World Tree Research Articles

Methodology for identifying the potential Alliance for Zero Extinction (AZE) tree species on a global scale

AbstractThere is a biodiversity crisis, and to prevent extinctions the most important sites to be effectively conserved must be identified. Key Biodiversity Areas (KBAs) include sites of importance for species survival. Alliance for Zero Extinction (AZE) sites, a subset of KBAs, contain ≥95% of the population of highly threatened species. Currently, only 47 tree species have been identified using the AZE criteria. The Global Tree Assessment, assessing the extinction risk of the world's tree species, has enabled trees to be incorporated into KBA and AZE sites. Here we present a methodology to utilize data from the IUCN Red List to identify potential AZE species for trees. This 10‐part methodology identified 2909 tree species as potential AZE species across the world, representing at least 5% of described tree species. As further tree species are assessments are published on the IUCN Red List, this methodology will be important for identifying potential AZE species. The methodology can be applied and adapted to any taxa on the IUCN Red List. This analysis serves as a prioritization mechanism for identifying species in urgent need of conservation action to prevent extinctions. The species identified can feed into national KBA identification efforts.

Achievement of SDGS globally in biodiversity conservation and reduction of greenhouse gas emissions by using green energy and maintaining forest cover

The global partnership for sustainable development is well-positioned to combat climate change and its impacts on ecosystems and biodiversity, aligning with the Sustainable Development Goals (SDGs) on climate, oceans, marine resources, forests, biodiversity, and land degradation. This study has assessed and evaluated the status of global forests and biodiversity, greenhouse emissions, and global energy perspectives, synthesizing track progress on goals 13 and 15 targets focusing on climate change trends, forest cover, and biodiversity status. Review and analysis of global forest resource and biodiversity assessment, GHG emission inventories, verification of CO2 measurement, statistical review of world energy and renewables contributions to reduction of GHG emissions, and applying quantitative data on environmental change to identify impact and implications showed that the targeted SDG goals are able to address the issues needed to build climate resilience: maintaining forests and biodiversity, achieving zero emissions, and adopting renewables. Forests, which cover 31% of the world's land surface, provide habitat, clean air and water, and help mitigate climate change. However, 13 million hectares are lost each year, resulting in the desertification of 3.6 billion hectares. The world's tree stock has decreased slightly due to a decrease in forest area, with 8% of 8,300 animal breeds extinct and 22% on the verge of extinction, highlighting the importance of sustainable ecosystem management and biodiversity conservation. Global GHG emissions are expected to rise slightly in 2021 to 8 GtCO2e, comparable to or exceeding 2019 levels, and global temperatures could rise over 1.5°C by 2030. Human activities, including greenhouse gas emissions, contribute to global warming, with surface temperatures rising 1.1°C between 2011 and 2020. Mitigation policies expand, but warming may exceed 1.5°C by 2030. The world faces challenges in achieving climate change goals, necessitating increased ambition and implementation. Integrating climate action and sustainable development using renewable energy sources like bioenergy, solar, geothermal, hydropower, and wind is the most effective approach.

Current state of knowledge on the extinction risk of Malaysian tree species: Proximate needs to mitigate loss

Societal Impact StatementAs one of the world's top megadiverse countries for tree species, Malaysia remains committed towards reducing tree population loss and species extinction. In order to ensure efficacy in the planning and implementation of conservation programmes, prioritisation of resources, and mainstreaming across the key drivers of biodiversity loss, it is essential to identify, document, and assess the extinction risk of families with high levels of endemism. In addition to being an integral component of ecosystems and their functions, from a socio‐ecological perspective, the rich biodiversity of Malaysia constitutes extraordinary natural capital that many people depend on for their livelihoods and well‐being.SummaryMalaysia is a megadiverse country for plant species. Knowledge of the diversity of Malaysian plant species is incomplete but has been significantly expanded by the Tree Flora of Sabah and Sarawak and Flora of Peninsular Malaysia projects. More than 400 new plant species, including at least 14 new genera, have been added since 1995. Between 1973 and 2015, Malaysia lost an estimated 29.4% natural forest cover; conserving plant species at immediate risk of extinction will help alleviate future loss of natural forests and biodiversity. With 9.2% of the world's tree species dwelling in Malaysia, of which 29.8% are endemic, species risk assessment is an important conservation planning tool for the Malaysian flora. Through the Global Tree Assessment project, Malaysia verified that approximately 24% of the tree diversity is exposed to a multitude of threats ranging from deforestation and forest degradation to poaching and incursion of invasive alien species. Here, we summarise the extent and types of extinction risk faced by several of our keystone tree families, namely, Dipterocarpaceae, and tree genera of Myristicaceae and Sapotaceae, whose timbers remain highly valued. We summarise the nature and aims of programmes that spur the country's conservation agenda for threatened plant species and describe some specific targets for Peninsular Malaysia, Sabah, and Sarawak. We focus on efforts that enhance in situ conservation and the understanding of population dynamics. Programmes that enable and support the main agenda, such as institutional capacity building and awareness of the importance of biodiversity, are also briefly explained.

Scientists' warning to humanity on tree extinctions

Societal Impact StatementTrees play vital roles in many of the world's ecosystems while providing many benefits to people. New evidence indicates that a third of tree species are threatened with extinction, representing a tree extinction crisis. Here we demonstrate how tree species extinction will lead to the loss of many other plants and animals and significantly alter the world's ecosystems. We also show how tree extinction will negatively affect billions of people through loss of livelihoods and benefits. We highlight a series of urgent actions needed to avert an ecological, cultural and socio‐economic catastrophe caused by widespread extinction of tree species.SummaryTrees are of exceptional ecological importance, playing a major functional role in the world's ecosystems, while also supporting many other plants, animals and fungi. Many tree species are also of direct value to people, providing a wide range of socio‐economic benefits. Loss of tree diversity could lead to abrupt declines in biodiversity, ecosystem functions and services and ultimately ecosystem collapse. Here we provide an overview of the current knowledge regarding the number of tree species that are threatened with extinction, and the threats that affect them, based on results of the Global Tree Assessment. This evidence suggests that a third of the world's tree species are currently threatened with extinction, which represents a major ecological crisis. We then examine the potential implications of tree extinctions, in terms of the functioning of the biosphere and impacts on human well‐being. Large‐scale extinction of tree species will lead to major biodiversity losses in other species groups and substantially alter the cycling of carbon, water and nutrients in the world's ecosystems. Tree extinction will also undermine the livelihoods of the billions of people who currently depend on trees and the benefits they provide. This warning to humanity aims to raise awareness of the tree extinction crisis, which is a major environmental issue that requires urgent global attention. We also identify some priority actions that need to be taken to reduce the extinction risk of tree species and to avert the ecological and socio‐economic catastrophe that will result from large‐scale extinction of tree species.

Taxonomic uncertainty and the challenge of estimating global species richness

Taxonomic uncertainty and the challenge of estimating global species richness

Costs of Fallacy Mind to the Global Economics

Costs of Fallacy Mind to the Global Economics

Diversity enhances carbon storage in tropical forests

AbstractAimTropical forests store 25% of global carbon and harbour 96% of the world's tree species, but it is not clear whether this high biodiversity matters for carbon storage. Few studies have teased apart the relative importance of forest attributes and environmental drivers for ecosystem functioning, and no such study exists for the tropics.LocationNeotropics.MethodsWe relate aboveground biomass (AGB) to forest attributes (diversity and structure) and environmental drivers (annual rainfall and soil fertility) using data from 144,000 trees, 2050 forest plots and 59 forest sites. The sites span the complete latitudinal and climatic gradients in the lowland Neotropics, with rainfall ranging from 750 to 4350 mm year−1. Relationships were analysed within forest sites at scales of 0.1 and 1 ha and across forest sites along large‐scale environmental gradients. We used a structural equation model to test the hypothesis that species richness, forest structural attributes and environmental drivers have independent, positive effects on AGB.ResultsAcross sites, AGB was most strongly driven by rainfall, followed by average tree stem diameter and rarefied species richness, which all had positive effects on AGB. Our indicator of soil fertility (cation exchange capacity) had a negligible effect on AGB, perhaps because we used a global soil database. Taxonomic forest attributes (i.e. species richness, rarefied richness and Shannon diversity) had the strongest relationships with AGB at small spatial scales, where an additional species can still make a difference in terms of niche complementarity, while structural forest attributes (i.e. tree density and tree size) had strong relationships with AGB at all spatial scales.Main conclusionsBiodiversity has an independent, positive effect on AGB and ecosystem functioning, not only in relatively simple temperate systems but also in structurally complex hyperdiverse tropical forests. Biodiversity conservation should therefore be a key component of the UN Reducing Emissions from Deforestation and Degradation strategy.

Towards a Global Tree Assessment

AbstractAlthough trees have high economic, cultural and ecological value, increasing numbers of species are potentially at risk of extinction because of forest loss and degradation as a result of human activities, including overharvesting, fire and grazing. Emerging threats include climate change and its interaction with the spread of pests and diseases. The impact of such threats on the conservation status of trees is poorly understood. Here we highlight the need to conduct a comprehensive conservation assessment of the world's tree species, building on previous assessments undertaken for the IUCN Red List. We suggest that recent developments in plant systematics, online databases, remote sensing data and associated analytical tools offer an unprecedented opportunity to conduct such an assessment. We provide an overview of how a Global Tree Assessment could be achieved in practice, through participative, open-access approaches to data sharing and evaluation.

Estimating Coextinction Risks from Epidemic Tree Death: Affiliate Lichen Communities among Diseased Host Tree Populations of Fraxinus excelsior

At least 10% of the world’s tree species are threatened with extinction and pathogens are increasingly implicated in tree threats. Coextinction and threats to affiliates as a consequence of the loss or decline of their host trees is a poorly understood phenomenon. Ash dieback is an emerging infectious disease causing severe dieback of common ash Fraxinus excelsior throughout Europe. We utilized available empirical data on affiliate epiphytic lichen diversity (174 species and 17,800 observations) among 20 ash dieback infected host tree populations of F. excelsior on the island Gotland in the Baltic Sea, Sweden. From this, we used structured scenario projections scaled with empirical data of ash dieback disease to generate probabilistic models for estimating local and regional lichen coextinction risks. Average coextinction probabilities (Ā) were 0.38 (95% CI ±0.09) for lichens occurring on F. excelsior and 0.14 (95% CI ±0.03) when considering lichen persistence on all tree species. Ā was strongly linked to local disease incidence levels and generally increasing with lichen host specificity to F. excelsior and decreasing population size. Coextinctions reduced affiliate community viability, with significant local reductions in species richness and shifts in lichen species composition. Affiliates were projected to become locally extirpated before their hosts, illuminating the need to also consider host tree declines. Traditionally managed open wooded meadows had the highest incidence of ash dieback disease and significantly higher proportions of affiliate species projected to go extinct, compared with unmanaged closed forests and semi-open grazed sites. Most cothreatened species were not previously red-listed, which suggest that tree epidemics cause many unforeseen threats to species. Our analysis shows that epidemic tree deaths represent an insidious, mostly overlooked, threat to sessile affiliate communities in forested environments. Current conservation and management strategies must account for secondary extinctions associated with epidemic tree death.

The Splendor of the World's Tree: The Angelic Language of Salvation in Jacopone of Todi

Splendor of the World's Tree: The Angelic Language of Salvation in Jacopone of Todi. This essay examines the mystical language of Jacopone of Todi, one of the most important poets of the Middle Ages. For many scholars, the essential contradiction of Jacopone's Lauds is the apparently unsettled relationship between apophasis and language. Jacopone's mystical poetry is usually seen as contradictory and unsystematic. The author believes that in the lauds revolving around the tree image Jacopone expresses a unique form of apocalyptic poetics. Read in the light of Bonaventure's theology, the author shows that Bonaventure's concept of hierarchic man is the foundation of Jacopone's expression. For Jacopone, Francis of Assisi symbolizes a human being who has climbed a divine tree of spiritual and linguistic purification and has thus acquired an angelic nature. However, in order to complete his mystical ascension the concordant man must share his spiritual insight with us; that is, he must preach the goo...