Category: Carrying Capacity

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biodiversity Carrying Capacity Durango Herald Population Public Health

More About Wild Species

The article below may be copied or published but must remain intact, with attribution to the author. I also request that the words “First published in the Durango Herald” accompany any publication. For more information, please write the author at: richard@population-matters.org.

 

More About Wild Species

© Richard Grossman MD, 2008

 

The library of life is burning and we do not even know the titles of the books.

Dr. Gro Harlem Brundtland, former Prime Minister of Norway

 

            September’s article announced a contest to write about your favorite species of animal. It gave hints about my favorite animal, and promised to reveal what it is. Although the contest’s official deadline is past, I welcome submissions at: contest@population-matters.org.

            Why am fixated on wild species? Because they make up our most precious treasure, biodiversity. Biodiversity, or biological diversity, refers to the huge number of different plants and animals that have developed over the ages. Almost two million different species have been described and cataloged. Biologists suggest that the actual number of different species is many times this great. There may be another eight million animals and plants that haven’t been described yet!

            My friend, Al Schneider, just found a new species of plant in the sunflower family north of Cortez. Gutierrezia elegans has just been given its common name, Lone Mesa snakeweed. For more information and pictures of this pretty plant you can go to Al’s website: www.swcoloradowildflowers.com. Just think, there may be many more undescribed species right where we live!

The tragedy is that we are losing biodiversity faster than species are being described. Our era is dominated by humans, and we are causing species to go extinct at an alarming rate. The last time that there was such a rapid loss of biodiversity was the end of the epoch of dinosaurs.

There are several ways humans cause species to die off. One is by direct killing, such as the dodo, a flightless bird that was hunted to extinction. Another is by introduction of exotic species. Australia had no proper mammals except for the dingo, (Canis lupus dingo, probably brought by the first aboriginal settlers) until Europeans arrived. They introduced foxes, rabbits and other domestic animals that out-competed and wiped out many of the more primative marsupials.

Pollution threatens many living things, including whole species. The bird with the largest wingspan in North America is an example. The California condor (Gymnogyps californianus) was headed toward extinction from lead poisoning. They would feed on carrion that had been shot with lead bullets. An aggressive program of limiting lead shot and hatching chicks in a laboratory has reestablished these amazing birds.

In most of the world, including the USA, the largest threat to biodiversity is habitat destruction. People in our country are living in larger homes on larger lots with larger lawns, competing with wildlife. Roads and highways block migration routes of many animals, thus creating killing zones for many who attempt to cross. As the human population grows and we consume more, our impact on the natural world is exploding.

Dr. E.O. Wilson, the famed Harvard biologist, made a superb video in which he pleads for preservation of biodiversity. Search for it at: www.ted.com. Wilson uses the acronym HIPPO to help remember the causes of loss of biodiversity: Habitat destruction, Invasive species, Pollution, Population growth (human), and Overharvesting. There is also a beautiful book in the Durango Public Library titled Sustaining Life: how human health depends on biodiversity. This book shows the many ways we depend on species that we might not even be aware of.

The growing human population—and our extravagant consumption—are the primary factors that threaten biodiversity. The Living Planet Report 2008 tells it like it is. Prepared in part by the World Wildlife Fund, this is an account of the state of our natural world. It is available at: www.footprintnetwork.org. The report describes the economic value of biodiversity and the many services that the natural world performs for us. The report compares our use of resources with what is available.

Oh, yes; my favorite species is Hyles lineata, the white-lined sphinx moth. Like most sphinx (or hawk) moths, it has a wide body. It is usually seen in the evening or night, although I have seen them in broad daylight.

One of this species’ endearing qualities is its vision. H. lineata can discriminate colors when the light is very dim. Whereas humans need sunlight to see colors, and some animals perceive them even in dim moonlight, my favorite (other than H. sapiens) species can discriminate colors by faint starlight! Even on the darkest night these moths can find their favorite flowers to sip nectar.

There is amazing diversity in the natural world. Unless we slow our population growth and our consumption, we will leave scant resources for our progeny.

 

Published in the Durango Herald 11-2008

Categories
Action Carrying Capacity Environment Global Climate Change Population

Stop Wildfires

The article below may be copied or published but must remain intact, with attribution to the author. I also request that the words “First published in the Durango Herald” accompany any publication. For more information, please write the author at: richard@population-matters.org.

 

Stop Wildfires

© Richard Grossman MD, 2008

 

Only you can prevent forest fires

Smokey Bear

 

            Prevention and control of wildfires are big concerns as the summer progresses. For years we had thought that their increased size and numbers were caused by management practices over the past century. Strong evidence supports another theory.

            Our Forest Service tried to maximize the productivity of National Forests by suppressing fire. Their theory, starting a century ago, was that saving forests from fire would make them more fruitful—more board feet of lumber could be harvested. Biologists now recognize that fire is actually beneficial to the ecology of forests. For instance, a fire in a southwestern ponderosa pine forest is usually down low and burns the undergrowth while sparing the trees themselves. Small plants that would sap the water and minerals in the soil are reduced so that he trees can grow better. Furthermore, fire creates an ideal seedbed for ponderosa seedlings by consuming dead organic matter on the soil surface.

            Moreover, suppression of fire can cause problems. The underbrush and dead wood build up. When lightening does strike, there is so much fuel waiting to blaze that an inferno can result.

            An article published in Science magazine reported a detailed study of wildfires in the western United States over the past 35 years. The authors compared this database with information about forestry practices and climate/precipitation. They found that large wildfire activity increased markedly starting in the 1980’s. They also found that the increase in fires correlated best with increased spring and summer temperatures and with earlier spring snowmelt.

            Even if snow pack at the end of the winter were adequate, it would melt off earlier than in the past. This lack of moisture, combined with higher temperatures during spring and summer, make for a long, dry fire season.

            It seems that we are seeing an effect of global climate change close to home.

            Gardeners may have already noted a change. Most seed packages have information about where it is appropriate to grow the plants. For instance, La Plata County is in plant Hardiness Zone 5 or 6, determined by the lowest winter temperatures. The National Arbor Day Foundation has revised its zone map to reflect a warming of the climate from 1990 and 2006. Find more information about this, including a map showing where the zones have changed, in Wikipedia.

            Another example of an effect of climate change is found in the Bay of Bengal, at the delta of the sacred Ganges River. Warming has caused a significant rise in the sea level, submerging islands there. The island of Lohachara was the first to be abandoned, leaving 10,000 landless refugees. Unfortunately, there are many more islands to follow. Two locals, Nick Manning and Tyler Quintano, documented this tragedy in their movie “Between the Tides.”

The whole country of Kiribati is threatened by flooding. Citizens of this collection of 33 low coral atolls peppered in the South Pacific are preparing abandon their homeland as it is gradually being inundated. They may be followed shortly by residents of other Pacific nations, including Tuvalu and Vanuatu. So far, no other country is willing to house these environmental refugees, who may number more than 300,000 people.

Yes, Southwest Colorado had a colder-than-usual winter last year with great snowpack.  No, global climate change does not mean that all parts of the planet are getting warmer, or that there isn’t variation from year to year.

Climate change models predict an increase in average temperature and

greater variation in temperature than we are accustomed to. Models also predict more extreme weather events, such as severe hurricanes. The weight of the evidence is that our climate is changing for the worse—and we are the cause. What can we do about it?

Dr. Chris Rapley, head of the Science Museum in London, has come up with the cheapest and most obvious answer to slow global climate change. We need to improve access to contraception by education and healthcare. “I am not advocating genocide” said Rapley. He does advocate reducing the birthrate—fewer people on the planet will mean less carbon dioxide being pumped into the atmosphere. “To achieve this goal you would only have to spend a fraction of the money that would be needed to bring about technological fixes…. However, everyone has decided, quietly, to ignore the issue.”

            Everyone, that is, other than readers of the Durango Herald. Many of us have recognized that human population growth is the basis of countless problems that we face today.