Molecular Phylogenetics of Physa acuta (Pulmonata: Basommatophora): an Invasive species in Central Punjab Pakistan

Physids belong to Class Gastropoda; belong to Phylum Mollusca and being bioindicators, intermediate hosts of parasites and pests hold a key position in the ecosystem. There are three species of Genus Physa i.e. P. fontinalis, Physa acuta and P. gyrina water bodies of Central Punjab and were characterized on the basis of molecular markers High level of genetic diversity was revealed by polymorphic RAPD, however SSR markers were not amplified. The multivariate analysis revealed polymorphism ranging from 9.09 percent to 50 percent among the three Physid species. Total number of 79 loci were observed for the three species under study and 24 loci were observed to be polymorphic. These RAPD fragment(s) can be developed into co dominant markers (SCAR) by cloning and can be further sequenced for the development of the Physa species specific markers to identify the introduced and native species in Pakistan.

Acacia dealbata Link. Aboveground Biomass Assessment: Sustainability of Control and Eradication Actions to Reduce Rural Fires Risk

Invasive species are an environmental problem affecting worldwide ecosystems. In the case of Acacia dealbata Link., the negative impacts affect the productivity of the forests due to the competition established with native species while contributing to a significant increment in the available fuel load, increasing the risk of fire. In Portugal, chemical and mechanical methods are mostly used in the control of these species. However, the costs are often unsustainable in the medium term, being abandoned before completing the tasks, allowing the recovery of the invasive species. The establishment of value chains for the biomass resulting from these actions was pointed out by several authors as a solution for the sustainability of the control process, as it contributes to reducing costs. However, the problems in quantifying the biomass availability make it challenging to organize and optimize these actions. This work, which started from a dendrometrical analysis carried out in stands of A. dealbata, created a model to assess woody biomass availability. The model proved to be statistically significant for stands with trees younger than 20 years old. However, the amount of data collected and the configuration of the settlements analyzed do not allow extrapolation of the model presented to older settlements.

Invasive Alien Plants and Invasion Risk Assessment on Pingtan Island

Pingtan Island is the largest island in Fujian Province and the fifth largest island in China. The invasion of a large number of alien plants has had a profound impact on the local ecological environment. Because the harm caused by alien invasive plants varies greatly between different ecosystems and even in different habitats, the risk assessment index system suitable for one region may not be suitable for other regions. Therefore, it is necessary to establish a risk assessment index system for invasive alien plants on Pingtan Island. Alien plant communities in different habitats were studied by means of quadrat investigation and professional literature review. Some invasive alien species were selected and compiled into a list of invasive alien plants on Pingtan Island, and their species composition, origin, flora, life forms, and habitats were statistically grouped. There were 104 species in 80 genera and 37 families of alien invasive plants. Asteraceae, Fabaceae, Amaranthaceae, and Poaceae were the main families, accounting for 26.7%, 6.7%, 6.7% and 5.8% of the total species, respectively. The geographical components of families and genera have obvious tropical properties, accounting for 51.3% and 66.6% of the total species, respectively. These originated mainly from South America and North America, accounting for 45.5% and 30.1% of the total frequency, respectively. Annual herbs, biennial herbs, and perennial herbs accounted for 84.6% of the total species. Based on a DPSIR conceptual model and an AHP method, an invasion risk assessment of 104 invasive alien plants was conducted. The ecological adaptability, habitat distribution and landscape impact of species were considered in the selection of indicators and the formulation of standards. A total of 23 high-risk invasive species were identified at level I, 37 medium-risk invasive species at level II, and 44 low-risk invasive species at level III. Lantana camara L. had the highest risk score (49), followed by Cenchrus echinatus L. (45), Spartina alterniflora Loisel. (45), and Panicum repens L. (43.5). Suggestions are put forward to prevent the invasion of alien plants on Pingtan Island and to provide a theoretical basis for promoting the healthy and stable development of the ecological environment on the island.

Two Shades of Grey: Effect of Temperature on Seed Germination of the Escaping Ornamental Species Lychnis Coronaria and Stachys Byzantina

This paper describes germination and cytological variability in two popular ornamental and potentially invasive species, lamb’s ear Stachys byzantina and rose campion Lychnis coronaria. Both xerophytic species have the potential to invade natural habitats across Europe and create viable naturalised populations, with subsequent impacts on native vegetation. To assess the species’ invasiveness, seeds were collected from naturalised populations and germination rate recorded under different temperature regimes. Flow cytometry, used to record cytological variability, indicated that all populations of both species were cytologically homogeneous. Germination success, a key spreading factor in both species, was significantly influenced by temperature, with final germination of L. coronaria being extremely high at temperatures > 15/10 °C (98.5%) and extremely low at temperatures < 10/5 °C (2.9%). In comparison, final germination in S. byzantina highest at 22/15 °C (55.6%), reducing to 40.3% at 15/10 °C and just 0.3% at temperatures < 10/5 °C. No significant differences in germination rate were observed between escaping and non-escaping populations, though there were differences between particular populations. Our results indicate germination temperature limits between species consistent with sizes of primary distribution and distance between primary and secondary distribution borders. However, the observed germination rates allow for successful generative reproduction of both species over their secondary distribution areas, suggesting that these species are likely to become invasive species of European grasslands soon.

Building a synthesis of economic costs of biological invasions in New Zealand

Biological invasions are a major component of anthropogenic environmental change, incurring substantial economic costs across all sectors of society and ecosystems. However, the economic costs of invasions have been disparately reported, lacking synthesis across taxonomic and sectorial scales. Using the newly compiled InvaCost database, we analyse reported economic damage and management costs incurred by biological invasions in New Zealand — a country renowned for its approaches to invasive species management — from 1968 to 2020. In total, US$69 billion (NZ$97 billion) is currently reported over this ~50 year period, with approximately US$9 billion of this considered highly reliable, observed (c.f. projected) costs. Most (82%) of these observed economic costs are associated with damage, with comparatively little invested in management (18%). Reported costs are increasing over time, with damage averaging US$120 million per year and exceeding management expenditure in all decades. Where specified, most reported costs are from terrestrial plants and animals, with damages most often borne by primary industries such as agriculture and forestry. Management costs are associated more with interventions by authorities and stakeholders. However, some known ecologically (c.f. economically) impactful invasive species are notably absent from estimated damage costs, and management costs are not reported for a number of game animals and agricultural pathogens. Given these gaps for known and potentially damaging invaders, we urge improved cost reporting at the national scale, including improving public accessibility through increased access and digitisation of records, particularly in overlooked socioeconomic sectors and habitats. This also further highlights the importance of investment in management to curtail future damages across all sectors.

Are invasive hymenopteran species replacing native mud dauber wasp-associated taxa on the Seychelles Archipelago?

Nest aggregations of mud dauber wasps increase substrate heterogeneity and provide suitable sites for colonization by other invertebrate species. The mud dauber wasp Sceliphron fuscum Klug, 1801 (Hymenoptera: Sphecidae) abundantly occurs throughout the Seychelles Archipelago, Republic of Seychelles. Here, we estimated the taxonomic richness of the hymenopteran assemblage associated with S. fuscum’s nest aggregations, using material collected from the Inner Seychelles in 2016. Furthermore, we examine available historical survey data in order to assess possible changes in this association over decades. We discovered that from 1936 to 1938, seven hymenopteran species were associated with the nest aggregations of S. fuscum on Mahé and Praslin islands, representing six native taxa and one invasive species. From the material collected in 2016, we found one native and three invasive hymenopteran species associated to S. fuscum nests. Our findings could indicate a replacement of native species associated with the mud dauber wasps’ nest aggregations by recently introduced alien taxa on the Seychelles Archipelago.