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We analyze the Lotka–Volterra n prey-1 predator system with no direct interspecific interaction between prey species, in which every prey species undergoes the effect of apparent competition via a single shared predator with all other prey species. We prove that the considered system necessarily has a globally asymptotically stable equilibrium, and we find the necessary and sufficient condition to determine which of feasible equilibria becomes asymptotically stable. Such an asymptotically stable equilibrium shows which prey species goes extinct or persists, and we investigate the composition of persistent prey species at the equilibrium apparent competition system. Making use of the results, we discuss the transition of apparent competition system with a persistent single shared predator through the extermination and invasion of prey species. Our results imply that the long-lasting apparent competition system with a persistent single shared predator would tend toward an implicit functional homogenization in coexisting prey species, or would transfer to a 1 prey-1 predator system in which the predator must be observed as a specialist (monophagy). [ABSTRACT FROM AUTHOR]

Suites of coevolved traits related to reproduction and demography enable species to persist in the face of environmental change. In the case of biological invasions, the suite of life history traits, “life history strategies,” can be linked to successful establishment after an introduction. Conservation translocations share many similarities with biological invasions, yet studies examining the relationship between life history and translocation outcome are scarce. We collected data on key life history traits for all herpetofauna profiled in the IUCN Global Conservation Translocation Perspectives series to examine how life history can predict outcomes and difficulties of conservation translocations. For reptiles, our model showed that age at maturity showed a significant positive association with higher probabilities of more successful outcomes, while increased clutch/litter size and lifespan predicted less successful outcomes. We found no relationship between any life history trait and translocation outcome for amphibians. Our results showed that difficulties with conservation translocations are related more to phylogeny than life history. Amphibian translocations faced more difficulties due to the physical environment of release sites, but reptile translocations experienced more socio‐political difficulties. These relationships provide important insights for conservation practitioners that can be used in the feasibility and planning stages of translocations to anticipate and avoid challenges facing this complex and increasingly common form of conservation intervention. [ABSTRACT FROM AUTHOR]

Invasive fish species can play an important role in aquatic ecosystems and have a significant impact on ecosystem dynamics, which influences primary production, planktonic communities, and aquatic macrophytes. The presence and density of invasive fish can disrupt nutrient ratios and ecological processes, leading to potential ecological consequences for invaded habitats. This experimental investigation focused on the invasive armored catfish species P. ambrosettii (Loricariidae) and postulated that high densities of armored catfish in invaded environments may affect nutrient cycling due to high N: P excretion rates. Furthermore, we sought to identify how these changes in nutrient concentration impact phytoplankton, protozooplankton, and the biomass of two invasive macrophytes. We carried out a 30-day experimental study at the Nupélia Applied Ecology Laboratory at the State University of Maringá with 20 fiber cement mesocosms with a volume of 135 L. These mesocosms had continuous water circulation and were used to simulate the natural conditions of lakes invaded by P. ambrosettii. We simulated five treatments that represented density at different levels of invasion: control (no fish), low-density (one fish), medium–low (two fish), medium–high (three fish) and high-density (four fish). The treatments affected abiotic variables such as pH, dissolved oxygen, and electrical conductivity, and nitrogen and phosphorus concentrations increased with increasing fish density, as expected. In turn, nutrient concentrations had effects on chlorophyll-a and macrophyte biomass. The chlorophyll-a and Eichhornia crassipes biomass were positively related to the increase in phosphorus, while Hydrilla verticillata showed a positive relationship with both nutrients nitrogen and phosphorous. The zooplankton community showed different density behaviors in relation to treatments. Its composition was influenced by the different treatments, and it underwent significant variations along the nutrient gradient. As predicted, the different densities of P. ambrosettii led to changes in the structure of the ecosystem. In treatments with higher fish densities, the environment was characterized by low oxygenation, high conductivity, and high concentrations of nitrogen and phosphorus. These conditions favored the dominance of phytoplankton and aquatic macrophytes, while the density and species composition of zooplankton was low. The effects observed in this experimental study contribute to insights into the field of invasion biology and its relationships with nutrient dynamics. The effects that may arise from the invasion and high population density of the armored catfish Pterygoplichthys in invaded locations reinforce the importance of understanding these processes in the functioning of the ecosystem and how this directly or indirectly impacts the dynamics of coexisting communities in natural environments. [ABSTRACT FROM AUTHOR]

The invasion of exotic species of natural spaces constitutes a global conservation problem. In the Siboney-Juticí Ecological Reserve, Leucaena leucocephala is considered one of the main threats to the conservation of the semideciduous microphyll forest. The objective of this study is to characterize the richness and structure of the semideciduous microphyll forest in areas with different levels of Leucaena leucocephala coverage in said reserve. For the study, 15 plots of 400 m2 were established at three levels of coverage of the invasive species: ABSMNI (undisturbed forests), ABSM-PI (40-60 % coverage of Leucaena leucocephala) and ABSMTI (70 % cover of Leucaena leucocephala). The number of individuals per species and their presence in each of the stratus were estimated, in addition, the height of the woody species was considered. For each of the levels studied, the specific richness, the relative abundance of the species and the floristic composition by stratus were determined; as well as the floristic similarities between each of the levels. In ABSM-NI, 55 species were recorded, in ABSM-PI 51 and in ABSM-TI 43. At the three levels of cover, the strata (tree, shrub, herbaceous) and lianas were maintained. In ABSM-TI the epiphytes were not recorded. The greatest biological similarity was between ABSM-PI and ABSM-TI; some of the shared species are ruderal and colonize areas with some type of disturbance. The main transformation was in the composition and abundance of the species as the coverage of the invasive species increased. In ABSM-TI, the specific richness and abundance/cover of secondary vegetation species increased, to the detriment of other typical forest species. In the sites with the greatest coverage of the invasive species, a decrease in the specific composition and height of the tree stratus occurs. At this site, an increase in the specific composition of the shrub and herbaceous strata was also observed. Epiphytes were only recorded in ABSM-NI and ABSM-PI. [ABSTRACT FROM AUTHOR]

A long dispersal distance is widely used to indicate high invasiveness, but it ignores the temporal dimensions of plant invasion. Faster dispersal rates (= distance/time) of invasive species than native ones have been widely used in modeling species invasion and planning control management. However, the comparison of dispersal rate between invasive and native plants, particularly for dispersal on a local or landscape scale, has not been tested with a comprehensive dataset. Moreover, both the effects of plant functional traits on the dispersal rate and variation in the functional-trait effects between invasive and native plants remain elusive. Compiling studies from 30 countries globally, we compared seed dispersal rates (km/year) on a local or landscape scale between 64 observations of invasive and 78 observations of native plants given effects of plant life forms, disturbance levels, and measurement methods. Furthermore, we compared the effects of functional traits on dispersal rate between invasive and native species. We found that: (1) Trait values were similar between the invasive and native plants except for the greater height of woody native plants than woody invasive ones; (2) Compared within the same plant life form, the faster dispersal rates of invasive species were found in herbaceous plants, not in woody plants, and disturbance level and measurement methods did not affect the rate comparison; (3) Plant height and seed length had significant effects on dispersal rates of both invasive and native plants, but the effect of leaf dry matter content (LDMC) was only significant on herbaceous invasive plants. The comparison of dispersal rate between invasive and native plants varied by plant life form. The convergent values but divergent dispersal effects of plant traits between invasive and native species suggest that the trait effects on invasiveness could be better understood by trait association with key factors in invasiveness, e.g., dispersal rate, than the direct trait comparison between invasive and native plants.

Microplastics (MPs) have received great concern in recent years, and whether the bacteria carried by traveling MPs would cause ecological risks is a hot topic for debate. The colonized bacteria (i.e., hitchhikers) on traveling MPs which become invasive species in the new environment, need to be completed in three steps: arriving, falling, and growing. However, most previous studies only focused on the first step, which we think is insufficient to discuss species invasion. Thus, in this frontier review, we reviewed the progress of the current research on the uniqueness of bacterial communities on MPs, and we summarized that the uniqueness of the plastisphere was not as high as previously thought. Moreover, we explained why the three steps were necessary to complete the bacterial species invasion. Furthermore, we analyzed the technical difficulties hindering discussing MPs as invasive species carriers, as well as the perspectives in future research. Therefore, this frontier review presents new insights into the role of MPs as bacterial carriers, and suggests study directions for future research.

Earth systems are nearing a global tipping point, beyond which the dynamics of biological communities will become unstable. One major driver of instability is species invasion, especially by organisms that act as "ecosystem engineers" through their modification of abiotic and biotic factors. To understand how native organisms respond to modified habitat, it is essential to examine biological communities within invaded and non-invaded habitat, identifying compositional shifts in native and non-native taxa as well as measuring how modification by ecosystem engineers has affected interactions among community members. Using dietary metabarcoding, our study examines the response of a native Hawaiian generalist predator (Araneae: Pagiopalus spp.) to habitat modification by comparing biotic interactions across metapopulations of spiders collected in native forest and sites invaded by kāhili ginger. Our study shows that, although there are shared components of the dietary community, spiders in invaded habitat are eating a less consistent and more diverse diet consisting of more non-native arthropods which are rarely or entirely undetected in spiders collected from native forest. Additionally, the frequency of novel interactions with parasites was significantly higher in invaded sites, reflected by the frequency and diversity of non-native Hymenoptera parasites and entomopathogenic fungi. The study highlights the role of habitat modification driven by an invasive plant in altering community structure and biotic interactions, threatening the stability of the ecosystem through significant changes to the biotic community.

Some species of freshwater gastropods, known for their adaptability and resilience, have gained attention globally as invasive species. However, to date, only one invasive population of freshwater snails has been documented beyond the Arctic Circle. In this study, we report the discovery of two non-indigenous species, Planorbella duryi (Wetherby, 1879) and Physella acuta (Draparnaud, 1805), north of 69°N in the Norilsk Industrial District (Central Siberia). Their identification was based on morphological features and COI gene sequences. Both species are native to the temperate and subtropical zones of North America and may have entered the Arctic Asian reservoirs through aquarium introductions. The distribution of these populations is constrained to areas affected by thermal pollution, and their further spread into pristine reservoirs of Northern Siberia is unlikely. [ABSTRACT FROM AUTHOR]

The impacts of global change—from shifts in climate to overfishing to land use change—can depend heavily on local abiotic context. Building an understanding of how to downscale global change scenarios to local impacts is often difficult, however, and requires historical data across large gradients of variability. Such data are often not available—particularly in peer reviewed or gray literature. However, these data can sometimes be gleaned from casual records of natural history—field notebooks, data sheet marginalia, course notes, and more. Here, we provide an example of one such approach for the Gulf of Maine, as we seek to understand how environmental context can influence local outcomes of region‐wide shifts in subtidal community structure. We explore a decade of hand‐drawn algal cover maps around Appledore Island made by Dr. Art Borror while teaching at the Shoals Marine Lab. Appledore's steep wave exposure gradient—from exposed to the open ocean to fully protected—provides a living laboratory to test interactions between global change and local conditions. We then recreate Borror's methods two and a half decades later. We show that overfishing‐driven urchin outbreaks in the 1980s were slowed or stopped by wave exposure and benthic topography. Similarly, local variation appears to have curtailed current invasions by filamentous red algae. Last, some formerly dominant kelps have disappeared over the past 40 years—an observation verified by subtidal surveys. Global change is altering life in the seas around us. While underutilized, solid natural history observations stand as a key resource for us to begin to understand how global change will translate to the heterogeneous mosaic of life in a future Gulf of Maine and other ecosystems around the world. [ABSTRACT FROM AUTHOR]

Marine heatwaves have altered ecosystems globally, including changing community composition and facilitating the spread of invasive species. In south Puget Sound, Washington (USA), non-native Pacific oysters (Magallana gigas) have been farmed extensively for almost a century and grown in enhancement sites, however, they have only recently recruited in the wild. This study explores how the appearance of Pacific oysters was related spatially (eight sites) and temporally (decade) to warmer summer water temperatures in south Puget Sound and compares oyster persistence across five sites where recruitment occurred. The largest recruitment event from 2012-2020 was in the summer of 2015, in the middle of the east Pacific Blob marine heatwave which led to warm water temperatures off the west coast of North America. Throughout the study period, the number of oyster recruits each year was positively correlated with warmer water temperatures. Oyster population densities differed across the five sites where recruitment occurred and generally declined after 2015, but showed no site by year interactions, which is consistent with spatially-variable recruitment and similar post-recruitment survival. Mean oyster shell heights also differed among sites, which could reflect different growth trajectories or recreational harvest patterns. This study supports the claim that warming sea surface temperatures may interact with species introductions to change modern biogeography. [ABSTRACT FROM AUTHOR]

Copyright of Biology Teaching is the property of East China Normal University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract A long dispersal distance is widely used to indicate high invasiveness, but it ignores the temporal dimensions of plant invasion. Faster dispersal rates (= distance/time) of invasive species than native ones have been widely used in modeling species invasion and planning control management. However, the comparison of dispersal rate between invasive and native plants, particularly for dispersal on a local or landscape scale, has not been tested with a comprehensive dataset. Moreover, both the effects of plant functional traits on the dispersal rate and variation in the functional-trait effects between invasive and native plants remain elusive. Compiling studies from 30 countries globally, we compared seed dispersal rates (km/year) on a local or landscape scale between 64 observations of invasive and 78 observations of native plants given effects of plant life forms, disturbance levels, and measurement methods. Furthermore, we compared the effects of functional traits on dispersal rate between invasive and native species. We found that: (1) Trait values were similar between the invasive and native plants except for the greater height of woody native plants than woody invasive ones; (2) Compared within the same plant life form, the faster dispersal rates of invasive species were found in herbaceous plants, not in woody plants, and disturbance level and measurement methods did not affect the rate comparison; (3) Plant height and seed length had significant effects on dispersal rates of both invasive and native plants, but the effect of leaf dry matter content (LDMC) was only significant on herbaceous invasive plants. The comparison of dispersal rate between invasive and native plants varied by plant life form. The convergent values but divergent dispersal effects of plant traits between invasive and native species suggest that the trait effects on invasiveness could be better understood by trait association with key factors in invasiveness, e.g., dispersal rate, than the direct trait comparison between invasive and native plants.

Abstract The impacts of global change—from shifts in climate to overfishing to land use change—can depend heavily on local abiotic context. Building an understanding of how to downscale global change scenarios to local impacts is often difficult, however, and requires historical data across large gradients of variability. Such data are often not available—particularly in peer reviewed or gray literature. However, these data can sometimes be gleaned from casual records of natural history—field notebooks, data sheet marginalia, course notes, and more. Here, we provide an example of one such approach for the Gulf of Maine, as we seek to understand how environmental context can influence local outcomes of region‐wide shifts in subtidal community structure. We explore a decade of hand‐drawn algal cover maps around Appledore Island made by Dr. Art Borror while teaching at the Shoals Marine Lab. Appledore's steep wave exposure gradient—from exposed to the open ocean to fully protected—provides a living laboratory to test interactions between global change and local conditions. We then recreate Borror's methods two and a half decades later. We show that overfishing‐driven urchin outbreaks in the 1980s were slowed or stopped by wave exposure and benthic topography. Similarly, local variation appears to have curtailed current invasions by filamentous red algae. Last, some formerly dominant kelps have disappeared over the past 40 years—an observation verified by subtidal surveys. Global change is altering life in the seas around us. While underutilized, solid natural history observations stand as a key resource for us to begin to understand how global change will translate to the heterogeneous mosaic of life in a future Gulf of Maine and other ecosystems around the world.

Marine heatwaves have altered ecosystems globally, including changing community composition and facilitating the spread of invasive species. In south Puget Sound, Washington (USA), non-native Pacific oysters (Magallana gigas) have been farmed extensively for almost a century and grown in enhancement sites, however, they have only recently recruited in the wild. This study explores how the appearance of Pacific oysters was related spatially (eight sites) and temporally (decade) to warmer summer water temperatures in south Puget Sound and compares oyster persistence across five sites where recruitment occurred. The largest recruitment event from 2012-2020 was in the summer of 2015, in the middle of the east Pacific Blob marine heatwave which led to warm water temperatures off the west coast of North America. Throughout the study period, the number of oyster recruits each year was positively correlated with warmer water temperatures. Oyster population densities differed across the five sites where recruitment occurred and generally declined after 2015, but showed no site by year interactions, which is consistent with spatially-variable recruitment and similar post-recruitment survival. Mean oyster shell heights also differed among sites, which could reflect different growth trajectories or recreational harvest patterns. This study supports the claim that warming sea surface temperatures may interact with species introductions to change modern biogeography.

In May 2020, a bottom-trawl survey in the southern Bohai Sea collected the portunid crab Charybdis bimaculata, a species formerly found in the northern Yellow Sea. In subsequent surveys, C. bimaculata was found to be abundant and likely to occupy habitats and niches of native species. To study the suitability of habitat in the southern Bohai Sea for this crab, nine trawl surveys were conducted between 2020 and 2022 to monitor its dispersal. Using Biomod2 software and combining species occurrence and environmental data, a distribution model for C. bimaculata in the southern Bohai Sea is developed. We analyze relationships between this and other crustacean species by comparing niche widths and their overlap. A random forest model outperforms eight others, and has the highest evaluation indices among single algorithm species-distribution models. The evaluation index of an ensemble model is significantly higher than those of single algorithm models, indicating its greater accuracy and robustness. We report suitable habitat for C. bimaculata to occur mainly in central and northeastern Laizhou Bay, and for this habitat suitability to shift over years from the middle to northeastern waters. Niche width showed a negative trend from 2020 to 2022, and is greater in May than August for each year. Niche overlaps between C. bimaculata and other major crustaceans in the southern Bohai Sea exist. We consider that increased sea surface temperature caused by climate change enabled invasion of C. bimaculata from northern Yellow Sea waters into the southern Bohai Sea, where it can overwinter and complete its life cycle. These results provide a scientific basis upon which monitoring of C. bimaculata in the Bohai Sea can be strengthened to better cope with its invasion and any negative impact on local biodiversity. [ABSTRACT FROM AUTHOR]

Conservation practices from the perspective of functional diversity (FD) and conservation prioritization need to account for the impacts of exotic species in freshwater ecosystems. This work first simulated the influence of exotic species on the values of FD in a schemed mechanistic model, and then a practical case study of conservation prioritization was performed in the Min River, the largest river in southeastern China, to discuss whether including exotic species alters prioritization. The mechanistic model revealed that exotic species significantly altered the expected FD if the number of exotic species occupied 2% of the community. Joint species distribution modelling indicated that the highest FD occurred in the west, northwest and north upstreams of the Min River. Values of FD in 64.69% of the basin decreased after the exotic species were removed from calculation. Conservation prioritization with the Zonation software proved that if first the habitats of exotic species were removed during prioritization, 62.75% of the highest prioritized areas were shifted, average species representation of the endemic species was improved and mean conservation efficiency was increased by 7.53%. Existence of exotic species will significantly alter the metrics of biodiversity and the solution for conservation prioritization, and negatively weighting exotic species in the scope of conservation prioritization is suggested to better protect endemic species. This work advocates a thorough estimate of the impacts of exotic species on FD and conservation prioritization, providing complementary evidence for conservation biology and valuable implications for local freshwater fish conservation. [ABSTRACT FROM AUTHOR]

Spartina alterniflora Loisel, widely recognized as an aggressive invader of estuaries and salt marshes worldwide, was recently reported in Korean waters as rapidly invading intertidal mudflats, growing in circular patches. For more effective control management of the invasive cordgrass, we developed a modified ignition logistic model based on the satellite imageries to estimate the settlement time of the first individual stand and the doubling period of the patch spread in the early colonization state. The present model is designed for estimating the starting time and the doubling period of the patch spread at the growth stage, which is a salient feature different from other logistic models. The importance of estimating the starting time of the invasion may lie in figuring out what ecological changes occurred at that time. A Monte-Carlo simulation is combined with our model to obtain reliable predictions against the noisy data. As a result of applying the model to the Northwest Pacific invading tidal flats of Korea, China, and Japan, it turns out that the doubling periods of the patch spread are generally shorter and similar to each other, which range from 0.6 to 2.1 years. This is probably attributed to the genetically hybridized populations of Spartina alterniflora invading this region. [ABSTRACT FROM AUTHOR]

The Qinghai-Tibet Plateau (QTP) serves as the source of many large rivers in Asia, and also serves as a natural habitat for rare wildlife and a genetic reservoir for plateau species. The exceptional ecological environment of the QTP has fostered diverse fish species. However, due to climate change and human activities, fish species in this area are facing serious threats, while large spatial scale investigation is a big challenge. Environmental DNA (eDNA) metabarcoding, as an innovative monitoring technology, offers a simple, fast, and environmentally friendly approach to explore fish communities on the QTP. This study utilized eDNA technology to assess the diversity, composition, and potential environmental influences of riverine fish communities across the QTP. A total of 90 fish species were identified belonging to 79 genera, 34 families, and 18 orders. The dominant species were Schizothorax chongi, Gymnocypris przewalskii, Carassius carassius, and Botia striata. PCoA and ADONIS indicated significant differences among fish community in different river basins of the Qinghai-Tibet Plateau. Canonical correspondence analysis (CCA) revealed that the ratio of SRP to TP, average NDVI, average elevation, and proportion of bare land significantly influenced the distribution of fish community. This study provided a novel monitoring method and insight for fish communities and implied potential species invasion on the QTP.

1. Non‐native species may be the cause of native species declines or an effect of habitat degradations that promote the former and damage the latter. Social insects are extraordinarily successful organisms, and non‐native social insects, such as ants, often are very successful invaders of novel habitats. 2. The red imported fire ant (Solenopsis invicta) and the Asian needle ant (Brachyponera chinensis) are widespread non‐native invaders in the eastern United States that bring ecological, economic and social impacts, but their putative effects on native ant communities may be concomitant with habitat degradation rather than inherent in their invasion. 3. Given this gap in understanding, our goal was to examine how experimental warming influenced native and non‐native ant communities. Specifically, we hypothesised that (a) non‐native ant abundance and species richness will increase in warmed plots and that (b) warming‐induced increases in the non‐native ant populations will correspond with decreases in native ant abundance and species richness. 4. To test these hypotheses, we used three levels of experimental forest edge soil warming (warming targeted at +0, +3, and +5°C above ambient soil temperature) in a mixed deciduous forest in the Georgia (USA) Piedmont. We used repeated pitfall trapping to investigate how the experimental warming influenced the composition of native and non‐native ant communities with a focus on how warming combined with S. invicta and B. chinensis invasion impacted native ant communities. 5. Our results suggest that experimental warming promoted the non‐native invasive ants, particularly S. invicta and B. chinensis. We also found that B. chinensis somewhat inhibited native ant communities, but not because of warming. The warmed environment benefited both non‐native invasive ants at the expense of native ants but, given that B. chinensis negatively impacted the native ants with far fewer workers than S. invicta, B. chinensis may pose a greater threat to native ant communities than S. invicta in a warmer world. [ABSTRACT FROM AUTHOR]

Invasive species pose a severe threat to biodiversity around the world. Managing the consequences of invasion is difficult in aquatic settings, as the rate at which invaders establish typically outpaces the resources available to eradicate them. For proactive management measures to be implemented, prior knowledge of the probability of invasion is required. In this study, we created a spatial model of the probability of the Pirarucu (Arapaima gigas) invasion in the Western Ghats. The Western Ghats, one of the world's top biodiversity hotspots, is home to numerous endemic species, many of which are now threatened. An ensemble modelling approach using 10 models, including machine learning techniques such as Artificial Neural Network (ANN), Maximum Entropy (MaxEnt), Random Forest (RF), Generalised Boosted Regression Model (GBM) and Classification Tree Analysis (CTA), was adopted. The model was built using the species' occurrence data and nine climate variables. The findings revealed that southern regions of the Western Ghats have a high risk of Pirarucu invasion. Sri Lanka also has a much greater geographical area with a higher percentage of appropriate habitats for the species. The study becomes vital as this exotic species was repeatedly reported from the rivers since the extensive floods in the region in 2018. The developed model will assist managers in prioritising locations and initiating monitoring and management steps to prevent the spread before they establish in the wild. With earlier Pirarucu invasions in Bolivia, Peru and East Asia and recent climatic vagaries in the Western Ghats, the native biodiversity of the region is in grave danger of being displaced. [ABSTRACT FROM AUTHOR]

Between 1958 and 2018, multiple roadside surveys were conducted on the upper altitudinal limits of the alpine Maunaloa (now preferred Hawaiian language spelling of Mauna Loa) vascular flora from near tree line (2,525 m) to the NOAA Mauna Loa Observatory (MLO) at 3,397 m. Five native plant species were encountered in 1958 on numerous sparsely vegetated historic and prehistoric basaltic lava flows. A resurvey of the roadside 50 years later (2008) yielded 22 species including nine new native species and eight aliens. The aliens were limited to a few individuals at sites disturbed by human activity. Here, floristic change along the transect was reassessed after 60 years (2018), recording a total of 30 species with 15 natives and 15 aliens. Floristic diversity and shifts in altitudinal limits are evaluated in relation to well documented and dramatic local climate change over recent decades, along with the competing influences of substrate-control and increasing human disturbance. The results indicate that lava substrate age and textural variation, along with human mediated propagule pressure, and associated disturbance exert greater impact than rapid climate change in explaining current patterns of plant distribution and diversity in this hyper-arid, alpine environment. This long-term monitoring effort of alpine lava flows has also informed and reinforced a more general moisture/substrate-control model for early primary succession extending to lower subalpine mountain elevations involving the two dominant lava flow textural classes: ' a ' ā and pāhoehoe. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chongqing University of Technology (Natural Science) is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Detailed understanding of the mechanisms enabling or limiting the impacts of invasive generalist predators is needed. Harmonia axyridis is an invasive generalist coccinellid predator that may have destabilised coccinellid communities worldwide and is an excellent candidate for investigating invasion dynamics.We evaluated four hypotheses: (1) Nine years after being detected in Central Brazil, Ha. axyridis has dominated the coccinellid community. This is facilitated by (2) its broader aphid prey range than the other aphidophagous coccinellids, (3) its superiority as an asymmetrical intraguild predator, and (4) the invasibility of the present coccinellid community.We sampled the invertebrate communities associated with six organic vegetable farms in Brazil during 2017 and 2018, conducted a feeding trial to measure prey niche breadth and overlap, and estimated intra‐ and interspecific interaction strengths corresponding to first‐order Lotka‐Volterra parameters to evaluate the strength of intraguild predation and create a community matrix.We found (1) Ha. axyridis comprised ≤8.3% of the coccinellid community. (2) Hi. convergens had the broadest prey niche and dominated the prey niche of Ha. axyridis. (3) We could not determine from the population data if Ha. axyridis was the dominant intraguild predator because its density was too low and constant. (4) The community matrix indicated that the present‐day coccinellid community was stable.We conclude Ha. axyridis has not become invasive in Central Brazil, in part because it does not have the broadest prey niche breadth and the present coccinellid community is stable to the present perturbation of Ha. axyridis. [ABSTRACT FROM AUTHOR]

Currently, we lack enough knowledge to fully explain how the impacts of species invasion on native communities are attributed to multifaceted, individual‐based behavioural outcomes.Here, we illustrate the long‐term population dynamics of the native long‐tailed sun skink (Eutropis longicaudata) before and after the invasion of the common sun skink (Eutropis multifasciata). We conducted diet investigation, morphological measurement, and a series of behavioural experiments both in the field and laboratory. We explained how the impacts of the invasive skink on the native skink can cascade towards the population level based on these individual‐level behavioural data.We present evidence of competition exclusion of the native skink population resulting from the invasion of the common sun skink. The drastic decline found in the native skink population was largely accounted for by low recruitment, as shown by the decrease in its clutch numbers correspondingly.We also found dominance of the invasive skink in both exploitation competition and intraguild predation. Considering the highly overlapping morphological and dietary niches between the two species, our findings imply that the native skink has undergone strong food competition and predation pressure on its eggs and juveniles.Interestingly, the native skink started to display parental care behaviour 2 years after the invasion event, and its clutch survival rate has recovered since then. The shift in parental care behaviour may help the native skink cope with this new predation pressure from the invasive skink.Overall, the two competitive skinks showed low chances of coexisting. The negative population growth of this native skink species may be primarily derived from poor reproductive performance, given a sharp decline in its clutch numbers and its inferiority in exploitation competition, despite rebounding clutch survival rates. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Non-native species invasion, habitat fragmentation and climate change individually impose negative impacts on natural systems, but their synergistic effects may do more harm than the sum of their parts. We examined the combined effects of these global change drivers by studying the impacts of experimental warming on seed-dispersing forest ant nesting and foraging in the Southeastern U.S. to determine if warming and forest fragmentation facilitated non-native ant invasion effects on native ants. Spring ant phenology and activities were monitored for two years (2019–2020) at weekly bait stations and in artificial nest occupancy. We found that, when combined, forest edge habitat and experimental warming favored invasive non-native ant frequency, but the experimental warming alone did not appear to facilitate non-native ant incursion into forested habitat. We did find, however, that experimental warming exacerbated the negative effects of non-native ants on native ant foraging. Moreover, fragmented edge habitat strongly limited native forest ant foraging and experimental warming increased the negative effects of non-native ant invaders on native ants. Ultimately, the non-native ants displaced native seed-dispersing ants from artificial nests, and the displacement progressively increasing with greater experimental warming. Our results suggest that global change drivers such as warming, habitat fragmentation and species invasion imposed negative impacts individually, but their combined effects were worse than the sum of their parts. Moreover, our results indicate that predicting species reactions to global change poses great challenges given that the strongest impacts were the non-additive effects. [ABSTRACT FROM AUTHOR]

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Ecological assembly-the process of ecological community formation through species introductions-has recently seen exciting theoretical advancements across dynamical, informational, and probabilistic approaches. However, these theories often remain inaccessible to non-theoreticians, and they lack a unifying lens. Here, I introduce the assembly graph as an integrative tool to connect these emerging theories. The assembly graph visually represents assembly dynamics, where nodes symbolise species combinations and edges represent transitions driven by species introductions. Through the lens of assembly graphs, I review how ecological processes reduce uncertainty in random species arrivals (informational approach), identify graphical properties that guarantee species coexistence and examine how the class of dynamical models constrain the topology of assembly graphs (dynamical approach), and quantify transition probabilities with incomplete information (probabilistic approach). To facilitate empirical testing, I also review methods to decompose complex assembly graphs into smaller, measurable components, as well as computational tools for deriving empirical assembly graphs. In sum, this math-light review of theoretical progress aims to catalyse empirical research towards a predictive understanding of ecological assembly., (© 2025 John Wiley & Sons Ltd.)

iological invasion poses several biotic and abiotic challenges due to abrupt distribution shifts. Invasive species may benefit from local adaptation responding to environmental stresses during colonization. Saltcedar (Tamarix), a notorious invasive shrub in the western US introduced from Eurasia may have adapted to low rainfall as the species widely occupies the arid land throughout the southwestern US. We investigated variation of quantitative traits in saltcedar between two regions exhibiting opposing average annual precipitations under experimentally manipulated water treatments to test local adaptation. We measured eight quantitative traits, proxies for fitness and genotyped 64 individual samples using genotype by sequencing technique. To test local adaptation, we applied QCT - FCT test based on null distribution of FCT estimated from 2,697 genome-wide SNPs and QCT estimated for the eight phenotypic traits measured. Saltcedar in the southwestern US exhibited a significant interaction between the degree of leaf loss (biomass loss by senesced leaves to total biomass) under simulated drought conditions and the origins from which the genotypes were collected, either relatively high or low rainfall regimes. The divergence found in leaf loss was significantly greater among regions than the expected given the genetic divergence on neutral loci suggesting signature of local adaptation responding to drought. The results demonstrate adaptive potential of saltcedar populations to extreme drought. As extreme aridity is often predicted in climate models across the southwestern US, the western saltcedar genotypes locally adapted to drought may further expand their ranges in this region. [ABSTRACT FROM AUTHOR]

Biological invasion poses several biotic and abiotic challenges due to abrupt distribution shifts. Invasive species may benefit from local adaptation responding to environmental stresses during colonization. Saltcedar (Tamarix), a notorious invasive shrub in the western US introduced from Eurasia may have adapted to low rainfall as the species widely occupies the arid land throughout the southwestern US. We investigated variation of quantitative traits in saltcedar between two regions exhibiting opposing average annual precipitations under experimentally manipulated water treatments to test local adaptation. We measured eight quantitative traits, proxies for fitness and genotyped 64 individual samples using genotype by sequencing technique. To test local adaptation, we applied QCT - FCT test based on null distribution of FCT estimated from 2,697 genome-wide SNPs and QCT estimated for the eight phenotypic traits measured. Saltcedar in the southwestern US exhibited a significant interaction between the degree of leaf loss (biomass loss by senesced leaves to total biomass) under simulated drought conditions and the origins from which the genotypes were collected, either relatively high or low rainfall regimes. The divergence found in leaf loss was significantly greater among regions than the expected given the genetic divergence on neutral loci suggesting signature of local adaptation responding to drought. The results demonstrate adaptive potential of saltcedar populations to extreme drought. As extreme aridity is often predicted in climate models across the southwestern US, the western saltcedar genotypes locally adapted to drought may further expand their ranges in this region.

Rangelands cover a large area of Mexico. The overgrazing of these grasslands favors the invasion of Mexican needlegrass (Amelichloa clandestina). The objective was to determine the impact of cutting and glyphosate application as means to control A. clandestina in northeastern Mexico. Two sites with dominance of A. clandestina were used. The treatments were; cutting of this grass (Tl), herbicide application (glyphosate; T2), and control (T3 = undisturbed plots). A completely randomized design was used, with three replicates. The lowest production of this grass was in the first cut in summer with 449 kg DM ha'1 for site one and in site two in the seventh cut in spring with 496 kg DM ha'1. Regardless of sampling date, treatments T2 and T3 registered the lowest biomass production, with 534 and 583 kg DM ha'1, on average, compared to Tl for site one. For site two, Tl and T2 presented the lowest phytomass production with 529 and 578 kg DM ha'1 and the highest was registered in Tl with 720 kg DM ha'1. The lowest values for intercepted solar radiation, height, density, and diameter of the crown were found in T2. In conclusion, leaving the species undisturbed and applying a herbicide has more effect on the predominance of Mexican needlegrass (Amelichloa clandestina) than cutting it, however, the biomass production was diminished when herbicide was applied. [ABSTRACT FROM AUTHOR]

Introduction of pests and diseases through trade is one of the main socio‐ecological challenges worldwide. Although Binomial sampling inspection at the border can reduce pest entry risk, it is common for consignments to fail inspection, wasting resources for both exporter and importer. Outsourcing the inspection to the exporting country could reduce the cost of inspection for both parties. However, there is then a need to assess the quality of the offshore inspection. In this paper, we develop an inverse method combining past inspection data on the pathway, an onshore inspection sample, and the Beta‐Binomial model to infer the sample size of the offshore inspection. We illustrate the method on two case studies: the importation of live plants through germplasm into Australia and the importation of pelleted seeds in New Zealand. In these case studies, we found that detecting four to five infested units in a single onshore inspection was typically sufficient to significantly doubt the presence of a compliant offshore inspection. We also ran a simulation experiment to quantify the statistical power to reject or accept the presence of compliant offshore inspection in practice: In highly infested pathways, we could detect the absence of offshore inspections after inspecting five consignments onshore. Less infested pathways required inspecting 20 to 60 consignments onshore. Our study demonstrates that Binomial sampling onshore can be used to assess the quality of offshore inspections. [ABSTRACT FROM AUTHOR]

Abstract In their seminal paper, Shea and Chesson (Trends in Ecology & Evolution, 2002, 17, 170) developed a highly cited model (S&C model) showing scale dependency in the native–exotic richness relationships. Two decades later, extensive additional data have been accumulated, leading to new findings and insights. Accordingly, two updates were made here to the original S&C model: (1) changing the “negative” richness relationship between natives and exotics to “non‐consistent” or “non‐significant”; and (2) modifying the original diagram to correctly represent native and exotic species richness and their correlations across both small and large scales.

Alien species invasions are considered to be one of the multiple key drivers that trigger ecological regime shifts in ecosystem structure and function. Predicting population collapse and understanding the self-reinforced feedback mechanisms that erode the resilience of native species are two major challenges in invasion ecology. However, to date, empirical evidence of species invasion-induced regime shifts remains scarce, and the minimum required data to generate early warning signals (EWSs) before critical transitions remains unclear, despite its importance for ecosystem management. By combining 80-year (i.e., 1936–2016) fishery data from Lake Qiandao and a theoretical competition model, we provide evidence that relative to nutrient enrichment and climate change, stocking alien fish species of silver carp (Hypophthalmichthys molitrix) and bighead carp (Aristichthys nobtilis) is the most important driver leading to the collapse of local fish populations. Detectable EWSs indicated by the variance, autocorrelation and composite resilience indicators require at least ten years of data before an abrupt decline, demonstrating that a long-term ecological monitoring program is necessary for providing insight into resilience dynamics. A structural equation model (SEM) suggests that the combined effects of eutrophication, high water levels and carp stocking-induced water clarity decline may play an important role in the reduced fitness of local fish populations, which subsequently increase the carrying capacity of alien fish populations. Our results demonstrate that stocking alien carps result in competitive exclusion of local fish populations, especially in the current context of water eutrophication and global climate changes. Furthermore, quantifying the minimum required time series length with detectable EWS across various ecosystems should be further studied given that this information is critical for flexible management policies to take actions to avert the harmful transitions.

1. Hyphantria cunea is a problematic invasive species that has caused considerable damage to agricultural and forestry ecosystems in China. 2. We compared 19 bioclimate variables between its native country (the United States of America) and China to elucidate the environmental factors associated with its presence. Using present climate data (1970–2000) and projected future climate data (2050 and 2070) based on two Representative Concentration Pathways (RCPs 2.6 and 8.5), we used MaxEnt to predict the suitable habitat areas for H. cunea in the USA and China. Using these analyses, we predicted the niche change of H. cunea in China using the 'ecospat' package in R. 3. Our model predicts that climate change will generally increase the extent of suitable habitat in both China and the USA, although low latitude areas will be limited by future climate change. We also report low niche overlap between the USA and Chinese populations of H. cuena and significant differences in bioclimate variables associate with its presence in each country. Therefore, our results suggest H. cunea has adapted to several climatic conditions in China. This indicates the niche of H. cunea may shift and adapt to novel environmental conditions over the course of its spread. 4. Overall, the analysis of the environmental characteristics, niche changes, and suitable areas of H. cunea provides a basis for pest control and management strategies aimed at preventing further spread. Our methods may also be used to study other similar invasive species. [ABSTRACT FROM AUTHOR]

Aim: A better understanding of native and non‐native species responses to environmental conditions, historical processes, and human pressures is crucial in the face of global environmental changes affecting biodiversity. Here, we evaluate the relative roles of environmental, historical and anthropogenic factors in influencing species richness of native and non‐native freshwater fishes in watersheds across North America. Location: North America (exclusive of Mexico). Time period: Recent. Major taxa studied: Freshwater fishes. Methods: We compiled an extensive dataset of native and non‐native fish richness in 2,993 watersheds across North America, together with corresponding data for environmental (climatic, geographic), historical and anthropogenic factors. We used variance partitioning and hierarchical partitioning to quantify the relative importance of environmental, historical and anthropogenic factors in explaining richness variation in native and non‐native [overall, and by geographic origin (foreign/translocated) and pathway (authorized/unauthorized)] fishes, while accounting for correlations among explanatory variables and spatial autocorrelation. Results: Overall importance of environmental and anthropogenic factors was greater than historical factors in explaining both native and non‐native richness. Precipitation‐related factors were more important in explaining native richness, whereas non‐native richness was largely associated with temperature‐related factors. However, richness related to authorized introductions was less constrained by temperature than unauthorized introductions. Dam density, road density and urbanization gradient were major anthropogenic factors related to non‐native richness, yet their relative importance varied among origin‐ and pathway‐based categories. Conclusions: Our findings indicate different environmental drivers influence native and non‐native fish richness patterns in North America. The accumulation of non‐native species in watersheds depends on the interaction between environmental conditions and anthropogenic‐based processes related to introduction history including geographic origin, introduction pathway, and propagule pressure, where the latter likely plays a major role. Warmer regions with high human population densities and more impoundments are more prone to fish invasions, mostly via unauthorized introductions. [ABSTRACT FROM AUTHOR]

In circumstances where populations of invasive species occur across variable landscapes, interactions among invaders, their parasites, and the surrounding environment may establish local coevolutionary trajectories for the participants. This can generate variable infection patterns when parasites interact with sympatric versus allopatric hosts. Identifying the potential for such patterns within an invasive-species framework is important for better predicting local infection outcomes and their subsequent impacts on the surrounding native community. To begin addressing this question, we exposed an invasive snail (Bithynia tentaculata) from two widely separated sites across the USA (Wisconsin and Montana) to the digenean parasite, Sphaeridiotrema pseudoglobulus, collected from Wisconsin. Parasite exposures generated high infection prevalences in both sympatric and allopatric snails. Furthermore, host survival, host growth, the proportion of patent snails, and the timing of patency did not differ between sympatric and allopatric combinations. Moreover, passaging parasites through snails of different origins had no effect on transmission success to subsequent hosts in the life cycle. However, the number of parasites emerging from snails and the pattern of their release varied based on snail origin. These latter observations suggest the potential for local adaptation in this system, but subsequent research is required to further substantiate this as a key factor underlying infection patterns in the association between S. pseudoglobulus and B. tentaculata. [ABSTRACT FROM AUTHOR]

The role of phenotypic plasticity in adaptive evolution has been debated for decades. This is because the strength of natural selection is dependent on the direction and magnitude of phenotypic responses to environmental signals. Therefore, the connection between plasticity and adaptation will depend on the patterns of plasticity harbored by ancestral populations before a change in the environment. Yet few studies have directly assessed ancestral variation in plasticity and tracked phenotypic changes over time. Here we resurrected historic propagules of Daphnia spanning multiple species and lakes in Wisconsin following the invasion and proliferation of a novel predator (spiny waterflea, Bythotrephes longimanus). This approach revealed extensive genetic variation in predator-induced plasticity in ancestral populations of Daphnia. It is unlikely that the standing patterns of plasticity shielded Daphnia from selection to permit long-term coexistence with a novel predator. Instead, this variation in plasticity provided the raw materials for Bythotrephes-mediated selection to drive rapid shifts in Daphnia behavior and life history. Surprisingly, there was little evidence for the evolution of trait plasticity as genetic variation in plasticity was maintained in the face of a novel predator. Such results provide insight into the link between plasticity and adaptation and highlight the importance of quantifying genetic variation in plasticity when evaluating the drivers of evolutionary change in the wild. [ABSTRACT FROM AUTHOR]

Wetland decline under post-European settlement and land use change across western Canada has led to mitigation strategies, including wetland creation. Created wetlands can trigger environmental change, including woody species encroachment, in turn altering vegetation and soil. We quantify changes in shrub abundance from prior to wetland creation (1949) until 60 years later (2012) within a Mixedgrass ecosystem of the Verger watershed in Alberta, Canada. In addition, we compare remaining grassland with areas colonized by shrubland on similar ecosites for differences in (1) plant composition, including native and introduced flora, (2) herbage yield and forage accessibility for livestock, and (3) soil properties (surface organic depth, bulk density, mineral nitrogen (N), and carbon (C) concentration). Repeat photos show Shepherdia argentea shrublands increased from 0 to 88 ha (to 1.15% of study area) following wetland creation, with the greatest increase in the last 20 years. Relative to grasslands, shrublands had lower total plant diversity but greater presence of introduced plant species. Shrub patches were 94% lower in herbaceous production, with 77% of shrublands non-utilized by cattle, collectively leading to reduced grazing capacity. Relative to grasslands, shrublands had a thicker soil surface mulch layer, and where cattle were present, had increased mineral soil N and C. Overall, shrub encroachment following wetland creation has markedly altered vegetation and soils in this once grassland landscape, with negative impacts on native plant diversity, herbage production and forage accessibility, and has implications for the management of shrub encroachment. [ABSTRACT FROM AUTHOR]

Negative interactions between species can generate divergent selection that causes character displacement. However, other processes cause similar divergence. We use spatial and temporal replication across island populations of Anolis lizards to assess the importance of negative interactions in driving trait shifts. Previous work showed that the establishment of Anolis sagrei on islands drove resident Anolis carolinensis to perch higher and evolve larger toepads. To further test the interaction's causality and predictability, we resurveyed a subset of islands nine years later. Anolis sagrei had established on one island between surveys. We found that A. carolinensis on this island now perch higher and have larger toepads. However, toepad morphology change on this island was not distinct from shifts on six other islands whose Anolis community composition had not changed. Thus, the presence of A. sagrei only partly explains A. carolinensis trait variation across space and time. We also found that A. carolinensis on islands with previously established A. sagrei now perch higher than a decade ago, and that current A. carolinensis perch height is correlated with A. sagrei density. Our results suggest that character displacement likely interacts with other evolutionary processes in this system, and that temporal data are key to detecting such interactions. [ABSTRACT FROM AUTHOR]

In recent years, researchers have recognized the importance of behavioral factors for invasive species success. There is evidence that an organism's ability to quickly react to stimuli may be one behavioral factor leading to invasive success. In this study, we analyzed the startle response of the invasive Asian shore crab Hemigrapsus sanguineus (De Haan, 1835), which measured here as a binary response variable of either active or inactive behavior when the rock they were under was suddenly lifted up. The behavior of H. sanguineus was compared to other crab species in the area to determine how species-dependent their responses were. This response was compared across an intertidal gradient with variation in temperature, intertidal elevation, substrate, time of day, and male-to-female ratios to determine if these affected the crabs' responses. We found that H. sanguineus was more responsive than other species, perhaps indicative of a generally high activity level for this species. Surprisingly, we found that their behavior was not affected by any environmental factors tested. The consistently active behavior of this crab could be one factor contributing to its high level of success as an invasive species. [ABSTRACT FROM AUTHOR]

Video-based person re-identification (re-id), which aims to match people through videos captured by non-overlapping camera views, has attracted lots of research interest recently. In this paper, we first propose a novel hybrid 2D and 3D convolution-based recurrent neural network (HCRN) for video-based person re-id task. Specifically, the 3D convolutional module can explore the local short-term fast-varying motion information, while the recurrent layer can leverage the global long-term spatial–temporal information. Based on HCRN, we design a scale-fusion framework to make full use of features of different scales to further improve the performance of video-based person re-id. More concretely, the scale-fusion framework preserves a complete subnetwork similar to HCRN for each scale to extract features and exchanges information between all subnetworks at several stages of the framework. Besides, we propose a training method called species invasion to further improve the performance of HCRN and scale-fusion framework by utilizing a large amount of unlabeled data. Experimental results on the publicly available PRID 2011, iLIDS-VID and MARS multi-shot pedestrian re-id datasets demonstrate the effectiveness of the proposed HCRN, scale-fusion framework and species invasion training method. [ABSTRACT FROM AUTHOR]

Ninety-six registrations of great white egret from ten districts of Novgorod Region in 2016–2018 were analyzed. The birds were seen from single individuals up to 170 birds in one flock. The main areas of registrations of this species are the surroundings of the city of Novgorod and Lake Ilmen. The birds were seen on the territory from February 25 to October 31. We did not get any documented evidence of this species breeding, but breeding is possible. At present, the great white egret has to be considered as a summering, possibly breeding, and occasionally wintering species of Novgorod Region. [ABSTRACT FROM AUTHOR]

Yancheng National Nature Reserve (YNNR) in Jiangsu province is the largest wintering habitat for red-crowned cranes (Grus japonensis) in the world. However, the Spartina alterniflora (S. alterniflora) expansion had caused a series of ecological problems. In the paper, by using ETM + images as data source, GIS technology and the InVEST model were used to analyze the influence of S. alterniflora expansion on the landscape pattern and habitat quality through scenario simulation. We found that: from 2000 to 2020, under the current conditions, the percentage of landscape (PLAND) of S. alterniflora marsh would increase from 17.525% to 51.522%, which would result in a risk of extinction for the Suaeda salsa (S. salsa) marsh; the habitat quality index (Q) would be decreased from 0.8183 to 0.7074. Under the condition of removing S. alterniflora, the PLAND of S. salsa marsh would be restored to 43.8317%, and the Q would be increased to 0.9463. Under the condition of controlling S. alterniflora expansion, the PLAND of S. alterniflora marsh would be decreased to 8.678%, the PLAND of S. salsa marsh would be restored to 43.8653%, and the Q would be increased to 0.9198. The results would be beneficial to the management of the YNNR. [ABSTRACT FROM AUTHOR]

Abiotic environmental change, local species extinctions and colonization of new species often co‐occur. Whether species colonization is driven by changes in abiotic conditions or reduced biotic resistance will affect community functional composition and ecosystem management. We use a grassland experiment to disentangle effects of climate warming and community diversity on plant species colonization. Community diversity had dramatic impacts on the biomass, richness and traits of plant colonists. Three times as many species colonized the monocultures than the high diversity 17 species communities (~30 vs. 10 species), and colonists collectively produced 10 times as much biomass in the monocultures than the high diversity communities (~30 vs. 3 g/m2). Colonists with resource‐acquisitive strategies (high specific leaf area, light seeds, short heights) accrued more biomass in low diversity communities, whereas species with conservative strategies accrued most biomass in high diversity communities. Communities with higher biomass of resident C4 grasses were more resistant to colonization by legume, nonlegume forb and C3 grass colonists, but not by C4 grass colonists. Compared with effects of diversity, 6 years of 3°C‐above‐ambient temperatures had little impact on plant colonization. Warmed subplots had ~3 fewer colonist species than ambient subplots and selected for heavier seeded colonists. They also showed diversity‐dependent changes in biomass of C3 grass colonists, which decreased under low diversity and increased under high diversity. Our findings suggest that species colonization is more strongly affected by biotic resistance from residents than 3°C of climate warming. If these results were extended to invasive species management, preserving community diversity should help limit plant invasion, even under climate warming. [ABSTRACT FROM AUTHOR]

In their seminal paper, Shea and Chesson (Trends in Ecology & Evolution, 2002, 17, 170) developed a highly cited model (S&C model) showing scale dependency in the native–exotic richness relationships. Two decades later, extensive additional data have been accumulated, leading to new findings and insights. Accordingly, two updates were made here to the original S&C model: (1) changing the "negative" richness relationship between natives and exotics to "non‐consistent" or "non‐significant"; and (2) modifying the original diagram to correctly represent native and exotic species richness and their correlations across both small and large scales. [ABSTRACT FROM AUTHOR]

A systematic review was conducted to identify trends and gaps in studies concerning nonnative populations in a neotropical floodplain and identify which population ecology topics has been predominant among studies in such floodplains. The large majority of the articles were field observational studies based on nonnative fish populations. A focus on ecological interactions, in particular competition and predation, was predominant in these studies. Hypotheses related to environmental filters and biotic resistance were used most frequently to support studies on river the floodplain, but many studies not addressed the invasion theory. Impoundment was the introduction vector associated with the largest number of studies of nonnative populations. We present conceptual aspects that may guide future studies on nonnative population ecology and inform conservation policies in floodplain ecosystems. [ABSTRACT FROM AUTHOR]

Species introduction can alter the structure and dynamics of biological communities and, therefore, understanding their feeding behavior and the effects that an exotic species can cause in the food web configuration is pivotal. We aimed to experimentally investigate the effects of the potential invasive species Kellicottia bostoniensis on different components of the microbial food web and to evaluate if the food preferences of this species change under different conditions of resource availability and interspecific interactions. We tested the hypothesis that the presence of K. bostoniensis would have direct and indirect effects on the different components of the planktonic food web. We designed three different assays (E) using prey size fractionation, being E1 composed of bacteria (HB) and picophytoplankton (PPP), E2 composed of HB, PPP and autotrophic and heterotrophic flagellates and, E3 with the whole planktonic community. Each one composed of a control in the absence of K. bostoniensis and a treatment with the presence of this species. Results showed that K. bostoniensis caused direct effects on its main food items, the heterotrophic and autotrophic flagellates, whereas no evidence of indirect effects was observed on the base components of the microbial web food, such as heterotrophic bacteria and picophytoplankton. In addition, a negative effect of the exotic rotifer on ciliates was observed. Finally, we emphasize that the impact of K. bostoniensis on aquatic ecosystem may be quite harmful, since this specie can act as a sink of matter and energy to higher trophic levels. [ABSTRACT FROM AUTHOR]