Scientists at the Institute for Applied Ecology at the University of Canberra, Australia, have found a turtle that does better in a suburban habitat than it does in nature reserves. Eastern long-necked turtles (Chelodina longicollis) living in the suburbs of Canberra occupy home ranges nearly three times larger than turtles in the nature reserves. They are better able to cope with periods of drought, have higher population abundances and growth rates, and at last equivalent recruitment levels.

Eastern long-necked turtles, common across much of south eastern Australia, can be found in many freshwater habitats in the wild and in towns and cities. The researchers compared turtles that lived in the suburbs of Canberra to those in adjacent nature reserves, attaching miniature radio transmitters to the turtles in each habitat and following their weekly movements over the course of a year. Both turtle populations made long journeys of up to two and a half kilometres between bodies of water. It was expected that given their extensive movements, the suburban turtles would have a high rate of encounters with vehicles on roads, and thus fewer would survive. In fact, suburban turtles did not suffer appreciably higher mortality than their counterparts on reserve lands, only one of the 36 radio tracked turtles being hit by a vehicle. Vegetated drainage lines and drainage culverts running under roads protected the turtles.

Given the severe droughts that have been affecting much of Australia, the different populations’ response to drought was also notable. Turtles in the nature reserves responded to the drying up of the wetlands by lying dormant buried under leaf litter. However, suburban turtles were able to maintain aquatic activities throughout periods of drought as suburban water bodies remained flooded. Suburban landscapes, despite their unique challenges, may therefore be higher quality habitats than nature reserves for turtles during drought. The researchers hope to further evaluate whether well-designed urban areas hold any promise as long term drought refuges for some turtle populations.

For further information, please see here.

Last night saw the second event organised by the Natural Capital Initiative, a joint partnership between the BES, the Institute of Biology and the Centre for Ecology & Hydrology. The topic under discussion was ‘Sustainable Cities’, with high-profile speakers presenting their arguments before a large audience of policymakers, urban designers, ecologists, students and members of the public.

Dr. William Bird, a practising GP and Strategic Health Advisor to Natural England, opened proceedings by reminding the audience of the oft-overlooked health benefits of green spaces. This was a particularly valuable way of contextualising the ensuing debate, giving the lie to any idea that green spaces are simply an abstract indulgence of the well-off, and instead clearly demonstrating that greening a city is a human welfare issue. Numerous studies have shown that when we see green areas and trees our blood pressure decreases, our heart rate drops and our brainwaves change to relaxed alpha waves. As a result, global studies have shown a clear link between obesity levels and areas with fewer green spaces. People have also been shown to live longer if they live by green spaces, though intriguingly, this effect is particularly noticeable amongst the poorest sectors of society. Green spaces can therefore serve to close the currently-widening gap between rich and poor levels of health and life expectancy, further highlighting the fact that greening cities is an important welfare issue.

Ken Livingstone, former Mayor of London, harked back to the great reformers of the Victorian Age who worked on issues such as disease, poverty and labour conditions, pointing out that these problems were worked upon and largely solved in the cities. He argued that it is the same again today, with 70-80% of the world’s carbon emissions coming from cities, leading to the conclusion that if we can achieve sustainable urban environments, we can basically sort climate change. He saw local power generation as an important factor in achieving this, pointing out that there is still only one power station at present in the whole of London. As a high-profile politician with excellent networks, it was sad to hear him so pessimistic about the world’s current efforts to combat climate change. He also reminded us of the sobering point that whilst the UK could be dramatically affected by climate change, as an island nation in the temperate zone it will avoid the worst ravages of climate change- it is the poorest and least resilient in developing nations who in fact will be most affected.

Peter Wilder, a prominent landscape architect, meanwhile outlined the need for ‘green infrastructure’, such as biofiltration systems, and a return to stewardship, whilst Malcolm Smith, a director at Arup, highlighted the fact that retro-fitting is the main answer when it comes to looking for solutions. Despite our great attraction to the glamour and spectacle of the new, he argued that 95% of the city is out there already, and so any meaningful solution has to be focused on the comparatively unsexy work of making existing homes and offices more sustainable. Finally Lorna Walker, an urban design consultant, argued that it is imperative to remember that individual people are at the centre of any solution to greening a city, and that technological change cannot simply be relied upon. Rather, it is imperative to ensure that the population is engaged with rather that turned off by anti-climate change measures. She also added that in London we already have a great starting point from which we can lead by example- 37% of the capital is designated green space (and astonishingly, that figure does not include gardens), and there is plenty of potential for inspirational improvement given the right leadership.

A high quality and wide-ranging debate with the audience followed, after which drinks and nibbles, as well as some excellent posters from PhD students, provided a relaxed opportunity to discuss some of the evening’s issues and to meet with other relevant actors in the urban environment sector.

For more details on this and future events of the Natural Capital Initiative, please visit here.

Despite the frequent public preconception that urban waterways such as canals and ditches are polluted eyesores, devoid of almost all wildlife, recent research has shown that they can have more macroinvertebrate diversity than similar water systems in rural areas. They can also provide habitat for several endangered species.

Urban habitats may provide an important refuge for biodiversity in the face of climate change and increasing fragmentation. However, to date there has been little data provided to assess the conservation value of urban areas, and very few studies focusing on urban water systems.

A new Dutch study compared the biodiversity value of urban waterways in two towns in the Netherlands with natural and manmade drainage systems in rural areas, such as small streams and rivulets. Macroinvertebrate species, including snails, mites, flies and exotic crustaceans, were studied.

Urban waterways with low levels of nutrients (particularly nitrogen and phosphorous), were found to have the highest diversity of macroinvertebrates, and the highest number of endangered species. Waters with high levels of nutrients and poorly developed vegetation meanwhile had low macroinvertebrate diversity. The number of exotic crustaceans was high in nutrient-rich waters, probably because they are better able to cope with harsher conditions, such as low oxygen levels, than native species.

The researchers concluded that the key factors for macroinvertebrate biodiversity in urban water systems are levels of nitrates, sediment composition, transparency and submerged vegetation.

For further information, please see: Vermonden, K., Leuven, R.S.E.W., van der Velde, G. et al. (2009). Urban drainage systems: An undervalued habitat for aquatic macroinvertebrates. Biological Conservation. 142: 1105-1115.

Speaking on BBC Radio 4’s Today programme, Conservation Director of the RSPB Dr Mark Avery, described the troubling plight of the House Sparrow Passer domesticus.

According to a recent study in the journal Animal Conservation by scientists from the RSPB, Natural England and De Montford University, house sparrows have declined by up to 68% of their 1970 population.

Commenting on the BBC website, Dr Peach of the RSPB, said:

“The trend towards paving of front gardens and laying decking in the back, and the popularity of ornamental plants from other parts of the world, has made many gardens no-go areas for once common British birds.”

It has been proposed that an absence of aphids and other insects during summer – crucial for feeding chicks – may have a strong role to play.

Moreover, these insects inhabit vegetation frequently associated with a healthy front garden; honeysuckle wild roses and hawthorn. The current fashion of paving over front gardens in cities, particularly in large cities like London, is no doubt linked to their demise and should be cause for a serious re-think amongst policy-makers.

When questioned, Leader of North Herts District Council, Councillor John Smith, was reluctant to concede that the loss of brownfield sites could be a potential contributory factor, believing it to be a local phenomenon.

Environment Minister Micheal Meacher was “very worried, [given that] we may have lost nearly 15 million birds in the last thirty years.” In the case of starlings, the Rt. Hon Meacher cited, that the loss of first year juveniles was known to be a contributory factor to their decline, possibly linked to diminishing autumn food supplies because of heavy pesticide use in intensive agriculture. A body of research highlights intensive agriculture as the cause of declines in farmland birds, and perhaps the combination of uber-urbanisation of town gardens is creating a ‘double whammy’ for the house sparrows.

Dr Avery and colleagues hopes to follow-up this report up with more detailed research in the near future, pending sufficient funding.

Hear the report on Radio4 here:

http://www.bbc.co.uk/radio4/today/reports/archive/science_nature/sparrows.shtml

Often urban expansion occurs concomitantly with economic growth in developing countries, not to mention land use change including the conversion of forest to agricultural land. A new study in Landscape and Urban Planning suggests that expansion of Panama City and Colon, both of which are surrounded by richly biodiverse rainforests, could result in future biodiversity loss.

Increased urbanisation is anticipated in these cities after a planned expansion of the shipping canal, and it is likely that this will result in increased forest loss. This could be exacerbated by the rural population, 61 per cent of whom live below the poverty threshold, and presently have no alternative but to remove standing forest for agriculture and income purposes.

The researchers looked at potential socio-economic and biophysical correlates of biodiversity loss including population density and growth, road density and poverty levels, rainfall, forest age and land use. They found that population wealth was linked to conversion of land to urban areas, i.e. the more wealth the more conversion. The researchers also found that agriculture was expanding into mature forests.

The rainforests offer a wealth of ecosystem services including the provision of clean water, flood and landslide prevention through water capture not to mention the carbon storage and climate regulating influences. However if an ecosystem services approach is not applied to the forests appropriately, it is likely that, as affluence increases in the urban areas, the true value of the forests will be taken for granted. This could result in increased forest clearance for what is perceived as more valuable urban development projects.

The authors suggest that ecotourism and agroforestry could provide alternative less destructive economic opportunities. If alternatives are positively explored it could assist the rural population move above the poverty threshold without destroying the valuable forests which they, and we all depend upon.

Source: Rompré G, Robinson WD and Desrochers A (2008). Causes of habitat loss in a Neotropical landscape: The Panama Canal corridor. Landscape and Urban Planning. 87: 129-139.

The Mayor of London, Boris Johnson, has today launched a new strategy for the UK’s Capital, aimed at better preparing the city and its people for the challenges of climate change. The strategy is claimed as a first for a world city.

Measures outlined in the strategy include measures to ‘green’ London; including the use and design of green spaces, green roofs and tree-planting to reduce water run-off and flooding, and greater preparedness for extreme weather events expected under climate change, specifically flooding, drought and heatwaves. There are plans to increase public awareness of flood risk in the capital, alongside a promotion, and compulsory introduction, of water metering to reduce water consumption.

Launching the strategy, the Mayor commented: “the range of weather conditions facing London…could seriously threaten our quality of life…and endanger our pre-eminence as one of the world’s leading cities”. The Mayor’s manifesto included an ambitious target to cut London’s carbon emissions by 60% by 2025.

Organisations are invited to comment on the first draft of the strategy. As a result of these comments, a second draft will be published for public consultation in 2009.

Access the Mayor’s website with official press release and the draft strategy