The role of soil biota during invasion of Impatiens glandulifera Royle and restoration at invaded sites.

This thesis focuses on the exotic plant Impatiens glandulifera, which has invaded many habitats in the UK, including north-east England. Soil biota are frequently implicated in influencing plant invasions and here this is investigated by examining the soil-mediated impacts of I. glandulifera on native plant species. Select native plants, along with I. glandulifera, were grown in field-collected soil that had been invaded and not invaded by I. glandulifera. Sterilised versus unsterilised soil was used to test if any differences detected were mediated by soil microbes. Results showed that the growth of the native plant species was not necessarily negatively affected by growing in soils invaded by I. glandulifera. Evidence was also found that I. glandulifera may alter mycorrhizal colonisation of a native plant species in invaded soils. A consistent effect of soil origin was also found, which demonstrates the complexity and context-dependency of plant invasions. Findings from plant-soil interaction studies were then applied to the context of native plant restoration at invaded sites; a management approach often side-lined in invasive plant species control. The utility of two soil treatments were tested for I. glandulifera control, firstly addition of arbuscular mycorrhizal fungi (AMF), which is a significant contributor to plant biodiversity in natural systems; secondly, additions of activated carbon (AC), which is often used to negate the negative soil-mediated impacts of invasive plant species, through adsorption of allelochemicals. No effect of AMF on plant cover was detected and results suggested that AC may actually increase cover of I. glandulifera and thus may not be a suitable restoration tool

Imagining alternative and better worlds:Isabel Fletcher talks with Adele E. Clarke

In this interview, Adele Clarke and Isabel Fletcher discuss the different routes that led Clarke to science and technology studies (STS), the field’s increasing engagement with biomedical topics, and her perspectives on its character today. Clarke describes how women’s health activism and teaching feminist critiques of bioscience/biomedicine led her to participate in academic networks now known as feminist STS and trans-national reproduction studies. She reflects on the importance of inter-/trans-disciplinary collaboration in her work, but also raises concerns that the rapid expansion of the field has resulted in inadequate training for newcomers in the “theory-method packages” of STS, and hence poor quality scholarship. For her, the future of STS lies in approaches analyzing the complex intersections between technoscience, gender, race, (post)coloniality, and indigenous knowledges, and in its expansion beyond Europe and North America, to Asia, Central and South America, and Africa. In her following reflection, Isabel Fletcher considers the importance of inter/trans-disciplinarity for STS and highlights the role a politically engaged STS can play in imagining alternative and better worlds

The effect of environmental degradation and land use change on malaria re-emergence in south Venezuela: a spatiotemporal modelling study

Background: Malaria transmission is highly dependent on environmental conditions. The association between climatic variables and malaria transmission is well established, but the interaction between variations in climate and land use change, such as deforestation, is less well understood. Earth observation data provide a valuable and accessible resource to investigate these environment–malaria associations, in particular where little ground truth data are available. Progress towards malaria elimination in Latin America is being hindered by a surge of cases in Venezuela, a country that accounted for 53% of cases in the region in 2019. The country's economic and political crisis has fuelled economic migration to gold mining areas in the south, where extraction activities are expanding malaria vector habitats and sustaining disease transmission. Methods: In this spatiotemporal modelling study, we used multisource Earth observation data, including meteorological, land use change, and socioeconomic factors, and data on mining activity, to investigate how changes in the ecological landscape might have facilitated increases in the incidence of malaria in the past 20 years. We modelled spatiotemporal malaria case data for 1996–2016 using a Bayesian hierarchical mixed-model framework for Bolívar state in Venezuela, a malaria foci where approximately 60% of national cases occur annually. We examined how mining activities were associated with malaria hotspots and also considered the potential effects of climate variation, seasonality, and spatial dependency structures. Findings: We found that malaria risk was increased in mining hotspots, which were important in sustaining transmission in Bolívar state. We also found that the effect of temperature and rainfall variation differed depending on the level of deforestation in Bolívar, where the increased risk of malaria with temperature was greatest in areas that were more deforested. Interpretation: Our findings provide important evidence of environmentally driven re-emergence of malaria and highlight the advantages of using Earth observation data for understanding malaria dynamics in areas with sparse or incomplete data records

The Relative Role of Climate Variation and Control Interventions on Malaria Elimination Efforts in El Oro, Ecuador: A Modeling Study

Malaria is a vector-borne disease of significant public health concern. Despite widespread success of many elimination initiatives, elimination efforts in some regions of the world have stalled. Barriers to malaria elimination include climate and land use changes, such as warming temperatures and urbanization, which can alter mosquito habitats. Socioeconomic factors, such as political instability and regional migration, also threaten elimination goals. This is particularly relevant in areas where local elimination has been achieved and consequently surveillance and control efforts are dwindling and are no longer a priority. Understanding how environmental change, impacts malaria elimination has important practical implications for vector control and disease surveillance strategies. It is important to consider climate change when monitoring the threat of malaria resurgence due to socioeconomic influences. However, there is limited assessment of how the combination of climate variation, interventions and socioeconomic pressures influence long-term trends in malaria transmission and elimination efforts. In this study, we used Bayesian hierarchical mixed models and malaria case data for a 29-year period to disentangle the impacts of climate variation and malaria control efforts on malaria risk in the Ecuadorian province of El Oro, which achieved local elimination in 2011. We found shifting patterns of malaria between rural and urban areas, with a relative increase of Plasmodium vivax in urbanized areas. Minimum temperature was an important driver of malaria seasonality and the association between warmer minimum temperatures and malaria incidence was greater for Plasmodium falciparum compared to P. vivax malaria. There was considerable heterogeneity in the impact of three chemical vector control measures on both P. falciparum and P. vivax malaria. We found statistically significant associations between two of the three measures [indoor residual spraying (IRS) and space spraying] and a reduction in malaria incidence, which varied between malaria type. We also found environmental suitability for malaria transmission is increasing in El Oro, which could limit future elimination efforts if malaria is allowed to re-establish. Our findings have important implications for understanding environmental obstacles to malaria elimination and highlights the importance of designing and sustaining elimination efforts in areas that remain vulnerable to resurgence

Climate services for health: From global observations to local interventions.

Despite the wealth of available climate data available, there is no consensus on the most appropriate product choice for health impact modelling and how this influences downstream climate-health decisions. We discuss challenges related to product choice, highlighting the importance of considering data biases and co-development of climate services between different sectors