Highway Transects Research Articles

High roadkill rates in the Dong Phayayen‐Khao Yai World Heritage Site: conservation implications of a rising threat to wildlife

AbstractRoad networks are increasing globally, and as such incur increased pressure on wildlife communities. Large‐scale road expansion and infrastructure development occurring throughout Asia (i.e. Belt and Road Initiative) will affect hundreds of threatened species, leading to an increase in wildlife‐vehicle collisions. However, only a limited number of studies have quantified road mortality within this threatened landscape. To rectify this, we monitored the spatial‐temporal patterns of vertebrate roadkill in the Dong Phayayen‐Khao Yai forest complex, an UNESCO World Heritage Site located in Thailand, considered a refuge for many globally threatened species. We ran 100 standardized road surveys between 2015 and 2017, on a 47.8‐km highway transect currently being expanded, and recorded a total of 1395 casualties from 124 species. After correcting for removal time and detection probability, we estimated an average of 9688 vertebrate mortalities per year. We observed a mortality peak during the dry season for almost all taxonomic groups, due to a combination of high bird and bat mortality events. All taxa showed significant spatial clustering, highlighting high‐risk road sections. We modelled the road and landscape features most likely to lead to higher mortality rates, disentangling small‐scale (250–500 m from road) from large‐scale effects (1000–2500 m). We recorded lower mortality rates and species diversity near forest sites in protected areas, representing either lower crossing events due to habitat quality or an already depleted environment. Spatial analyses provided information on hotspots and landscape factors, which can be used to inform future mitigations at multiple scales throughout the Southeast Asia region. Our study provides a baseline of the direct road impacts on vertebrate species in a tropical biodiversity hotspot, and we suggest that more studies be conducted to fully assess the direct road effects on the many threatened species in this landscape.

The effects of a national highway on the Endangered golden-brown mouse lemurMicrocebus ravelobensisin Ankarafantsika National Park, Madagascar

AbstractAlthough roads are often assumed to be barriers to the dispersal of arboreal species, there has been little empirical testing of this assumption. If arboreal animals are unable to cross roads, population subdivision may occur, or resources may become inaccessible. We tested the hypothesis that Route Nationale 4 (RN4), a paved highway, was a barrier to movement and dispersal of the Endangered golden-brown mouse lemurMicrocebus ravelobensisin Ankarafantsika National Park, in north-west Madagascar. During June–August 2015 we conducted a capture–mark–recapture study at three sites: two adjacent to RN4 and one within intact forest without a potential barrier. During 2,294 trap nights we captured 120 golden-brown mouse lemurs 1,032 times. In roadside habitats we captured significantly more males than females, whereas the opposite was the case in interior forest habitat. We detected eighteen crossings of highway transects by nine individuals; however, all potential dispersal events involved males. In roadside habitat, movement was significantly inhibited in both males and females. We present some of the first data on the effects of roads on movement patterns in arboreal Malagasy mammals, showing species- and sex-biased effects of roads as dispersal barriers. Our findings indicate that roads may not be complete barriers to dispersal in lemurs. We recommend that conservation managers and scientists examine explicitly the effects of roads and natural arboreal bridges in Madagascar in future studies.

A new map of permafrost distribution on the Tibetan Plateau

Abstract. The Tibetan Plateau (TP) has the largest areas of permafrost terrain in the mid- and low-latitude regions of the world. Some permafrost distribution maps have been compiled but, due to limited data sources, ambiguous criteria, inadequate validation, and deficiency of high-quality spatial data sets, there is high uncertainty in the mapping of the permafrost distribution on the TP. We generated a new permafrost map based on freezing and thawing indices from modified Moderate Resolution Imaging Spectroradiometer (MODIS) land surface temperatures (LSTs) and validated this map using various ground-based data sets. The soil thermal properties of five soil types across the TP were estimated according to an empirical equation and soil properties (moisture content and bulk density). The temperature at the top of permafrost (TTOP) model was applied to simulate the permafrost distribution. Permafrost, seasonally frozen ground, and unfrozen ground covered areas of 1.06 × 106 km2 (0.97–1.15 × 106 km2, 90 % confidence interval) (40 %), 1.46 × 106 (56 %), and 0.03 × 106 km2 (1 %), respectively, excluding glaciers and lakes. Ground-based observations of the permafrost distribution across the five investigated regions (IRs, located in the transition zones of the permafrost and seasonally frozen ground) and three highway transects (across the entire permafrost regions from north to south) were used to validate the model. Validation results showed that the kappa coefficient varied from 0.38 to 0.78 with a mean of 0.57 for the five IRs and 0.62 to 0.74 with a mean of 0.68 within the three transects. Compared with earlier studies, the TTOP modelling results show greater accuracy. The results provide more detailed information on the permafrost distribution and basic data for use in future research on the Tibetan Plateau permafrost.

Correlation Between Physiomechanical Parameters and Geotechnical Evaluations of Some Sandstones Along the Calabar/Odukpani–Ikom–Ogoja Highway Transect, Southeastern Nigeria

Sandstones are present in enormous quantity in parts of south-eastern Nigeria. However, engineering data for project design and construction are unavailable for these sandstones, which serve as aggregates and foundation for many infrastructures. Besides, it is expensive and time consuming to perform direct tests in the field to generate these data. This work presents an engineering evaluation for some of sandstones based on relatively simple and cheap tests and relationship. The aim was to determine compressive strength, Young’s modulus, density, porosity and water absorption. These physio-mechanical parameters were then used to establish relationships. On the basis of these relationships, an evaluation scheme was developed. The parameters with good relations were used to develop predictive equations for estimating uniaxial compressive strength. Evaluation of sandstones from south-eastern Nigeria showed variations from not suitable to suitable as construction materials. Practically, field observations showed no adverse effects on buildings and roads where these sandstones have been used for construction as foundations and aggregates.

Transition metals in coarse, fine, very fine and ultra-fine particles from an interstate highway transect near Detroit

As one component of a study investigating the impact of vehicle emissions on near-road air quality, human exposures, and potential health effects, particles were measured from September 21 to October 30, 2010 on both sides of a major roadway (Interstate-96) in Detroit. Traffic moved freely on this 12 lane freeway with a mean velocity of 69 mi/hr. with little braking and acceleration. The UC Davis DELTA Group rotating drum (DRUM) impactors were used to collect particles in 8 size ranges at sites nominally 100 m south, 10 m north, 100 m north, and 300 m north of the highway. Ultra-fine particles were continuously collected at the 10 m north and 100 m north sites. Samples were analyzed every 3 h for mass (soft beta ray transmission), 42 elements (synchrotron-induced x-ray fluorescence) and optical attenuation (350–800 nm spectroscopy). A three day period of steady southerly winds along the array allowed direct measurement of freeway emission rates for coarse (10 > Dp > 1.0 μm), PM2.5, very fine (0.26 > Dp > 0.09 μm), and ultra-fine (Dp < 0.09 μm) particles. The PM2.5 mass concentrations were modeled using literature emission rates during the south to north wind periods, and averaged 1.6 ± 0.5 μg/m3, versus the measured value of 2.0 ± 0.7 μg/m3. Using European freeway emission rates from 2010, and modeling them at the I-96 site, we would predict roughly 3.1 μg/m3 of PM2.5 particles, corrected from the 4.9 PM10 value by their measured road dust contributions. Using California car and truck emission rates of 1973, this value would have been about 16 μg/m3, corrected down from the 19 μg/m3 PM5.0 using measured roadway dust contributions. This would have included 2.7 μg/m3 of lead, versus the 0.0033 μg/m3 measured. Very fine particles were distributed across the array with a relatively weak falloff versus distance. For the ultra-fine particles, emissions of soot and metals seen in vehicular braking studies correlated with traffic at the 10 m site, but only the soot was statistically significant at the 100 m north site. Otherwise, the 10 m north and 100 m north sites were essentially identical in mean concentration and highly correlated in time for most of the 5 week study. This result supports earlier publications showing the ability of very fine and ultra-fine particles to transport to sites well removed from the freeway sources. The concentrations of very fine and ultra-fine metals from brake wear and zinc in motor oil observed in Detroit have the potential of being a significant component in statistically established PM2.5 mortality rates.

Artificial ultra-fine aerosol tracers for highway transect studies

The persistent evidence of health impacts of roadway aerosols requires extensive information for urban planning to avoid putting populations at risk, especially in-fill projects. The required information must cover both highway aerosol sources as well as transport into residential areas under a variety of roadway configurations, traffic conditions, downwind vegetation, and meteorology. Such studies are difficult and expensive to do, but were easier in the past when there was a robust fine aerosol tracer uniquely tied to traffic – lead. In this report we propose and test a modern alternative, highway safety flare aerosols. Roadway safety flares on vehicles in traffic can provide very fine and ultra-fine aerosols of unique composition that can be detected quantitatively far downwind of roadways due to a lack of upwind interferences. The collection method uses inexpensive portable aerosol collection hardware and x-ray analysis protocols. The time required for each transect is typically 1 h. Side by side tests showed precision at ± 4%. We have evaluated this technique both by aerosol removal in vegetation in a wind tunnel and by tracking aerosols downwind of freeways as a function of season, highway configuration and vegetation coverage. The results show that sound walls for at-grade freeways cause freeway pollution to extend much farther downwind than standard models predict. The elevated or fill section freeway on a berm projected essentially undiluted roadway aerosols at distances well beyond 325 m, deep into residential neighborhoods. Canopy vegetation with roughly 70% cover reduced very fine and ultra-fine aerosols by up to a factor of 2 at distances up to 200 m downwind.

古尔班通古特沙漠南部植物多样性的区域差异

PDF HTML阅读 XML下载 导出引用 引用提醒 古尔班通古特沙漠南部植物多样性的区域差异 DOI: 10.5846/stxb201402270338 作者: 作者单位: 新疆石河子大学,石河子大学生命科学学院,石河子大学,石河子大学生命科学学院 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——新疆联合基金重点项目(U1130304);国家自然科学基金资助项目(41061004) Regional differences in plant diversity in the southern Gurbantonggut desert Author: Affiliation: College of Life Science, Shihezi University,,College of Life Science, Shihezi University 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:植物多样性分布受环境影响,具有尺度依赖性,研究不同区域植物多样性的差异和分布规律有助于剖析群落多样性的整体形成和变化原因,进而为实施有效的保护和利用提供科学依据。以古尔班通古特沙漠植物多样性集中分布的南部为研究区,沿经向方向划分3条样带(绿洲边缘样带、克拉玛依至吉木萨尔的沙漠公路样带以及距离二者之间的沙漠腹地样带),同时根据沙垄高度、走向和生境差异将研究区划分为5个分区,对比研究各样带、各分区的α、β多样性特征及物种共性和差异性。结果表明:3条样带的α多样性变化为绿洲边缘样带 > 沙漠公路样带 > 沙漠腹地样带。随经度的增加,各样带的物种相似性和替代性特征表现相似的变化趋势。物种分析发现沙漠公路样带内短命植物分布较多,绿洲边缘样带以多年生草本和灌木群落为主,而沙漠腹地样带介于二者之间。各分区间的物种组成存在一定差异。沙漠西部、东部、莫索湾垦区附近、沙漠腹地等分区物种丰富度均较高,而古玛纳斯湖区的植物丰富度较低,与其余4个分区间的物种相似性小,相互替代性较强。总结认为古尔班通古特沙漠南部各分区间植物多样性受地史过程的影响较大,而样带间植物多样性受土壤质地、降水量等环境因素影响较大;沙漠东部似是整个南部沙漠的物种扩散中心。 Abstract:The distribution of plant diversity is influenced by the environment, such that one area is species-rich, another area species-poor and intermediate areas of moderate richness, so it is scale-dependent, so it is scale-dependent. Studying the variety and distributed regularity of plant diversity in different regions can help us understand the underlying reasons for plant community diversity and changes to this diversity, and determine how to effectively protect and use these plant resources. In this study, we focused on the south Gurbantonggut desert, a known center of plant diversity. We divided the study site along the meridional direction into the following three transects:the oasis edge, the desert highroad from Karamay to Jimusaer, and the desert hinterland. We also divided the study site into five regions, according to the height and trend of dunes and differences in habitats. We analyzed the α-diversity and β-diversity in all transects and regions, and summarized the similarities and differences in species composition. These results showed that the α-diversity in the three transects differed, with the order as follows:oasis edge transect > desert highway transect > desert hinterland transect. The β-diversity (species similarity and substitution) of the transects varied similarly with increasing longitude. According to the species composition analysis, the desert highway transect consisted mostly of ephemeral plants, the oasis edge transect had mostly perennial herbs and shrubs, and the diversity in the desert hinterland transect had a mix of ephemeral plants, perennial herbs, and shrubs. We also observed a difference in species composition among the regions. Species richness in the western part of the desert, the Mosuowan reclamation area, desert interior, and the eastern part of the desert was high, whereas that of the Manasi Lake area was relatively low. Although species similarity of the Manasi Lake was low, its species substitution rate was high, when compared with other regions. We concluded that plant diversity among the regions is driven by the geological processes of the species pool, and that plant diversity among the transects is driven by environmental factors such as soil texture and precipitation. The eastern part of the study area was determined to be the species diffusion center of the south Gurbantonggut desert. 参考文献 相似文献 引证文献

Updated paleomagnetic pole from Cretaceous plutonic rocks of the Sierra Nevada, California: Tectonic displacement of the Sierra Nevada block

We report remanent magnetization measurements from 13 sites in Cretaceous plutonic rocks in the northern Sierra Nevada (38°N–39.5°N). By increasing the number of available paleomagnetic sites, the new data tighten constraints on the displacement history of the Sierra Nevada block and its pre-extensional position relative to interior North America. We collected samples in freshly exposed outcrops along four highway transects. The rocks include diorite, granodiorite, and tonalite with potassium-argon ages (hornblende) ranging from 100 Ma to 83 Ma. By combining our results with previous paleomagnetic determinations from the central and southern Sierra Nevada (excluding sites from the rotated southern tip east of the White Wolf–Kern Canyon fault system), we find a mean paleomagnetic pole of 70.5°N, 188.2°E, A 95 = 2.6° ( N = 26, Fisher concentration parameter, K = 118). Thermal demagnetization indicates that the characteristic remanence is generally unblocked in a narrow range within 35 °C of the Curie temperature of pure magnetite. Small apparent polar wander during the Cretaceous normal-polarity superchron, plus prolonged acquisition of remanence at the site level, may account for the low dispersion of virtual geomagnetic poles and relatively large K value. Tilt estimates based on overlapping sediments, stream gradients, and thermochronology of the Sierra Nevada plutons vary from 0° to 3° down to the southwest. Without tilt correction, the mean paleomagnetic pole for the Sierra Nevada is essentially coincident with the North American reference pole during the Cretaceous stillstand (125 Ma to 80 Ma). At 95% confidence, the apparent latitude shift is 1.1° ± 3.0° (positive northward), and the apparent rotation is negligible, 0.0° ± 4.7°. Correcting for each degree of tilt, which is limited to 3° on geologic evidence, increases the rotation anomaly 2.2° counterclockwise, while the apparent latitude shift remains unchanged.

Combining Kohonen neural networks and variable selection by classification trees to cluster road soil samples

Kohonen neural networks, or Self-Organizing Maps (SOMs), were used to study the data sets generated in a survey of soil pollution along a four-season study. Each sampling season comprised 89 road soil samples and 12 analytical variables; namely, nine heavy metals (Cd, Co, Cu, Cr, Fe, Mn, Ni, Pb, and Zn) and three physicochemical parameters (loss on ignition, pH and humidity). The SOMs provided a rapid and intuitive means to recogniz3e four different groups of samples: roadside of a highway, highway transects, roadside of a main avenue and urban gardens. They became defined essentially by the physical characteristics of the sampling sites and by the intensity of the road traffic. In order to simplify the chemical understanding of the patterns defining the different groups of samples, to avoid noisy and/or redundant variables and to reduce the time required to develop a suitable SOM, the usefulness of a previous variable selection step using CART, Classification and Regression Trees, was investigated.

Biomass measurements and relationships with Landsat‐7/ETM+ and JERS‐1/SAR data over Canada's western sub‐arctic and low arctic

Information on biomass distribution is needed to estimate GHG emissions and removals from land use changes in Canada's north for UNFCCC reporting. This paper reports aboveground biomass measurements along the Dempster Highway transect in 2004, and around Yellowknife and the Lupin Gold Mine in 2005. The measured aboveground biomass ranges are 10–100 t ha−1 for woodlands, 1–100 t ha−1 for shrub sites, and 0.5–10 t ha−1 for grass/herbs sites. The root mean squared error (RMSE) of measurements is 21%, and the median absolute percentage error (MedAPE) is 14%. The combination of JERS backscatter and Landsat TM4/TM5 gives the best biomass equation for the Dempster Highway transect, with r 2 = 0.72 when using a one‐step approach (i.e. using all points) and 0.78 when using a two‐step approach (i.e. stratifying data into three classes: grass, shrub, and woodlands). The two‐step approach reduces the MedAPE from 53% to 33%. The validation against Yellowknife & Lupin data indicates that the equations have good transferability. The improvement of two‐step approach over the one‐step approach, however, is not significant for the validation dataset, suggesting that the one‐step approach is as good as the two‐step approach when applied over areas outside where the equations are developed. The relationships and error analysis of this study, as well as the final estimate of GHG emission/removal over Canada's north have been incorporated into Canada's 2006 UNFCCC report.

Livestock feed resources, production and management in the agro-pastoral system of the Hindu Kush – Karakoram – Himalayan region of Pakistan: The effect of accessibility

A survey of 59 small-holder households was used to gather information about livestock production within a small-holder farming system in the Northern Areas of Pakistan. A broader survey of 130 households was used to gather information about cropping patterns, and access to off-farm employment and educational opportunities. The aim was to provide a description of the livestock production system in the Northern Areas and investigate the effect of agro-ecological zone and proximity to transport infrastructure on small-holder practices, especially those relating to livestock management. Two transects were selected for study differing in the quality of their transport infrastructure; the Karakoram Highway transect was defined by the Karakoram Highway, a major transport link through the study region, while the Gilgit–Ghizer Region transect lay along a side valley with a more limited transport infrastructure. One village from each of the three main agro-ecological zones within the region was selected in each transport infrastructure transect. Results showed that average landholding size was 1.6 ha of which around 60% was cultivated. Overall herd size did not differ significantly by zone or transect but there were more animals derived from cross-breeding with exotic breeds in the Karakoram Highway transect. The amount of fodder stored for livestock was higher in the Karakoram Highway transect than in the Gilgit–Ghizer Region transect. There was more selling of livestock in the Gilgit–Ghizer Region transect and the use of draught animals was also more prevalent in the Gilgit–Ghizer Region. The household questionnaire indicated that cash cropping, off-farm employment and degree of formal education were all higher in the Karakoram Highway transect, providing indirect evidence for a household economy less reliant on traditional livestock keeping for income. In conclusion, the survey results reveal a traditional small-holder system with heavy reliance on livestock. Householders in the lower altitude zones and those close to transport infrastructure appear to rely less heavily on livestock for income but have fodder resources which are more appropriate for their complement of livestock.

The tectonic evolution of the Kohistan‐Karakoram collision belt along the Karakoram Highway transect, north Pakistan

The Kohistan arc terrane comprises an intra‐oceanic island arc of Cretaceous age separating the Indian plate to the south from the Karakoram (Asian) plate to the north within the Indus suture zone of north Pakistan. The intra‐oceanic arc volcanics (Chalt, Dras Group) were built on a foundation of dominantly mid‐ocean ridge basalt (MORB)‐related amphibolites of the Kamila Group. The subarc magma chamber is represented by multiple intrusions of a huge gabbro‐norite complex (Chilas complex), which includes some ultramafic assemblages of residual mantle harzburgite and dunite, layered cumulates, and hornblendites cut by late stage dikes of hornblende + plagioclase pegmatites. The Chilas complex norites intrude the Gilgit metasediments of lower amphibolite and greenschist facies in northern Kohistan, which also form xenolithic roof pendants within the top of the Chilas complex. Along the southern margin of Kohistan, Jijal and Sapat complex ultramafics (dunites, harzburgites and websterites) form remnant suprasubduction zone ophiolitic mantle rocks along the hanging wall of the Main Mantle Thrust, the Cretaceous obduction plane along which Kohistan was emplaced onto Indian plate rocks. Garnet granulites of the Jijal complex, formed at 12–14 kbars, represent original magmatic lower crustal rocks subducted to depths of at least 45 km and metamorphosed during high‐pressure and high‐temperature subduction of earlier arc‐related rocks. Obduction of the Sapat ophiolite and Kohistan arc occurred between ∼75 and 55 Ma.The closure of the Shyok suture zone separating Kohistan from the Karakoram plate must have occurred prior to 75 Ma, the age of the Jutal basic dikes which crosscut the closure‐related fabrics, mainly late north directed backthrusting in the lower Hunza valley. Andean‐type granitoid (gabbrodiorite‐granodiorite‐granite) emplacement along the Kohistan‐Ladakh batholith ended at the time of India‐Asia collision, ∼ 60–50 Myr ago. Postcollisional crustal thickening along the Karakoram led to multiple episodes of metamorphism from latest Cretaceous and throughout the Tertiary. Sillimanite grade metamorphism in Hunza was actually pre‐India‐Asia collision and may have resulted from the earlier Kohistan collision. Localized and sporadic crustal melting episodes across northern Kohistan (Indus confluence and Parri granite sheets) and the southern Karakoram (Hunza dikes and Sumayar and Mango Gusar leucogranites) occurred from 51 to 9 Ma and culminated in the huge Baltoro monzogranite‐leucogranite intrusion 25–21 Myr ago. A vast network of leucogranitic and pegmatitite dikes containing gem quality aquamarine + muscovite ± tourmaline ± garnet ± biotite quartz are younger than 5 Ma and form the final phase of intrusion in the Haramosh area and parts of the southern Karakoram area.

Comparison of winter-nocturnal geostationary satellite infrared-surface temperature with shelter—height temperature in Florida

Geostationary satellite surface temperatures derived from a Visible and Infrared Spin Scan Radiometer ( vissr) sensor (10.5 to 12.6 microns) were compared with 1.5-m air temperatures collected by a thermocouple on a traversing vehicle along rural highway transects in Florida, and with two fixed thermographs located in rural and agricultural areas. Statistical comparisons between satellite and 1.5-m observations yielded a mean correlation coefficient of 0.87 and an average sample standard deviation from regression of 1.57°C during clear nights for four winters (1978–1981). The satellite-temperature image of Lake Okeechobee was compared with its geographic outline for areal image registration. Manual overlays of temporal images were repeatable to within one pixel. Satellite-sensed water temperature of Lake Okeechobee was used as an indicator of satellite radiometer repeatability and stability.