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    Ecology: correct the digital data divide

    Autonomous sensing devices and machine-learning algorithms are being used increasingly to track ecological health and dynamics over large scales with fine resolution. However, nature management and conservation are being compromised by inequitable access to these transformative technologies.
    Competing Interests
    The authors declare no competing interests. More

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    Tree diversity enhances soil carbon and nitrogen sequestration in natural forests

    RESEARCH BRIEFINGS
    26 April 2023

    Biodiversity experiments show that a high diversity of plants increases the accumulation of soil carbon and nitrogen, but whether such conclusions hold in natural ecosystems is debated. An analysis of Canada’s National Forest Inventory provides strong evidence that the build-up of soil carbon and nitrogen on a decadal timescale increased with improved tree diversity in natural forest ecosystems. More

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    Full closure of high seas would triple the benefits

    The new United Nations High Seas Treaty (see Nature https://doi.org/j6f3; 2023) provides a path to generating conservation, economic and social-equity gains at global and national scales from a single policy change: close the high seas to fishing. The treaty requires only three-quarters of member countries to vote to establish a marine protected area, making all of these goals politically feasible.
    Competing Interests
    The author declares no competing interests. More

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    I explore my people’s sacred space to protect biodiversity

    As a deep-sea researcher at South Africa’s Department of Environmental Affairs, I lead marine research that helps the country to reach its ocean-sustainability goals, especially the establishment of marine-protected areas (MPAs). MPAs are like national parks, but in the ocean.To establish MPAs, we need to know what lives in them. I spend about half my time on the ocean, sampling species. Otherwise, I’m analysing data, planning expeditions and advising the minister on issues such as granting marine oil and gas permits.In this picture, I’m standing on the observer platform of our research vessel, the RV Algoa. As expedition chief scientist, I am responsible for the scientific crew.One area of continuing MPA research is Cape Canyon, off Western Cape. It’s a massive undersea system, up to 3 kilometres deep. We survey marine life there as a guide for where to establish MPAs.Our recent study (Z. Filander et al. Front. Mar. Sci. 9, 1025113; 2022) documented seabed-dwelling animals in Cape Canyon, including marine sponges, deep-water corals, a rare sea urchin (Dermechinus horridus) and an ancient sea star (Brisinga sp.). The canyon head of Cape Canyon has since been made into an MPA.My tribe, the amaBhaca of the Nguni people, has a strong tie with the ocean that began with our most-ancient ancestors. We go to the beach every New Year, but just to stand at the water’s edge. The ocean is a sacred space: we don’t interact with it.Some in my community viewed my work as disrespectful because I had not remained on the shore. I explained my research and why I do it to my community members — who are now excited by my work.As a Black and Indigenous female researcher who advises the government, I strive to ensure that marginalized communities’ perspectives are accurately represented. I address past injustices using ocean sciences as a vehicle for change. More

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    An evolutionary route to warning coloration

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    Tasmanian devils’ contagious cancers sequenced for first time

    Tasmanian devils are susceptible to facial cancers that are spread by biting.Credit: Gapvoy/Shutterstock

    For three decades, Tasmanian devils have battled contagious facial cancers that result in debilitating tumours. Now, a comprehensive genetic analysis of these cancers has tracked their evolution, offering clues about how they could spread in future.The study, published on 20 April in Science1, offers some of the first detailed insights into how the diseases emerged, evolved and spread. This lays the groundwork for modelling how they could affect Tasmanian devil populations in future, says Janine Deakin, a genomicist at the University of Canberra. “Looking at the genomics does give us that insight into the past as well as potentially into the future,” says Deakin. “We need to understand the enemy that we’re working with.”Devilish diseasesTasmanian devils (Sarcophilus harrisii) are carnivorous marsupials native to the island of Tasmania in southeast Australia. They are susceptible to two cancers that emerged separately: devil facial tumour 1 (DFT1) and devil facial tumour 2 (DFT2), which are both spread by biting. Cancers that pass from one host to another are rare in nature, but can have devastating effects, says study co-author Rodrigo Hamede, a disease ecologist at the University of Tasmania in Hobart. “In a matter of 10 years, we lost between 60–70% of the overall [devil] population,” he says.Although scientists have been aware of the two cancers for some time, little has been known about their evolution. To investigate, Hamede and his colleagues assembled a Tasmanian devil reference genome and compared it with DNA sequenced from 78 DFT1 and 41 DFT2 tumours. The team then constructed ‘family trees’ of these tumours to track their origin and mapped their mutations to build a picture of how the diseases have evolved.The results show that DFT1 — which has spread across most of Tasmania — emerged in 1986, around a decade before it was first detected in a female devil in the northeast of the island. That individual seems to have been a superspreader, passing its tumour cells on to at least six other devils. This eventually resulted in six major variants of DFT1.The team found that DFT2 didn’t arise until 2011, roughly three years before it was first detected in a male devil in southeast Tasmania. Unlike DFT1, DFT2 is found in only a small region of the island. The cancer is genetically similar to DFT1, but it mutates around three times faster. This could be due to the tumour cells dividing more quickly, providing more opportunity for mutations to occur, says Hamede. “The big question is whether these mutations are selective or not,” he says.In most cases, the facial cancers don’t become contagious until tumours appear, 6–12 months after infection. But the fast-growing DFT2 cancer could shrink this window, leading to more infections that spread faster, says Hamede. This could give the cancer and its variants a competitive edge over less transmissible types. “That will be a long-term evolutionary advantage,” says Hamede.Vulnerable populationsPrevious research2 has shown that Tasmanian devil populations are becoming more resilient, but the relatively recent emergence of DFT2 is concerning, says Hannah Siddle, a geneticist at the University of Queensland in Brisbane, Australia. “It leaves the devil vulnerable in the wild, particularly in those regions where both tumours circulate,” she says. “This could induce local population crashes or as-yet unknown selection on the host population.”Hamede says that more work needs to be done before researchers can predict how the cancers will evolve and spread through remaining Tasmanian devil populations. “This is an ongoing evolutionary process that we have been witnessing in action,” says Hamede. “This second transmissible cancer will make things more complex.” More

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    Is Africa’s Great Green Wall project withering?

    Senegal is one of the countries most actively involved in the Great Green Wall initiative.Credit: Hemis/Alamy

    ‘Not just another summit.’This is how the Élysée Palace, the office of France’s President Emmanuel Macron described last month’s high-level One Forest Summit, co-led by France and Gabon. The focus of this year’s event was on protecting forests and biodiversity in the face of climate change. It was hosted by Gabon, most of which is forested, and was held in Libreville. The event did garner some eye-catching headlines. France announced that it will contribute half of the funds for a €100-million (US$110 million) project to pay communities to protect forests and ecosystems. Under a scheme called the One Forest Vision, scientists will have the task of mapping carbon (including carbon sequestration) and biodiversity in the world’s tropical forests in the next five years. And business leaders have promised to create 10 million jobs related to the sustainable management of forests by 2030.These initiatives are part of what is called the Libreville Plan. The world needs it to succeed to have even a fighting chance of limiting global warming to within 1.5 °C of pre-industrial levels and turning the corner on the decline in species and ecosystems. But more than a month after the event, no further detail has been published to explain how these initiatives will be achieved — whether through existing institutional mechanisms or by creating new ones. The organizers must remedy that quickly. At the same time, they should explain how their new project fits in with continuing priorities from previous summits.
    Get Africa’s Great Green Wall back on track
    For example, what about unfinished business from the last summit, which took place in Paris in 2021? The One Planet Summit for Biodiversity ended with delegates recommitting to the Africa-led Great Green Wall initiative, one of the world’s most ambitious ecological-restoration schemes.The Sahel–Sahara region is home to many of the world’s poorest people, who live in some of the driest conditions and are among the most vulnerable to climate change. The green-wall project was formally adopted by the African Union in 2007, five years after the union’s creation. It was championed by two powerful heads of government: Nigeria’s Olusegun Obasanjo and Senegal’s Abdoulaye Wade. The aim is to restore 100 million hectares of degraded land in 11 countries straddling the Sahel south of the Sahara, from Senegal in the west to Djibouti in the east — all by 2030. Originally conceived as a 7,000-kilometre wall of trees, it has evolved into a more complex set of activities, including not only planting new trees but also improving soils, setting up community gardens and protecting existing forests.The project also aims to create 10 million jobs and to sequester 250 million tonnes of carbon dioxide. International donors promised to provide most of the project’s budget. But as Nature and others have pointed out, the pace of financing is too slow to achieve this target.
    How to make Africa’s ‘Great Green Wall’ a success
    As of 2020, one-fifth of degraded land (20 million hectares) had been restored and 350,000 of the promised 10 million jobs had been created. That is mainly, although not solely, because just US$2.5 billion of a required $30 billion has been spent since the project began.A United Nations representative told Nature that donors have committed $15 billion to a pipeline of 150 projects. But a UN report published in February acknowledges that it’s not clear how much of this is grants, how much is loans and how much is existing funding relabelled as Great Green Wall money (see go.nature.com/3uhwtae). Moreover, coordination between Great Green Wall countries and donors is weak.The report suggests that trust between the African Union and international donors is in short supply. Donor nations seem to be picking and choosing which countries to invest in, with a preference for those in relatively stable regions. So Ethiopia, Eritrea, Niger and Senegal are among the most active participants (see ‘Off-target’). The less-involved countries — Chad, Mali, Burkina Faso and Sudan, for example — also happen to be the ones that are ruled by their armed forces, with instability, insurgencies and high rates of internal displacement, lost livelihoods and poverty as people flee fighting. The situation in Sudan has become particularly precarious, because military and paramilitary forces are now in open conflict. Conservation and economic-development projects are challenging to achieve in such conditions. The tragedy is that international donors seem to be pulling away (or moving only slowly) just when the people of these countries need their help the most.

    Source: United Nations Convention to Combat Desertification; go.nature.com/3uhwtae

    The project has also found it hard to excite Africa’s top leaders in the way it did Obasanjo and Wade, both of whom saw it as something the continent could unite over in the early days of the African Union. Now, the continent’s Great Green Wall is at risk of becoming its Great Green Walled Garden — a network of isolated activities in a relatively small number of countries. It is also in danger of seemingly abandoning the people most in need of it. There are lessons here for the Libreville Plan. In embracing a new project, donors don’t want to give the impression that they are done with the Green Wall and ready to move on.International summits are not difficult to organize if you have the money, and pledges are easily made. But unkept promises fuel anger and mistrust, at the same time worsening both poverty and the environment. While we await details of the new forest conservation plan, it’s essential that the original vision of Africa’s Great Green Wall is not filed away in the ‘too difficult’ box. More

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    Why Earth’s giant kelp forests are worth $500 billion a year

    A kelp forest off the coast of California.Credit: Douglas Klug/Getty

    The vast swathes of kelp forest growing along the world’s coastlines are estimated to generate US$500 billion a year on average, making them considerably more valuable than previous studies have suggested, according to an analysis that assessed economic contributions made by six types of the seaweed.The study, published on 18 April in Nature Communications1, estimates that kelp forests provide services worth between $465 billion and $562 billion a year worldwide, mainly by providing a habitat for valuable fish and seafood species, and by removing nitrogen from contaminated seawater. The results suggest that each type of kelp forest (see ‘Seaweed services’) generates up to $147,100 per hectare annually, a figure that’s more than three times higher than previous estimates.“Until now, most kelp-forest evaluations were regional,” says Cristina Piñeiro-Corbeira, a marine ecologist at the University of A Coruña in Spain who was not involved in the project. “This study is a step forward in understanding kelp forests and their importance for human well-being on a global scale.”

    Source: Ref. 1

    Kelp forests are widespread in temperate and polar regions, with some 740 million people thought to live within 50 kilometres of one of these tracts of brown seaweed. They provide habitat for more than one thousand species, draw carbon dioxide from the atmosphere and help to remove nutrient pollution, such as nitrogen and phosphorus, from the ocean. “Outside of the tropics, kelp forests are really the dominant [coastal] habitat,” says study co-author Aaron Eger, a marine scientist at the University of New South Wales in Sydney, Australia. “These are the essential threads to marine ecosystems.”Despite this, few studies have attempted to quantify the economic value of kelp forests on a global scale. To address this gap, Eger and his colleagues assessed the value of common types of kelp forest by considering their contributions to fisheries, nutrient cycling and atmospheric CO2 removal. They collated kelp-distribution estimates, data from biodiversity surveys and current seafood prices from different regions.
    World leaders are waking up to the ocean’s role in a healthy planet
    The team’s estimates suggest that kelp forests provide an average harvest for fisheries of more than 900 kilograms per hectare a year, worth about $30,000. In many locations, lobsters and abalone accounted for more than one-quarter of a kelp site’s fisheries value. Pollack, giant seabass, South American morwongs and lingcod were the most valuable fish across the sites surveyed.Each hectare of kelp forest also removes an average of 657 kilograms of excess nitrogen — which flows into the ocean in waste water and agricultural runoff — from seawater, a service worth almost $74,000 per hectare per year. And together, kelp forests absorb almost five megatonnes of atmospheric CO2 each year, putting them on a par with other prominent carbon sinks, such as mangrove forests and terrestrial woodland. The economic value of this carbon removal is only $163 a year per hectare of kelp, however, owing to the low market price of carbon and its widespread presence in the ocean, says Eger. “The impacts of nitrogen are quite localized, so there is a higher demand to address the problem,” he says. “Carbon is diffuse and hard to attach to damages in any one location.”Kelp conservationPiñeiro-Corbeira says the findings could provide a push for kelp forests to be included more prominently in climate-change policies and could also encourage better ways of managing and conserving them. But she adds that because the study focuses on only three ecosystem services, it could still underestimate the value of kelp forests.The inclusion of other services — such as coastal protection, tourism and recreation — in the models is likely to further boost kelp forests’ estimated value, says Eger. The value might also increase as more areas are mapped and researchers gain a better understanding of how much kelp is in the ocean. “It has a strong potential to go up,” he says. More