Comparing determinants of alien bird impacts across two continents: implications for risk assessment and management

Invasive alien species can have serious adverse impacts on both the environment and the economy. Being able to predict the impacts of an alien species could assist in preventing or reducing these impacts. This study aimed to establish whether there are any life history traits consistently correlated with the impacts of alien birds across two continents, Europe and Australia, as a first step toward identifying life history traits that may have the potential to be adopted as predictors of alien bird impacts. A recently established impact scoring system was used in combination with a literature review to allocate impact scores to alien bird species with self‐sustaining populations in Australia. These scores were then tested for correlation with a series of life history traits. The results were compared to data from a previous study in Europe, undertaken using the same methodology, in order to establish whether there are any life history traits consistently correlated with impact across both continents. Habitat generalism was the only life history trait found to be consistently correlated with impact in both Europe and Australia. This trait shows promise as a potential predictor of alien bird impacts. The results support the findings of previous studies in this field, and could be used to inform decisions regarding the prevention and management of future invasions.     

The role of species traits and taxonomic patterns in alien bird impacts

Aim To test whether the distribution of alien bird impacts varies across bird families and regions of origin, and to investigate whether species traits associated with successful introductions can predict which species will have negative impacts in the new area of introduction. Location Europe and the Mediterranean Basin. Methods Combining historical information and published literature about negative economic, biological and human health impacts, we compared the distribution of impacts among bird families and native origins of bird species for three major types of impact (economic, biodiversity and human health). We examined the relationships between ecological, biological and reproductive characteristics of species and the severity of the impacts. Results The majority of alien species with reported impacts originated from the Afrotropical, Indo‐Malayan and Palaearctic biogeographical regions. The distribution of alien bird species in Europe with reported impacts shows a taxonomic bias and largely mirrors patterns of establishment. While most species had primarily either economic or biodiversity impacts, several species in the Anatidae, Corvidae, Passeridae, Phasianidae and Sturnidae families were associated with moderate to serious negative impacts on both economic resources and native biodiversity. After controlling for taxonomic effects, species with the greatest overall impacts were habitat generalists and multi‐brooded, while species with smaller bodies and the tendency to form large feeding or roosting flocks were linked with greater impacts on native biodiversity. Main conclusions This study presents the first synthesis of published impact data for alien birds and provides a broad‐scale perspective on factors that contribute to their impacts. The results show that accounting for both species traits and taxonomy improves our ability to predict the impacts of alien bird species. Because several species are currently in the early stages of establishment in Europe, there may be an opportunity to limit negative impacts with efforts that promote proactive strategies against species and families possessing the above characteristics.     

影响河北省外来物种入侵的社会经济因素分析

[目的]探讨影响河北省外来物种入侵的社会经济因素,以期能够为河北省外来物种的防控提供可行性建议对策.[方法]通过查阅期刊、专著和数据库等分析了河北省外来入侵物种情况,对2003、2007、2011、2015、2019年5个时间节点的进口贸易、旅游人数、境内公路公里数3个社会经济变量与外来入侵物种量进行相关性分析,明确影...     

Extrinsic factors and the population sizes of threatened birds

Attempts to explain the orders-of-magnitude variation observed in animal population sizes have principally focused on intrinsic differences between the taxa compared, but with limited success: most variation remains unexplained by such studies. However, animal population sizes may also vary in response to extrinsic factors, such as the environment occupied or the influence of human activities. Here, we use new estimates of the global population sizes of threatened bird species to examine extrinsic correlates of variation in their numbers, using general linear modelling and methods to control for phylogenetic relatedness. Threatened bird population sizes varied significantly with several extrinsic factors, including altitude, biogeographical region inhabited, type of extinction threat faced, and habitat used. They also vary with geographical range size, which was included in the analysis to control for its potentially confounding effects on the results. Details of the observed relationships, which vary with analytical method, are discussed. However, apart from geographical range size, none of the extrinsic variables analysed here explain more than a small percentage of the variation in threatened bird population sizes. Thus, it seems likely that a comprehensive explanation for why some species are common while others are rare will not be dominated by a single factor.     

Global patterns of specialization and coexistence in bird assemblages

Aim Increased specialization has been hypothesized to facilitate local coexistence and thus high species richness, but empirical evaluations of the richness–specialization relationships have been relatively scant. Here, we provide a first assessment of this relationship for terrestrial bird assemblages at global extent and from fine to coarse grains. Location World‐wide. Methods We use two indices of specialization that describe species‐level resource use: diet and habitat specialization. The relationship between richness and mean assemblage‐level specialization was independently assessed at realm, biome‐realm, 12,100 km² equal‐area grid cells and fine‐grained scales. To identify assemblages that are diverse relative to environmental conditions we: (1) applied quantile regressions, (2) statistically accounted for other environmental variables which may constrain richness, and (3) parsed the data according to the residuals of a model relating species richness to the environmental variables. Results Assemblage species richness increases with both measures of specialization at all scales. Statistically, richness appears constrained by levels of specialization, with the highest richness values only found in specialized assemblages. Richness is positively associated with specialization even after accounting for gradients in resource availability. Net primary productivity and assemblage specialization have complementary statistical effects on assemblage species richness. Contrary to expectations based on niche partitioning of local resources, the relationship between specialization and richness is steep even at coarse scales. Main conclusions The results demonstrate that for an entire clade, totalling > 9000 species, specialization and species richness are related, at least for diverse assemblages. The strong patterns observed across scales suggest that this relationship does not solely originate from (1) limits on coexistence in present‐day assemblages, or (2) increased specialization in richer assemblages imposed by species’ abilities to partition ecological space. Instead, regional‐scale influences on the species pool may determine much of the observed relationship between richness and specialization. Although causal attribution is not straightforward, these findings support the idea that, for the scale of our analysis, specialization may be related to the past origination of high‐diversity assemblages, rather than their contemporary assembly.     

Distribution of alien animal species richness in the Czech Republic

Biogeographical barriers formed by natural forces over billions of years have been substantially disrupted by human activity, particularly in recent centuries. In response to these anthropogenic changes, global homogenization of biota is observed at an ever‐increasing rate, causing environmental and economic losses as well as emerging health risks. Identifying factors underlying alien species richness is essential for prevention of future introductions and subsequent spread. In this study, we examined the effects of environmental and human‐related factors on distribution of alien animal species richness in the Czech Republic (Central Europe). We compiled a set of maps showing the level of invasion of six categories of alien animal species in each of 628 grid cells (ca. 12.0 × 11.1 km) covering the Czech Republic. Relationships between alien species richness and 12 variables characterizing climatic conditions, topography, land cover, and human population size were calculated using the generalized least squares method. Species richness of all alien species, of invertebrates, and of terrestrial species showed the strongest positive relationship with mean annual temperature, while the number of black and grey (proposed prominent invaders) and aquatic species was most closely related to the presence of large rivers. Alien vertebrates showed a strong negative relationship with annual precipitation. The highest alien animal species richness was found in and near large population centers and in agricultural landscapes in warm and dry lowlands. The gateways for alien aquatic species are rather large rivers over sport fishing and aquaculture import. Compiled maps create a powerful visual communication tool, useful in development of programs to prevent future introductions.     

福建外来物种入侵现状及对经济社会和生态的影响

福建已成为中国遭受外来物种入侵最严重的省份之一。本文概述了福建主要入侵物种的数量、种类、地理起源、分布、引入途径和入侵特点,系统分析了福建外来物种入侵严重的原因和外来物种入侵对福建生态安全、经济及社会的影响,在此基础上提出了针对外来物种入侵的防控对策。     

外来种米草的生态功能评价与控制

米草是禾本科米草属多年生植物 ,对高盐淤泥质滩涂具有高度生态适应性。本文综述了米草作为外来入侵种对一些国家和地区的环境影响及其生态控制措施。一方面 ,米草的种群爆发严重威胁当地生物多样性 ,阻碍社会、经济的可持续发展 ;另一方面 ,米草的抵御海岸侵蚀和促淤造陆功能在全球变化引起未来海平面上升的背景下具有重要意义。米草的生态控制以化学措施最为快速有效 ,但可能污染环境。物理措施工程量大 ,适合于小面积米草控制。生物防治最有发展前景 ,但目前应用不理想 ,且容易引起次生生物入侵。 3S技术、种群扩散和增长模型以及长期监测系统等已经被应用于米草生态控制。最后就加强米草生态控制的基础研究和如何提高米草生态控制水平提出了若干建议     

Explanations for bird species range size: ecological correlates and phylogenetic effects in the Canary Islands

Aim To explore the determinants of island occupancy of 48 terrestrial bird species in an oceanic archipelago, accounting for ecological components while controlling for phylogenetic effects. Location The seven main islands of the Canary archipelago. Methods We obtained field data on population density, habitat breadth and landscape distribution in Tenerife, Fuerteventura and La Palma, aiming to sample all available habitats and the gradient of altitudes. In total, 1715 line transects of 0.5 km were carried out during the breeding season. We also reviewed the literature for data on occupancy, the distance between the Canary Islands and the nearest distribution border on the mainland, body size and endemicity of the 48 terrestrial bird species studied. Phylogenetic eigenvector regression was used to quantify (and to control for) the amount of phylogenetic signal. Results The two measurements of occupancy (number of occupied islands or 10 × 10 km UTM squares) were tightly correlated and produced very similar results. The occupancy of the terrestrial birds of the Canary Islands during the breeding season had a very low phylogenetic effect. Species with broader habitat breadth, stronger preferences for urban environments, smaller body size, and a lower degree of endemicity had a broader geographical distribution in the archipelago, occupying a larger number of islands and 10 × 10 UTM squares. Main conclusions The habitat‐generalist species with a tolerance for novel urban environments tend to be present on more islands and to occupy a greater area, whereas large‐sized species that are genetically differentiated within the islands are less widespread. Therefore, some properties of the ranges of these species are explicable from basic biological features. A positive relationship of range size with local abundance, previously shown in continental studies, was not found, probably because it relies on free dispersal on continuous landmasses, which may not be applicable on oceanic islands.     

外来植食性广聚萤叶甲对非靶标植物的潜在影响

为评估以入侵豚草为食的外来广聚萤叶甲（Ophraella communa）对非靶标植物的潜在生态风险,采用选择性试验测定了广聚萤叶甲成虫和幼虫对当地代表性植物的取食选择,观察了幼虫在选出的植物上生长发育的适合度表现。结果表明：在5大类52种测试植物中,广聚萤叶甲成虫和幼虫不同程度地取食向日葵、苍耳、天明精、菊芋（仅成虫）、紫茎泽兰（仅幼虫）和石胡荽（仅幼虫）;野外罩笼非选择性测定发现,初孵幼虫在苍耳和向日葵8个品种上可完成发育,直到成虫产卵,并观察到在菊芋上完成幼虫发育,个别到成虫但未产卵;在这些植物上幼虫存活率明显降低,蛹质量明显减轻,成虫产卵明显减少。本文还分析了广聚萤叶甲对少数本土植物以及经济作物向日葵的潜在生态风险。     

The distribution and economic losses of alien species invasion to China

Invasive alien species have become one of the most serious environmental issues in the world. Data of taxon, origin, pathway, and environmental impacts of invasive alien microorganisms, invertebrates, amphibians and reptiles, fish, birds, mammals, herbs, trees, and, marine organisms in terrestrial, aquatic, and marine ecosystems of China were analyzed during 2001 and 2003, based on literature retrieval and field survey. There were 283 invasive alien species in China, and the number of species of invasive alien microorganisms, aquatic plants, terrestrial plants, aquatic invertebrates, terrestrial invertebrates, amphibians and reptiles, fish, and mammals were 19, 18, 170, 25, 33, 3, 10, and 5, respectively. The proportion of invasive alien species originated from America, Europe, Asia, Africa, and Oceania were 55.1, 21.7, 9.9, 8.1, and 0.6%, respectively. Methods for estimation of direct economic losses to agriculture, forestry, stockbreeding, fishery, road and water transportation, storage, water conservancy, environment and public facilities, and human health were established. Methods for estimation of indirect economic losses caused by invasive alien species to service functions of forest ecosystems, agricultural ecosystems, grassland ecosystems, and wetland ecosystems were also established. The total economic losses caused by invasive alien species to China were to the time of USD 14.45 billion, with direct and indirect economic losses accounting for 16.59% and 83.41% of total economic losses, respectively.     

不同带长微喷带灌溉对土壤水分布与冬小麦耗水特性及产量的影响

于2010-2012年度冬小麦生长季,选用高产冬小麦品种济麦22,采用测墒补灌方式,设置40 m(T₄₀)、60 m(T₆₀)和80 m(T₈₀)3种带长的微喷带灌溉处理,研究不同带长微喷带灌溉对土壤水分分布及冬小麦耗水特性和产量的影响.结果表明： 拔节期和开花期采用微喷带补灌,随微喷带带长缩短,灌溉水在土壤中的水平分布均匀系数显著增加.拔节期补灌,T₄₀和T₆₀处理在距畦首0～40 m范围内各小麦行间的0～200 cm土层土壤含水量均无显著差异;T₈₀处理在距畦首38～40 m、58～60 m和78～80 m处各小麦行间的0～200 cm各土层土壤含水量变化规律一致,均表现为随距微喷带的距离增加而减小.T₄₀处理的小麦在拔节至开花期间和开花至成熟期间分别对40～60 cm和20～80 cm土层土壤贮水的消耗量显著高于T₆₀和T₈₀处理,而对深层土壤贮水消耗量和总土壤贮水消耗量、开花期补灌水量、总灌水量和总耗水量显著低于T₆₀和T₈₀处理.随微喷带带长缩短,小麦籽粒产量、产量水分利用效率显著升高,而流量降低,在灌水量一定的情况下,单位时间内的有效灌溉面积减小.综合考虑小麦籽粒产量、水分利用效率和流量,40和60 m是本试验条件下的适宜微喷带带长.     

Cropland edge,forest succession,and landscape affect shrubland bird nest predation

The effects of habitat edges on nest survival of shrubland birds, many of which have experienced significant declines in the eastern United States, have not been thoroughly studied. In 2007 and 2008, we collected data on nests of 5 shrubland passerine species in 12 early successional forest patches in North Carolina, USA. We used model selection methods to assess the effect of distance to cropland and mature forest edge on nest predation rates and additionally accounted for temporal trends, nest stage, vegetation structure, and landscape context. For nests of all species combined, nest predation decreased with increasing distance to cropland edge, by nearly 50% at 250 m from the cropland edge. Nest predation of all species combined also was higher in patches with taller saplings and less understory vegetation, especially in the second year of our study when trees were 4–6 m tall. Predation of field sparrow (Spizella pusilla) nests was lower in landscapes with higher agricultural landcover. Nest predation risk for shrubland birds appears to be greater near agricultural edges than mature forest edges, and natural forest succession may drive patterns of local extirpation of shrubland birds in early successional forest patches. Thus, we suggest that habitat patches managed for shrubland bird populations should be considerably large or wide (>250 m) when adjacent to crop fields and maintained in structurally diverse early seral stages. © 2011 The Wildlife Society.     

不同栖息地状态下外来种入侵及对本地种生存影响的模拟

外来种入侵引起的生态及经济问题日益严重,人类活动导致大规模栖息地持续变化的背景下,外来种的入侵过程及本地物种多样性的演化更为复杂.在Tilman多物种共存模型基础上,建立了栖息地持续变化条件下的外来种入侵干扰模式,分别模拟了栖息地不变、持续毁坏及持续恢复条件下的外来种入侵及对本地物种多样性的生态影响.模拟结果表明:(1)拓殖率小(入侵性弱)的外来种不能成功定殖,栖息地的持续变化对其没有任何影响.(2)拓殖率增大的外来种入侵过程复杂,栖息地持续毁坏导致其灭绝时间相比于栖息地不变时明显推迟,栖息地持续恢复使其灭绝提前;一定时间内持续增加栖息地可以减小此类外来种入侵危害.(3)拓殖率足够大的外来种能够成功定殖,快速定殖-扩散的入侵过程不会因栖息地毁坏而迅速改变,其响应具有时间滞后性;栖息地持续恢复也有利于其迅速蔓延,占有率呈线性疯狂增长.(4)在具有外来种入侵的本地生态系统中,栖息地持续改变(增加或减少)对本地物种多样性的发展均不利.     

“973”项目“农林危险生物入侵机理与控制基础研究”简介

2002年12月,国家重点基础研究发展计划("973"项目)"农林危险生物入侵机理与控制基础研究"经科技部批准正式立项,2003年启动。文章主要介绍该项目的立项背景、主要研究内容、研究方案和技术路线、总体研究目标及研究进展。     

外来入侵植物和本地植物核DNA C-值的比较及其与入侵性的关系

用流式细胞仪测定了8科10属13种外来入侵植物、6种本地植物和1种外来非入侵植物的核DNAC-值。结果表明:作为整体,外来入侵植物的平均核DNAC-值显著低于本地种和外来非入侵种,但对同属不同类型植物进行比较,未发现一致的规律;在4个既包含外来入侵种又包含本地种的属中,泽兰属(Eupatorium)和鬼针草属(Bidens)外来入侵种的核DNAC-值显著低于同属本地种,莲子草属(Alternanthera)的2种外来入侵植物中仅有1个种的核DNAC-值显著低于同属本地种,而草胡椒属(Peperomia)外来入侵种的核DNAC-值显著高于同属本地种;表明核DNAC-值与外来植物入侵性无必然联系。     

中国农业生态系统外来种入侵及其管理现状

农业生态系统极易遭受外来生物入侵。作者根据文献资料和多年工作观察统计出入侵我国农业生态系统的外来生物共计92科175属239种, 其中植物155种, 动物55种, 微生物29种, 植物多为有意引入后逸生, 而动物和微生物则主要是无意引入。外来入侵种发生数量呈现从南到北、从东到西逐渐减少的趋势。这些入侵种中, 来源于美洲的最多(占45.04%), 其次是欧洲(22.90%); 菜地(包括温室大棚)和果园入侵种最多, 分别达64.85%和66.53%, 而半年期的秋熟旱地和夏熟旱地分别占34.31%和23.85%。其中17种外来杂草、10种害虫、7种病原菌为恶性有害生物, 应作为防除的重点目标。目前农业生态系统外来入侵物种的控制以化学防治为主, 但由于长期施用化学农药, 在侵入我国农田的入侵种中, 已有51种在世界不同地区演化出抗药性生物型, 因而需重视生物防治、农业和生态防治以及检疫等的综合应用。今后外来种对农业生态系统的入侵格局、机制和趋势, 入侵途径以及生物入侵和抗药性生物型对农业生态系统中有害生物群落演替的影响、转基因作物导致的生物入侵等问题值得关注。