Search

Terrestrial vegetation plays a vital role in global carbon recycling, but it is also affected by compound events (CEs); however, little is known about the impacts of these CEs on vegetation in terms of their occurrence and magnitude. Using meteorological observations and vegetation indices (leaf area index (LAI), gross primary productivity (GPP), and net primary productivity (NPP)) from 1981 to 2020, we explored the occurrence of 13 CEs types and identified the dominant CEs types across different eco-geographical regions of China, and quantified the response of various vegetation types to dominant CEs. We found that CEs of extreme hot-dry, extreme hot-dry-high fire weather, dry-high fire weather, and high fire weather-strong wind were the dominant types of compound events during the growing season in China, and their hazards increased at a rate of >0.1HI/10a during 1981–2020. We further detected that more than 60% of the total vegetation areas showed a strong negative correlation with compound extreme hot-dry-high fire weather-strong wind events, which was relatively higher than compound extreme hot-dry events. The response of vegetation to compound events varied at the national scale, which was related to the vegetation type, dominant compound event type, and local natural conditions. This study highlights the benefits of a multivariate perspective on compound events and reveals the regional differences in the response of vegetation to compound events, which can provide initial guidance to assess the regional compound event risk of vegetation against the background of carbon neutrality by 2060.

Abstract Frequent droughts have aggravated the occurrence of wildfires and led to substantial losses in terrestrial ecosystems. However, our understanding of compound drought-wildfire events, including the hotspots, spatiotemporal patterns, trends, and their impacts on global vegetation growth, remains unclear. Utilizing satellite data on terrestrial water storage, burned areas, and gross primary production (GPP) from 2002 to 2020, we identified a positive correlation between droughts and wildfires and mapped the global patterns of compound drought-wildfire events. Approximately 38.6% of vegetated areas across the globe witnessed rise in probability of compound drought-wildfire events (

Abstract Due to the complex natural environment and large regional differentiation in China, the dependence of multiple climate-related hazards on compound events (CEs) and their response to climate change are still unclear. Using daily meteorological observations (1961–2020) and climate simulations from the Coupled Model Intercomparison Project Phase 6, statistically strong dependences among hot, dry, and high fire risk are revealed in China. The average temperature from 1991 to 2020 was 1 °C higher than that from 1961 to 1990, and the probabilities of CEs exhibiting extreme hot-dry, dry-high fire risk, and extreme hot-dry-high fire risk increased significantly by 74.8%, 60.5%, and 26.8%, respectively. Although most CEs occur more frequently in China at the end of the 21st century, the increase rates in low emissions are lower. These findings have implications for developing climate adaptation and mitigation strategies to cope with increased CEs in critical geographical regions.

Due to the greater negative impacts on humans and ecosystems, compound events (CEs) have received increasing attention in China over recent decades. Previous studies mainly considered combinations of frequent hazards (e.g., extreme hot and dry events or heatwaves and extreme precipitation), potentially leading to an inadequate understanding of CEs hotspots, as the occurrence of CEs varies considerably with the diverse hazard types and their temporal sequence (multivariate compound events (MCEs) and temporally compounding events (TCEs)). Here, using daily meteorological observations from 1961 to 2020, we identify 44 CEs types considering the temporal sequences of various hazards from that period and explore their occurrence patterns in China. The results show that 12 CEs types related to extreme hot or dry events widely and frequently (return period < 1 year) occur in China, particularly compound extreme hot-dry-high fire risk events (return period of 0.2–0.4 yrs). Regarding the temporal sequences, MCEs and TCEs have similar spatial distributions, but the magnitudes of MCEs are approximately 1.1 to 2.6 times those of TCEs. This difference is obvious in CEs formed by multiple hazards (>2). By considering occurrence patterns (return period and magnitude), temporal trends, and correlations between different hazards, we determine that the southern humid regions of China are prone to CEs. These results provide a general reference on the national scale for identifying CEs hotspots where more climate action is needed in the future.

Most wildland-urban interface (WUI) areas in the world will face severe wildfire risks due to climate warming and rapid urbanization. Mitigating the damage caused by WUI fires has become a worthy topic for fire researchers and managers. In recent years, WUI fires have occurred in China and caused significant property damage, and even threatened some communities. To understand the research status and promote WUI fire management in China, this paper collected all research articles published from 1991 to 2021 on the topic. We performed a bibliometric analysis for the year, author, institution, country, journal, and keywords. The results show that 717 research articles were published in the field of WUI fire management over this period. The annual number of published articles has exceeded 40 since 2013 and is expected to reach 80 in 2022. The United States has the most active research institutions and groups working in the field of WUI fire management, with 507 published articles over the past three decades, accounting for 70.7% of the total articles. Ninety percent of the top ten authors or institutions come from the United States. The International Journal of Wildland Fire, an important journal in the field of wildfire, has published 96 research articles on the topic over the same period, accounting for 13.4% of the total. Research focused on WUI fire occurrence and its influencing factors, fire behavior simulation, fire risk assessment, and fuel treatment. Future research on WUI fire management will explore the impacts of climate change on the WUI fire regime, improve risk assessment methods, and enhance fire mitigation strategies.

Climate change threatens agricultural production and leads to an increasing contradiction between food supply and needs. Greenhouse gas (GHG) emissions from agricultural activities will exacerbate climate change in the future. Solving food security has become a major challenge around the world. The development of climate-resilient agriculture (CRA) is critical to address or slow climate change and is also helpful to improve agricultural quality and efficiency. Based on a review of previous studies and a deep understanding of CRA goals, this paper introduced a comprehensive assessment framework to evaluate CRA. This assessment framework combined four dimensions, i.e., agricultural productivity, farmer income, climate adaptability, and the green development level, and has 71 evaluation indicators. The highlights of this framework are to analyze the impacts of climate change on agricultural development and to stress the synergy of mitigation and adaptation strategies. All indicators represent various factors related to the development of CRA and have been used in previous studies. Therefore, the comprehensive assessment framework can be used as an evaluation tool for analyzing the changes in agroecosystem resilience under climate change, which is also helpful to implement scientific management to ensure sustainable agricultural development and food security.

Accounting for 41.7% of China’s total land area, grasslands are linked to the livelihoods of over 20 million people. Although grassland fires cause severe damage in China every year, their spatiotemporal patterns and climate drivers are not well understood. In this study, we used grassland fire record forms provided by the National Forestry and Grassland Administration and grassland fire location data from the Wildfire Atlas of China to examine the spatiotemporal patterns and and seasonality of fires in China for the period from 2008 to 2020. We found that most grassland fires occurred in Inner Mongolia in northern China, specifically in the Hulun Buir and Xilingol grasslands. We found distinct differences in fire seasonality in northern China, which has a major fire season in April, versus southwestern China, where the major fire season occurs in February, March and April. April grassland fires in northern China are the result of strong winds, typically from the west, and spring drought. A secondary fire season in northern China occurs in October and is also driven by strong winds. The fire season in southwestern China seems to be less shaped by climatic factors such as wind speed, precipitation, and drought. This study provides support for decision-making by fire prevention and fire management authorities in China.

Understanding fire regimes is central to fire management. In our study, we analyzed the fire weather and forest fire regime of China using fire data from satellite remote sensing and statistics from 2000 to 2020. The fire weather index system was calculated from observed weather data for 2007 to 2017. Using qualitative and quantitative methods, we created a zoning system for China based on the spatial distribution characteristics of fire regimes and vegetation. The fire seasons varied between regions because of differences in vegetation, climate and ignition sources. The fire seasons in the north were spring and autumn. In the south and southwest forest regions, the fire seasons were winter and spring. Most forest fires occurred in southern China, but the average burned area per fire was lower compared with fires in the northeast. The zoning system includes 13 forest fire regime zones with specific fire characteristics according to quantitative variables. These zones are further divided into 17 fire regime units based on qualitative variables. Each fire regime unit has unique characteristics for regime, climate and vegetation type. Human activity was the main cause of fires, especially in south China, where the population density is high. Fire management should be tailored to each fire regime type based on fire characteristics and management targets.

The frequent occurrence of fatalities from wildfires is an ongoing problem in China, even though great improvements have been achieved in overall wildfire management in recent years. We analysed the occurrence patterns and correlative environments of fatalities from forest fires in China from 1951 to 2018. Changes in fire policies affected changes in the numbers of fires, forest area burned and number of fatalities before and after 1987, after the large Great Black Dragon Fire that burned in the Daxing'anling Mountains in northeastern China. Most fatalities occurred in the southern, southwestern and eastern forest regions of the country where population centres are concentrated, while most of the burned area was distributed in forests of northeast China with fewer population centres. Fatalities were correlated with higher values of fire weather indices, coniferous forests, coniferous and broad-leaved mixed forests, moderate-average slopes (5.1-15°), and primarily small fires of less than 100 ha in area. These results should be a first step to help improve awareness of inherent dangers during wildfires and to assist fire managers and policy-makers in strengthening safety procedures for both professional firefighters and the public to reduce wildfire fatalities in the future. [ABSTRACT FROM AUTHOR]