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The Cost Effectiveness of Ecological Restoration Demonstrated

Administrator — Sat, 04 Dec 2010 04:38:20 +0000

Research recently published in the Proceedings of the National Academy of Sciences (PNAS) provides new evidence that ecological restoration can provide a cost effective response to environmental degradation.
The research focused on the dryland forests of Latin America, and examined the cost effectiveness of ecological restoration techniques such as tree planting and forest regeneration. This was achieved using a novel research approach, which involved mapping the value of different benefits provided by these forests.
The research was conducted by a team of ecologists from the UK, Mexico, Chile and Argentina, headed by Professor Adrian Newton of Bournemouth University, UK.
Worldwide, billions of dollars are now being spent annually on different approaches to ecological restoration, which aims to reverse the process of environmental degradation. However, very little evidence is available regarding whether such interventions are cost effective. The problem of environmental degradation is most intense in arid and semi-arid areas, which together cover nearly 30% of the earth’s surface and comprise half the surface area of the world’s developing countries.
Despite their aridity, dryland areas are of global importance for biodiversity, being the centres of origin for many agricultural crops and other economically important species. Rural communities in dryland areas are often highly dependent on forest resources to support their livelihoods, particularly fuelwood and fodder. However, in many areas dryland forests have been subjected to unsustainable land use practices, including expansion of rangeland for livestock, overharvesting (particularly for fuelwood), conversion to agriculture and rapid growth of urban settlements. These processes have resulted in the widespread degradation of dryland ecosystems, which has resulted in negative impacts on biodiversity, soil fertility and water availability, and on the livelihoods of local people.
Environmental degradation presents a major challenge to policy initiatives aiming to support sustainable development. Restoration of dryland forest ecosystems can potentially offer a solution to this problem. With this in mind, the team of academics led by Jenny Birch, analysed six different study areas across Latin America. As she explains: “Values were analysed through interviews with local people and other stakeholders and by reference to the scientific literature. Research focused on valuing the benefits provided by forests to people, including carbon sequestration, timber, non-timber products (such as medicines and honey), and tourism. The costs of forest restoration were also estimated, including loss of livestock production, cost of fencing, fire suppression and tree establishment.”
Three different restoration approaches were examined, which were compared using a simulation model of forest landscapes. This enables the potential future impact of restoration approaches on the provision of benefits to people to be compared.
The results showed that ecological restoration of dry forests is most likely to be cost effective if ‘passive’ approaches are adopted, which support the natural process of forest recovery. ‘Active’ restoration approaches, involving tree planting, are less likely to be cost effective, because of the high costs associated with new tree establishment. However, in each of the study landscapes, some locations were identified where even this approach is likely to be cost effective.
Professor Adrian Newton, who coordinated the research project, explained the potential impact of the study as follow:
“At the recent meeting of the Convention of Biological Diversity in Nagoya, Japan, countries of the world committed to a new target to restore 15% of degraded ecosystems worldwide by 2020. Our research demonstrates that in dryland areas, where it is most needed, investment in ecological restoration can provide a net increase in the value of ecosystems to people. Hopefully, our research will encourage decision-makers to support restoration efforts, so that the global restoration target is achieved.”
Source:
The above story is taken from materials provided by Bournemouth University UK
Reference: Bournemouth University (2010, November 23). Cost effectiveness of ecological restoration demonstrated.

How Cities Mimic Life

Administrator — Mon, 14 Sep 2009 18:52:58 +0000

Mega cities are now thought to replicate living organisms in that they Breathe, Consume Energy, Excrete Wastes And Pollute — It is interesting that the scientific trend of viewing the world’s biggest cities as analogous to living, breathing organisms is fostering a deep new
understanding of how poor air quality in mega cities can harm residents, people
living far downwind, and also play a major role in global climate change. At any rate, that’s the conclusion of a report on the “urban metabolism” model of mega cities presented at the 238th National Meeting of the American Chemical Society (ACS).

Urban Metabolism
It was reported that the concept of ‘urban metabolism’ has existed for decades and views large cities as living entities that consume energy, food, water, and other raw materials, and release wastes. These releases include carbon dioxide, the main greenhouse gas; air pollutants, sewage and other water pollutants; and even excess heat that collects in vast expanses of concrete pavement and stone buildings. Humans directly produce a significant share of this waste, but emissions from industrial, power generation and transportation systems emit the largest quantities of greenhouse gases and other air pollutants. Other urban metabolisers include sewage systems, landfills, domestic pets and pests like rats, which in some cities outnumber people.
During the last five years, this body of knowledge has drawn into sharper focus the hazards of poor air quality in mega cities, not just on the large local populations but also on population centres, agricultural activities and natural ecosystems located downwind from these sprawling areas. Researchers now acknowledge that carbon dioxide and other pollutants in mega cities make them immense drivers of climate change. They impact climate on both a regional and global level because these long-lived greenhouse gases are dispersed around the world.” More than half the world’s population today lives in cities, and the world’s largest urban areas are growing rapidly. The number of mega cities — metropolitan areas with populations exceeding 10 million — has grown from just three in 1975 to about 20 today.

The Culprits
The most highly polluted mega cities are in developing countries. They include Dhaka, Bangladesh; Cairo, Egypt; and Karachi, Pakistan. Some mega cities in less developed regions have recently mounted air quality management campaigns that have resulted in lower levels of pollution; they include Mexico City, Mexico; Beijing, China; Sao Paulo, Brazil; and Buenos Aires, Argentina. Even the cleanest mega cities like Tokyo/Osaka in Japan and New York City and Los Angeles in the United States — all in the developed world — still have serious problems.
The hot weather and frequent atmospheric inversions in southern California, for instance, foster Los Angeles’ legendary smog problem. Mexico City’s high altitude/low latitude location produces high levels of solar ultraviolet radiation that drive photochemical smog production, and the even higher surrounding mountains trap the resulting pollutants in and over the city on most days.
That causes a very serious situation for residents of Mexico City. There are very unhealthy levels of ozone and fine particle pollutants that produce large numbers of premature deaths each year. Studies show that for each increase of 10 micrograms per cubic metre of these particles, you get roughly a 10 percent increase in premature deaths, producing a decrease in average life expectancy of about 0.8 years. Hospital visits, including bronchitis and asthma cases, also rise.

Controlling urban growth key to improving global air quality
Scientists believe that controlling urban growth in the developing world is key to improving the world’s air quality. Urban pollutant levels in poor countries will remain high, with increased emissions expected as the city populations and economic activities increase. Until mega cities are rich enough to devote significant funds to reduce their emissions, two factors will invariably increase the stresses on their environment — increasing vehicular traffic and industrial growth.

California and Mexico reversing the trend
An example of attempts at reversing this trend can be seen in Southern California, which has taken successful action to modify its urban metabolism, pioneering efforts to reduce motor vehicle emissions. Mexico City — unlike most mega cities in less-developed countries — has also taken successful steps to partially address poor air quality. In the past two decades, the Mexican Government has introduced policies to improve air quality, including requiring pollution control devices like catalytic converters on newer vehicles, reducing sulphur levels in petrol and diesel fuel and relocating some large industrial emitters outside the Valley of Mexico. However, in other parts of the world for example the Mega cities in Asia and Africa urgently need to modify their urban metabolism in similar ways with a few fundamental changes such as getting rid of lead in their gasoline. In the developed world, we can institute emissions controls on diesel vehicles, which create hazardous fine particles, and we can also reduce pollution by using more rail-based mass transport or setting up specialized bus routes.”
The urban metabolism model can reveal how developed-world mega cities, such as Tokyo, New York and Los Angeles, have improved their air quality despite a rise in population. The study also assesses how developing-world mega cities are seriously grappling with the problem.

Adapted from materials provided by American Chemical Society.
American Chemical Society (2009, August 18). How Cities Mimic Life:
Mega cities Breathe, Consume Energy, Excrete Wastes And Pollute.

Ecological Impact Of African Cities

Administrator — Fri, 11 Sep 2009 18:50:11 +0000

African cities are growing faster than anywhere else in the world. This is having a major impact, but few ecologists are studying the urban environment and effect of cities on rural areas. One of the most important ecological changes in Africa’s history is being over-looked.
Joy Clancy from the University of Twente has reviewed the problem in the current issue of the African Journal of Ecology. She says “A hundred years ago 95% of the African population was rural, today 38% live in cities with about half the population expected to be urban by 2010.” This rapid growth is resulting in huge changes in natural resource use, but the effects are highly controversial. “Some environmentalists say that demand for fuel wood and charcoal from cities are causing deforestation, but in fact it is change in land use that is the main driver” continues Joy. “The real change is around cities – the ‘peri-urban’ areas – where woodlands are cleared for agriculture to feed the new centres of population.” She points out “When this is added to the effect on water demand and waste disposal on aquatic ecosystems, then African cities can have an ecological footprint much larger than their actual extent.” But there is little research on the ecology of cities “Africa is famous for its wildlife and the ecology of places such as the Serengeti are familiar to people all over the world, but remarkably few ecologists are studying urban environments” says Jon Lovett, associate editor of the African Journal of Ecology. “Although we know a lot about lions and wildebeest, the real ecological challenges are in the cities and these are being ignored” he continues. “We need a massive shift in focus to tackle the most urgent environmental issues”.
Reference:
Joy S. Clancy (2008). Urban ecological footprints in Africa. African Journal of
Ecology Vol. 46 Iss 4.