The Great London:
Biodiversity

Gaps in our information about biodiversity means we are at risk of focussing our conservation efforts in the wrong places.

New research from Newcastle University, UK, University College London (UCL) and the University of Queensland, Australia, highlights the uncertainty around our global biodiversity data because of the way we record species sightings.

The study explains how a lack of information about a species in a particular location doesn't necessarily mean it's not there and that recording when we don't see something is as important as recording when we do.

Changing the way we record data

Publishing their findings in the journal Biology Letters, the team say we need to change the way we record sightings -- or a lack of them -- so we can better prioritise our conservation efforts in light of the Convention on Biological Diversity.

Dr Phil McGowan, one of the study's authors and a Senior Lecturer in Biodiversity and Conservation at Newcastle University, said: "Where there is no recent biodiversity data from an area then we might assume a species is no longer found there, but there could be a number of other possible reasons for this lack of data. It could be that its habitat is inaccessible -- either geographically or due to human activity such as ongoing conflict -- or perhaps it's simply a case that no-one has been looking for it. Unless we know where people have looked for a particular species and not found it then we can't be confident that it's not there."

Galliformes and man

To test the research, the team used the rigorously compiled database of European and Asian Galliformes -- a group of birds which includes the pheasant, grouse and quail.

"Our long-standing love of the Galliformes goes back hundreds of years which means we have records that are likely to be much better than for other groups of animals or plants," explains Dr McGowan.

"Not only have these birds been hunted for food, but their spectacular colours made them valuable as trophies and to stock the private aviaries of the wealthy. In the late 1800s and the turn of the last century, the Galliformes were prized specimens in museum and private collections and today they are still a favourite with bird watchers."

Data absent from 40% of the study area

Analysing 153,150 records dating from 1727 to 2008 and covering an area from the UK to Siberia and down to Indonesia, the team found that after 1980, there was no available data at 40% of the locations where Galliformes had previously been present.

The study suggests two possible scenarios.

Dr Elizabeth Boakes, the study's lead author and a teaching fellow at University College London, said: "We have no evidence of populations existing past 1980 in 40% of our locations. However, absence of evidence is not evidence of absence. One scenario is that populations have been lost from these areas, probably due to hunting or habitat loss. The other scenario is that the species are still locally present but that nobody has been to look for them. Our study shows that which scenario you choose to believe makes a huge difference to measures used in conservation priority-setting such as species richness and geographic range. It's important that we make the right call and that means a big shake up in the way we currently monitor biodiversity. We need to record what we don't see as well as what we do see and we need to be recording across much wider areas."

Meeting international targets

Involving 192 countries and the EU, the Convention on Biological Diversity is dedicated to promoting sustainable development.

The goals include the Strategic Plan for Biodiversity which says we must at least halve and, where feasible, bring close to zero the rate of loss of natural habitats, including forests, and halt extinction of those species we know to be under threat.

"In order to start meeting these goals we must first understand exactly which organisms are close to extinction and need prioritising in order to meet this target," explains Dr McGowan, who is Co-chair of IUCN Species Survival Commission's Policy Subcommittee and a member of its Strategic Conservation Planning Subcommittee.

"The IUCN Red List of Threatened Species is a good starting point but as our research shows, it's only as accurate as the data that's been collected. Going forward, we need to make sure we are recording when we've not seen something just as much as when we do and that's where keen and informed members of the public -- such as bird watching groups -- could really help us."

Source: Newcastle University [March 08, 2016]

Global populations of vertebrates -- mammals, birds, reptiles, amphibians, and fish -- have declined by 58 percent between 1970 and 2012, states a new report from World Wildlife Fund (WWF). Animals living in the world's lakes, rivers, and freshwater systems have experienced the most dramatic population declines, at 81 percent. Because of human activity, the report states that without immediate intervention global wildlife populations could drop two-thirds by 2020.

"This research delivers a wake-up call that for decades we've treated our planet as if it's disposable," said Carter Roberts, WWF president and CEO. "We created this problem. The good news is that we can fix it. It requires updating our approach to food, energy, transportation, and how we live our lives. We share the same planet. We rely on it for our survival. So we are all responsible for its protection."

The top threat to wildlife is habitat loss and degradation, driven primarily by increasing demand for food and energy. According to the report, global food production is the leading cause for destruction of habitats and overexploitation of wildlife. Agriculture currently occupies approximately one-third of Earth's total land area and accounts for 70 percent of all freshwater use.

Wild animals are not the only ones at risk; the report states that increased pressure threatens the natural resources that all life -- including humanity -- depend on.

The report demonstrates the need to rethink how we produce, consume, measure success and value the natural environment, and calls for an urgent system change by individuals, businesses and governments. The report also illustrates the positive momentum that is building by highlighting recent global agreements on climate change and sustainable development. In particular, the report recognizes the 2030 Agenda for Sustainable Development as an essential guide to decision-making that can ensure that the environment is valued alongside economic and social interests.

"A strong natural environment is the key to defeating poverty, improving health and developing a just and prosperous future," said Marco Lambertini, WWF director general. "We have proven that we know what it takes to build a resilient planet for future generations, we just need to act on that knowledge."

>Living Planet Report 2016: Risk and resilience in a new era is the eleventh edition of WWF's biennial flagship publication. The report tracks over 14,000 vertebrate populations of over 3,700 species from 1970 to 2012 and includes research from the Global Footprint Network and the Zoological Society of London.

Source: World Wildlife Fund [October 27, 2016]

The first annual State of the World's Plants report, which involved more than 80 scientists and took a year to produce, is a baseline assessment of current knowledge on the diversity of plants on earth, the global threats these plants currently face, as well as the policies in place and their effectiveness in dealing with threats.

"This is the first ever global assessment on the state of the world's plants. We already have a 'State of the World's ...birds, sea-turtles, forests, cities, mothers, fathers, children even antibiotics' but not plants. I find this remarkable given the importance of plants to all of our lives- from food, medicines, clothing, building materials and biofuels, to climate regulation. This report therefore provides the first step in filling this critical knowledge gap." said Professor Kathy Willis, Director of Science at the Royal Botanic Gardens, Kew at the report launch on Monday.

"But to have effect, the findings must serve to galvanise the international scientific, conservation, business and governmental communities to work together to fill the knowledge gaps we've highlighted and expand international collaboration, partnerships and frameworks for plant conservation and use," she added.

The status of plants outlined in the report is based on the most up to date knowledge from around the world as of 2016 and is divided into three sections; describing the world's plants, global threats to plants and policies and international trade.

Naming and Counting

The first section focuses on the diversity of plants on earth, noting that there are now an estimated 391,000 vascular plants known to science of which 369,000 are flowering plants -- with around 2,000 new vascular plant species described annually. Some of the most exciting were found during fieldwork while many others were detected only after they have already been preserved and filed as herbarium specimens and a few have been discovered in the glasshouses at Kew.

One of the largest carnivorous plants known (1.5m in height), a new insect-eating plant of the sundew genus called Drosera magnifica was even first discovered on Facebook. Eighteen new species of the genus Ipomoea in the morning glory family, were described from Bolivia last year, among them a close relative of the sweet potato, Ipomoea batatas, offering exciting options for the future of this crop.

"But there are still large parts of the world where very little is known about plants. Identification of these important plant areas is now critical." said Steve Bachman, strategic output leader for the State of the World´s Plants report, RBG Kew. "Similarly, we still only know a fraction of the genetic diversity of plants and whole-genome sequences are currently available for just 139 species of vascular plants. Activity in this area needs to speed up," he added.

Useful plants

In terms of the uses of plants, the report collates data from multiple data sources to reveal that at least 31,000 plant species have a documented use for medicines, food, materials and so on. The majority (17,810 plants) of those now documented have a medicinal use.

Aside from the plants that are currently in use, the report looks at where collection efforts should focus to include plants that will be useful in the future. One set of plant species of critical importance to global food security are the wild relatives of crops, a pool of genetic variation that can help to drive the improvement of our crops into the future. A recent inventory has revealed that there are currently 3,546 prioritised global plant taxa identified as 'crop wild relatives' and Kew's Millennium Seed Bank (MSB) includes 688 crop wild relatives among its over 78,000 accessions, but there are still substantial gaps.

Research in this sector has found that the traits that have been bred into crops over years of domestication are not necessarily the same ones that will provide the greatest climate resilience. Given that many of the wild populations of these species are under considerable threat due to land-use and climate change there is an urgent need to conserve those species not adequately represented in current collections. More seed banking will help preserve a wider range of alternatives to the crops on which the world over relies today (report pages 20-23).

Climate change

The report also explores current knowledge around the impact of climate change on plants and finds that while there is a good understanding for some regions of the world, there are still large areas for which little or no research exists. In those areas where good data is available, clear impacts are visible, including changes in flowering times, turnover in plant communities and movement of species with changing climates.

Research referenced in the report shows that all but one of the world's biomes have experienced more than 10% change in land-cover type in the past decade due to the combined impacts of land-use and climate change.

This research, led by teams at the International Center for Tropical Agriculture in Colombia is also the first of its kind to allocate timeframes for the changes in policy and practice needed to maintain food production and security in Africa. It identifies that up to 30% of areas growing maize and bananas, and up to 60% of those growing beans, are likely to become unviable by the end of the century. But it also highlights some crops like cassava and yams that are showing much greater resilience and could worth focusing on in years to come (report pages 36-39).

"Having proof that root crops like cassava and yams are among the climate-smart crops of the future for sub Saharan Africa is vital for informing policy and planning today," added Professor Willis.

Further research into building a climate resilient coffee economy in Ethiopia published in this report highlights how coffee production is likely to be drastically affected by climate change, but claims that this could be offset if there were interventions now to develop new areas for coffee plantations, which may even lead to gains in coffee production.

Important plant areas

1,771 important plant areas have been identified globally but very few currently have conservation protection. In the UK alone, 165 such sites have been recognised, including parts of the Atlantic woodlands and the Celtic rainforests which are considered to be globally important. These sites include the Lizard in Cornwall, the Brecklands in East Anglia and parts of the west coast of Scotland. Important plant areas have also been identified in several of the UK Overseas Territories including the Falkland Islands and plans are underway to extend this programme to the Caribbean UK Overseas Territories.

Invasive species

A large movement of invasive alien plant species is also occurring. Nearly 5000 plant species are now documented as invasive in global surveys. These plants are causing large declines in native plants, damaging natural ecosystems, transforming land-cover and often causing huge economic losses. In the UK, this includes the highly invasive Japanese knotweed (Reynoutria japonica), introduced as an ornamental plant to Britain in the mid-19th century and costing Great Britain more than £165 million annually to control (report pages 48-51).

The report calls for closer collaboration between institutions and organisations working with invasive species to enable the establishment of a single global list that documents taxonomy, threat, distribution, control and other relevant information. Stricter enforcement of legislation and increased implementation of quarantine procedures would minimise the risk of further.

Plant diseases

There are many emerging threats also occurring with plant diseases, and research effort into these diseases is skewed towards countries with a wealthier research infrastructure.

Threats and extinction

Best estimates lead us to believe that 21% of the world's plants are currently threatened with extinction and ongoing monitoring will allow us to determine whether the trend is of plants slipping closer towards extinction or becoming less threatened.

Plants and policies

Although trade in plants supports livelihoods worldwide, illegal or unsustainable trade is causing additional pressure on wild biodiversity and strict enforcement of international legislation is crucial. Adoption and implementation of policies such as CITES (Convention on International Trade in Endangered Species) have had demonstrable benefits and there is cause for optimism that the Nagoya Protocol will enhance the effectiveness with which countries conserve and utilise their biodiversity.

One of the main plant groups that are still widely traded are orchids, a fact confirmed by data from the UK borderforce. Of all plants plants seized at Heathrow airport in 2015 over 42% were wild orchids.

"This is the most significant horizon-scanning document to be released by Kew in recent decades and I hope as many people as possible will access the findings," said Richard Deverell, Director of the Royal Botanic Gardens, Kew.

"Plants represent one of the most important constituents of biodiversity, the foundation of most of the world's ecosystems and hold the potential to tackle many of the world's present and future challenges. We are uniquely placed to unlock their importance and are proud to have both the catalogue of over 250 years of collections and active scientific field work globally that allows us to interpret the data so it will have multiple uses for generations to come," he added.

Read the report >here.

Source: Royal Botanic Gardens Kew [May 11, 2016]

Species across the world are rapidly going extinct due to human activities, but humans are also causing rapid evolution and the emergence of new species. A new study published today summarises the causes of humanmade speciation, and discusses why newly evolved species cannot simply replace extinct wild species. The study was led by the Center for Macroecology, Evolution and Climate at the University of Copenhagen.

A growing number of examples show that humans not only contribute to the extinction of species but also drive evolution, and in some cases the emergence of entirely new species. This can take place through mechanisms such as accidental introductions, domestication of animals and crops, unnatural selection due to hunting, or the emergence of novel ecosystems such as the urban environment.

Although tempting to conclude that human activities thus benefit as well as deplete global biodiversity, the authors stress that extinct wild species cannot simply be replaced with newly evolved ones, and that nature conservation remains just as urgent.

"The prospect of 'artificially' gaining novel species through human activities is unlikely to elicit the feeling that it can offset losses of 'natural' species. Indeed, many people might find the prospect of an artificially biodiverse world just as daunting as an artificially impoverished one" says lead author and Postdoc Joseph Bull from the Center for Macroecology, Evolution and Climate at the University of Copenhagen.

The study which was carried out in collaboration with the University of Queensland was published in >Proceedings of Royal Society B. It highlights numerous examples of how human activities influence species' evolution. For instance: as the common house mosquito adapted to the environment of the underground railway system in London, it established a subterranean population. Now named the 'London Underground mosquito', it can no longer interbreed with its above ground counterpart and is effectively thought to be a new species.

"We also see examples of domestication resulting in new species. According to a recent study, at least six of the world's 40 most important agricultural crops are considered entirely new" explains Joseph Bull.

Furthermore, unnatural selection due to hunting can lead to new traits emerging in animals, which can eventually lead to new species, and deliberate or accidental relocation of species can lead to hybridization with other species. Due to the latter, more new plant species in Europe have appeared than are documented to have gone extinct over the last three centuries.

Although it is not possible to quantify exactly how many speciation events have been caused through human activities, the impact is potentially considerable, the study states.

"In this context, 'number of species' becomes a deeply unsatisfactory measure of conservation trends, because it does not reflect many important aspects of biodiversity. Achieving a neutral net outcome for species numbers cannot be considered acceptable if weighing wild fauna against relatively homogenous domesticated species. However, considering speciation alongside extinction may well prove important in developing a better understanding of our impact upon global biodiversity. We call for a discussion about what we, as a society, actually want to conserve about nature" says Associate Professor Martine Maron from the University of Queensland.

Researchers do agree that current extinction rates may soon lead to a 6th period of mass extinction. Since the last Ice Age, 11.500 years ago, it is estimated that 255 mammals and 523 bird species has gone extinct, often due to human activity. In the same period, humans have relocated almost 900 known species and domesticated more than 470 animals and close to 270 plant species.

Source: Faculty of Science - University of Copenhagen [June 28, 2016]

Even if people completely stopped converting tropical forests into farmland, the impacts of tropical deforestation would continue to be felt for many years to come. That's the conclusion of researchers reporting in the Cell Press journal >Current Biology who have used historical rates and patterns of tropical deforestation around the globe to estimate the resulting carbon emissions and species losses over time.

The findings highlight the importance of accounting for the time lag between deforestation and its environmental impacts in meeting conservation goals.

"We show that even if deforestation had completely halted in 2010, time lags ensured there would still be a carbon emissions debt equivalent to five to ten years of global deforestation and an extinction debt of more than 140 bird, mammal, and amphibian forest-specific species, which, if paid, would increase the number of 20th century extinctions in these groups by 120 percent," says Isabel Rosa (@isamdr86) of the Imperial College of London. "Given the magnitude of these debts, commitments to reduce emissions and biodiversity loss are unlikely to be realized without specific actions that directly address this damaging environmental legacy."

It takes time after trees are cut down before the wood and other plant matter left at the site fully decay, releasing carbon into the atmosphere. The resulting loss of habitat also leads to species losses, but those effects also tend to occur gradually.

In the new study, Rosa and her colleagues used a spatially explicit land cover change model to reconstruct the annual rates and spatial patterns of tropical deforestation from 1950 to 2009 in the Amazon, Congo Basin, and Southeast Asia. Using those patterns, they estimated the resulting gross vegetation carbon emissions and species losses.

The findings show that current emissions and species extinctions are mostly tied to past actions. As a result, the researchers explain, changes in annual deforestation rates will initially have a smaller than expected effect on annual carbon emissions. For example, they write, a 30 percent reduction in deforestation rates as seen in the Brazilian Amazon between 2005 and 2010 only cut carbon emissions over the same time period by 10 percent.

The researchers also show that modern deforestation has left us with an estimated extinction debt of 144 vertebrate species found only in tropical forests. That's 20 percent more than the number of extinctions known to have occurred in vertebrate groups in more than a century.

"I expected an increase in both carbon emissions and species extinctions debts, but the magnitude of these debts was surprising," Rosa says.

The findings show that reaching national and global emissions targets will be even more challenging than anticipated.

"We need to do more if we want to avoid paying these debts, thus preventing further loss of species and carbon emissions," Rosa said. "We need to preserve existing habitats, but also restore forests that have been degraded. Allowing the forest to regrow on areas that have been deforested helps by creating 'new' suitable areas for species to survive in while allowing some of this excess carbon to be stored back in the new trees rather than emitted into the atmosphere."

Rosa says she'll continue to pursue the use of their models to support better policy and management decisions.

Source: Cell Press [July 28, 2016]

Typically ignored, the millions of microorganisms that we tread upon daily play a major role in the decomposition of soil matter -- one that is of far greater significance than that of the whales and pandas that tend to steal our attention. A group of researchers has just shown that there is an enormous diversity among a group of bacteria-eating microorganisms known as Cercozoa. In four small soil samples, each consisting of a half gram of soil, they discovered more than 1000 different species per sample. The research suggests that a drier climate in the years ahead due to climate change will contribute to a shift in the number of soil microorganisms, and thus, a shift in the decomposition of soil matter, with as of yet to be known consequences.

A team led by researchers from the Section for Terrestrial Ecology (Flemming Ekelund, Christopher B. Harder and Regin Ronn, at the Department of Biology, University of Copenhagen) has just published an article in the >ISME Journal. The group's studies show that there is enormous species diversity among an oft-overlooked group of organisms known as Cercozoa. In four small soil samples, each consisting of just a half gram of soil, the researchers discovered more than 1000 different species per sample. The research was conducted in collaboration with Section for Microbiology staff (Department of Biology, University of Copenhagen) and the eminent British scientist, David Bass (Natural History Museum, London), and is supported by national research councils and the Carlsberg Foundation.

Associate Professor Flemming Ekelund of the Department of Biology explains, "Cercozoa are small bacteria-eating microorganisms that play a prominent role in soil ecology. Serious interest in these organisms began about 25-30 years ago, as people began to wonder what caused bacteria to disappear from soil. As interest took root, the number of known species increased sharply."

The name Cercozoa is derived from the Greek word, kerkos (tail), as some of the species within the group have a tail like end, and zoon (animal), as these organisms were previously thought to be a type of animal.

A single teaspoon of soil (a couple of grams) contains millions of microorganisms, so it is hopeless to create a species list by studying organisms one by one. Furthermore, many of these organisms belong to species unknown to science.

"We took small soil samples (½-1 gram), from which we analysed DNA strands (genetic material) from hundreds of thousands of organisms" (deep sequencing), explains Christoffer Bugge Harder. "However, it's difficult to catalogue and systematise this huge amount of data. To do so, we used the Section of Microbiology's capacity to deploy specialized statistics tools. Our British colleague, David Bass, contributed precise DNA references for the species in the group that have already been thoroughly catalogued. For now, this remains at just under 1000."

The studies were conducted in correlation with a climate experiment (Climate) that investigates the consequences of climate change in Denmark, as many climate researchers expect it to present itself, by 2075. Besides being able to report an enormous number of species in these samples, the research also demonstrated that a more arid climate, as expected in 2075, will probably lend to a shift in the occurrence of microorganism species; particularly within a group referred to as testate amoebae.

Researchers already know that climate change will result in significant shifts in plant and animal frequency. But it can also lead to changed frequencies among microorganisms, which means that climate change could have an impact on the ecological processes at work in soil. More studies are needed for researchers to specify the impact of an offset and the amount of microorganisms found in soil as a result of global warming.

Source: Faculty of Science - University of Copenhagen [June 21, 2016]

Scientists from Wageningen UR and other institutes are proposing a new research model - the turnover model - as a way of answering the question why there are always so many plant species in tropical rainforests.

In their publication in New Phytologist magazine, the Dutch, British and Swiss scientists show that major evolutionary changes, such as the origin of large groups of species, occur with a reasonably constant frequency while the origin of new species is an explosive process.

Various models

Darwin’s contemporary Alfred Russel Wallace already argued that the Tropics are, in essence, a museum of biodiversity. As tropical climates are stable, Wallace suggested that species would gradually increase in number over longer time periods, the so-called museum model. More recently, however, it was suggested that the Pleistocene ice ages, and the impact thereof on the climate in the Tropics, resulted in recent explosions of speciation, the so-called cradle model.

Both models are supported by previous research into patterns of diversification in tropical plants. This research is performed by means of reconstructed ‘phylogenetic trees’; genealogical trees that show the interrelated  descent of plant species. Where analyses of plant families focused on studying as many evolutionary lines as possible from the family, diversity was shown to increase gradually. For instance, the development of diversity in important tropical plant groups such as palm trees, the leguminous family and the soursop family, appear to follow the museum model. However, within these large plant families there are also plant genera that seem to follow the cradle model: so-called radiations in which many different species developed recently and over a short period of time.

Equatiing seems impossible

Equating these two models seems an impossible task. How can a large plant family that presents an explosive increase in the number of species diversify as an entire family following the museum model? The answer lies in analysing more species per family, and better modelling speciation over long periods in evolution via the computer.

Mahogany trees

Scientists from Wageningen UR, Kew (London) and Zürich compiled the largest amount of data so far for the Meliaceae , or mahogany family. This family mainly grows in the Tropics, and is known for valuable wood such as mahogany and Spanish cedar. Parts of the nuclear and chloroplast genome of approximately 35% of the species were sequenced; a technology in which all the building blocks of the DNA are mapped.

The analysis of evolutionary diversification showed that the diversity of larger groups, such as plant genera and families, does develop in accordance with the museum model, i.e., with a certain constant frequency in the origin of new branches. The scientists showed that, in addition to this ‘museum fundament’, the origin of individual species is an explosive process which occurs in accordance with the cradle model.

‘Young’ species

The research shows that the mahogany family developed approximately 68 million years ago. The circa 200 mahogany species that grow in the South American rainforests are largely the result of two explosions in speciation (radiations) that occurred independently in two evolutionary lines in the late Miocene epoch, which was less than 10 million years ago.

An interesting aspect of this explosive origin of large numbers of species within the mahogany family is that it involves two different groups within the family which independently evolved the same ecological adaptations, such as plant height and an adaptation of seeds to the same animal species that distribute them. In addition, the two groups show a similar speed of speciation. These abrupt increases in speciation speed occurred after the mahogany family had left its original habitat (tropical dry forests and seasonal forests) and colonised the rainforests, where they were faced with different climate conditions.

New model for evolution

The results of the study show that most mahogany species in the Tropics are relatively recent. It can be assumed that this also applies to other families. The authors propose a new model, the turnover model, in which the number of evolutionary lines increases with a more or less constant speed, while speciation occurs separately and in a more explosive way.

Source: Wageningen University [June 19, 2015]

Levels of global biodiversity loss may negatively impact on ecosystem function and the sustainability of human societies, according to UCL-led research.

"This is the first time we've quantified the effect of habitat loss on biodiversity globally in such detail and we've found that across most of the world biodiversity loss is no longer within the safe limit suggested by ecologists" explained lead researcher, Dr Tim Newbold from UCL and previously at UNEP-WCMC.

"We know biodiversity loss affects ecosystem function but how it does this is not entirely clear. What we do know is that in many parts of the world, we are approaching a situation where human intervention might be needed to sustain ecosystem function."

The team found that grasslands, savannas and shrublands were most affected by biodiversity loss, followed closely by many of the world's forests and woodlands. They say the ability of biodiversity in these areas to support key ecosystem functions such as growth of living organisms and nutrient cycling has become increasingly uncertain.

The study, published in >Science, led by researchers from UCL, the Natural History Museum and UNEP-WCMC, found that levels of biodiversity loss are so high that if left unchecked, they could undermine efforts towards long-term sustainable development.

For 58.1% of the world's land surface, which is home to 71.4% of the global population, the level of biodiversity loss is substantial enough to question the ability of ecosystems to support human societies. The loss is due to changes in land use and puts levels of biodiversity beyond the 'safe limit' recently proposed by the planetary boundaries -- an international framework that defines a safe operating space for humanity.

"It's worrying that land use has already pushed biodiversity below the level proposed as a safe limit," said Professor Andy Purvis of the Natural History Museum, London, who also worked on the study. "Decision-makers worry a lot about economic recessions, but an ecological recession could have even worse consequences -- and the biodiversity damage we've had means we're at risk of that happening. Until and unless we can bring biodiversity back up, we're playing ecological roulette."

The team used data from hundreds of scientists across the globe to analyse 2.38 million records for 39,123 species at 18,659 sites where are captured in the database of the PREDICTS project. The analyses were then applied to estimate how biodiversity in every square kilometre land has changed since before humans modified the habitat.

They found that biodiversity hotspots -- those that have seen habitat loss in the past but have a lot of species only found in that area -- are threatened, showing high levels of biodiversity decline. Other high biodiversity areas, such as Amazonia, which have seen no land use change have higher levels of biodiversity and more scope for proactive conservation.

"The greatest changes have happened in those places where most people live, which might affect physical and psychological wellbeing. To address this, we would have to preserve the remaining areas of natural vegetation and restore human-used lands," added Dr Newbold.

The team hope the results will be used to inform conservation policy, nationally and internationally, and to facilitate this, have made the maps from this paper and all of the underlying data publicly available.

Source: University College London - UCL [July 14, 2016]

An intriguing study involving walking stick insects led by the University of Sheffield in England and the University of Colorado Boulder shows how natural selection, the engine of evolution, can also impede the formation of new species.

The team studied a plant-eating stick insect species from California called Timema cristinae known for its cryptic camouflage that allows it to hide from hungry birds, said CU-Boulder Assistant Professor Samuel Flaxman. T. cristinae comes in several different types -- one is green and blends in with the broad green leaves of a particular shrub species, while a second green variant sports a white, vertical stripe that helps disguise it on a different species of shrub with narrow, needle-like leaves.

While Darwinian natural selection has begun pushing the two green forms of walking sticks down separate paths that could lead to the formation of two new species, the team found that a third melanistic, or brown variation of T. cristinae appears to be thwarting the process, said Flaxman. The brown version is known to successfully camouflage itself among the stems of both shrub species inhabited by its green brethren, he said.

Using field investigations, laboratory genetics, modern genome sequencing and computer simulations, the team concluded the brown version of T. cristinae is shuttling enough genes between the green stick insects living on different shrubs to prevent strong divergent adaptation and speciation. The brown variant of the walking stick species also is favored by natural selection because it has a slight advantage in mate selection and a stronger resistance to fungal infections than its green counterparts.

"This is one of the best demonstrations we know of regarding the counteractive effects of natural selection on speciation," said Flaxman of CU-Boulder's Department of Ecology and Evolutionary Biology, second author on the new study. "We show how the brown population essentially carries genes back and forth between the green populations, acting as a genetic bridge that causes a slowdown in divergence."

A paper on the subject appeared in a recent issue of the journal Current Biology. Other study co-authors were from the University of Sheffield, Royal Holloway University of London, Utah State University, the University of Nevada, Reno and the University of Lausanne in Switzerland.

"This movement of genes between environments slows down the genetic divergence of these stick insect populations, impeding the formation of new species," said Aaron Comeault, a former CU-Boulder graduate student and lead study author who conducted the research while at the University of Sheffield. Comeault is now a postdoctoral researcher at the University of North Carolina at Chapel Hill.

The new results underscore how combining natural history and cutting-edge genetics can help researchers gain a better understanding of how evolution operates in nature. It also shows how natural selection can sometimes promote but other times hinder the formation of new species, according to the research team.

Walking sticks are one of nature's oddest insect groups and range in size from the half-inch long T. cristinae to species in Borneo and Vietnam that are more than a foot long. Most walking sticks rely on plant mimicry to protect them from predators.

Source: University of Colorado at Boulder [August 06, 2015]

Planet Earth may contain millions fewer species than previously thought and estimates are converging, according to research led by Griffith University.

In a paper published by the journal Proceedings of the National Academy of Sciences (PNAS), Professor Nigel Stork of Griffith’s Environmental Futures Research Institute reveals findings that narrow global species estimates for beetles, insects and terrestrial arthropods.

The research features an entirely new method of species calculation derived from samples of beetles from the comprehensive collection at London’s Natural History Museum.

“It has been said we don’t know to the nearest order of magnitude just how many species with which we share the planet. Some say it could be as low as two million; others suggest up to 100 million,” says Professor Stork.

“By narrowing down how many species exist within the largest group – the insects and other arthropods — we are now in a position to try to improve estimates for all species, including plants, fungi and vertebrates.

“Understanding how many species there are and how many there might have been is critical to understanding how much humans have impacted biodiversity and whether we are at the start of, or even in the middle of, an extinction crisis.”

About 25 per cent of all species that have been described are beetles. However, when combined with other insects the figure climbs to more than half of all described and named species on Earth.

New method of estimation

For this reason, Professor Stork and his colleagues focused on asking how many species of beetles and insects there actually are, in the process applying a new method of estimation arising from a tendency for larger species of British beetles to be described before smaller species.

“Because of the global spread of major beetle lineages, we made the assumption that the size distribution of the very well known British beetles might be similar to that of beetles worldwide,” says Professor Stork.

“So, if we could get a measurement of the body sizes of the beetles from around the world, we might be able to plot where these fitted in time against the British beetles.”

After measuring a sample from the Natural History Museum’s worldwide collection of beetles, Professor Stork compared the mean body size with the changing body sizes of British beetles to reveal that roughly 10 per cent of the world’s beetles have been named and described.

This figure sheds intriguing light on previous estimates of global species richness.

In the 1980s, there were just two methods of estimating species. In the case of beetles, these gave a mean of 17.5 million species and a range of 4.9-40.7 million. For all terrestrial arthropods, the mean was 36.8 million and a range of 7-80 million.

However, the new research shows that four current methods of estimation – dating from 2001 onwards — suggest much lower figures, namely a mean of 1.5 million for beetles (range 0.9-2.1 million) and 6.8 million for terrestrial arthropods (range 5.9-7.8 million).

“While all methods of estimating global species richness make assumptions, what is important here is that four largely unrelated methods, including the new body size method, produce similar estimates,” says Professor Stork.

“With estimates converging in this way, this suggests we are closer to finding the real numbers than before.

“It also means we can improve regional species richness. For Australian fauna and flora, for example, we should be able to make better estimates of just how many species there are and which groups need more taxonomic attention.”

Diversity of life

Professor Ian Owens, Director of Science at the Natural History Museum, says this research is a great example of how natural history collections support high-impact scientific research that addresses challenging questions such as the diversity of life.

“The Natural History Museum’s beetle collection is one of the most important and extensive in the world, so I’m delighted that it has played such a fundamental part in this study that uses a novel approach to estimating how many species of beetle exist,” says Professor Owens.

“The results are very exciting and are a big step forward to establishing a baseline for biodiversity.”

Meanwhile, co-author of the PNAS paper — the University of Melbourne’s Associate Professor Andrew Hamilton – says efforts to come up with new or modified ways of resolving how many species exist are beginning to prove fruitful.

Professor Stork says the research has important conservation ramifications.

“Success in planning for conservation and adopting remedial management actions can only be achieved if we know what species there are, how many need protection and where,” he says. “Otherwise, we have no baseline against which to measure our successes.

“Furthermore, it is arguably not only the final number of species that is important, but what we discover about biodiversity in the process.

“The degree to which we can or cannot accurately estimate the number of species or the scale of organismal diversity on Earth is a measure of our ignorance in understanding the ecological and evolutionary forces that create and maintain the biodiversity on our planet.

“Attacking this question also drives scientific enquiry and is of public interest. Society expects science to know what species exist on Earth, as it expects science to discover nuclear particles and molecules.

“These discoveries open doors to more utilitarian interests.”

Source: Griffith University [June 02, 2015]