9 research outputs found
Climatic suitability and compatibility of the invasive Iris pseudacorus L.(Iridaceae) in the Southern Hemisphere: Considerations for biocontrol
Iris pseudacorus L. (Iridaceae) is an emergent macrophyte native to Europe, North Africa and western Asia. Considered invasive in wetland habitats around the world, this species is now the target of a biocontrol programme in the Southern Hemisphere. Native range surveys of the weed led to the selection of the flea beetle, Aphthona nonstriata Goeze (Coleoptera: Chrysomelidae), as a candidate biocontrol agent. An important aspect to consider in weed biocontrol is the ability of an agent to establish and thrive in the environment where it is released. Climatic incompatibility between source and intended release sites can in fact limit the success of a biocontrol programme. In the current study, the potential climatic niche of I. pseudacorus and A. nonstriata in the Southern Hemisphere was analysed. The ecological niche modelling software MaxEnt was used to map the climatic suitability of both organisms across invaded regions in South America, southern Africa and Australasia. Furthermore, occurrence records from each invaded range were used independently to model the climatic compatibility of I. pseudacorus in Europe, in order to prioritize areas of the native range to explore during future surveys for potential biocontrol agents. The models identified areas at high risk of invasion by I. pseudacorus in northern Argentina, Uruguay, southern Brazil and central Chile, as well as numerous provinces of eastern South Africa, Lesotho, southern Australia and New Zealand. Accordingly, the highest climatic suitability for A. nonstriata was predicted across the humid temperate climates of north-east Argentina, Uruguay, southern Brazil, southern South Africa, south-east Australia and New Zealand. These results can eventually be used in future release plans to prioritize areas where establishment and survival of the agent is expected to be highest. At the same time, it may be useful to search the native range of the weed for biological control agents showing high climatic adaptation towards the intended release sites of each invaded range. In this regards, our climatic compatibility models identified high-priority areas across the Mediterranean regions of Italy and southern France, as well as the temperate regions of central and western Europe. Altogether, the current study provides useful new information to tackle the invasion and advance the biocontrol programme of I. pseudacorus in the Southern Hemisphere
Contrasting effects of climate change on the invasion risk and biocontrol potential of the invasive Iris pseudacorus L. between Northern and Southern Hemisphere
Iris pseudacorus is both a prized ornamental and an invasive aquatic plant that tends to grow dense monospecific stands, displacing the local vegetation and altering the hydrology of freshwater ecosystems. Originally from Europe, this species has historically invaded North America, China and Japan, and more recently spread through Argentina, South Africa and Australasia, where it is now a target for biological control. Field surveys within its native range have led to the selection of three candidate biocontrol agents. Prioritizing the best candidates for different regions constitutes a critical step, which could save significant time and resources before further cost-intensive experimental studies are conducted. Climate change is seldom taken into consideration in the prioritization process. In this regard, climatic suitability can be used to model the potential distributions of weeds and their candidate agents, both in space and time, thus allowing to identify areas at risk of invasion and predict where agents will be able to establish long-term. Accordingly, the objectives of this work were (i) to predict I. pseudacorus invasions and range shifts in the context of climate change; (ii) to identify wetland areas most at risk of invasion under present and future climatic conditions; and (iii) to prioritize the best suite of candidate biocontrol agents for different invaded ranges, worldwide. To do so, we modelled the present and future (2040–2060) climatic suitability of I. pseudacorus and its candidate agents using the software MaxEnt. Our results highlight a clear distinction between predictions for the Northern and Southern Hemispheres. In North America and eastern Asia, the area climatically suitable for I. pseudacorus is expected to increase and shift northwards. As for its biocontrol agents, very low suitability is predicted across these regions, further decreasing under future climatic conditions. On the other hand, climatically suitable areas for the plant in South America, southern Africa and Australasia are predicted, on average, to reduce in response to climate change. A decrease in climatic suitability is also expected for its candidate biocontrol agents which, however, would still maintain a significant range overlap with their host. These results can be used to prioritize areas most at risk of invasion and identify which combination of candidates could potentially provide the best level of control across different invaded ranges
The Endangered Sardinian Grass Snake: Distribution Update, Bioclimatic Niche Modelling, Dorsal Pattern Characterisation, and Literature Review
The Sardinian grass snake, Natrix helvetica cetti, is an endangered endemic snake subspecies with a restricted and highly fragmented geographic distribution. Information on its ecology and detailed geographic distribution are scarce and may negatively impact on its conservation status. Therefore, a literature review on its taxonomy, morphology, ecology, and conservation is presented here. Moreover, field records from the authors, citizen science and the existing literature provide an updated geographic distribution highlighting its presence within 13 new and 7 historic 10 x 10 km cells. Bioclimatic niche modelling was then applied to explore patterns of habitat suitability and phenotypic variation within N. h. cetti. The geographic distribution of the species was found to be positively correlated with altitude and precipitation values, whereas temperatures howed a negative correlation. Taken together, these outcomes may explain the snake’s presence, particularly in eastern Sardinia. In addition, analysis of distribution overlap with the competing viperine snake (N. maura) and the urodeles as possible overlooked trophic resources (Speleomantes spp. and Euproctus platycephalus) showed overlaps of 66% and 79%, respectively. Finally, geographical or bioclimatic correlations did not explain phenotypic variation patterns observed in this highly polymorphic taxon.
Perspectives on future research to investigate N. h. cetti’s decline and support effective conservation measures are discussed
Rana temporaria on Monti della Laga (Central Italy): isolated population or wide distribution? First record in Abruzzo and Marche
In Central Italy Rana temporaria is only known to occur as a glacial relict on the eastern side of Monti della Laga (Lazio). In this study we report the presence of the species in other areas of the mountain chain, with documented sightings in five distinct localities in Marche and Abruzzo. We use these new records, together with other occurrence data from the Apennine chain, to generate a species distribution model and perform an analysis of the geological preference of the species in Central Italy. Although the model indicates a wide area of Marche and Abruzzo as suitable for R. temporaria, the actual distribution of the species in northern and central Apennine appears strongly associated with sandstones. Therefore, we argue that the presence of this geological substrate on Monti della Laga, but not in surrounding karst uplands, could be among the factors explaining its isolation. Our study aims at paving the way for future surveys and measures to protect these isolated populations from the threat posed by climate change
The tale of the black viper: distribution and bioclimatic niche modelling of melanistic Vipera aspis in Italy
For decades, the evolutionary role of melanism in reptiles has been highly debated. According to the thermal melanism hypothesis, melanistic phenotypes should provide thermal advantages, thus positively impacting various biological aspects of these individuals. Nevertheless, these benefits seem to be countered by environmental constraints and predatory pressure. Here, we mapped for the first time the distribution of the melanistic phenotypes in the highly polymorphic asp viper (Vipera aspis). We focused our research effort on the Italian peninsula, where this species reaches its highest level of taxonomic diversity with three currently described subspecies. Furthermore, we investigated via bioclimatic niche modelling, the influence of a wide array of bioclimatic variables on the distribution of melanism in Italian asp vipers. In general, our results seem to support the implications of the thermal melanism hypothesis, highlighting the central influence of mean annual temperature and elevation on the geographic distribution of melanistic V. aspis. At the finest scale, our analyses have highlighted a distinction in bioclimatic niches among the three assessed subspecies. However, further fine-scale investigations are needed in order to exclude the potential influence of latitude and elevation on the observed the intersubspecific bioclimatic niche segregation pattern
Smoking status during first-line immunotherapy and chemotherapy in NSCLC patients: A case–control matched analysis from a large multicenter study
Background: Improved outcome in tobacco smoking patients with non-small cell lung cancer (NSCLC) following immunotherapy has previously been reported. However, little is known regarding this association during first-line immunotherapy in patients with high PD-L1 expression. In this study we compared clinical outcomes according to the smoking status of two large multicenter cohorts. Methods: We compared clinical outcomes according to the smoking status (never smokers vs. current/former smokers) of two retrospective multicenter cohorts of metastatic NSCLC patients, treated with first-line pembrolizumab and platinum-based chemotherapy. Results: A total of 962 NSCLC patients with PD-L1 expression ≥50% who received first-line pembrolizumab and 462 NSCLC patients who received first-line platinum-based chemotherapy were included in the study. Never smokers were confirmed to have a significantly higher risk of disease progression (hazard ratio [HR] = 1.49 [95% CI: 1.15–1.92], p = 0.0022) and death (HR = 1.38 [95% CI: 1.02–1.87], p = 0.0348) within the pembrolizumab cohort. On the contrary, a nonsignificant trend towards a reduced risk of disease progression (HR = 0.74 [95% CI: 0.52–1.05], p = 0.1003) and death (HR = 0.67 [95% CI: 0.45–1.01], p = 0.0593) were reported for never smokers within the chemotherapy cohort. After a random case–control matching, 424 patients from both cohorts were paired. Within the matched pembrolizumab cohort, never smokers had a significantly shorter progression-free survival (PFS) (HR = 1.68 [95% CI: 1.17–2.40], p = 0.0045) and a nonsignificant trend towards a shortened overall survival (OS) (HR = 1.32 [95% CI: 0.84–2.07], p = 0.2205). On the contrary, never smokers had a significantly longer PFS (HR = 0.68 [95% CI: 0.49–0.95], p = 0.0255) and OS (HR = 0.66 [95% CI: 0.45–0.97], p = 0,0356) compared to current/former smoker patients within the matched chemotherapy cohort. On pooled multivariable analysis, the interaction term between smoking status and treatment modality was concordantly statistically significant with respect to ORR (p = 0.0074), PFS (p = 0.0001) and OS (p = 0.0020), confirming the significantly different impact of smoking status across the two cohorts. Conclusions: Among metastatic NSCLC patients with PD-L1 expression ≥50% receiving first-line pembrolizumab, current/former smokers experienced improved PFS and OS. On the contrary, worse outcomes were reported among current/former smokers receiving first-line chemotherapy
Prospects for the biological control of Iris pseudacorus L(Iridaceae)
Native to Europe, North Africa and western Asia, Iris pseudacorus L. (Iridaceae) has invaded natural and human-modified wetlands worldwide. This species is considered a noxious weed in several countries including Argentina, South Africa and New Zealand. Its broad ecological tolerance, high resilience and reproductive potential make current mechanical and chemical control measures cost-ineffective, and biological control is considered a suitable alternative. In order to prioritise candidate biocontrol agents, a list of organisms reported to attack the plant within its native range has been assembled, and information about their host-range and damaging potential gathered from the literature. Furthermore, surveys for natural enemies of the plant were conducted in Belgium and northern Italy. The insect fauna associated with I. pseudacorus at the sites surveyed comprised mostly incidental visitors and polyphagous feeders, with the exception of the sawfly Rhadinoceraea micans Klug (Hymenoptera: Tenthredinidae), the seed weevil Mononychus punctumalbum Herbst (Coleoptera: Curculionidae), and the flea beetle Aphthona nonstriata Goeze (Coleoptera: Chrysomelidae). The potential of these species for biocontrol was evaluated, and A. nonstriata was given highest priority. A population of this species was imported to quarantine in South Africa, where it is currently undergoing host-specificity testing. Importation of the two remaining candidates is expected shortly. In conclusion, the prospects for the biological control of I. pseudacorus appear promising
Citizen Science Improves the Known and Potential Distribution of a Strong Wetland Invader: Implications for Niche Modeling and Invasion Management
Invasive alien species are one of the main causes of biodiversity loss and ecosystem alteration. Obtaining up-to-date occurrence records and accurate invasion risk maps has become crucial to develop timely and effective management strategies. Unfortunately, gathering and validating distribution data can be labor-intensive and time-consuming, with different data sources unavoidably leading to biases in the results. In this study, we evaluated the performance of a tailored citizen science project compared with other data sources, in mapping the current and potential distribution of Iris pseudacorus, a strong invasive alien plant in Argentina. To do so, we used geographic information systems and ecological niche modeling with Maxent, and compared data from: i) a citizen science tailored project; ii) the Global Biodiversity Information Facility (GBIF); and iii) an exhaustive professional data collection (i.e. field samplings across Argentina, literature and collections review). Results suggest that the citizen science tailored project provided a larger and more diversified amount of data compared to the other sources. All data-sources showed good performance in the ecological niche models, however, data from the tailored citizen science project predicted a greater suitable area, including regions not yet reported. This allowed us to better identify critical and vulnerable areas, where management and prevention strategies are necessary. Professional data provided more reports in non-urban areas, whereas citizen science based data sources (i.e. GBIF and the citizen science project conducted in this study) reported more sites in urban areas, which indicates that different data-sources are complementary and there is a big potential in combining methods. We encourage the use of tailored citizen science campaigns to gather a more diverse amount of data, generating better knowledge about aquatic invasive species and helping decision-making in ecosystem management.Fil: Gervazoni, Paula Belen. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste. Centro de EcologĂa Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de EcologĂa Aplicada del Litoral; ArgentinaFil: Minuti, Gianmarco. Vrije Unviversiteit Brussel; BĂ©lgicaFil: Fuentes RodrĂguez, Daniela Alejandra. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales. Departamento de Ciencias BiolĂłgicas. Centro de Investigaciones de FitopatologĂa. Provincia de Buenos Aires. GobernaciĂłn. ComisiĂłn de Investigaciones CientĂficas. Centro de Investigaciones de FitopatologĂa; ArgentinaFil: Coetzee, Julie. Rhodes University; SudáfricaFil: Sosa, Alejandro JoaquĂn. FundaciĂłn para el Estudio de Especies Invasivas; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Sabater, Lara Milena. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste. Centro de EcologĂa Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de EcologĂa Aplicada del Litoral; ArgentinaFil: Franceschini, Maria Celeste. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste. Centro de EcologĂa Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de EcologĂa Aplicada del Litoral; Argentin