Biological Invasions最新文献

Flooded areas can create temporary connections between adjacent drainages and are a relatively understudied pathway for the spread of aquatic invasive species. The Nonindigenous Aquatic Species Database’s Flood and Storm Tracker maps were developed to help natural resource managers with post-storm aquatic invasive species detection and assessment efforts. As of the summer of 2023, 16 Flood and Storm Tracker maps have been published from hurricanes and flooding events in the United States and territorial islands. Three regions along the coasts of the Gulf of Mexico and Atlantic Ocean had overlapping areas of repeated flood impacts, and fifteen pairs of adjacent river basins were potentially connected during floods. Each map had a median of 77 non-native freshwater taxa and a median of 3 U.S. prohibited species within their respective flood-impacted area. The Flood and Storm Tracker maps provide resource managers with information about new aquatic invasions due to potential flood dispersal that can assist with early detection and rapid response systems.

There are 230 UNESCO World Heritage Sites that were designated based on their important natural features. These represent some of the most iconic and important natural places on Earth, with immense value for biodiversity conservation, ecosystem service supply and cultural well-being. Many of these sites are degraded by anthropogenic drivers, including socioeconomic factors (population growth, poverty and tourism), extractive activities (logging, mining, and hunting), external threats (fire, climate change, land-use change, pollution), and biological threats (disease and invasive species). Of these, invasive species remain one of the most problematic for management, and once introduced, populations can grow exponentially and spread to other locations even when actively managed. Given the economic and environmental threats imposed by invasive species, we asked how they compare to the other anthropogenic threats. We reviewed the primary literature for each World Heritage Site and scored the prevalence of 12 different anthropogenic drivers. We found that invasive species rank as one of the most frequently identified threats and pose the greatest degree of concern compared to all other threats, on par with the threat from pollution and greater than logging, land-use change and climate change. We compared our scoring, based on review of the literature, with that of the UNESCO and IUCN monitoring reports. Although there was general agreement between these two assessments, the literature provided information on 55 sites not included in the monitoring reports. We further examine the invasive species examined in the articles and the degree of their perceived impacts on biodiversity, habitat, rare species, ecosystem function, tourism, and economic impacts. It is important that invasive species are well monitored and managed in WHSs to reduce their impacts and meet policy mandated targets and conservation goals.

Biological invasions are a major stressor on ecosystems worldwide, but tools to predict their predatory impact remain limited. Here, we quantified invader impacts using two complementary approaches: functional responses (to reveal per capita and multiple predator interaction strengths) and ecomorphology (to reveal trophic profiles and competitive overlap). We compared Mozambique tilapia Oreochromis mossambicus, a native southern African cichlid, and a near-trophically analogous invasive congener, the Nile tilapia Oreochromis niloticus. Both Nile tilapia and Mozambique tilapia exhibited a potentially prey population destabilizing Type II functional response. In both single and multiple predator pairings, invasive Nile tilapia had significantly greater prey consumption rates than native Mozambique tilapia, and thereby a greater predatory impact than its native congeneric. Attack rates were greater for Nile tilapia than Mozambique tilapia, with both species showing more similar handling times and maximum feeding rates. No evidence for multiple predator effects was detected within or between these species, and therefore impacts of both species increased additively in the presence of conspecific or heterospecific competitors. Morphological trait analyses found general differences between these two species, with the invasive Nile tilapia having distinctively larger lower jaw closing force, gill resistance and gill raker length, which facilitated greater feeding capacities over the native species. Trophic profiles predicted using morphological trait differences showed high dietary overlap and served as evidence for potential exploitative competition between the two species. These results reveal superior interaction strengths and ecomorphological trait profiles of an invasive over native species which could influence impact and native species replacement dynamics. Novel applications of functional response and ecomorphology provide complementary insights into predatory and competitive impacts from invasive species, aiding impact prediction across environmental contexts.

The invasive species Bubalus bubalis was introduced in Guaporé Biological Reserve in 1953. Since then, the buffaloes have become feral, posing a threat to the populations, communities, and natural ecosystems of the region. In the last decade, there has been no study or monitoring of the invasive population and its potential impacts. We utilized systematic flights and multitemporal remote sensing analysis to address (i) What is the distribution range, abundance and density of Asian buffalo in the protected area? (ii) How has this species changed the land scape in the protected area over the past 34 years? The population survey resulted in 4.782 ± 533.27 buffaloes within 966.22 km², population density of 4.9 ± 0.55 buffaloes per km². The study also identified a 51% expansion of occupied areas within the Guaporé Reserve over the last 10 years. The multitemporal remote sensing analysis revealed significant environmental changes over the years, resulting in 48% loss of naturally flooded areas in the region occupied by buffalo. The government must take urgent measures to develop and implement a plan to control and eradicate this invasive species.

Species arrival sequence in new habitats impacts plant community development. This ‘priority-effect’ is documented, but mechanisms by which early arriving plants dominate future communities are less clear, complicating our ability to predict community assembly under future climate warming and assess invasive species threats. This is particularly important for ecosystems that are vulnerable to invasive species, such as those of the Antarctic Peninsula. To test how phenological differences and arrival order affect community composition of invasive plants, we simulated maritime Antarctic climate conditions, and a warming scenario. We established monocultures of six species potentially invasive to the Antarctic Peninsula (three forbs and three grasses), which exhibit a range of germination times ranging from 22 and 68 d, and a mixed community of all species. Before entering a simulated winter, half of each monoculture (n = 10) received the full seed mixture while the other half received seeds of their respective starting species. During the following simulated growing season, we quantified if the community composition was influenced by arrival order and whether species germination and growth responses differed from their monocultures and starting species. Community compositions differed across all starting communities and were typically dominated by the starting species. Phenological differences influenced individual and total biomass and plant height, but faster germinating species did not consistently dominate the final plant community. Forbs and grasses negatively impacted each other’s biomass. Warming enhanced priority effects (more negative or positive). Phenological priority has ecologically relevant influences on community assembly, but its effect on plant growth is context dependent in terms of species and temperature conditions. In particular, our data suggest that phenological priority influences plant biomass and size while niche pre-emption affects seed germination. Future trajectories of polar terrestrial plant communities will depend on the arrival order of colonizing non-native plants and their germination rates.

Raw Water Transfer (RWT) schemes move large volumes of freshwater between separate waterbodies to supply water as a specific commodity. Water is translocated by complex purpose-built networks of pipelines, tunnels and water supply canals. RWTs form hydrological connections between waterbodies across various spatial scales, and create a pathway of introduction and spread for a diverse range of invasive non-native species (INNS). Though occurring globally in large numbers, RWTs are not currently well represented by the standard pathway classification framework adopted by the Convention on Biodiversity (CBD). At present, RWTs are included within the ‘corridor’ category, which denotes the natural spread of organisms to neighbouring regions through transport infrastructure i.e. navigable canals/artificial waterways. However, RWTs are not routes for vehicle transport, and species are translocated between often non-adjoining waterbodies by the intentional transfer of water, not via natural spread. We provide a background for the complex RWT pathway and evidence of INNS spread through RWT schemes globally, and explore several options for improved RWT classification within the CBD framework—we recommend that the current corridor category is modified slightly to accommodate the addition of RWTs as a distinct sub-category, as separate from a clearly defined ‘navigable canal/artificial waterways’ sub-category. Accurate classification will increase understanding and awareness of this high-risk pathway, and support much-needed insight into its distinct stakeholders and drivers. Further, delineating RWTs from navigable canals/artificial waterways will help to identify widespread opportunities for pathway management and policy development, in addition to supporting more accurate future assessments of the risks and economic costs of the corridor pathway category.

Managing invasive alien species (IAS) is a significant challenge for both ecological and socioeconomic systems. Our understanding of the role of information sources in stakeholders’ IAS management is elusive for the majority of insect invaders. We focused on the fall armyworm (FAW), Spodoptera frugiperda, one of the most damaging alien insects worldwide, to explore the role of information sources in farmers’ management of alien agricultural pests. We developed a theoretical framework containing three components and seven indicators, conducted extensive household questionnaires in the region bordering Myanmar, Laos, and Vietnam in southwestern China, and used quantitative descriptions, ordinal logistic regressions, and Mann–Whitney U-tests in statistical analyses. Our results showed that farmers had a generally low level of recognition ability, medium level of control ability, and high level of engagement initiative in FAW management, and farmers’ FAW management was significantly associated with socio-demographic variables. Farmers obtained FAW-relevant information from four sources with a high preference for training workshops and agricultural retail stores; further, training workshops played a more effective role than agricultural retail stores in farmers’ FAW management. Here, we show for the first time that training workshops are the most effective sources of information in farmers’ FAW management, and agricultural retail stores serve as necessary support. Future research could extend these conclusions by including socioeconomic mechanisms such as informational feedback loops and public-private partnerships among stakeholders. Our findings contribute to theoretical insights into the role of information sources in IAS control, and to optimized management of alien agricultural pests.

The intrusion of non-native species into freshwater ecosystems can lead to rapid shifts in fish community dynamics, posing significant threats to biodiversity and ecological stability. In this study, we examined the changes in the fish community within the Kerkini Reservoir, a Ramsar Site in Greece, influenced by the establishment of invasive fish species. Through standardized seasonal surveys conducted in 2007–2008 and 2023, we assessed changes in fish species composition, abundance, and functional traits. Our findings revealed a shift in dominance, with invasive species such as Gymnocephalus cernua emerging as key players in the reservoir's fish fauna. Moreover, high numbers of fish specimens and biomass were recorded, highlighting the reservoir’s high productivity. However, concerns arise regarding the ecological impacts of invasive species, particularly G. cernua, which exhibits traits associated with ecological disruption and competition with native species. A shift towards the dominance of species with shorter lifespans, smaller sizes and lower trophic levels was observed. In addition, the observed decline in native species abundance, coupled with poor ecological quality assessments, underscores the need for proactive management measures to preserve ecosystem integrity. This study contributes valuable insights into the ecological dynamics of a system considered a biodiversity hotspot. It also highlights the proliferation of invasive fish species as a primary driver and underscores the importance of ongoing monitoring and conservation efforts. However, future research is needed, focusing on further understanding the long-term effects of invasive species establishment and their implications for native fish populations and ecosystem functioning.

Most alpine ecosystems are subject to non-native species invasion as climate warms and human disturbance increases. Therefore, it is important to identify the main barriers and facilitators of alpine plant invasions. While there is much research in continental alpine areas, there is limited research in maritime environments, which have distinctive biological, edaphic and geomorphologic features due to the scarcity of snow in winter. Here, we examine the contribution of anthropogenic and biotic factors on non-native plant invasions in the alpine areas of lutruwita (Tasmania), Australia. Specifically, we test whether disturbances associated with roads and livestock grazing facilitate non-native plant invasion and if biotic resistance from native plants and wild grazing animals inhibits such invasion. We used floristic data from: a statewide database; data from long-term grazing exclosures, and data from paired quadrats on roadsides and natural vegetation. Our results showed that non-native plants were associated with roadside disturbance and livestock grazing, with the latter having a legacy effect of 50 years. The persistent effect of stock grazing was evident in the exclusion experiment monitored over 30 years, where non-native plants occurred sporadically in time and space. In contrast, we found that the presence of wild grazing mammals, complete vegetation cover and high native richness, restricted non-native plants, emphasizing the importance of biotic resistance in controlling non-native plant invasions. These results indicate that livestock removal and road closure could be effective in reversing non-native plant invasion in this and other areas with wild vertebrate herbivores and high plant cover.

While conducting a landscape genomics study of invasive tammar wallabies (Notamacropus eugenii) in Aotearoa New Zealand we discovered that parma wallabies (N. parma) are also present in the North Island. This population has gone undetected for at least 30 years (and potentially for over a century), hidden amongst the morphologically similar tammar wallabies. The fact that an invasive wallaby species could remain undetected for so long, highlights the need for greater monitoring efforts for invasive species including genomic species identification.