biodiversity – Page 2 – Cabot Institute for the Environment blog

Can we share our planet with wildlife?

Posted on December 3, 2013April 19, 2023 by janet.crompton

Monty Don, Shared Planet, BBC Radio 4

Our environment provides us with amazing resources. As well as the obvious things like food, wood and water, it provides services like pollination, climate regulation and waste decomposition. However we are putting our delicate ecosystem out of balance by destroying habitats, over-exploiting animals and plants, polluting the air and rivers and causing climate change at a rate that hasn’t been seen since the extinction of the dinosaurs.

Last week the Cabot Institute hosted a debate for BBC Radio 4’s Shared Planet programme, asking whether we can better manage resources to live within our planet’s means, or whether there are simply too many of us to co-exist with wildlife.

Fred Pearce

Fred Pearce, science and environment writer, was one of the panellists. He argued that nature is dynamic and with better management of the resources we already have, we can reduce our consumption and live within the planet’s ability to recover.

Kieran Suckling

Kieran Suckling, Executive Director of the Center for Biological Diversity in Arizona, had a more pessimistic view. He believes that the human population is going to rise to a level far greater than the planet can sustain, and if we do not control our population level we will not be able to prevent ecological destruction on a global scale.

Global Extinctions
We are losing biodiversiy at an unprecedented rate. The 2012 Living Planet Report by the WWF estimated that we lost 28% of global biodiversity between 1970 and 2008. Fred took a more holistic view, that while of course we have a huge effect on the natural environment and should try and minimise damage, nature is resilient and will fight back. Foxes invading urban environments, weeds in a garden and rainforests’ ability to regrow in 15 years show that nature isn’t as fragile as we think. Animals and plants that depend on very specific environments are likely to be more at risk than more generalist species however and Kieran argued that we have an “ethical responsibility” to keep all remaining species alive.

How can we feed everyone sustainably?

Riau deforestation for oil palm plantation
Image by Aidenvironment, 2006

Every day around 870 million people do not get enough food. How can we hope to feed a predicted 9.6 billion people by 2050 whilst growing food more sustainably? Suckling described how industrial agricultural practices are highly damaging to the environment, for example pesticides which probably have a severe impact on bees. He argued that organic farms are unlikely to provide enough food for the growing population.

Globally, 19% of forests are protected, but rising demand for fuel and agricultural land means we are losing 80,000 acres of rainforest each day and probably 50,000 species of animals and plants every year. The good news, Pearce said, is that that we already produce enough food to feed the predicted 9 billion people, although we waste enough for 3 billion. Recent reports showed that 15 million tonnes of food is thrown away in the UK each year. He argued that we should be encouraged by the notion that “we can reduce our footprint just by being more economical”. The real challenge is how to make people understand that food waste is both socially and environmentally unethical.

Education
Fred mentioned that overall women are having half the number of children that their mothers had. This is in part thanks to medical advances, meaning that most children will survive to adulthood so fewer births are needed to build a family. It is also an education success story. Both the panellists agreed that “when education and freedom levels rise, the population starts to grow more slowly”. Opportunities for women to educate themselves will be critical in changing gender stereotypes and reducing the numbers of unwanted pregnancies. This is good news for human rights as well as managing our growing population’s impact on the environment.

Economics
The environment provides $33 trillion of benefit to us every year by pollinating crops, purifying water, cycling nutrients and keeping our climate stable. It would cost an estimated $76 billion annually to protect the environment, which is only about 20% of the money spent on soft drinks each year. Fred believes that putting a true price on economic resources and the cost of carbon emissions means that simple economics could solve the problem of environmental degradation by showing businesses that conservation is the less costly option. Kieran disagreed, arguing that both environmental and social problems stem from a capitalist consumer society. As the WWF Living Planet Report stated, “in too many cases, the over-exploitation of resources and damage or destruction of ecosystems are highly profitable for a few stakeholders in the short term”. Businesses and politicians work on too short a time scale to care about the long-term effects of environmental degradation.

So are there too many people for wildlife to thrive?
The debate ventured into the ethical question of whether animals and the environment should have the same right to live as humans. Does sustainable living have to be an “us versus them” question? Fred took a humanist view, but argued that we as a species need the services that nature provides. Kieran argued that we must not simply steal the most resources we can get away with, but live sustainably with other species.

Before the debate I believed that there are too many people on the planet for wildlife to flourish and at the end I would probably say I still felt the same way, however Fred managed to instil a bigger sense of hope in me. If governments really do get their acts together and we as a global population get our wasteful consumerism under control, we can turn the tides and make this a better world for both people and the wildlife we share it with.

If you would like to listen to the Shared Planet programme, it will be aired on BBC Radio 4 on Tuesday 24 December 2013 at 11 am.

This blog is written by Sarah Jose, Biological Sciences, University of Bristol

You can follow Sarah on Twitter @JoseSci

Sarah Jose

Is ash dieback under control?

Posted on September 23, 2013April 20, 2023 by janet.crompton

Image by FERA

European ash tree is an important component of British woodlands. It has been stayed popular and recommended for planting due to its economic and aesthetic value, also the fact that its resistance towards grey squirrels. In UK, it has been estimated that among all the 141000ha big woodlands (>0.5ha), 5.4% of their composition is ash trees. However, since its first discovery in Poland in 1992, the ash dieback disease, caused by fungus Chalara fraxinea, has spread over the European continent and devastated ash populations in certain areas. On 19.Sep, Rob Spence for Forestry Commission came to Bristol to talk about thecurrent stage of ash dieback control in England.

Chalara fraxinea is the asexual stage of Hymenoscyphus pseudoalbidus, and also the infectious stage. Ascospores are produced from fruiting bodies on the dead branches in the litter, and can be transmitted by wind to more than 10km. Ascospores are not durable, thus its infection window is limited to summer months. The spores tend to attack the young trees due to their lower resistance to the disease, cause crown necrosis and eventually death. In mature plants, the effect of the disease is less severe. However, the disease can seriously compromise the condition of mature trees, and make them succumb to other diseases.

Source: BBC website

Current distribution of the disease in England is largely constrained in tree nurseries, except for East Anglia, where a number of cases have been reported in the wild. The prevalence of the disease in the nurseries all over the country is thought to be due to the fact that seeds are germinated outside of UK, and then saplings and young trees are imported back into UK from the continent, which may already be infected. However, the large outbreak in East Anglia is more likely attributed to extreme weather conditions which bring spores from the continent.

The control effort in southwest is focusing on confining the disease. Unlike East Anglia, the cases of ash dieback in wild are still rare. The Forestry Commission has been conducting aerial surveys to spot early infections, also, two smartphone apps, Tree Alert and OPAL can be used to take photos of suspected infected trees and send to the experts for identification. As the staff of the Forestry Commission is very limited, it becomes very unrealistic for them to come to field for most cases.

It is also worth noting that around 1-2% of the natural population is resistant against the disease. Researches are going on in The Sainsbury’s Lab and John Innes Centre in Norwich, as well as some European institutes trying to identify the resistant genes and possible approaches to deter the spread of the fungus through biological approaches. On country level, a ban has been placed on ash import from outside of the country and transfer of living ash tissues within the country, though the timber transport are still allowed as they are regarded as low risk.

In my point of view, ash dieback is well controlled at this stage. Despite the eventual widespread is inevitable, but this kind of selection bottlenecks has happened widely in nature since the evolution starts. Although there is no reason to reduce our effort in protecting ash trees, as long as we keep the genetic diversity with the susceptible populations while introducing and expanding the resistant traits within the population, the disease will be controlled in macro-scale.

This blog is written by Dan Lan, Biological Sciences, University of Bristol

Neonicotinoids: Are they killing our bees?

Posted on September 11, 2013April 20, 2023 by janet.crompton

The UK government has announced that whilst it accepts the European Union ban on neonicotinoid pesticides, it does not believe that there is enough scientific evidence to support this action.

In April, the EU banned the use of neonicotinoid pesticides for two years starting in December because of concerns over their effect on bees. The use of these pesticides will not be allowed on flowering crops that attract bees or by the general public, however winter crops may still be treated. Fifteen countries voted for this ban, with eight voting against it (including the UK and Germany) and four countries abstaining.

Neonicotinoids were originally thought to have less of an impact on the environment and human health than other leading pesticides. They are systemic insecticides, which means they are transported throughout the plant in the vascular system making all tissues toxic to herbivorous insects looking for an easy meal. The most common application in the UK is to treat seeds before they are sown to ensure that even tiny seedlings are protected against pests.

Image by Kath Baldock

The major concern over neonicotinoids is whether nectar and pollen contains levels of pesticide is high enough to cause problems for bees. It has already been shown that they do not contain a lethal dose, however this is not the full story. Bees live in complex social colonies and work together to ensure that there is enough food for developing larvae and the queen. Since neonicotinoids were introduced in the early 1990s bee populations have been in decline and there is a growing feeling of unease that the two may be connected. Scientific research has provided evidence both for and against a possible link leaving governments, farmers, chemical companies environmentalists and beekeepers in an endless debate about whether or not a ban would save our bees.

Several studies on bees have shown that sublethal levels of neonicotinoids disrupt bee behaviour and memory. These chemicals target nicotinic acetylcholine receptors, one of the major ways that signals are sent through the insect central nervous system. Scientists at Newcastle University recently showed that bees exposed to neonicotinoids were less able to form long-term memories associating a smell with a reward, an important behaviour when foraging for pollen and nectar in the wild.

Researchers at the University of Stirling fed bumble bee colonies on pollen and sugar water laced with neonicotinoids for two weeks to simulate field-like exposure to flowering oil seed rape. When the colonies were placed into the field, those that had been fed the pesticides grew more slowly and produced 85% less queens compared with those fed on untreated pollen and nectar. The production of new queens is vital for bee survival because they start new colonies the next year. Studies in other bee species have found that only the largest colonies produce queens, so if neonicotinoids have even a small effect on colony size it may have a devastating effect on queen production.

So why does the government argue that there is not enough scientific evidence to support a ban on neonicotinoids?

Image by Kath Baldock

In 2012, the Food and Environment Research Agency set up a field trial using bumble bee colonies placed on sites growing either neonicotinoid-treated oil seed rape or untreated seeds. They found no significant difference between the amount of queens produced on each site, although the colonies near neonicotinoid-treated crops grew more slowly. The study also found that the levels of pesticide present in the crops was much lower than previously reported.

I personally think that both laboratory and field studies bring important information to the debate, however neither has the full answer. Whilst more realistic, the government’s field trial suffered from a lack of replication, variation in flowering times and various alternative food sources available to bees. Only 35% of pollen collected by the bees was from the oil seed rape plants, so where oil seed rape comprises the majority of flowering plants available to bees the effect on neonicotinoids may be more pronounced. The laboratory research can control more variables to establish a more clear picture, however the bees in these studies were often given only neonicotinoid-treated pollen and nectar to eat, which clearly is not the case in a rural landscape. Flies and beetles have been shown to avoid neonicotinoids, which could mean that bees would find alternative food sources where possible. This would have a major impact on crop pollination.

We desperately need well-designed field studies looking at the effect of neonicotinoids on bees and the environment in general. Despite an EU moratorium on growing neonicotinoid treated crops, an allowance should be made for scientists to set up controlled field trials to study the effect of these pesticides on bees during the two year ban. It could be our only chance to determine the danger these chemicals pose to vital pollinators and the wider environment.

This blog is written by Sarah Jose, Biological Sciences, University of Bristol

Sarah Jose

Sustainable landscapes for the future

Posted on July 23, 2013April 20, 2023 by janet.crompton

On the 18th of July, the Cabot Institute at the University of Bristol hosted a one day conference for academics, landscape designers, industrial partners and policy makers to discuss how to create sustainable urban landscapes for the future. The event was organised to promote the exchange of ideas and to combine expertise from all stages of the process to determine how to create spaces that would maximise biodiversity and environmental benefits whilst remaining somewhere that people love to use.

City Academy Meadow, Bristol

A common theme throughout the conference was whether green spaces in cities can be designed to accommodate the needs of both local wildlife and people. Professor Nigel Dunnett from the University of Sheffield was one of the principle designers of the Olympic Park landscape, where he created a stunning biodiverse pictorial meadow with a long flowering season. His presentation highlighted the importance of creating a landscape that wildlife will benefit from, but critically that people will use and love. Professor Dunnett argued that we take more joy from seeing a beautiful expanse of flowers than a lawn monoculture and that “beauty in biodiversity is about people in ecology”. Landscape architect Kym Jones echoed this, describing landscapes that people don’t want to use as “socially unsustainable”, no matter how many environmentally-friendly boxes they tick.

Professor Dunnett’s urban meadows are controversial because he often uses non-native plant species in his design to increase the flowering period. Professor Jane Memmott of the University of Bristol Urban Pollinators research group presented data collected at nature reserves, farms and urban green spaces around Bristol that suggest most pollinators don’t really mind whether native or non-indigenous plant species are used, as long as they produce a lot of flowers. She reported that whilst pollinators are more numerous in nature reserves than urban sites, the cities retain a high level of species diversity that it is important to protect in the future. This called into question the BREEAM system of measuring sustainability in new developments, which does not usually allow non-native species to be incorporated into a design.

Professor Graham Stone

The debate about whether people would accept more biodiverse landscapes continued by questioning public opinion. Many established parks are attached to historical expectations of that place; typically well-manicured lawns and pruned trees. The group agreed that it was time to try and change the public’s perception to accept a little wilderness in parks and gardens as a habitat for local wildlife. Urban meadows begin to look neglected after flowering, however Professor Graham Stone of the University of Edinburgh mentioned that it is important to let the plants produce their seeds to provide birds with an important food source in the autumn. Bristol City Council have been trialling annual meadows in central reservations around the approaches to the city, and reported that they had not had any complaints from local residents about plants looking untidy when dying back at the end of the season. With sustainable landscaping becoming more popular in UK schools and communities, it is hoped that the public perception towards ecologically friendly designs have already begun to change.

Dr. Sarah Webster presented DEFRA’s hopes for sustainable urban developments. The 2010 Making Space for Nature report outlined new guidelines for reducing the huge pressures on wildlife, which state that new landscapes should enhance the UK’s ecological network by being bigger, better and more connected to existing habitats. DEFRA is currently trialling “biodiversity offsets”, where companies restore an equivalent area for every habitat that is unavoidably lost during a development. It is currently undecided whether or not these offsets will be mandatory if introduced, and it remains difficult to quantify the importance of a habitat in order to produce a new site of equal value to the environment. If this scheme goes ahead, careful planning could ensure that urban landscapes become more connected and form ecological networks within cities.

One of the major difficulties facing the landscape industry is how to measure the economic benefits of sustainability. Howard Wood presented his work with Lyon Parks Department in France, an ambitious project that saved hundreds of thousands of Euros over a year using ecologically-friendly design and maintenance. His team made their own compost from green plant waste and horse manure, killed weeds using hot water, used bio-control methods to remove pests, planted annual meadows to reduce mowing and maintenance of lawns, and used wood chippings as mulch to reduce weeds and improve soil water retention. The group decided that one of the key aims for the future is to improve the baseline knowledge of how much money different types of sustainable landscape cost to create or maintain, and whether they will cost councils and developers less in contrast to the traditional landscape designs.

The day ended with a request from the landscape industry partners for academics to make new sustainability research more easily accessible and understandable. Kym Jones mentioned that sustainability is now an integral part of landscape design, but landscape architects need to have the facts about its importance and value to be able to sell it to their clients. The overwhelming feeling was that green lawns alone are not enough; urban meadows promote biodiversity whilst producing beautiful displays of colour for people to enjoy. Professor Dunnett summed the day up best for me when he said, “we need to mix aesthetics and beauty with the science”. We are building places for people and local wildlife, and innovative new approaches

This blog is written by Sarah Jose, Biological Sciences, University of Bristol

Sarah Jose