bespoke permittee-led restoration project model, resulting in a patchwork of restored wetlands, and (b) recently-established aggregated and anticipated “banking” approaches whereby larger sets of adjacent parcels offset the impacts of several projects. Two ecological equivalence methods for sizing offsets were simulated: (a) the historically-prevalent area-based approach and (b) recently introduced approaches whereby offsets are sized to ensure NNL of wetland functions. Simulations showed that a mix of functional methods with minimum area requirements was more likely to achieve NNL of wetland area and function across the study area and within each subwatershed. Our methodology can be used to test the carrying capacity of a landscape to support urban expansion and its associated offsetting in order to formulate more sustainable development plans.

Optimum Design of Reinforced Concrete One-Way Ribbed Slabs Using Genetic Algorithm

This paper deals with the problem of optimum design of reinforced concrete one-way ribbed using genetic algorithms. ACI-Coefficient method is used for the structural analysis and design of slabs. The cost function represents the cost of concrete, steel, and formwork for the slab. The design variables are taken as slab thickness, spacing between ribs, lower width of ribbed, upper width of ribbed, depth of rib, depth of beam, shear reinforcement spacing of ribs, bar diameter and spacing of top slab, depth of the neutral axis from bottom fiber, beam width, and areas of flexural reinforcement at moment critical section along ribs and beams. The constraints include the constraints of the joist construction constraints stated by ACI-code, constraints on the top slab thickness to satisfy fire resistance, constraints on the areas of steel reinforcement to satisfy the flexural and the minimum area requirements, the constraints on the total slab thickness to satisfy deflection, and flexural behavior. The parameters were taken in this study included: the span length(4-12)m, the compressive of concrete(25-60) MPa, the strength of steel (345-600)MPa, the live load (2-7)KN/m2, unit cost ratio(cost of concrete/cost of steel)(0.1-0.35), aspect ratio (1-2), the formwork cost(10,000-22,000)I.D. The results show that, when discussed the span length, the ratio of (total slab depth/span length) should be (1/18-1/4) using G.A, to get the optimum slab design. It is also concluded that the optimum ratio of (depth of rib/lower rib width) is to be ranged within (1.243-2.917) using G.A. The optimum (rib spacing/span length) ratio is found to be ranged from (1/40- 1/5) using G.A, the results also showed that the range of the optimum (slab thickness/spacing of rib) ratio is found to be ranged as (1/4-1/2) using G.A, in order to find the optimum solution.A computer program is written using MATLAB for the implementation of structural analysis and the design of one-way ribbed slabs by the ACI coefficient method. The optimization process is performed using the built-in genetic algorithm toolbox of MATLAB.

Conversion of automotive paint sludge to activated carbon via microwave pyrolysis technique for supercapacitor application

Conversion of waste to wealth has been one of the ways to reduce the volume of industrial waste to disposal site, hence reducing the impact to the environment. In this work, paint sludge from an automotive industry (APS) was converted into activated carbon through chemical activation (potassium hydroxide (KOH)) using microwave pyrolysis technique. The effect of power and radiation time on the produced activated carbon were investigated and characterised (carbon content, surface area, and pore volume) to identify the possibility of application as a supercapacitor. Potassium hydroxide activation of the APS char via microwave pyrolysis has shown that power level and radiation time has influenced the yield of the APS activated carbon. A longer radiation time and higher power supply has produced activated carbon having higher carbon contents, lower impurities, higher surface area and higher pore volume. Thus, the APS activated carbon obtained via microwave pyrolysis at power supply 1000 W and 45 minutes radiation time had produced the highest surface area and total pore volume of 434.3 m2/g and 0.2901 cm3/g, respectively. However, the produced activated carbon is not suitable for the supercapacitor application as the minimum surface area requirement must be more than 1000 m2/g. The pore size of the activated APS char produced in this study was in the range of mesopores size which was also considered very poor for supercapacitor application. The outcome of this research has shown that the produced activated carbon could otherwise be used for other application than a supercapacitor.

Nestedness and underlying processes of bird assemblages in Nanjing urban parks.

Nestedness is an important pattern frequently reported for species assemblages on islands or fragmented systems. However, to date, there are few studies that comprehensively investigated faunal nestedness and underlying processes in urbanized landscapes. In this study, we examined the nestedness of bird assemblages and its underlying causal mechanisms in 37 urban parks in Nanjing, China. We used the line-transect method to survey birds from April 2019 to January 2020. We used the Weighted Nestedness metric based on Overlap and Decreasing Fill (WNODF) to estimate the nestedness of bird assemblages. We applied spearman partial correlation test to examine the relationships between nestedness ranks of sites and park characteristics (area, isolation, anthropogenic noise, number of habitat types, and building index), as well as between nestedness ranks of species and their ecological traits (body size, geographic range size, clutch size, minimum area requirement, dispersal ratio, and habitat specificity). We found that bird assemblages in urban parks were significantly nested. Park area, habitat diversity, building index, habitat specificity, and minimum area requirement of birds were significantly correlated with nestedness. Therefore, the nestedness of bird assemblages was caused by selective extinction, habitat nestedness, and urbanization. However, the nestedness of bird assemblages did not result from passive sampling, selective colonization, or human disturbance. Overall, to maximize the number of species preserved in our system, conservation priority should be given to parks with large area, rich habitat diversity, and less building index. From a species perspective, we should focus on species with large area requirement and high habitat specificity for their effective conservation.

Working landscapes need at least 20% native habitat

AbstractInternational agreements aim to conserve 17% of Earth's land area by 2020 but include no area‐based conservation targets within the working landscapes that support human needs through farming, ranching, and forestry. Through a review of country‐level legislation, we found that just 38% of countries have minimum area requirements for conserving native habitats within working landscapes. We argue for increasing native habitats to at least 20% of working landscape area where it is below this minimum. Such target has benefits for food security, nature's contributions to people, and the connectivity and effectiveness of protected area networks in biomes in which protected areas are underrepresented. We also argue for maintaining native habitat at higher levels where it currently exceeds the 20% minimum, and performed a literature review that shows that even more than 50% native habitat restoration is needed in particular landscapes. The post‐2020 Global Biodiversity Framework is an opportune moment to include a minimum habitat restoration target for working landscapes that contributes to, but does not compete with, initiatives for expanding protected areas, the UN Decade on Ecosystem Restoration (2021–2030) and the UN Sustainable Development Goals.

Extinction debt of fishes in Great Lakes coastal wetlands

Declines in North American freshwater biodiversity can be largely attributed to anthropogenic disturbances that reduce habitat quantity, quality, and connectivity. In the Laurentian Great Lakes, wetlands have been significantly lost as a result of agricultural land-use practice, yet high species richness and several at-risk fishes persist. These patterns lead to the hypothesis that Great Lakes wetland fishes are in extinction debt, meaning there is a time lag between habitat loss and local extinction. To test this hypothesis, we sampled current species richness of wetland-specialist fishes in protected and unprotected wetlands in the Lake Erie basin. We predicted species richness in unprotected wetlands using parameter estimates (slope and intercept) from protected wetlands. Extinction debt was measured as a positive difference between predicted and observed species richness. We determined how much area would be required to support current species richness and compared this to minimum-area requirements for eight at-risk fishes. Species richness was significantly higher than predicted in unprotected wetlands, indicating that fishes in them are in extinction debt. This result indicates that there is time available to restore disturbed wetlands and prevent local extinction. We identified 17 wetlands of high priority for restoration (>10 species bound for extinction) and determined that the restoration of 178 km2 of wetland habitat would reduce the risk of future biodiversity loss. This is the first direct study of extinction debt in freshwater fishes. Additional extinction-debt assessments in aquatic systems are needed to extend the ecological theory and fundamental application of extinction debt beyond terrestrial systems.

Evaluation of reproducibility of the chemical solubility of dental ceramics using ISO 6872:2015

Statement of problemThe current chemical solubility method in the International Standards Organization (ISO) 6872 (2015) specifies only the total surface area of specimens for testing (≥30 cm2) but does not describe the morphology or geometry. This could impact the reproducibility of the test outcomes. PurposeThe purpose of this in vitro study was to investigate the factors influencing the reliability of the ISO 6872:2015 “Dentistry-Ceramic materials” test for chemical solubility. Material and methodsChemical solubility analysis of a range of materials and specimen geometries was performed in accordance with ISO 6872:2015. Yttria-stabilized tetragonal zirconia polycrystal (Y-TZP), VITABLOCS Mark II, IPS e.max Press, and IPS e.max ZirPress materials were formed into a range of cubic and spherical geometries to comply with the 30-cm2 minimum surface area requirement. The surface microstructure of the specimens was analyzed using a scanning electron microscope, inductively coupled plasma optical emission spectrometry (ICP-OES) was used to analyze the solutes, and surface hardness of the specimens was measured by using a Vickers hardness tester before and after testing. An optimized solubility test was devised, which eliminated specimen handling once the specimens had been ground and polished. This modified test was performed on VITABLOCS Mark II and Y-TZP. ResultsThe results of the original chemical solubility method of ISO 6872:2015 showed significantly variable findings for each tested material, with a predictable relationship between geometry and chemical solubility. The hardness values decreased significantly after the solubility testing. The optimized method showed significantly improved reproducibility of the chemical solubility measurement compared with the original ISO 6872:2015 test. ConclusionsThe results of the current chemical solubility standard method can be manipulated while still complying with the ISO 6872:2015 standard.

The small-island effect and nestedness in assemblages of medium- and large-bodied mammals on Chinese reservoir land-bridge islands

Large hydroelectric dams have become a major driver of habitat loss and fragmentation worldwide. The small-island effect (SIE) and nestedness are two general biogeographical patterns that have important implications for biodiversity conservation in fragmented systems. In this study, we tested for the existence of the SIE and nestedness patterns in medium- and large-bodied mammals (>1kg) (hereafter mammals) on land-bridge islands created by a large hydroelectric dam in the Thousand Island Lake, China. We used the camera trapping method to determine the distribution of mammals on 32 study islands from May 2011 to March 2014. To evaluate whether an SIE exists in mammals, we used the information-theoretic multimodel inference approach to compare the fit of a simple logarithmic model with two most widely used breakpoint regression models. Model selection based on corrected Akaike’s information criterion (AICc) identified the left-horizontal SIE model and the continuous two-slope SIE model as the two best models. Thus, we found strong evidence for the existence of an SIE in our study system. The SIE in mammal assemblages may result from episodic disturbances, stochastic events and nutrient subsidies from the lake. We used the metric NODF to quantify nestedness and found that mammal assemblages were significantly nested. The nestedness of mammal assemblages was significantly correlated with island area and species traits linked to extinction risk (i.e. minimum area requirement). Our results indicate that conservation priorities should be on protecting large islands and species with large area requirement for the effective conservation of mammals in this fragmented reservoir system.

Quality assurance in molecular testing: Assessing minimum tumour area requirements for PCR amplification and MALDI-TOF ms using ffpe tissues

We sought to accurately determine the minimal tumour area required for accurate mutation detection from FFPE blocks with MALDI-TOF mass spectrometry, using Leica Laser microdissection (LMD 7) and Agena OncoFocus mutation panel. The panel uses 107 multiplexed PCRs to detect <200 mutations in EGFR, BRAF, KRAS, NRAS and KIT genes.

Loss of only the smallest patches will reduce species diversity in most discrete habitat networks.

Under many global-change scenarios, small habitat patches are the most vulnerable to destruction. For example, smaller ponds are at greater risk in a drying climate and their loss would remove any obligate aquatic individuals present. We asked what proportional loss of species diversity from metacommunities comprised of discrete habitat patches should be expected from attrition (complete loss) of only the smallest patches under such a premise. We analyzed 175 published datasets for different taxonomic groups (vertebrates, invertebrates, and plants) and habitat types (islands, habitat islands, and fragments). We simulated the destruction of only the smallest patches to an approximate 20% of total area (range: 15.2%-24.2%) and analyzed species loss. Mean [±95% CI] species loss was 12.7% [10.8, 14.6], although 18.3% of datasets lost no species. Four broad patterns of species loss were evident, reflecting underlying differences in minimum area requirements and the degree of species turnover among patches. Regression modeling showed species loss increased with greater species turnover among patches (βSIM ) and decreased with greater area scaling of diversity (i.e., larger power-law island species-area relationship exponents). Losses also increased with greater numbers of single-patch endemics and with increasing proportions of patches destroyed. After accounting for these predictors, neither taxonomic group nor habitat type increased explained variation in species loss. Attrition of the smallest patches removed species in >80% of metacommunities, despite all larger patches and >75% of total area remaining intact. At both 10% and 20% area reduction, median species loss across all datasets was around 50% higher than predicted from methods based on the species-area relationship. We conclude that any mechanism of global change that selectively destroys small habitat patches will lead to imminent extinctions in most discrete metacommunities.

How small an island? Speciation by endemic mammals (Apomys, Muridae) on an oceanic Philippine island

AbstractAimTo investigate the influence of oceanic island area on speciation by small mammals, in the context of other land vertebrates.LocationMindoro Island (9,735 km2), an oceanic island in the Philippines.MethodsExtensive field surveys on Mindoro, followed by sequencing one mitochondrial and three nuclear genes for use in phylogenetic, population genetic and coalescent‐based analyses, and by morphometric analysis of craniodental data.ResultsOur analyses documented the presence on Mindoro of an endemic clade of probably four species of Apomys, subgenus Megapomys. The common ancestor likely arrived from Luzon Island across a narrow sea channel between 2.4 and 1.5 Ma; the four probable species occur allopatrically, with variation in their ranges along elevational gradients. Mindoro thus becomes the smallest oceanic island on which speciation by small mammals has been documented.Main conclusionsA review of land‐living vertebrates suggests that bats and large mammals have the greatest area requirements for speciation, whereas frogs, lizards, birds and small mammals have lower and similar minimum area requirements. However, with the exception of Anolis lizards, data are scattered and limited; much research is needed to document the impact of island area on speciation. The existence of a lower limit implies that the biological processes that influence species richness do not operate equivalently along a gradient of island areas: speciation within islands may not contribute to changes in species richness below some limit, unlike colonization and extinction, which operate at all island sizes.

Influence of specific surface area on coal dust explosibility using the 20-L chamber

The relationship between the explosion inerting effectiveness of rock dusts on coal dusts, as a function of the specific surface area (cm2/g) of each component is examined through the use of 20-L explosion chamber testing. More specifically, a linear relationship is demonstrated for the rock dust to coal dust (or incombustible to combustible) content of such inerted mixtures with the specific surface area of the coal and the inverse of that area of the rock dust. Hence, the inerting effectiveness, defined as above, is more generally linearly dependent on the ratio of the two surface areas. The focus on specific surface areas, particularly of the rock dust, provide supporting data for minimum surface area requirements in addition to the 70% less than 200 mesh requirement specified in 30 CFR 75.2.