Tuesday, 26 August 2003

Endangered insects?

The Bank Holiday weekend in England was generally warm and sunny, and so most people are now convinced that global warming is occurring. In fact, despite my earlier pessimistic comments about the lack of insects, I seem to have noticed quite a few more in recent weeks. The Buddleia bush which has just finished flowering attracted clouds of butterflies -- peacocks, small tortoiseshells, red admirals and commas. And the nettles I left for butterflies were shrouded in the nests of the black woolly bear caterpillars. And there are certainly a lot of dragonflies buzzing around the country lanes.

However, there are still not the number of flies and other insects that there should be. Sitting in the garden eating dinner on Friday evening (which was particularly warm) there was the odd fly -- but fifty years ago, there would have been dozens. The reasons are obvious enough -- just drive through the countryside, and this time of the year, when harvest has more or less finished, it is a brown sterile desert. Acre after acre (or hectare after hectare) of bare earth, with hardly any forms of life, freshly ploughed, ready for the next bout of spraying. Visit a local rubbish tip -- once home to myriad insects, and it it is near sterile. It's a miracle that any wildlife survives. The house crickets which once infested most rubbish dumps are now, to all intents and purposes an endangered species.

This year was the first time I have not seen a cuckoo. It suddenly dawned on me yesterday. I had heard the odd one in spring, and not really thought about it, but suddenly it is nearly September, and i've not actually seen one, for the first time since I started birdwatching nearly 50 years ago. In those days I heard and saw them in the Suburbs of London every year. Even 20 years ago they were the sort of bird one might expect to see practically every time one went for a walk in rural Suffolk -- but no longer.

Wednesday, 20 August 2003

Biodiversity and the Jenga Principle

and other musings by John Burton

Biodiversity is a term first used in 1985 and Sir Martin Holdgate the former Director of IUCN regarded it as the 'Total sum of life's variety on Earth, expressed at the genetic, species and ecosystem level' . In fact the term has entered into common parlance as a synonym for species diversity, and is in consequence, often misleading. Areas that are important for biodiversity are indeed often species rich, but an over-emphasis on species-rich, so-called ‘biodiversity hotspots’ can not only be misleading, but detrimental to conservation.

One of the objects of ‘hotspots’ was to prioritise conservation action, but such prioritisation is a gross simplication, and fraught with problems. First and foremost there is the issue of the reliability of the data it is based on. It is not uncommon for birds to be used as indicator’ species. This is because it is claimed that birds are among the best-studied taxa, with relatively few new taxa to be described. This claim is not entirely justified, since recent years have actually seen an upsurge in new taxa being recognised. There is also the question as to whether or not one group of taxa can be used to reflect species richness in others. BirdLife published such comparisons but the results were very disappointing, and showed very little convergence between the distribution of mammalian, reptilian and amphibian narrow endemics with birds or with each other.

A glance at any of the maps of the so-called biodiversity hotspots shows that there is a huge concentration in the tropical regions, but hardly any of these regions have been studied anything like as well as Europe or North America, where new species continue to be described every year. Other concentrations occur where there is large altitudinal variation in a relative small area, such as the Eastern Mediterranean. Areas such as Patagonia, the Putsa, Gobi Desert are ignored despite having many interesting and unique species, including endemics.

And this is where Jenga comes in. Most readers will know that Jenga is a simple game of manual dexterity. A tower of wood blocks is created, and then the contestants take it in turns to remove blocks without causing the tower to collapse, but leaving the top layer intact. If a large tower is created, clearly under normal circumstances, more pieces can be removed before it collapses, than from a small tower. If the blocks are used to represent species within an ecosystem, the analogy works pretty well. A simple ecosystem, (pampas) is formed from large blocks (species) but relatively few of them, to create the entire tower (biomass). As a tower it is relatively stable, but as soon as one or two blocks are removed near the base, the slightest jolt will lead it to collapse (other species become extinct). A complex ecosystem (rainforest) is not even a single tower, but a complex series of towers, more like a pyramid, comprising hundreds of blocks. Lots of blocks can be removed before serious damage occurs to the structure, even from near the base.

These are the extremes, and I am sure the analogy can be developed further -- it would also make an interesting and marketable game. But it is in the less clearly defined habitats – those of the temperate regions, the concept is most likely to be useful.

What we should be looking at are habitats that are likely to cease to operate as ecosystems (Jenga towers) and concentrate on conserving those. Using this approach, I believe it is possible to prioritise conservation action. Madagascar, which is clearly comprised of a tower of unique blocks, has already lost most of its base layers, and so compared with the Amazon or Congo, is much nearer to collapse.

And applying the concept to Europe it is apparent that the whole region is in serious danger. In the past 50 years so much of what was at least partially able to support an ecosystem (farmland) has undergone ‘desertification’, that it is unlikely that the rest of the ecosystems can survive. The disappearance of birds such as the house sparrow, may even be a symptom of this collapse.

Previous experience has led me to always question the basis of setting priorities. In 1988 I was involved with the creation of the Programme for Belize, a conservation initiative to acquire land in Central America. Several international conservation bodies were approached for support, but the World Wildlife Fund in the UK declined to put its name to the project at the time, because it was not a ‘priority’ area. 15 years on, with the benefit of hindsight, we can now state that that area is part of the largest remaining continuous tract of forest in the whole of northern Central America. It is one of the few forests capable of sustaining viable populations of species such as Jaguar and Puma, as well as providing habitat for a wide range of other species. The problem with most of the prioritisation systems that have been used recently, is that they have usually been developed by biologists and scientists, and priorities do not only involve science -- even though scientists might argue they take other factors into account. Counting numbers of species, and degrees of rarity is only part of the equation, and in some cases a relatively unimportant part. Other factors that need to be taken into account include the following:
  • Economic considerations: What is the cost of buying or protecting the land? Can it generate income? Can it be self sustaining? What subsidies are needed?
  • Political considerations: Is there a local will to conserve it? What happens if outsiders become involved?. NIMBYism and the reverse. And there are many, many other considerations that need to be taken into account.
  • Spatial considerations: How big is the area? Can it be protected? How near is it to other protected areas? How does it relate to the economic geography of the surrounding country?

The conclusion many conservationists would reach after considering all the above, as well as the huge range of factors normally considered when evaluating endangered species, is that each case needs to be treated on its own merits, and that the world is in such a state of crisis that ALL remaining natural habitats are under threat of some sort and need protection and conservation.My personal conclusion is that the only way of implementing a realistic prioritisation is opportunistically. Too many of the world’s conservation bodies are sitting on piles of cash and/or carrying out yet more research. Truly a case of fiddling when Rome is nearly burned to the ground. It would be interesting to have some PhD students carry out research into the economics of conservation research, to look at what has been spent on endangered species research over the past 40 years, and compare that with other uses of the money, such as land acquisition. How many millions of dollars have been spent on researching elephants, rhinos tigers and gorillas? How many reserves could have been bought and protected with that money?

New Elephant species in new journal?

An exciting publishing development is to be found on the internet at www.plosbiology.org. The Public Library of Science is an online, fully refereed journal, but unlike the numerous other journals now being published online, there is no hefty charge being made to view or download the papers published on it. Congratulations to all those who helped bring the project to fruition.

One of the first papers published is the result of a DNA study of the elephants of Borneo. The generally accepted wisdom has been that the elephant population of Borneo was the result of human introductions, probably around 300-500 years ago. But a large team of researchers, headed by Prithivarj Fernando, from Columbia University, New York, have been able to demonstrate that the elephant population probably diverged from the mainland populations around 300,000 years ago, when Borneo was separated from the mainland. Although the authors do not go as far as suggesting the population should be regarded as a separate species, they do believe that “this study, has profound implications for the fate of Borneo’s largest mammals. Wild Asian Elephant populations are disappearing as expanding human development disrupts their migration routes, depletes their food sources, and destroys their habitat. Recognising these elephants as native to Borneo makes their conservation a high priority and gives biologists important clues about how to manage them.”

Back in 1950 , a taxonomist who seemed to delight in creating new species and subspecies on the sligtest pretext, managed to describe at least 10 subspecies of Asian Elephant, some based on data as scant as a single Medieval stone carving or an early description in Persian. Among these poorly described subspecies was Elephas maximas borneensis, and despite the inadequacy of Deraniyagala's research, if the Bornean population is to have a name, because of the taxonomic laws odf priority, it will be Deraniyagala's authorship that will be associated with the name.

Monday, 11 August 2003

The human population problem

The heat wave continues in the UK and the rest of Europe. Forest fires are causing untold damage to wildlife, and it will take decades for some of the habitats to recover. A few habitats, that are adapted to fire, will bounce back more quickly and some may even benefit -- but only a minority. And of course, the press is full of speculations about global warming. But a few hot summers are not indicators of global warming, and it really is rather futile speculating on whether or not global warming is occurring, and if it is, is it a result of carbon emmissions.

Whatever the scientists say, it will be decades, if not centuries, before we can answer many of the questions. There have been frequent periods of warm summers in the past, just as there have been decades of cool weather. Vineyards flourished as far noth as Lincolnshire in the English Middle Ages, then it got colder for a few centuries.

What is certainly true, however, is that for the past three centuries mankind has been chucking huge quantities of pollutants of various forms into the environment in quantities that are bound to be damaging to the sustainability of the planet. Rivers have been poisoned, forests destroyed, deserts created, and finally CFCs and other pollutants released into the atmosphere. Whatever the link with global warming, this cannot be doing any good to the planet.

But before rushing into alternatives, and so-called renewables, we should look at all of the alternatives very carefully. What are the hidden costs to the environment? Nuclear power once seemed a universal panacea to all our energy problems. It still might be, but what about all the security risks?

The fundamental cause of all these problems is the burgeoning human population of the planet, most of which seem to aspire to live at the standard of living found in the USA. This cannot be sustainable, but the movement to limit population growth that was flourishing in the 1970s seems to have almost disappeared. The effects of higher and higher living standard aspirations in Britian, include more and more land disappearing under housing developments. And each person demands a bigger and bigger living space, more resources to heat, and air condition that living space. So even a 1% growth in population means a huge increase in resource depletion. And while governments claim to be encouraging energy conservation, business is simultaneously trying to sell everyone more and more material goods, all of which require energy and resources to manufacture them, and more and more of those goods require energy to run them.

The only way such growth can be sustainable is if populations start declining. But it will take decades to reverse current trends -- unless war and disease intervene, which seems increasingly likely. Something to think about while sunbathing in the heatwave.