IUFRO RG 8.04, Bangkok 15-19 January 2024

Session 1 – Asian forest ecosystems under changing environment

Asian region, in particular Southeast Asia, is particularly vulnerable to climate change and air pollution due to rising economy, large population, high pollutant emissions, high biodiversity, and a large number of forest-dependent communities. Despite economic growth in some Asian countries, other Asian countries (i.e., developing countries) are suffering the negative impacts of climate change on freshwater resources, coastal systems, food production, and human livelihoods.

Forest ecosystems are particularly sensitive to changes in temperature and precipitation, which can alter future composition of forests in Asia and create an uncertainty in the nature and extent of the services they provide. Forests present a major opportunity for climate change adaptation and mitigation, as they have the potential to act either as a carbon source accelerating climate change impacts (through deforestation and forest degradation), or as a carbon sink reducing climate change impacts (through afforestation and sustainable management). The IPCC highlights the importance of the overall Agriculture, Forestry and Land Use sector mitigation options that, if sustainably implemented, can deliver large-scale greenhouses emission reductions and enhanced removal.

The main aim of this session is to address the recent progress of forest/tree responses to environmental changes and strategies to mitigate climate change/air pollution and its effects in Asia, with a focus on developing countries.

Session 2 - Urban greening: a win-win strategy for air quality, climate, biodiversity, and citizen well-being

Urban environments that are stressful for plant function and growth will become increasingly widespread in the future. Cities, where 56% of the world population lived in 2020, have to cope with rising poor air quality (e.g., ozone, particulate matter and nitrogen dioxide) and urban heat islands, affecting human health, quality of life, citizen well-being, and ecosystem services provided by urban forests.

Urban trees are the most important elements of urban ecosystems and contribute to reducing air pollution in cities, increasing carbon stock, mitigating the urban heat islands, providing cooling and shading, regulating water runoff, reducing noise as well as providing social and psychological benefits, enhancing citizens’ well-being and human health. Therefore, regreening the cities is seen as a win-win strategy co-benefitting air quality and climate, and a mitigation and adaptation strategy in the context of climate change.

Phytoremediation is a scientific technology aimed at reducing particulate matter (PM), ozone, and Volatile Organic Compounds (VOCs) for the benefit of humans, animals, and plants. Extensive research and development have been conducted on the utilization of plants for the treatment of organic pollutants, for instance for the BTEX group (Benzene, Toluene, Ethylbenzene, Xylene). Phytoremediation is considered as a promising and effective technology for environmental remediation. It offers several advantages, such as being cost-effective, environmentally friendly, and capable of treating a wide range of contaminants.

However, urban vegetation or an inappropriate application of phytoremediation can enhance air pollution and allergenicity by increasing emissions of biogenic VOCs and pollens. Municipalities and city planners need a quantitative and concrete assessment of the role of urban vegetation in affecting air quality at the city scale as well as guidelines for tree planting and maintenance strategy to maximize air quality and minimize disservices.

The main objectives of this session are to i) estimate the climate change and air pollution mitigation potential of vegetation in the urban and peri-urban environment; ii) focus on the effects of the main air pollutants on urban vegetation and develop the guideline for maintenance strategy; and iii) investigate the emissions of biogenic VOCs and pollen from urban greening.

Session 3 - Plant ecosystems in a changing world: monitoring, modeling, and risk assessment

New approaches (e.g. field experiments, Earth-Observation, epidemiological studies) and sophisticated modeling are under development to study plant ecosystems in a changing world. Based on observations, modeling approaches are emerging to develop coupled biogeochemical-ecological models, to predict the combined effects of climate change, air pollution, atmospheric deposition and other stressors on plant ecosystems functioning and diversity.

The main objective of this session is to discuss different approaches to bridge the knowledge gaps in different scientific domains (air pollution, atmospheric deposition, climate change, impacts in terms of growth, health, yield, distribution and biodiversity loss) in order to: i) translate observations and predictions into future scenarios, including socio-economic implications; ii) improve understanding of the interaction and feedbacks between climate change, air pollutants and effects upon plant ecosystems; iii) quantify the ecosystems responses to air pollution and changing climate conditions; and iv) provide risk maps for plant ecosystems at regional and local scale.

Session 4 - Tropospheric ozone: a threat to terrestrial ecosystems and biodiversity

Ground-level ozone pollution continues to be a serious issue for terrestrial ecosystems and biodiversity, in particular in Southeast Asia. For risk assessment, new monitoring approaches, epidemiological studies and sophisticated modeling are developing, for instance the Phytotoxic Ozone Dose. Ozone levels and deposition are affected by the vegetation type. This session will allow all experts in the interactions between ozone, forest ecosystems and biodiversity to meet and discuss the state of the art and the strategies for continuous improvements.

The main aim of this session is to evaluate strategies for maximizing productivity and other environmental services of forest ecosystems under ozone stress. The session will contribute to i) develop a better understanding of ozone impacts on terrestrial ecosystems and biodiversity; ii) evaluate different metrics for forests protection; iii) provide best practices for sustainable forest management; and iv) guide management decisions and efficient policy recommendations toward increased health, sustainability, and productivity forest resilience worldwide.

Session 5 - Atmospheric deposition: consequences for forest ecosystems

Atmospheric deposition, particularly heavy metals, nitrogen (N) and sulfur (S), continues to impact aquatic and terrestrial ecosystems across the globe. In South Asia, East Asia, Southeast Asia and Japan, N and S deposition remain at high levels. In China, N and S deposition levels are the highest reported in the world, and studies of the ecological effects on atmospheric deposition are relatively recent, with much yet to be discovered regarding plant ecosystem responses. Nutrient limitations, and the effect of N deposition on carbon sequestration, are now recognized as important process information to be included in global carbon models.

More research is needed to incorporate climate change and air pollution as interactive factors in developing critical loads models for forest ecosystems under conditions of multiple biotic and other environmental stressors.

The main aim of this session focusses on how atmospheric deposition is impacting forest ecosystems and their function, and to integrate research findings so that solid management strategies can be developed for better environmental policies and adaptation of forest ecosystems that ensure sustainability.

Session 6 - Genetic, biochemical, and physiological mechanisms underlying stress responses of forest ecosystems

The main aim of this session focuses on discussing physiological, biochemical, and genetic mechanisms, and their inter-linkages, underlying forest responses to climate change and air pollution. As well, genetic variation in acclimation and adaptive phenological, physiological and anatomical traits will be addressed.

The session will: i) explore the current state of knowledge on climate change and air pollution stress on forest ecosystems; ii) examine the linkages between genetic responses and resulting physiological activities, i.e., genetic control of physiological responses; and iii) identify priorities and challenges of future research towards consolidating forest ecosystems health, productivity, sustainability, and ecosystem services worldwide.

Session 7 - Forest ecosystems under multiple stressors

Forests are suffering from multiple and interactive effects of air pollution (ozone, nitrogen oxides, excess nitrogen deposition), climate change (increase in CO₂, temperature, extreme climatic events) and other stressors such as pest outbreaks, wildfires, and land use change. The main aim of this session is to evaluate strategies for maximizing productivity and other environmental services of trees under multiple stressors.

The main objective of this session is to highlight the effects of multiple stressors on forest ecosystems and ecosystem services, whether abiotic or biotic, at the intersection of different trophic levels, and at the stand to landscape level. The productivity of trees will be also discussed along with ecological processes in tree systems, including interactions between plant-plant, plant-herbivore, plant-insects, and pollination as well as associations with symbiotic organisms such as mycorrhizae in trees.

Session 8 - Radioactive contamination of forest ecosystems

The main aim of this session focuses on the radioactive contamination in forest ecosystems to clarify the behavior of radionuclides in forest ecosystems, and to develop countermeasures to radioactive contamination in order to support forest production and forest utilization. Forests are complex ecosystems and occupy large territories, so decontamination is generally not suitable for forest land. There is an urgent need for developing specific guidelines and best practices for managing forests affected by radioactive contamination.

The session will address three main topics: i) Monitoring and modeling of radionuclide dynamics in forest ecosystems; ii) Mechanisms of radiocesium transfer in forest ecosystems; and iii) Countermeasures and management in contaminated forests.