Context-dependent conservation responses to emerging wildlife diseases

Emerging infectious diseases pose an important threat to wildlife. While established protocols exist for combating outbreaks of human and agricultural pathogens, appropriate management actions before, during, and after the invasion of wildlife pathogens have not been developed. We describe stage-specific goals and management actions that minimize disease impacts on wildlife, and the research required to implement them. Before pathogen arrival, reducing the probability of introduction through quarantine and trade restrictions is key because prevention is more cost effective than subsequent responses. On the invasion front, the main goals are limiting pathogen spread and preventing establishment. In locations experiencing an epidemic, management should focus on reducing transmission and disease, and promoting the development of resistance or tolerance. Finally, if pathogen and host populations reach a stable stage, then recovery of host populations in the face of new threats is paramount. Successful management of wildlife disease requires risk-taking, rapid implementation, and an adaptive approach."Funding was provided by the US National Science Foundation (grants EF-0914866, DGE-0741448, DEB-1115069, DEB-1336290) and the National Institutes of Health (grant 1R010AI090159)."https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1890/14024

Changing geographic ranges of ticks and tick-borne pathogens: drivers, mechanisms and consequences for pathogen diversity

The geographic ranges of ticks and tick-borne pathogens are changing due to global and local environmental (including climatic) changes. In this review we explore current knowledge of the drivers for changes in the ranges of ticks and tick-borne pathogen species and strains via effects on their basic reproduction number (R-0), and the mechanisms of dispersal that allow ticks and tick-borne pathogens to invade suitable environments. Using the expanding geographic distribution of the vectors and agent of Lyme disease as an example we then investigate what could be expected of the diversity of tick-borne pathogens during the process of range expansion, and compare this with what is currently being observed. Lastly we explore how historic population and range expansions and contractions could be reflected in the phylogeography of ticks and tick-borne pathogens seen in recent years, and conclude that combined study of currently changing tick and tick-borne pathogen ranges and diversity, with phylogeographic analysis, may help us better predict future patterns of invasion and diversity

Who, where and when? The complexity of tracking amphibian chytrid pathogens

This cumulative thesis focuses on the study of amphibian chytrid pathogens (Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans). It includes contributions from three different manuscripts, two of which have been published, while the third one is in the review process. The research presents the results of an effort to collect, organize and analyze data from published reports of infection. The first chapter discusses a framework for cryptic species and points out many of the problems that complicate the study of chytrid pathogens and their hosts (e.g. cryptic lineages and pseudoindigenous lineages). The second and third chapters focus on Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans, respectively. These sections constitute the core of this thesis. In this work, data from reports of chytrid infection was systematically collected from over 600 publications and their supplementary materials. The analysis of the data provided information that individual reports could not, and allowed to identify over 1000 host species, including possible vectors of disease and threatened amphibian species. Furthermore, the overlapping distribution of infected species revealed information on areas suitable for the pathogen. The database resulting from this work is also a useful tool to prioritize the areas that need to be intensively studied in the future and to implement conservation measures

Challenges in modelling the dynamics of infectious diseases at the wildlife–human interface

The Covid-19 pandemic is of zoonotic origin, and many other emerging infections of humans have their origin in an animal host population. We review the challenges involved in modelling the dynamics of wildlife-human interfaces governing infectious disease emergence and spread. We argue that we need a better understanding of the dynamic nature of such interfaces, the underpinning diversity of pathogens and host-pathogen association networks, and the scales and frequencies at which environmental conditions enable spillover and host shifting from animals to humans to occur. The major drivers of the emergence of zoonoses are anthropogenic, including the global change in climate and land use. These, and other ecological processes pose challenges that must be overcome to counterbalance pandemic risk. The development of more detailed and nuanced models will provide better tools for analysing and understanding infectious disease emergence and spread

The role of forest genetic resources in responding to biotic and abiotic factors in the context of anthropogenic climate change

The current distribution of forest genetic resources on Earth is the result of a combination of natural processes and human actions. Over time, tree populations have become adapted to their habitats including the local ecological disturbances they face. As the planet enters a phase of human-induced climate change of unprecedented speed and magnitude, however, previously locally-adapted populations are rendered less suitable for new conditions, and ‘natural’ biotic and abiotic disturbances are taken outside their historic distribution, frequency and intensity ranges. Tree populations rely on phenotypic plasticity to survive in extant locations, on genetic adaptation to modify their local phenotypic optimum or on migration to new suitable environmental conditions. The rate of required change, however, may outpace the ability to respond, and tree species and populations may become locally extinct after specific, but as yet unknown and unquantified, tipping points are reached. Here, we review the importance of forest genetic resources as a source of evolutionary potential for adaptation to changes in climate and other ecological factors. We particularly consider climate-related responses in the context of linkages to disturbances such as pests, diseases and fire, and associated feedback loops. The importance of management strategies to conserve evolutionary potential is emphasised and recommendations for policy-makers are provided

Challenges in modelling the dynamics of infectious diseases at the wildlife-human interface.

Funder: Alborada TrustThe Covid-19 pandemic is of zoonotic origin, and many other emerging infections of humans have their origin in an animal host population. We review the challenges involved in modelling the dynamics of wildlife-human interfaces governing infectious disease emergence and spread. We argue that we need a better understanding of the dynamic nature of such interfaces, the underpinning diversity of pathogens and host-pathogen association networks, and the scales and frequencies at which environmental conditions enable spillover and host shifting from animals to humans to occur. The major drivers of the emergence of zoonoses are anthropogenic, including the global change in climate and land use. These, and other ecological processes pose challenges that must be overcome to counterbalance pandemic risk. The development of more detailed and nuanced models will provide better tools for analysing and understanding infectious disease emergence and spread

Botanic gardens and plant pathogens: a risk-based approach at the Royal Botanic Garden Edinburgh

Introduced and emerging plant diseases as a result of live plant movements are increasingly recognised as a global environmental and economic threat. This presents a fundamental challenge to botanic gardens and other ex situ plant conservation organisations: how to continue this important work while recognising and mitigating the plant health risks. The approach taken by the Royal Botanic Garden Edinburgh is presented as a case study, showing how we have reduced ecological and evolutionary opportunities for pests in ex situ conservation and are monitoring the success of these efforts. We have developed protocols in quarantine and horticultural practice, expanded visitor engagement and public education, and taken a precautionary approach towards plant distribution supported by in-house diagnostics and working closely with statutory authorities. We hope that by sharing activities as well as difficulties, botanic gardens can acknowledge and address the new biosecurity landscape

Managing Threats to the Health of Tree Plantations in Asia

Plantation forestry is making a significant positive contribution to the environment as well as to the livelihoods of millions of people in Asia. This chapter examines some of the major constraints facing commercial acacia and eucalypt plantations in South-east and East Asia and discusses adaptive actions in the face of climate change. Particular emphasis is placed on Vietnam and China but examples are also drawn from other parts of SE Asia where forest plantations are making a significant contribution to forest cover. The area of forest cover in Asia has declined greatly in the past 50 years due to an expanding population, and increasing demand for forest products and land for food and energy crops. For example, based on available documents, in 1943 Vietnam had 14.3 million ha of forests, with 43% forest cover; but by the year 1990 only 9.18 million ha remained, with a forest cover of 27.2%. During the period 1980 to 1990, the average forest lost was more than 100,000 ha each year. However, from 1990 to the present, the forest area has increased gradually, due to afforestation and rehabilitation of natural forest. Based on the official statement in Decision No. 1267/QD/BNN-KL-LN, dated 4 May 2009, as of 31 December 2009, the total national forest area was 13.2 million ha (forest cover of 39.1%), including 2.9 million ha of plantation forest. Recently, China too has also been able to reverse the decline in forest cover due to forest protection and afforestation. According to the 7th national forest resource inventory finished in 2008, there were 195.4 million ha (14.9 billion m3 of standing wood volume) of forest in China, an increase of 20.5 million ha (1.1 billion m3 standing wood volume) over the previous audit 5 years earlier. Of the increased forest area and volume, 3.9 million ha were from natural forests, and 8.4 million ha were from tree plantations. In the region, logging of natural forests is proceeding at alarming rates in some countries and is tightly controlled in others. In China, the “national natural forest protection program” was started in 2000, and any logging in natural forest is illegal, as is the case in Thailand. Following that the “national reforestation program” was initiated to established tree plantations in bare land for natural protection in north-west China and wood production in southern China. Forests are classified as ecological forests and natural forest reserves which the government will pay about 120 RMB per ha annually to the forest owners, or commercial forests for wood production. Likewise, the Government of Vietnam has given high priority to forest rehabilitation, as Program 327 and the 5 Million Hectare Rehabilitation Program (MHRP). Program 327, which lasted from 1993 until 1998, was effective in increasing afforestation and forest rehabilitation. The 5MHRP (1998 – 2010) had the objective of rehabilitating 5 million ha of forests and protecting existing forests, in order to increase forest cover to 43%. Unlike China and Thailand, Vietnam obtains more than 90% of its timber volume from natural forest