scholarly journals Widespread homogenization of plant communities in the Anthropocene

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Barnabas H. Daru ◽  
T. Jonathan Davies ◽  
Charles G. Willis ◽  
Emily K. Meineke ◽  
Argo Ronk ◽  
...  

AbstractNative biodiversity decline and non-native species spread are major features of the Anthropocene. Both processes can drive biotic homogenization by reducing trait and phylogenetic differences in species assemblages between regions, thus diminishing the regional distinctiveness of biotas and likely have negative impacts on key ecosystem functions. However, a global assessment of this phenomenon is lacking. Here, using a dataset of >200,000 plant species, we demonstrate widespread and temporal decreases in species and phylogenetic turnover across grain sizes and spatial extents. The extent of homogenization within major biomes is pronounced and is overwhelmingly explained by non-native species naturalizations. Asia and North America are major sources of non-native species; however, the species they export tend to be phylogenetically close to recipient floras. Australia, the Pacific and Europe, in contrast, contribute fewer species to the global pool of non-natives, but represent a disproportionate amount of phylogenetic diversity. The timeline of most naturalisations coincides with widespread human migration within the last ~500 years, and demonstrates the profound influence humans exert on regional biotas beyond changes in species richness.

Insects ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 545
Author(s):  
Sara Straffon Díaz ◽  
Luca Carisio ◽  
Aulo Manino ◽  
Paolo Biella ◽  
Marco Porporato

Megachile sculpturalis (Smith, 1853) is the first exotic bee species in Europe. Its remarkably fast expansion across this continent is leading to a growing concern on the extent of negative impacts to the native fauna. To evaluate the interactions of exotic bees with local wild bees, we set up trap nests for above-ground nesting bees on a semi-urban area of north-western Italy. We aimed to investigate the interaction in artificial traps between the exotic and native wild bees and to assess offspring traits accounting for exotic bee fitness: progeny sex ratio and incidence of natural enemies. We found that the tunnels occupied by exotic bees were already cohabited by O. cornuta, and thus the cells of later nesting alien bees may block the native bee emergence for the next year. The progeny sex ratio of M. sculpturalis was strongly unbalanced toward males, indicating a temporary adverse population trend in the local invaded area. In addition, we documented the presence of three native natural enemies affecting the brood of the exotic bee. Our results bring out new insights on how the M. sculpturalis indirectly competes with native species and on its performance in new locations.


Work ◽  
2021 ◽  
pp. 1-10
Author(s):  
Amy Wagenfeld ◽  
Daniel Winterbottom

BACKGROUND: Adjusting to incarceration is traumatic. An under-utilized strategy understood to buffer and counteract the negative impacts of incarceration are nature interventions. OBJECTIVE: Outcomes of an interdisciplinary design studio course focused on developing masterplans for a women’s prison in the Pacific Northwest (US) are presented. Course objectives included comprehension and application of therapeutic and culturally expressive design principles to increase the benefits of environmental design within a carceral setting; collaboration, developing a deeper, more representative understanding of how design processes can improve the lives of marginalized populations; and enhancing design skills, including at masterplan and schematic scale using an iterative process and reflection. METHODS: A landscape architect, occupational therapist, and architect teaching team, with support from architects and justice specialists facilitated an elective design studio course to redesign the Washington Corrections Center for Women campus. RESULTS: In a ten-week academic quarter, six student design teams created conceptual masterplans for therapeutic outdoor spaces at the Washington Corrections Center for Women. Students presented their plans to prison staff, current and ex-offenders, and architects and landscape architects in practice, and then received positive feedback. CONCLUSION: Despite well-documented need for and value of nature interventions to improve health and wellbeing for everyone regardless of circumstance or situation, the project awaits administrative approval to move forward to installation.


2008 ◽  
Vol 65 (5) ◽  
pp. 788-794 ◽  
Author(s):  
Thomas W. Therriault ◽  
Leif-Matthias Herborg

Abstract Therriault, T. W., and Herborg, L-M. 2008. Predicting the potential distribution of the vase tunicate Ciona intestinalis in Canadian waters: informing a risk assessment. – ICES Journal of Marine Science, 65: 788–794. A crucial step in characterizing the potential risk posed by non-native species is determining whether a potential invader can establish in the introduced range and what its potential distribution could be. To this end, various environmental models ranging from simple to complex have been applied to predict the potential distribution of an invader, with varying levels of success. Recently, in marine waters, tunicates have received much attention, largely because of their negative impacts on shellfish aquaculture. One of these species is the vase tunicate Ciona intestinalis, which recently has had a negative impact on aquaculture operations in Atlantic Canada and could pose a risk in Pacific Canada. To inform the risk assessment of this species, we evaluated two different types of environmental model. Simple models based on reported temperature or salinity tolerances were relatively uninformative, because almost all waters were deemed suitable. In contrast, a more complex genetic algorithm for rule-set prediction (GARP) environmental niche model, based on documented Canadian occurrence points, provided informative projections of the potential distribution in Canadian waters. In addition to informing risk assessments, these predictions can be used to focus monitoring activities, particularly towards vectors that could transport C. intestinalis to these favourable environments.


2015 ◽  
Vol 8 (1) ◽  
pp. 72-80 ◽  
Author(s):  
Shayla A. Burnett ◽  
Brian A. Mealor

AbstractDowny brome inhibits revegetation efforts following ecosystem disturbance. Imazapic is a commonly used herbicide for downy brome management, but more information is needed regarding effective application timing for restoration efforts. We wished to determine (1) if native species establishment exhibited a tradeoff between downy brome competition and injury from herbicide and (2) if this differed between pre- and postemergent applications of imazapic. We used a standard replacement series design and overlaid herbicide treatments. Nine weeks after planting, aboveground biomass was harvested and relative yield (RY) indices calculated. Both imazapic applications reduced downy brome biomass by 91% or more (P < 0.05). Imazapic caused drastic reductions in native biomass but less than what was caused by downy brome competition (P < 0.05). Natives were less injured by a pre- than postemergent application (P < 0.05). In situations where downy brome may impact restoration efforts, pre-emergent applications of imazapic at 70 g ai ha−1 (0.06 lb ai ac−1) may reduce downy brome with less negative impacts on newly-seeded native grasses than post-emergent applications. Ensuring sufficient proportions of native species seeds on restoration sites may reduce downy brome.


2021 ◽  
Author(s):  
◽  
Kirill Woodhouse

<p>Exotic species often slip through international borders undetected. Many perish but for some species introduction to a foreign land or sea brings release from natural enemies and a chance to establish a population. Increased global trade has increased the frequency of species introductions through stowaways and lapses in biosecurity. Once an invader is established there is the opportunity for explosive population growth at the detriment of native species and humans. The marine aquarium trade is a significant vector of species introductions, including algal introductions. The most publicized introduction from aquaria was the release of the green alga Caulerpa taxifolia from the Oceanographic Museum in Monaco. C. taxifolia introduction had large negative impacts on the invaded ecosystem.  Molecular barcoding of tropical macroalgae entering the New Zealand aquarium trade was implemented using various molecular markers (cox1, cox3, rbcL tufA, LSU). Both NCBI Blast searches and maximum-likelihood phylogenies were used to identify the isolates. A total of 62 species of tropical macroalgae were identified from coral rocks imported into New Zealand, plus samples from reef hobbyists. Some species found are known as invasive elsewhere, for example, Caulerpa cylindracea, C. racemosa, C. sertularioides, Ulva ohnoi and Chaetomorpha vieillardii. All three major groups of algae were well represented in my findings with 26 species of red algae, 24 species of green algae and 12 species of brown algae. Temperature tolerance limits are the largest determinant in survival in algae, while salinity and pH are less significant. Temperature tolerance of tropical algae to the minimum Sea Surface Temperature in Auckland (14°C) and Wellington (11°C) was tested. My results show that one species Chaetomorpha vieillardii can survive at Auckland minimum winter sea surface temperatures. Our findings have important implications for New Zealand biosecurity, as not only are a large diversity of exotic macroalgae entering the New Zealand marine aquarium trade unregulated, but there is also the potential for them to survive in New Zealand waters.   </p>


2018 ◽  
Vol 5 (5) ◽  
pp. 172477 ◽  
Author(s):  
Dailos Hernández-Brito ◽  
Martina Carrete ◽  
Carlos Ibáñez ◽  
Javier Juste ◽  
José L. Tella

The identification of effects of invasive species is challenging owing to their multifaceted impacts on native biota. Negative impacts are most often reflected in individual fitness rather than in population dynamics of native species and are less expected in low-biodiversity habitats, such as urban environments. We report the long-term effects of invasive rose-ringed parakeets on the largest known population of a threatened bat species, the greater noctule, located in an urban park. Both species share preferences for the same tree cavities for breeding. While the number of parakeet nests increased by a factor of 20 in 14 years, the number of trees occupied by noctules declined by 81%. Parakeets occupied most cavities previously used by noctules, and spatial analyses showed that noctules tried to avoid cavities close to parakeets. Parakeets were highly aggressive towards noctules, trying to occupy their cavities, often resulting in noctule death. This led to a dramatic population decline, but also an unusual aggregation of the occupied trees, probably disrupting the complex social behaviour of this bat species. These results indicate a strong impact through site displacement and killing of competitors, and highlight the need for long-term research to identify unexpected impacts that would otherwise be overlooked.


2017 ◽  
Vol 23 (3) ◽  
pp. 258 ◽  
Author(s):  
Monica A. M. Gruber ◽  
Meghan Cooling ◽  
Allan R. Burne

Invasive species are one of the most serious threats to biodiversity. Up-to-date and accurate information on the distribution of invasive species is an important biosecurity risk analysis tool. Several databases are available to determine the distributions of invasive and native species. However, keeping this information current is a real challenge. Ants are among the most widespread invasive species. Five species of ants are listed in the IUCN list of damaging invasive species, and many other species are also invasive in the Pacific. We sought to determine and update the distribution information for the 18 most problematic invasive ant species in the Pacific to assist Small Island Developing States with risk analysis. We compared the information on six public databases, conducted a literature review, and contacted experts on invasive ants in the Pacific region to resolve conflicting information. While most public records were accurate we found some new records had not yet been incorporated in the public databases, and some information was inaccurate. The maintenance of public databases faces an enormous challenge in balancing completeness (~15 000 ant species in this case) with accuracy (the impossibility of constantly surveying) and utility.


Author(s):  
Nathan G King ◽  
Sophie B Wilmes ◽  
David Smyth ◽  
Jonathan Tinker ◽  
Peter E Robins ◽  
...  

Abstract Invasive non-native species and global warming are two of the greatest components of global ecosystem change. The Pacific oyster, Crassostrea gigas, is the world most cultivated shellfish and was introduced throughout the Northwest European Shelf (NWES) under the premise it could not complete its life cycle. Recent warming trends have changed this and wild populations can be found as far north as Nordic Scandinavia. Under the RCP8.5 concentration pathway, we predict that the majority of NWES coastline will be within C. gigas’s thermal recruitment niche by 2100. Given the widespread occurrence of current naturalized C. gigas populations, its large larval dispersal potential and a lack of feasible management solutions, C. gigas will likely undergo a considerable range expansion this century. The time taken to reach maturity is predicted to decrease by up to 60 days, which may lead to precocious spawning events, facilitating expansion further. Crassostrea gigas can form extensive reefs completely transforming native systems. This may compromise native biodiversity, protected habitats, and commercial species. However, naturalization can also deliver a number of beneficial ecosystem goods and services to human society. Whether naturalization is deemed positive or negative will depend on biogeographic context, the perceptions of stakeholders, and the wider management priorities.


2020 ◽  
Vol 93 (4) ◽  
pp. 567-586 ◽  
Author(s):  
Elisabeth Pötzelsberger ◽  
Katharina Lapin ◽  
Giuseppe Brundu ◽  
Tim Adriaens ◽  
Vlatko Andonovski ◽  
...  

Abstract Europe has a history rich in examples of successful and problematic introductions of trees with a native origin outside of Europe (non-native trees, NNT). Many international legal frameworks such as treaties and conventions and also the European Union have responded to the global concern about potential negative impacts of NNT that may become invasive in natural ecosystems. It is, however, national and regional legislation in particular that affects current and future management decisions in the forest sector and shapes the landscapes of Europe. We identified all relevant legal instruments regulating NNT, the different legal approaches and the regulatory intensity in 40 European countries (no microstates). Information on hard and effective soft law instruments were collected by means of a targeted questionnaire and consultation of international and national legislation information systems and databases. In total, 335 relevant legal instruments were in place in June/July 2019 to regulate the use of NNT in the investigated 116 geopolitical legal units (countries as well as sub-national regions with their own legislation). Countries and regions were empirically categorized according to ad hoc-defined legislation indicators. These indicators pay respect to the general bans on the introduction of non-native species, the generally allowed and prohibited NNT, approval mechanisms and specific areas or cases where NNT are restricted or prohibited. Our study revealed a very diverse landscape of legal frameworks across Europe, with a large variety of approaches to regulating NNT being pursued and the intensity of restriction ranging from very few restrictions on species choice and plantation surface area to the complete banning of NNT from forests. The main conclusion is that there is a clear need for more co-ordinated, science-based policies both at the local and international levels to enhance the advantages of NNT and mitigate potential negative effects.


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