# World forests, global change, and emerging pests and pathogens

Jean-Francois Guegan, Benoît de Thoisy, Mireia Gómez-Gallego, Hervé Jactel

► To cite this version:

Jean-Francois Guegan, Benoît de Thoisy, Mireia Gómez-Gallego, Hervé Jactel. World forests, global change, and emerging pests and pathogens. Current Opinion in Environmental Sustainability, 2023, 61, pp.101266. 10.1016/j.cosust.2023.101266. hal-04099860

HAL Id: hal-04099860

https://hal.inrae.fr/hal-04099860

Submitted on 9 Jun 2023

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
<figure><img src="image_2.png" /></figure>

ELSEVIER

# World forests, global change, and emerging pests and pathogens

Jean-François Guégan<sup>1,2,*</sup>, Benoît de Thoisy<sup>3,‡</sup>, Mireia Gomez-Gallego<sup>4,#</sup> and Hervé Jactel<sup>5,§</sup>

<figure><img src="image_3.png" /></figure>

Check for
updates

Global changes play today an important role in altering patterns of human, animal, and plant host-pathogen interactions and invasive pest species. With rapid development in sequencing technology, there is also an increase in pathogen and pest studies adopting a macroscale, biogeographical perspective, and we present the most recent elements on existing ecological and biogeographical trends. We also compare the results on the one hand on emerging infectious diseases of animals and humans, and on the other hand on plant pathogens and pests. International exchanges of people, animals, and plant products currently contribute to their geographical extension but with notable differences across disease and pest systems, and regions. This review highlights that the subject of pathogens and plant pests, traditionally rooted in agronomic approaches, lacks work on macroecology and biogeography. We discuss the research orientations to better anticipate their ecological and economic impacts in order to better achieve environmental sustainability.

## Addresses

Corresponding author: Guégan, Jean-François
(jean-francois.guegan@inrae.fr)

**Abbreviations:** Forests, Global changes; Emerging infectious diseases, Pests; Plant pathogens, Deforestation; Emerging threats, Emerging risks

**Current Opinion in Environmental Sustainability** 2023, 61:101266

This review comes from a themed issue on **Emerging pests and pathogens**

Edited by **Peter Søgaard Jørgensen**

For complete overview of the section, please refer to the article collection, "Re-assessing the challenges of emerging pests and pathogens for sustainable development post-COVID"

Available online 7 February 2023

Received: 6 April 2022; Revised: 4 January 2023;

Accepted: 13 January 2023

https://doi.org/10.1016/j.cosust.2023.101266

1877-3435/© 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

## Introduction

According to FAO and UNEP [1], the total cover of the world's forests is 31% (4.06 billion hectares), half still being relatively intact from human disturbances, and more than one-third being primary forest. Forest cover is not equally distributed and five countries, that is, the Russian Federation, Brazil, Canada, United States, and China, harbor more than half of the world's forests. However, worldwide forests are facing increasing anthropogenic disturbances jeopardizing Earth system processes and ecosystem services (e.g. climate regulation through carbon sequestration, habitats for wildlife, water cycle regulation, vital resources for native peoples, and resources for use and trade), and therefore their sustainability as natural heritage [2]. Among disturbances are biological invasions by non-native pests and pathogens, which can have serious impacts on forest ecosystem resilience, productivity, and biodiversity [3]. Forests also shelter a large biodiversity of microbial

<footnote n="1"><sup>1</sup>UMR MIVEGEC, ESC INRAE, IRD, CNRS, Université de Montpellier, Centre IRD de Montpellier, B.P. 64501, 34394 Montpellier Cedex 5, France</footnote>

<footnote n="2"><sup>2</sup>UMR EPIA, INRAE, VetAgro Sup, Centre INRAE, 63122 Saint Genès Champanelle, France</footnote>

<footnote n="3"><sup>3</sup>Institut Pasteur de la Guyane, Laboratoire des Interactions Virus Hôtes, 16 avenue Pasteur, 97300 Cayenne, Guyane, France</footnote>

<footnote n="4"><sup>4</sup>UMR IAM, Université de Lorraine, INRAE, 54000 Nancy, France</footnote>

<footnote n="5"><sup>5</sup>UMR Biogeco, INRAE, University of Bordeaux, 33612 Cestas, France</footnote>

<footnote><sup>*</sup>ORCID number: 0000-0002-7218-107X</footnote>

<footnote><sup>‡</sup>ORCID number: 0000-0002-8420-5112</footnote>

<footnote><sup>#</sup>ORCID number: 0000-0001-6713-1708</footnote>

<footnote><sup>§</sup>ORCID number: 0000-0002-8106-5310</footnote>
<figure><img src="image_4.png" /><figcaption>Figure 1</figcaption></figure>

**Cross-cutting research questions.** (a) Illustration of the questions posed in this review that compares the forest-pathogen/pest relationships, and discusses current research findings. (b) Comparison of ecological and biogeographical factors for forest ecosystems affecting the emergence and transmission of human and animal pathogens, plant pathogens, and pests. To go further, we recommend reading the following references (e.g. [5] for microbial biogeography, [4,6] for animal and human pathogen macroepidemiology, and [7] for different pathogen systems).

forms and potential insect pests [4]. Therefore, growing forest fragmentation and loss represent a huge risk for global health security, and increasing exposure of forests to human activity might increase the risk of new emerging diseases in plants, animals, and humans in peripheral human-dominated areas [4].

Despite the existence of impact assessments of biological invasions on the world's forests on the one hand, and on the risks of emerging forest-associated diseases on the other hand, attempts to analyze in a comparative approach their both respective and joint impacts are lacking. Here, we explore how disease ecology and biogeography may explain invasion/pathogen-forest trends to identify potential mechanisms that drive biological invasions and disease emergence (Figure 1). Notably, pathogen and pest taxa may vary in their ability to conform to macroecological patterns due to differences in habitats, in taxonomic groups, or to the importance of international trade of their associated hosts. Despite potential comparable drivers and trends, a very distinct tradition and training between disease ecologists, plant pathologists and plant entomologists lead to distinct approaches and perspectives to study environmental sustainability. Because of a lack of macroscale studies for pests and plant pathogens, we conclude by outlining several outstanding questions and recommendations for future studies.

## World forests in the tempest: recent evolution and threats

Three major trends characterize the current dynamics of forests. First, primary forests are still being heavily deforested with a loss of 7.3 million ha/year and 5 million ha/year in tropical countries since 2010 [8]. The main reasons are legal and illegal logging to meet the growing demand for wood products, new transport infrastructures, expansion of agricultural land and industrial plantations, and cattle ranching [9]. Accelerated deforestation of the Amazon rainforest has been observed at an unprecedented scale for the first six months of 2022.

The second trend is the increase in natural disturbances as a result of global warming, causing tree dieback and mortality, and new emerging or re-emerging diseases. Drought, storms, fires, and temperature rise can trigger large-scale mortality events and large pest and pathogen outbreaks (mainly bark beetles) that lead to massive tree death. In Europe, disturbance-induced forest mortality amounted to 56 million m3/year in 2000–2010, and an estimated 33 billion tons of woody biomass could be further lost [10].

The third trend is an increase in plantation forests, at a rate of 3–4 million ha/year since the beginning of the century; they are primarily monocultures that are more vulnerable to natural disturbances, biological invasions,
and pest damage [11]. In the tropics and southern hemisphere, planted forests consist mainly of a few exotic tree genera (e.g. eucalyptus) contributing to global spread of exotic pests and pathogens, especially via bridgehead processes.

## Forest loss and fragmentation increase pest and pathogen exchanges with human-dominated landscapes

A greater species diversity occurs in tropical regions compared with temperate zones, producing latitudinal gradients for diverse organism groups. For human and animal infections, depending on host and parasite taxa, these large-scale patterns can also be observed [4]. Many of these pathogens are present only in the tropics, mostly embedded into natural rainforest, that is, the endemics or neglected tropical diseases [4]. Others with a currently widespread distribution may also support a tropical origin: zoonotic infections such as HIV-1 and HIV-2 are originating from SIVcpz in Central African chimpanzee and plain gorilla, and SIVstm in Western African monkey, respectively; the African swine fever virus that remained endemic in Africa affects both domestic and feral swine in Eurasia today. However, global changes have seriously scrambled these patterns by mixing tropical with temperate infectious diseases [4].

Concerning forest pathogens and pests, those trends are less supported by current literature (Figure 1). Although insect species richness follows a latitudinal gradient, biogeographic patterns of herbivorous insects are less clear [12], and invasion by forest pests first depends on the biogeography of their respective host trees. Some aggressive plant pathogens, such as *Phytophthora ramorum* and *P. cinnamomi*, with a putative origin in tropical areas, cause important damages in the temperate ecosystems where they have been introduced. Interestingly, a higher diversity of soil fungi, recognized as plant pathogens, has been reported closer to the equator [13], but controversy exists [14]. The most frequent patterns are movements of exotic insects sharing the same tree genera, notably between North America and Europe, or different regions of Eurasia [15]. There are a few examples of species from tropical regions invading temperate forests. With the increased trade with southern countries and global warming in northern countries, these cases could increase. Macroscale patterns of forest pest and pathogen invasions can also be confounded by the international movement of host trees, such as eucalyptus plantations that have been established on many continents other than native-range Australia.

At local scale, forested landscapes have long been known to be reservoirs and occasional sinks for pathogens and pests. There is evidence of human and animal pathogens moving from the main forest to human populations. Edge habitats surrounding forest patches are known for

their increased abundance in arthropods and vertebrate hosts due to ideal breeding or feeding habitat conditions [16]. This creates new opportunities for these organisms to act as bridge hosts, *en route* for mobilizing pathogens present into fragmented habitats to domestic animals and human occupying surrounding habitats [17]. Human activity generally leads to landscape homogenization with biodiversity loss and forest fragmentation. This may affect the dynamics of wildlife disease agents and pests and produce new infections or invasions [18]. Disease ecology studies have shown that biodiversity loss would increase infectious disease burden and risk to humans, that is, dilution effect, but other studies support alternative explanations such as no or an opposite amplification effect [18].

Imported trees for planting are the main pathway of accidental pathogen introduction into new geographical areas [19]. The damaging fungus, *P. ramorum*, native to the East Asian Laurosilva forests [20], was introduced through the ornamental plant industry in restoration projects in California, and to wider forested areas in the United Kingdom [21]. The urban-forest interface is also a hotspot for spillovers; in Europe, nearly 90% of exotic forest insect species were first established in urban and peri-urban areas, and then spread to the surrounding forests [22]. *P. ramorum* shows multiple new pathogen-host associations across its non-native distribution with several reservoir plant hosts that contribute to the ongoing epidemics [23]. The agriculture-forest interface also contributes to plant disease epidemics through spillover from wild to domesticated plants, and/or by providing potential new host-pathogen associations and opportunities for rapid evolutionary responses [24]. Asian soybean rust depends on the alternation of crop and unmanaged vegetation allowing overwintering pathogen survival [25]. Land use change, urbanization, and forest fragmentation can then amplify the role of forested areas as sources of plant diseases. At the same time, increasingly fragmented forests can lead to the exposure of these new areas to plant pathogens.

Insect pest invasions follow the global trend of biological invasions, with an exponential increase [26]. The current rate of new exotic insect species detected per year in forests since 2000 is approximately 6 in Europe, 2 in China [27], and 3 in the United States [14]. Their intentional introduction into forests, mainly through the release of biological control agents, has declined sharply, while unintentional introductions through imported goods and products represent today the main pathway [14]. Particularly, live plants trade and wood materials transport are the main pathways for long-distance introductions [28]. The main functional groups of invasive forest insects are sap and foliar feeders (associated with plants for planting) and wood-boring insects (with wood pieces) [14]. This explains why they are increasingly
coming from Southeast Asia where the majority of goods imported into Europe and America come from [29], a trend similar to that observed for recent human pandemics [30]. The use of budwood for propagation has been also identified as a pathway of introduction for forest pests, and was responsible for the invasion by the Asian chestnut gall wasp *Dryocosmus kuriphilus* in the United States [28].

## Which categories of pest species and pathogens/hosts and vectors are likely to invade forest ecosystems and emerge from forests?

Animal and human-emerging diseases share with biological invasions and plant pathogens the same dependence on human activities [31]. Crossing geographic barriers, leading to disease emergence in new areas, results from human or animal dispersal of pathogens [32] and of their hosts, mainly synanthropic species such as rodents and mosquitoes. Pathogen evolution may lead to increased capability to infect new hosts and habitats, even if the impacts of host genetic background on the pathogen post-emergence evolution are still unclear [33]. Human and animal viruses share some characteristics with a high potential for emergence: single-stranded RNA viruses are highly adaptable due to high mutation and evolution rate, and, being shared by multiple vertebrate hosts, the ability to switch to a wide species range [34]. In plant pathogens, interspecific hybridization can generate increased pathogenicity and variability of pathogen responses, such as the hybrid fungus *Phytophthora x alni*, an agent of the severe alder decline in Europe [35]. For forest pests, there are no clear data on the intrinsic causes for the emergence of more virulent species, the sudden increase in damage being rather attributable to environmental changes.

A recent meta-analysis recognized other abiotic and biotic drivers of zoonotic disease emergence. Areas with low biodiversity were long thought to favor emergence, but changes of the respective abundances of species in pristine versus human-dominated ecosystems, rather than host richness modifications, need to be better scrutinized [17]. Most zoonotic diseases rely on host species that are dominant in anthropized ecosystems having experienced a strong biodiversity decline, but not in naturally low-diversity habitats [36]. Urban and synanthropic animals harbor less potential human pathogens than previously expected [37], and some animal and zoonotic pathogens have been found to be favored by land use transitions [38]. Rather than clear-cut interfaces between forested areas and human-dominated ecosystems, a continuum of changing ecological conditions seems to favor increasing disease risk and emergence.

Concerning pest biological invasions, at the point of arrival, the likelihood of exotic forest pest establishment increases with forest species diversity at regional scale, because it increases the probability of finding a suitable host tree species [39]. However, consistent with the invasion paradox, the level of damage decreases with increasing forest diversity at the local scale, due to associational resistance [40].

The risk of spillover of alien forest insects depends mainly on the existence of common host plants and the degree of herbivore specialization. The Asian gall wasp has found large host reserves in natural European forests, leading to outbreaks that resulted in a large reduction of production in chestnut orchards. More worryingly, recently several cosmopolitan and highly polyphagous beetle species have been detected worldwide, with exchanges between forest and urban or agricultural environments, such as the Japanese beetle (*Popillia japonica*) or the shot hole borer (*Euwallacea fornicatus*) [41].

The main sources of plant pathogens likely to emerge from forests are poorly explored [42]. Ascomycota fungi are the most frequent group causing emerging forest diseases (70%) followed by Oomycota (21%) in Europe [42]. While ascomycete introduction has continuously increased during the last decades, the rate of introduction of oomycetes has dramatically accelerated since the 1990s in Europe [42]. *Phytophthora* pathogens, presenting high pathogenicity and hybridization rates, typify the pathogen class that will pose the highest biosecurity challenges [43]. Further, root-infecting pathogens are reported in more countries and in more host plant families than foliar-infecting pathogens. Finally, generalist pathogens present higher phytosanitary risk. Two traits have been linked to generalist behavior and might be good predictors of risk: fast growth rates at their optimum temperature and long-term survival for dormant propagules [44].

## Forested landscapes — pest and disease relationships are complex and nonlinear

The relationship between changes in forest cover and pest and disease emergence risk is complex, context-specific, and often nonlinear. Landscape configuration may strongly influence pest and disease spillover and spread as demonstrated for human zoonosis (e.g. Ebola virus [45]) and plant pathogens (e.g. Asian soybean rust [25]). Emerging zoonotic and vector-borne diseases do not directly result from deforestation or fragmentation but from a compounded impact of forest loss and spatial distribution of forest remnants. Typically, emerging zoonoses vary with forest cover in a bell-shaped curve
<figure><img src="image_5.png" /><figcaption>Figure 2</figcaption></figure>

**Disease/pest-forest relationships.** (a) Number of worldwide epidemic outbreak cases in humans per forest cover percentage per country for years 1990 (black histograms) and 2020 (gray histograms). (b) Trend in the number of tree pathogen occurrences. Both outbreak cases in humans and tree pathogen occurrences peak at medium forest cover values. (c) Mean number of human disease cases per epidemic outbreak with forest cover evolution between 1990 and 2020. Negative value indicates loss of forest cover, and positive value forest cover gain. Highest mean number of human cases in worldwide outbreaks are present for largest forest cover loss.

(b) Data source from [42]. (c) Data for (a) and (c) from [48] and reinterpreted.
(Figure 2a) because massive deforestation tends to reduce interface zones. Human malaria due to *Plasmodium falciparum* in Brazil, human incidence of zoonotic malaria by *P. knowlesi* in South-East Asia [46], and human cus-taneous leishmaniasis in Southern America follow this trend [47]. A similar trend is also observed for tree pa-thogens (Figure 2b). However, worldwide, human dis-ease risk is the highest for the greatest losses of forest cover between 1990 and 2010 (Figure 2c). Fragmenta-tion of forest landscapes appears to have a negative ef-fect on alien pest richness, suggesting higher establishment in the most forested areas. Nevertheless, an increase in the amount of edges between forests and anthropized environments leads to an apparent increase in exotic species diversity. Once established, the spread rate of invasive forest pests is favored by the con-nectivity between suitable tree habitat patches but prevented or slowed down by the landscape hetero-geneity resulting from unfavorable habitat patches.

By contrast, the recrudescence of human incidence in Lyme disease and other tick-borne diseases in the United States and Europe appears to be related to reforestation and increased wilderness areas. Locally, host biodiversity changes may lead to opposite me chanisms on pathogen cycles, simultaneously diluting and amplifying transmission [36]. Research evidence identifies potential opposite influence of change in forest cover on disease occurrence [46] with a negative effect of the proportion of cleared forest near homes on human outbreaks, but with a positive effect of forest loss at relatively large spatial scales on disease cases [47].

The paradox of the ‘skin of shagreen’ and main recommendations

From the Neolithic period, through the massive defor-
estation of the 11th century by Cistercian monks in
Western Europe and the current deforestation in many
tropical regions, world's forests have slowly shrunk in
surface area such as a trickle. Once dominant as eco-
systems, they are now threatened.

First, the drivers of pest and pathogen emergence and
their spread need to be better understood, and field
experiments along forest use gradients will help identify
the fine-scale processes behind these threats [49]. Fu-
ture work should shift from studies on pest or pathogen
species to that of functional groups (based on relevant
life traits) to provide a more mechanistic understanding
of emerging/invasive processes [50]. Ecological traits of
human-dominated ecosystems and how social changes
can alter ecological networks, transmission modes, and
pathways at different spatial and temporal scales should

inform the probability to host new pathogens/pests and
potential hosts.

Second, sampling effort and bias still remain a major problem. Sample collection, methods, and statistics should be standardized in order to avoid sampled area gaps, under- and overestimation of both taxonomic host groups and microorganisms. Gap trends indicate that ef-fort is less important in tropical regions while they harbor a vast forest domain. In addition, biogeographic studies on forest pests and pathogens on a global scale are needed to verify whether emergence and spread follow the same patterns as animal and human pathogens.

Third, an important question is how forests/human-
dominated ecosystem interfaces may favor pathogen
diversification and increase pest and pathogen circula-
tion across these landscapes, facilitating spillover into
wild and domestic animals, wild and cultivated plants,
and humans.

In addition, we should develop long-term longitudinal
studies to understand forest and habitat interface pa-
thogen and pest fluctuations due to ecological and evo-
lutionary processes, and the impacts of global changes on
these interactions. For example, monitoring selected
forest plots, their natural enemies, and also animal and
human microbes, in time and space, appears to be of
major importance.

Finally, shared international databases of pathogens,
pests, and their host species should considerably help
decipher which are the host–pathogen and host–pest
groups the most sensitive to local and global changes and
thus better predict future invasion and spread.

These recommendations provide a roadmap to guide
research forecasts of forest-associated human, animal,
and plant microbial and pest distributions and spread
under global changes.

Funding

J-FG and BdT are supported by an ‘Investissement d’Avenir’ grant from the Agence Nationale de la Recherche (CEBA ANR-10-LABX-2501). The lead author received a US NSF-NIH-NIFA (NSF#1911457) Ecology of infectious diseases award. BdT acknowledges the RESERVOIRS Project (European Regional Development Funds). HJ and MGG were supported by the HOMED project (http://homed-project.eu/), which received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 771271.
CRediT authorship contribution statement

J-FG conceptualized the review paper, and all authors (J-FG, BdT, MGG, and HJ) contributed equally to the writing and editing of the present review.

Data Availability

No data were used for the research described in the article.

Declaration of Competing Interest

The authors declare having no conflict(s) of interest(s).

Acknowledgements

The authors thank IRD, INRAE, Institut Pasteur de Guyane, and Universities of Montpellier, Bordeaux, and Nancy.

References and recommended reading

Papers of particular interest, published within the period of review, have been highlighted as:

• of special interest

•• of outstanding interest

1. FAO, UNEP: The State of the World's Forests (SOFO). FAO and UNEP Publishers; 2020:214 (https://www.fao.org/documents/card/en/c/ca8642en).

2. Ripple WJ, DellaSala DA, Baumann F, Gregg J, Betts MG, Law BE, Bradshaw CJA, Wolf C: **Zoonotic diseases and our troubled relationship with nature. Am J Health Promot 2022**, **36**:382-385,
https://doi.org/10.1177/08901171211064224

3. Zenni RD, Essl F, García-Berthou E, McDermott SM: The
**economic costs of biological invasions around the world. NeoBiota 2021**, *67*:1-9, https://doi.org/10.3897/neobiota.67.69971.

In this editorial work of a special issue, the authors discuss on a stan-
dardized assessment of costs of biological invasions that is lacking for
most regions of the world. In the issue, the different authors report on
the economic cost-dimension of biological invasions, and provide a
global, unique perspective detailing the economic costs of biological
invasions worldwide.

4. Guégan J-F, Ayouba A, Cappelle J, Thoisy B de: Emerging

* infectious diseases and tropical forests: unleashing the beast within. *Environ Res Lett* 2020, **15**:083007([https://iopscience.iop.org/article/10.1088/1748-9326/ab8dd7/pdf](https://iopscience.iop.org/article/10.1088/1748-9326/ab8dd7/pdf)).

In this systematic literature review, the authors show that forest-derived infection studies are relatively unexplored with very scarce data, and both taxonomically and geographically biased. Ability to understand forest-pathogens relationships depends on long-term monitoring programs and coordinated disease management.

5. Dickey JR, Swenie RA, Turner SC, Winfrey CC, Yaffar D, Padukone A, Beals KK, Sheldon KS, Kivlin SN: **The utility of macroecological rules for microbial biogeography. Front Ecol Evol** 2021, **9**:633155, https://doi.org/10.3389/fevo.2021.633155

6. Stephens PR, Altizer S, Smith KF, Aguirre AA, Brown JH, Budischak SA, Byers JE, Dallas TA, Davies TJ, et al.: **The macroecology of infectious diseases: a new perspective on global-scale drivers of pathogen distributions and impacts. Ecol Lett** 2016, **19**:1159-1171, https://doi.org/10.1111/ele.12644

7. Huang ZYX, Van Langevelde F, Estrada-Peña A, Suzán G, De Boer WF: **The diversity-disease relationship: evidence for and criticisms of the dilution effect. Parasitology** 2016, **143**:1075-1086, https://doi.org/10.1017/S0031182016000536

8. Vancutsem C, Achard F, Pekel JF, Vieilledent G, Carboni S, Simonetti D, Gallego J, Aragao LOEC, Nasi R: **Long-term (1990–2019) monitoring of forest cover changes in the humid

tropics. Sci Adv 2021, 7:eabe1603, https://doi.org/10.1126/sciadv.abe1603

9. Curtis PG, Slay CM, Harris NL, Tyukavina A, Hansen MC: **Classifying drivers of global forest loss. Science** 2018, **361**:1108-1111, https://doi.org/10.1126/science.aau3445

10. Forzieri G, Girardello M, Ceccherini G, Spinoni J, Feyen L,

* Hartmann H, Beck PSA, Camps-Valls G, Chirici G, Mauri A, Cescatti A: **Emergent vulnerability to climate-driven disturbances in European forests. Nat Commun** 2021, **12**:1-12, https://doi.org/10.1038/s41467-021-21399-7.

Quantify the vulnerability of European forests to fires, wind throws and insect outbreaks, this work shows that about 33.4 billion tons of forest biomass could be seriously affected by these disturbances, with a clear trend in overall forest vulnerability driven by a warming-induced reduction in plant defense mechanisms to insect outbreaks, especially at high latitudes.

11. Jactel H, Bauhus J, Boberg J, Bonal D, Castagneyrol B, Gardiner B, Gonzalez-Olabarria JR, Koricheva J, Meurisse N, Brockerhoff EG: **Tree diversity drives forest stand resistance to natural disturbances. Curr Rep** 2017, **3**:223-243, https://doi.org/10.1007/s40725-017-0064-1

12. Zvereva EL, Kozlov MV: **Latitudinal gradient in the intensity of**

* **biotic interactions in terrestrial ecosystems: sources of variation and differences from the diversity gradient revealed by meta-analysis. Ecol Lett** 2021, **24**:2506-2520, https://doi.org/10.1111/ele.13851.

In using a meta-analysis, the authors explored the variation in the
strength of latitudinal changes in herbivory, carnivory and parasitism,
and compared these with gradients in the diversity of different groups of
animals. This work shows that both herbivory and carnivory decrease
towards the poles, while parasitism increases.

13. Tedersoo L, Bahram M, Polme S, Köljalg P, Yorou NS, Wijesundera R, Villarreal Ruiz L, Vasco-Palacios AM, Thu PQ, Ave S, Smith ME, et al.: **Global diversity and geography of soil fungi. Science** 2014, **346**:1256688, https://doi.org/10.1126/science.1256688

14. Vétrovsky T, Kohout P, Kopecky M, Machac A, Man M, Bahmann

* BD, Brabcova V, Choi J, Meszarosova L, Human ZR, Lepinay C, et al.: **A meta-analysis of global fungal distribution reveals climate-driven patterns. Nat Commun** 2019, **10**:5142, https://doi.org/10.1038/s41467-019-13164-8.

According to this meta-study based on a large dataset of fungal taxa, evolutionary and environmental factors that shape fungal biogeography are incompletely understood. It identifies climate as an important driver of fungal biogeography, and indicates that mycorrhizal fungi appear to have narrower climatic tolerances than pathogenic fungi.

15. Brockerhoff EG, Liebhold AM: **Ecology of forest insect invasions. Biol Invasions** 2017, **19**:3141-3159, https://doi.org/10.1007/s10530-017-1514-1

16. Zohdy S, Schwartz TS, Oaks JR: **The coevolution effect as a driver of spillover. Trends Parasitol** 2019, **35**:399-408, https://doi.org/10.1016/j.pt.2019.03.010

17. Gibb R, Redding DW, Chin KQ, Donnelly CA, Blackburn TM,

* **Newbold T, Jones KE: Zoonotic host diversity increases in human-dominated ecosystems. Nature** 2020, **584**:398-402, https://doi.org/10.1038/s41586-020-2562-8.

The authors in analyzing numerous ecological assemblages and host species worldwide, show that land use change (i.e. secondary, agricultural and urban ecosystems) has global and systematic effects on local zoonotic host communities compared with nearby undisturbed habitats. This effect is strongest for rodent, bat and passerine bird zoonotic host species, thus pinpointing the role of these taxa as zoonotic reservoirs.

18. Thoisy B, de, Duron O, Epelboin L, Musset L, Quénel P, Roche B, Binetruy F, Briolant S, Carvalho L, Chavy A, Couppié P, Demar M, Douine M, Dusfour I, Epelboin Y, Flamand C, et al.: **Ecology, evolution, and epidemiology of zoonotic and vector-borne infectious diseases in French Guiana: transdisciplinarity does matter to tackle new emerging threats. Infect Genet Evol** 2021, **93**:104916, https://doi.org/10.1016/j.meegid.2021.104916

19. Ghelardini L, Luchi N, Pecori F, Pepori AL, Danti R, Della Rocca G, Capretti P, Tsopelas P, Santini A: **Ecology of invasive forest pathogens. Biol Invasions** 2017, **19**:3183-3200, https://doi.org/10.1007/s10530-017-1487-0
20. Jung T, Horta Jung M, Webber JF, Kageyama K, Hieno A, Masuya H, Uematsu S, Pérez-Sierra A, Harris AR, Forster J, Rees H, et al.: *The destructive tree pathogen Phytophthora ramorum* originates from the Laurosilva forests of East Asia. *J Fungi* 2021, 7:226, https://doi.org/10.3390/jof7030226

21. Sims LL, Garbelotto M: *Phytophthora* species repeatedly introduced in Northern California through restoration projects can spread. *Biol Invasions* 2021, 23:2173-2190, https://doi.org/10.1007/s10530-021-02496-6

22. Branco M, Nunes P, Roques A, Fernandes MR, Orazio C, Jactel H:
*Urban trees facilitate the establishment of non-native forest insects. NeoBiota* 2019, 52:25-46, https://doi.org/10.3897/neobiota.52.36358.

Based on a literature search and a pan-European database on non-native species feeding on woody plants, the authors demonstrate that urban trees constitute facilitators for the development of non-native forest pests locally and regionally. They recommend that cities should thus be intensely surveyed as first open doors for pest invasion.

23. DiLeo MV, Bostock RM, Rizzo DM: Microclimate impacts survival and prevalence of *Phytophthora ramorum* in *Umbellularia californica*, a key reservoir host of sudden Oak Death in Northern California forests. *PLoS One* 2014, 9:e98195, https://doi.org/10.1371/journal.pone.0098195

24. Susi H, Laine AL: Agricultural land use disrupts biodiversity mediation of virus infections in wild plant populations. *New Phytol* 2021, 230:2447-2458, https://doi.org/10.1111/nph.17156

25. Fabiszewski AM, Umbanhowar JM, Mitchell CE: Modeling landscape-scale pathogen spillover between domesticated and wild hosts: asian soybean rust and kudzu. *Ecol Appl* 2010, 20:582-592, https://doi.org/10.1890/08-0820.1

26. Seebens H, Blackburn TM, Dyer EE, Genovesi P, Hulme PE, Jeschke JM, Pagad S, Pysek P, Winter M, Arianoutsou M, Bacher S, et al.: No saturation in the accumulation of alien species worldwide. *Nat Commun* 2017, 8:14435, https://doi.org/10.1038/ncomms14435

27. Roques A, Shi J, Auger-Rozenberg MA, Ren L, Augustin S, Luo YQ: Are invasive patterns of non-native insects related to woody plants differing between Europe and China? *Front Glob Change* 2019, 2, https://doi.org/10.3389/fggc.2019.00091

28. Meurisse N, Rassati D, Hurley BP, Brockerhoff EG, Haack RA: Common pathways by which non-native forest insects move internationally and domestically. *J Pest Sci* 2019, 92:13-27, https://doi.org/10.1007/s10340-018-0990-0

29. Liebhold AM, Brockerhoff EG, Kimberley M: Depletion of heterogeneous source species pools predicts future invasion rates. *J Appl Ecol* 2017, 54:1968-1977, https://doi.org/10.1111/1365-2664.12895

30. Morens DM, Fauci AS: Emerging pandemic diseases: how we got to COVID-19. *Cell* 2020, 182:1077-1092, https://doi.org/10.1016/j.cell.2020.08.021

31. Dunn AM, Hatcher MJ: Parasites and biological invasions: parallels, interactions, and control. *Trends Parasitol* 2015, 31:189-199, https://doi.org/10.1016/j.pt.2014.12.003.

In this review paper, the authors examine how biological invasion and emerging infectious diseases are interlinked. Whereas international policies exist for emerging diseases and managed species, the authors discuss the lack of international cooperation for invasive species and wildlife parasites that could stimulate the different stakeholders to adopt international policy.

32. Ogden NH, Wilson JR, Richardson DM, Hui C, Davies SJ,

•• Kumschick S, Le Roux JJ, Measey J, Saul W-C, Pulliam JRC: Emerging infectious diseases and biological invasions: a call for a One Health collaboration in science and management. *R Soc Open Sci* 2019, 6:181577, https://doi.org/10.1098/rsos.18157.

This review highlights the similarities and differences between research on emerging diseases and biological invasions, and discusses shared management insights and approaches. Better collaborations between

invasion scientists, disease ecologists and epidemiologists would thus be mutually beneficial for research, control and management.

33. Bonneau C, Longdon B: Emerging pathogen evolution. Using evolutionary theory to understand the fate of novel infectious pathogens. *EMBO Rep* 2020, 21:e51374, https://doi.org/10.15252/embr.202051374

34. Singh BB, Ward MP, Dhand NK: Inherent virus characteristics and host range drive the zoonotic and emerging potential of viruses. *Transbound Emerg Dis* 2022, 69:799-813, https://doi.org/10.1111/tded.14361

35. Mizeriene G, Cerny K, Zyka V, Bakonyi J, Nagy ZÁ, Oliva J, Redondo MA, Corcobado T, Martín-Garcia J, Prospero S: Patterns of genetic diversification in the invasive hydrid plant pathogen *phytophthora* x alni and its parental species *P. uniformis*. *Phytopathology* 2020, 110:1959-1969, https://doi.org/10.1094/PHYTO-12-19-0475-R

36. Kocher A, Cornuault J, Gantier JC, Manzi S, Chavy A, Girod R, Dusfour I, Forget P-M, Ginouves M, Prévost G, Guégan J-F, Bañuls A-L, Thoisy B de, Murienne J: Biodiversity and vector-borne diseases: host dilution and vector amplification occur simultaneously for Amazonian leishmaniases. *Mol Ecol* 2022, https://doi.org/10.1111/mec.16341

37. Albery GF, Carlson CJ, Cohen LE, Eskew EA, Gibb R, Ryan SJ, Sweeny AR, Becker DJ: Urban-adapted mammal species have more known pathogens. *Nat Ecol Evol* 2022, 6:794-801, https://doi.org/10.1038/s41559-022-01723-0

38. Nova N, Athni TJ, Childs ML, Mandle L, Mordecai EA: Global change and emerging Infectious diseases. *Authorea* 2021, 20:193-205 (https://www.authorea.com/doi/full/10.22541/au.163578736.62541507).

39. Liebhold AM, McCullough DG, Blackburn LM, Frankel SJ, Von Holle B, Aukema JE: A highly aggregated geographical distribution of forest pest invasions in the USA. *Divers Distrib* 2013, 19:1208-1216, https://doi.org/10.1111/ddi.12112

40. Jactel H, Moreira X, Castagneyrol B: Tree diversity and forest resistance to insect pests: patterns, mechanisms, and prospects. *Annu Rev Entomol* 2021, 66:277-296, https://doi.org/10.1146/annurev-ento-041720-075234.

This review paper provides a quantitative assessment of tree diversity effects on insect herbivory and discuss plausible mechanisms. In particular, the authors show that tree species diversity mainly reduced damage of specialist insect herbivores in mixed stands with phylogenetically distant tree species.

41. Paap T, Wingfield MJ, Wilhelm de Beer Z, Roets F: Lessons from a major pest invasion: the polyphagous shot hole borer in South Africa. *South Afr J Sci* 2020, 116:1-4, https://doi.org/10.17159/sajs.2020/8757

42. Santini A, Ghelardini L, De Pace C, Desprez-Loustau ML, Capretti P, Chandelier A, Cech T, Chira D, Diamandis S, Gaitniekis T, Hantula J, et al.: Biogeographical patterns and determinants of invasion by forest pathogens in Europe. *New Phytol* 2013, 197:238-250, https://doi.org/10.1111/j.1469-8137.2012.04364.x

43. Barwell LJ, Perez-Sierra A, Henricot B, Haris A, Burgess TI, Hardy G, Scott P, Williams N, Cooke DEL, Green S, Chapman DS, Purse BV: Evolutionary trait-based approaches for predicting future global impacts of plant pathogens in the genus *Phytophthora*. *J Appl Ecol* 2021, 58:718-730 https://doi.org/10.1111/1365-2664.13820

44. De Fine Licht HH: Does pathogen plasticity facilitate host shifts? *PLoS Pathog* 2018, 14:e1006961, https://doi.org/10.1371/journal.ppat.1006961

45. Rulli MC, Santini M, Hayman DTS, D'Odorico P: The nexus between forest fragmentation in Africa and Ebola virus disease outbreaks. *Sci Rep* 2017, 7:41613.

46. Brock PM, Fornace KM, Grigg MJ, Anstey NM, William T, Cox J, Drakeley CJ, Ferguson HM, Kao RR: Predictive analysis across spatial scales links zoonotic malaria to deforestation. *Proc R*
Soc Lond Ser B 2019, 286:20182351, https://doi.org/10.1098/rspb. 2018.2351

47. Chavy A, Ferreira Dales Nava A, Luiz Bessa Luz S, Ramirez JD, Herrera G, Vasconcelos dos Santos T, Ginouves M, Demar M, Prévot G, Guégan J-F, de Thoisy B: **Ecological niche modelling for predicting the risk of cutaneous leishmaniasis in the Neotropical moist forest biome. PLoS Negl Trop Dis** 2019, **13:e0007629**, https://doi.org/10.1371/journal.pntd.0007629

48. Stephens PR, Gottdenker N, Schatz AM, Schmidt JP, Drake JM: **Characteristics of the 100 largest modern zoonotic disease outbreaks. Philos Trans R Soc Lond Ser B** 2021, **376**:20200535, https://doi.org/10.1098/rstb.2020.0535

49. Allen T, Murray KA, Zambrana-Torrelio C, Morse SS, Rondinini C,

* Di Marco M, Breit N, Olival KJ, Daszak P: **Global hotspots and correlates of emerging zoonotic diseases. Nat Commun** 2017, **8**:1124, https://doi.org/10.1038/s41467-017-00923-8.

Using an updated global database on emerging diseases, the authors show that emerging risks are higher in forested tropical regions experiencing land-use modifications and where wild mammal biodiversity is also high. The paper presents a new global hotspot map in zoonotic disease risk index.

50. Halliday FW, Jalo M, Laine A-L: **The effect of host community functional traits on plant disease risk varies along an elevated gradient. Elife** 2021, **10:e67340**, https://doi.org/10.7554/eLife. 67340