Little evidence of a road‐effect zone for nocturnal,flying insects

Roads and traffic may be contributing to global declines of insect populations. The ecological effects of roads often extend far into the surrounding habitat, over a distance known as the road‐effect zone. The quality of habitat in the road‐effect zone is generally degraded (e.g., due to edge effects, noise, light, and chemical pollution) and can be reflected in species presence, abundance, or demographic parameters. Road‐effect zones have been quantified for some vertebrate species but are yet to be quantified for insects. Investigating the road‐effect zone for insects will provide a better understanding of how roads impact ecosystems, which is particularly important given the role insects play as pollinators, predators, and prey for other species. We quantified the road‐effect zone for nocturnal flying insects along three major freeways in agricultural landscapes in southeast Australia. We collected insects using light traps at six points along 2‐km transects perpendicular to each highway (n = 17). We sorted the samples into order, and dried and weighed each order to obtain a measure of dry biomass. Using regression models within a Bayesian framework of inference, we estimated the change in biomass of each order with distance from the road, while accounting for environmental variables such as temperature, moon phase, and vegetation structure. The biomass of nine of the ten orders sampled did not change with distance from the freeway. Orthoptera (i.e., grasshoppers and crickets) was the only order whose biomass increased with distance from the freeway. From our findings, we suggest that the impacts of roads on insects are unlikely extending into the surrounding landscape over a distance of 2 km. Therefore, if there are impacts of roads on insects, these are more likely to be concentrated at the road itself, or on finer taxonomic scales such as family or genus level.     

Understanding the interacting factors that determine ecological effectiveness of terrestrial protected areas

Protected areas are recognized as an essential tool to safeguard habitat integrity and biodiversity in the Anthropocene. Substantial efforts have been made to clarify the conditions under which they deliver conservation outcomes effectively. Location, spatial design, management strategy and threats, have commonly been identified as key factors. The impacts of these factors have, however, often been evaluated independently, and there is limited information on how their combined and interactive effects can improve or hinder protected area effectiveness. Here we develop a framework for understanding the combined effects of these factors. This has important implications for how protected areas are established and maintained.     

我国道路对野生动物影响研究的现状与挑战

全球交通基础设施网络的不断扩张导致的栖息地丧失和破碎化已成为生物多样性下降的主要影响因素之一。国外开展了大量的道路对野生动物生存影响的研究, 相对而言, 我国在该领域的研究刚刚起步。本文通过总结截止于2021年国内的144篇案例研究文献以及新浪微博中210条道路交通伤害信息, 将我国道路对野生动物的影响分为栖息地丧失、栖息地破碎化、回避或聚集路边、阻碍或促进迁移、种群隔离、野生动物通道和道路交通伤害等方面, 从研究方法、研究地点、研究物种和研究结果等不同角度进行梳理和总结。近年来, 我国的相关研究呈现不断增长的趋势, 研究地点主要集中在可可西里、长白山和秦岭地区; 研究物种主要为青藏高原有蹄类、大熊猫(Ailuropoda melanoleuca)和亚洲象(Elephas maximus)。未来重点发展方向应包括: (1)道路野生动物基础数据采集平台建设; (2)我国不同动物地理分区的道路野生动物相关研究; (3)深入开展学科交叉与部门合作以及国际交流合作。公众在社交媒体发布的相关信息表明近年来公众对道路交通伤害问题越来越关注, 未来开展基于公民科学收集道路交通伤害数据具有迫切性和可行性。     

改善颗粒物污染的道路绿地植被屏障研究进展

减少道路环境的颗粒物污染对通勤者的健康至关重要。道路绿地在交通排放和邻近区域之间形成屏障,但这种植被屏障是否可以有效消减局部颗粒物污染仍然需要深入研究和探讨。结合现有研究成果,阐述了植被对颗粒物污染的影响途径;分析了街道峡谷和开放道路两种典型城市道路环境中,植被组成及群落结构设计的关键特征对颗粒物分布和扩散的影响;总结了有利于消减颗粒物浓度的植被单株性状和叶片微形态;探讨了影响颗粒物浓度的其他因子的耦合作用;针对不同道路环境提出了有效的植被屏障设计建议,并指出了植被群落设计和叶片微形态方面的研究趋势,以期优化道路植被规划,改善路域空气质量。     

Road density and wetland context alter population structure of a freshwater turtle

Roads are detrimental to wildlife populations that require contiguous networks of terrestrial and aquatic habitats. Many species of freshwater turtles are sensitive to habitat fragmentation caused by roads, and are susceptible to road mortality during overland migrations. The common long‐necked turtle (Chelodina longicollis) is an Australian freshwater turtle that frequently moves between wetlands, and so populations may incur negative impacts from road effects. Here, we assessed the relationship between C. longicollis and road density and landscape variables within populations inhabiting 20 wetlands distributed throughout greater Melbourne, Australia. The size frequency distribution of C. longicollis at sites surrounded by high road densities was skewed towards larger individuals, but there was no difference in the frequency of juveniles between high and low road density sites. Regression modelling revealed a clear positive relationship between road density and carapace length (CL) of C. longicollis; the mean CL at a site with the highest road density was predicted to be 23% greater than mean CL at a site surrounded by no roads. Female CL was also positively related to road density. There was a clear positive relationship between wetland age and CL, although this relationship was not as strong. While there was no relationship evident between road density and the proportion of female C. longicollis at a site, more females were captured at smaller ephemeral sites surrounded by a high proportion of green open space and located near drainage lines. We did not find evidence of sex‐related differences in road effects. These results suggest that roads may be affecting C. longicollis in the study area, but the direct cause of any effects is difficult to identify.     

生态旅游对大熊猫影响评价方法研究——以四川唐家河国家级自然保护区为例

旅游活动及伴随的人流、车流逐渐成为野生动物的主要干扰源,威胁着濒危物种的繁殖和生存。准确认识旅游活动对野生动物的影响是制定保护对策和提高保护成效的基础,但生态学领域有关旅游对野生动物影响的量化研究还比较少,可借鉴的评估方法仍较为缺乏。本研究比较唐家河国家级自然保护区旅游开发前(2000年)和开发后(2012年)大熊猫(Ailuropoda melanoleuca)痕迹点距离路线的平均回避距离和最小回避距离,发现大熊猫对徒步路线表现出明显的回避效应,表明近年来的旅游活动对大熊猫确实产生了影响。通过最小回避距离和距离递增法确定旅游活动对大熊猫的影响等级和阈值距离。确定了距离徒步路线和自驾路线的第一等级距离阈值分别为0~57 m和0~460 m、第二等级为57~800 m和460~1 000 m、第三等级为800~1 400 m和大于1 000 m。基于距离徒步路线和自驾路线一定范围内的痕迹点分布数量,大熊猫对不同路线两侧每100 m的栖息地平均利用频率分别为1.9±0.23和0.8±0.15,通过Mann-Whitney U检验,发现二者间存在显著性差异(Z=﹣3.48,P=0.000)。通过对每100 m海拔区间内大熊猫痕迹距离自驾路线和徒步路线的距离分析,发现二者差异显著(t=3.76,P=0.003),对自驾路线,大熊猫在海拔2 000~2 100 m时回避距离最小,而对徒步路线,最小回避距离发生在2 100~2 200 m。基于本研究,为自然保护区内最小接触区或禁止旅游区的划分提供了依据,同时为其他保护区探索适合的生态旅游影响评价方法提供了示范和经验。     

Assessments of contamination and human health risks of heavy metals in the road dust from a mining county in Guangxi,China

A total of 32 road dust samples were collected from mining areas and a control area in Nandan County, Guangxi, in order to investigate the contamination characteristics of heavy metals and associated health risks to local residents. The results indicated that elevated concentrations of As, Cd, Cu, Pb, Sb, and Zn were found in road dust in mining areas compared with control areas and background values. Pearson's correlation analysis and principal component analysis indicated that As, Cd, Cu, Pb, Sb, and Zn in road dust mainly originated from anthropogenic sources (e.g., vehicles emission, mining activities, and smelting activities), whereas Cr, Co, and Ni were associated with natural sources (e.g., soil weathering). Furthermore, noncarcinogenic hazards to both adults and children were found in mining areas, while noncarcinogenic health risks in the control area were negligible. The health hazard was mostly ascribed to the ingestion, followed by the dermal contact, and the inhalation. The cancer risks from As, Cd, Co, Cr, and Ni in all studied areas were within safe levels as the R values were below the threshold of 1 × 10^?6.     

Functional response of plant assemblages to management practices in road–field boundaries

Questions

Management practices implemented on road verges are partly established to preserve biodiversity in agricultural landscapes. Their evaluation was primarily based on the analysis of the taxonomic structure and composition of communities. What is the relationship between management practices and the functional characteristics of road–field plants within elements?

Location

West‐central France.

Methods

We sampled the berm, the embankment and the field margin of 40 road–field boundaries located in west‐central France, an area where delayed mowing of some berms has been practised since 2009 for biodiversity reasons. We characterized management practices implemented on the different elements, i.e., the frequency and timing of mowing (early summer or late summer), the frequency of herbicide treatment in field margins and the N input rate. We retrieved from databases seven functional traits and types known to be influenced by management practices. To identify relationships between traits or types and environmental variables we first performed partial RLQ analyses to remove any potential confounding effect of the landscape context studied. We then computed fourth‐corner statistics to quantify relationships between traits or types, environmental variables and partial RLQ axes.

Results

Late mowing of the berm promoted nitrophilous species within berms and competitive rather than ruderal species within arable field margins. The frequency of herbicide treatment in field margins promoted broad‐leaf species within this element and, to a lesser extent, within embankments. Finally, the functional characteristics of communities of the three elements were not influenced by the level of N input in field margins.

Conclusions

In our environmental context, managing road verges affected the functional structure of plant assemblages both within them and within their adjacent arable field margins. We suggest a single early mowing of berms as a valuable practice for both conservation purposes and weed risk control in adjacent field margins.     

Are wildlife escape ramps needed along Australian highways?

Road escape ramps are structures developed in the USA to enable large mammals that become trapped on the roadside of a wildlife fence to escape the road and avoid vehicle collision. They are now commonly installed in eastern Australia to enable the Koala (Phascolarctos cinereus) and other fauna to escape through a roadside exclusion fence and return to the forest. We investigated the use of seven of 14 escape ramps over three years on the Oxley Highway at Port Macquarie in New South Wales. The Swamp Wallaby (Wallabia bicolor) was the most frequently detected species, traversing the escape ramps on 502 occasions, followed by bandicoots (Isoodon macrourus and Perameles nasuta) on 148 occasions. Various other species were detected but no Koalas. Swamp Wallabies moved through the escape ramps in the reverse direction (i.e. towards the road) in 53% of detections of that species and bandicoots in 14% of their detections. There was no obvious pattern by these species of proportionately higher use of ramps closer to the end of the exclusion fences. The large number of reverse passages through the escape ramps reveals a poor design of these structures. Trials with taller ramps are required to determine how to minimise reverse passages. Concurrent monitoring of three underpasses detected numerous crossings by large mammals including Swamp Wallabies, and some crossings by Koalas. We believe evidence is needed to demonstrate the necessity for escape ramps along Australian highways.