Greater focus needed on alien plant impacts in protected areas

Alien plants pose significant threats to protected areas worldwide yet many studies only describe the degree to which these areas have become invaded. Research must move toward a better understanding of alien plant impacts since managers urgently require an appropriate evidence base to prioritize control/eradication targets. We analyze a global database of quantitative studies of alien plant impacts to evaluate existing knowledge of alien plant impacts within and outside protected areas. Although protected areas are a significant focus for quantitative impact studies, the biogeographic emphasis of most research effort does not coincide with the global distribution of protected areas nor the plant species or life-forms recognized to have greatest impacts on ecosystems. While impacts were often as significant within protected areas as outside, only a minority of studies provide any subsequent management recommendations. There is therefore considerable scope to improve the evidence base on alien plant management in protected areas

Blurring alien introduction pathways risks losing the focus on invasive species policy

The pathways by which alien species are introduced to new regions fall into six broad classes: deliberate release; escape from captivity; contaminant of a commodity; stowaway on a transport vector; via an infrastructure corridor (without which spread would not be possible) or unaided from other invaded regions (Hulme et al. 2008). However, Gilroy et al. (2016) argue that species dispersing naturally, through the infrastructure corridor or unaided pathway, should be classed as native rather than alien. We contend their proposal is not only unworkable but also unwise

Scoring environmental and socioeconomic impacts of alien plants invasive in Europe

The categorization of invasive alien species based on their impact is an important way of improving the management of biological invasions. The impact of 128 alien species of plants in Europe was evaluated using the Generic Impact Scoring System (GISS) originally developed for mammals. Based on information in the literature their environmental and socioeconomic impacts were assessed and assigned to one of six different categories. In each category, the impact was classified on a five-degree scale, which reflects the impact intensity. To identify species with the greatest impacts, we used the maximum score recorded in each category and their sums. Data from the whole invaded range were considered, which resulted in scoring the potential impact of each species, not necessarily currently realized in Europe. Environmental impacts are most often manifested via competition with native species (recorded for 83 % of the species), while socioeconomic impacts are associated mostly with human health (78 %). The sums of environmental and socioeconomic impacts were significantly correlated, which indicates that the same suite of species traits is associated with both types of impacts. In terms of plant life forms, annual plants have on average lower environmental impacts than perennial plants, and aquatic species have a higher socioeconomic impact than other life forms. Applying the GISS to plants, the most species-rich taxonomic group of alien organisms in Europe, is an important step towards providing managers and policymakers with a robust tool for identifying and prioritizing alien species with the highest impact

Alien and aboriginal flora of the Amur section of the Trans-Siberian Railway and its relationships with the characteristics of natural biomes

Trans-Siberian Railway, from the settlement of Yerofey Pavlovich to Kundur-Khabarovskiy railway station, with the total length of 1043 km (11 % of the TSR)explored. The study encompassed sixteen railway stations located in two biomes, including Amur-Zeya Boreal Taiga with variants southern taiga and subtaiga, and Zeya-Bureya Nemoral Broadleaved Forests and Forest-Steppe one

ФЛОРА СИБИРСКОГО УЧАСТКА ТРАНССИБИРСКОЙ ЖЕЛЕЗНОДОРОЖНОЙ МАГИСТРАЛИ В ПРЕДЕЛАХ РАЗЛИЧНЫХ ЕСТЕСТВЕННЫХ БИОМОВ

Проведена инвентаризация видов растений на сибирском участке Транссибирской магистрали (ТСМ) между городами Новосибирск и Красноярск. Исследуемая территория расположена в двух естественных биомах: Тоболо-Приобском лесостепном и Бореальном Ангарском подтаежном. Изучен растительный покров 10-ти железнодорожных станций и участков железной дороги на перегонах: 4 – на территории Новосибирской области и 6 – на территории Красноярского края. На изученном участке ТСМ выявлено 209 видов сосудистых растений: 19 древесных, 107 поликарпических и 83 вида монокарпических травянистых растений. В Бореальном Ангарском подтаежном биоме отмечено 154 вида, что составляет (73,7%), а в Тоболо-Приобском лесостепном – 150 (71,8%) относительно общего числа видов, выявленных в обоих биомах. Наиболее высокое сходство коэффициента Съеренсена отмечено между флорой прилегающих территорий к ж.-д. откосам Тоболо-Приобского лесостепного биома и флорой остальных экотопов железных дорог Бореального Ангарского подтаежного биома, кроме флоры дренажных канав. Выявлено существенное сходство между флорами железных дорог обоих биомов. Самое низкое сходство в пределах ТСМ отмечено для флор дренажных канав Бореального Ангарского подтаежного биома с откосами железной дороги, полосой отчуждения и канавами Тоболо-Приобского лесостепного биома (по 13,0%). Чужеродными являются 56 видов (27,0% от общего списка видов). К инвазионным отнесено 22 таксона, девять из которых входит в Топ-100 самых опасных инвазионных видов Росси

Флора Транссибирской железнодорожной магистрали и ее сопряженность с характеристиками естественных биомов на территории Байкальской Сибири

Проведена инвентаризация чужеродных и аборигенных видов растений вдоль Транссибирской магистрали на участке Тайшет - Улан-Удэ. Выявлена корреляция между характеристиками биомов и основными флористическими показателям

Флора уральско-западносибирского участка Транссибирской железнодорожной магистрали в различных естественных биомах

Проведена инвентаризация видов растений на уральско-западносибирском участке Транссибирской магистрали между городами Екатеринбург и Тюмень протяженностью 325 км. Исследован растительный покров 9-ти железнодорожных станций и участков железной дороги на перегонах: 5 – на территории Свердловской и 4 – на территории Тюменской областей. Исследуемый участок Транссиба расположен в двух естественных биомах: Таежном Среднесибирском Восточноуральском и Западносибирском южном мелколиственно-лесном. Выявлено 213 видов сосудистых растений: 28 древесных, 104 поликарпических и 81 вид монокарпических травянистых растений. В Таежном Среднесибирском восточноуральском биоме отмечено 153 вида (72%), в то время как в Западносибирском южном мелколиственно-лесном их 149 (70%). Наиболее высокое сходство значения коэффициента Съеренсена (Ks = 59,0%) наблюдается между флорами, формирующимися на железнодорожном полотне Таежного Среднесибирского Восточноуральского и железнодорожном откосе Западносибирского южного мелколиственно-лесного биомов. Самое низкое сходство наблюдается между флорами дренажных канав этих биомов (32,0%). Чужеродными являются 75 видов (35%). К инвазионным отнесено 55 видов, 42 из которых расселяются с запада на восток (европейские виды и виды, успешно натурализовавшиеся в Европе) и 13 видов (азиатского происхождения) расселяются с востока на запад. Десять из отмеченных на уральско-западносибирском участке Транссиба таксонов входят в Топ-100 самых опасных инвазионных видов Росси

Climate change will increase naturalization risk from garden plants in Europe

Aim: Plant invasions often follow initial introduction with a considerable delay. The current non-native flora of a region may hence contain species that are not yet naturalized but may become so in the future, especially if climate change lifts limitations on species spread. In Europe, non-native garden plants represent a huge pool of potential future invaders. Here, we evaluate the naturalization risk from this species pool and how it may change under a warmer climate. Location Europe. Methods: We selected all species naturalized anywhere in the world but not yet in Europe from the set of non-native European garden plants. For this subset of 783 species, we used species distribution models to assess their potential European ranges under different scenarios of climate change. Moreover, we defined geographical hotspots of naturalization risk from those species by combining projections of climatic suitability with maps of the area available for ornamental plant cultivation. Results: Under current climate, 165 species would already find suitable conditions in > 5% of Europe. Although climate change substantially increases the potential range of many species, there are also some that are predicted to lose climatically suitable area under a changing climate, particularly species native to boreal and Mediterranean biomes. Overall, hotspots of naturalization risk defined by climatic suitability alone, or by a combination of climatic suitability and appropriate land cover, are projected to increase by up to 102% or 64%, respectively. Main conclusions: Our results suggest that the risk of naturalization of European garden plants will increase with warming climate, and thus it is very likely that the risk of negative impacts from invasion by these plants will also grow. It is therefore crucial to increase awareness of the possibility of biological invasions among horticulturalists, particularly in the face of a warming climate

Explaining the variation in impacts of non-native plants on local-scale species richness: the role of phylogenetic relatedness

Aim To assess how the magnitude of impacts of non-native plants on species richness of resident plants and animals varies in relation to the traits and phylogenetic position of the non-native as well as characteristics of the invaded site. Location Global. Methods Meta-analysis and phylogenetic regressions based on 216 studies were used to examine the effects of 96 non-native plant species on species richness of resident plants and animals while considering differences in non-native species traits (life-form, clonality or vegetative reproduction, and nitrogen-fixing ability) and characteristics of the invaded site (ecosystem type, insularity and climatic region). Results Plots with non-native plants had lower resident plant (–20.5%) and animal species richness (–26.4%) than paired uninvaded control plots. Nitrogenfixing ability, followed by phylogeny and clonality were the best predictors of the magnitude of impacts of non-native plants on native plant species richness. Non-nitrogen-fixing and clonal non-native plants reduced species richness more than nitrogen-fixing and non-clonal invaders. However, life-form and characteristics of the invaded sites did not appear to be important. In the case of resident animal species richness, only the phylogenetic position of the non-native and whether invaded sites were islands or not influenced impacts, with a more pronounced decrease found on islands than mainlands. Main conclusions The presence of a phylogenetic signal on the magnitude of the impacts of non-native plants on resident plant and animal richness indicates that closely related non-native plants tend to have similar impacts. This suggests that the magnitude of the impact might depend on shared plant traits not explored in our study. Our results therefore support the need to include the phylogenetic similarity of non-native plants to known invaders in risk assessment analysis