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The possibility that the Amazon forest system could soon reach a tipping point, inducing large-scale collapse, has raised global concern 1 – 3 . For 65 million years, Amazonian forests remained relatively resilient to climatic variability. Now, the region is increasingly exposed to unprecedented stress from warming temperatures, extreme droughts, deforestation and fires, even in central and remote parts of the system 1 . Long existing feedbacks between the forest and environmental conditions are being replaced by novel feedbacks that modify ecosystem resilience, increasing the risk of critical transition. Here we analyse existing evidence for five major drivers of water stress on Amazonian forests, as well as potential critical thresholds of those drivers that, if crossed, could trigger local, regional or even biome-wide forest collapse. By combining spatial information on various disturbances, we estimate that by 2050, 10% to 47% of Amazonian forests will be exposed to compounding disturbances that may trigger unexpected ecosystem transitions and potentially exacerbate regional climate change. Using examples of disturbed forests across the Amazon, we identify the three most plausible ecosystem trajectories, involving different feedbacks and environmental conditions. We discuss how the inherent complexity of the Amazon adds uncertainty about future dynamics, but also reveals opportunities for action. Keeping the Amazon forest resilient in the Anthropocene will depend on a combination of local efforts to end deforestation and degradation and to expand restoration, with global efforts to stop greenhouse gas emissions. Analyses of drivers of water stress are used to predict likely trajectories of the Amazon forest system and suggests potential actions that could prevent system collapse.

The links between plantation expansion and deforestation in Borneo are debated. We used satellite imagery to map annual loss of old‐growth forests, expansion of industrial plantations (oil palm and pulpwood), and their overlap in Borneo from 2001 to 2017. In 17 years, forest area declined by 14% (6.04 Mha), including 3.06 Mha of forest ultimately converted into industrial plantations. Plantations expanded by 170% (6.20 Mha: 88% oil palm; 12% pulpwood). Most forests converted to plantations were cleared and planted in the same year (92%; 2.83 Mha). Annual forest loss generally increased before peaking in 2016 (0.61 Mha) and declining sharply in 2017 (0.25 Mha). After peaks in 2009 and 2012, plantation expansion and associated forest conversion have been declining in Indonesia and Malaysia. Annual plantation expansion is positively correlated with annual forest loss in both countries. The correlation vanishes when we consider plantation expansion versus forests that are cleared but not converted to plantations. The price of crude palm oil is positively correlated with plantation expansion in the following year in Indonesian (not Malaysian) Borneo. Low palm oil prices, wet conditions, and improved fire prevention all likely contributed to reduced 2017 deforestation. Oversight of company conduct requires transparent concession ownership.

Tropical forests make an approximately neutral contribution to the global carbon cycle, with intact and recovering forests taking in as much carbon as is released through deforestation and degradation. In the near future, tropical forests are likely to become a carbon source, owing to continued forest loss and the effect of climate change on the ability of the remaining forests to capture excess atmospheric carbon dioxide. This will make it harder to limit global warming to below 2 °C. Encouragingly, recent international agreements commit to halting deforestation and degradation, but a lack of fundamental data for use in monitoring and model design makes policy action difficult. Tropical forests currently make a neutral contribution to the global carbon cycle, but they are likely to become a carbon source in the near future.

Nowadays, the challenges related to technological and environmental development are becoming increasingly complex. Among the environmentally significant issues, wildfires pose a serious threat to the global ecosystem. The damages inflicted upon forests are manifold, leading not only to the destruction of terrestrial ecosystems but also to climate changes. Consequently, reducing their impact on both people and nature requires the adoption of effective approaches for prevention, early warning, and well-coordinated interventions. This document presents an analysis of the evolution of various technologies used in the detection, monitoring, and prevention of forest fires from past years to the present. It highlights the strengths, limitations, and future developments in this field. Forest fires have emerged as a critical environmental concern due to their devastating effects on ecosystems and the potential repercussions on the climate. Understanding the evolution of technology in addressing this issue is essential to formulate more effective strategies for mitigating and preventing wildfires.

Analyses of potential and actual biomass stocks indicate that trade-offs exist between conserving carbon stocks on managed land and raising the contribution of biomass to raw material and energy supply for the mitigation of climate change. Land management impact on biomass Land use by humans leads to loss of carbon from the Earth's biomass. Karl-Heinz Erb and colleagues estimate the amount of carbon that has been lost from terrestrial vegetation as a result of land conversion and management by compiling global maps of current terrestrial carbon stocks and potential carbon stocks that would exist without human disturbance. They find that land use has halved terrestrial carbon stocks. The effects of land management (forest management and grazing) seem to be similar to those of land conversion: land conversion accounts for 53–58% of the carbon stock losses and land management accounts for 42–47%. The findings imply that avoiding deforestation is necessary but not sufficient for climate-change mitigation. Carbon stocks in vegetation have a key role in the climate system 1 , 2 , 3 , 4 . However, the magnitude, patterns and uncertainties of carbon stocks and the effect of land use on the stocks remain poorly quantified. Here we show, using state-of-the-art datasets, that vegetation currently stores around 450 petagrams of carbon. In the hypothetical absence of land use, potential vegetation would store around 916 petagrams of carbon, under current climate conditions. This difference highlights the massive effect of land use on biomass stocks. Deforestation and other land-cover changes are responsible for 53–58% of the difference between current and potential biomass stocks. Land management effects (the biomass stock changes induced by land use within the same land cover) contribute 42–47%, but have been underestimated in the literature. Therefore, avoiding deforestation is necessary but not sufficient for mitigation of climate change. Our results imply that trade-offs exist between conserving carbon stocks on managed land and raising the contribution of biomass to raw material and energy supply for the mitigation of climate change. Efforts to raise biomass stocks are currently verifiable only in temperate forests, where their potential is limited. By contrast, large uncertainties hinder verification in the tropical forest, where the largest potential is located, pointing to challenges for the upcoming stocktaking exercises under the Paris agreement.

The report on global land use and agriculture comes amid accelerating deforestation in the Amazon. The report on global land use and agriculture comes amid accelerating deforestation in the Amazon. A cowboy drives cattle at a farm in the Brazilian rainforest

Assessing the current status and identifying the mechanisms threatening endangered plants are significant challenges and fundamental to biodiversity conservation, particularly for protecting Tertiary relict trees and plant species with extremely small populations (PSESP). Ulmus elongata (Ulmus, Ulmaceae) with high values for the ornamental application, is a Tertiary relict tree species and one of the members from PSESP in China. Currently, the wild populations of U. elongata have been threatened by excessive deforestation and urbanization, but limited knowledges of its genetic diversity seriously hinder conservation efforts. Therefore, a further study on the genetic diversity and drivers of genetic pattern in U. elongata is crucial for preserving genetic resources and can serve as a reference for other Tertiary relict plants and PSESP under climate change. Here, a total of 12 populations from 70 individuals of U. elongata were collected covering its geographical distribution in China. Utilizing chloroplast genome datasets, we found that U. elongata exhibited remarkably low nucleotide diversity and gene flow (Ï = 0.00013, Nm = 0.03). Analysis of molecular variance (AMOVA) showed that genetic variation in U. elongata occurs mainly between eight clades (60.95%). The Mantel tests indicated a significant correlation between genetic differentiation and geographical distances (r = 0.3777, p < 0.05) in U. elongata populations. A notable phylogeographic structure was identified in U. elongata, comprising eight distinct haplogroups (N.sub.ST = 0.917, G.sub.ST = 0.876, p < 0.05), which was attributed to the global cooling in the East Asia and Quaternary climate oscillations. Overall, our study using Ulmus elongata as a representative supported the hypothesis that plants belonging to Tertiary relict species and PSESP simultaneously exhibits significantly lower genetic diversity compared to those are either Tertiary relict species or PSESP individually. Furthermore, the low genetic diversity and significant genetic differentiation in U. elongata populations can be primarily ascribed to a combination of factors, including habitat fragmentation resulting from human activities, populations contraction during LGM and small population sizes. This provides a crucial foundation for guiding conservation efforts and implementing management strategies for other Tertiary relict tree species and PSESP. Our findings also provide evidence for the important roles of East Asian monsoon system and climate oscillations in shaping the phylogeographic pattern in subtropical broad-leaved forests.

The pathogens that cause most emerging infectious diseases in humans originate in animals, particularly wildlife, and then spill over into humans. The accelerating frequency with which humans and domestic animals encounter wildlife because of activities such as land-use change, animal husbandry, and markets and trade in live wildlife has created growing opportunities for pathogen spillover. The risk of pathogen spillover and early disease spread among domestic animals and humans, however, can be reduced by stopping the clearing and degradation of tropical and subtropical forests, improving health and economic security of communities living in emerging infectious disease hotspots, enhancing biosecurity in animal husbandry, shutting down or strictly regulating wildlife markets and trade, and expanding pathogen surveillance. We summarize expert opinions on how to implement these goals to prevent outbreaks, epidemics, and pandemics.