by Daniel B. Botkin, Henrik Saxe, Miguel B. Araújo, Richard Betts, Richard H. W. Bradshaw, Tomas Cedhagen, Peter Chesson, Terry P. Dawson, Julie R. Etterson, Daniel P. Faith, Simon Ferrier, Antoine Guisan, Anja Skjoldborg Hansen, David W. Hilbert, Craig Loehle, Chris Margules, Mark New, Matthew J. Sobel, And David R. B. Stockwell. Published in BioScience 57(3): 227-236.

In 2004 a group of scientists, including myself, met and discussed what needed to be done to improve the ability to forecast the possible effects of global warming on biodiversity.  The result was a paper published in BioScience, the journal of the American Institute of Biological Sciences (AIBS).

In that paper, we proposed a “Quarternary Conundrum” — we found that the fossil record gave results about climate change and biodiversity that did not agree with modern forecasts.  Here is what we wrote about that idea.  (If you are interested in more from this paper, let me know and I will post more of it, or you can obtain it from AIBS.)

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Current forecasting methods suggest that global warming will cause many extinctions, but the fossil record indicates that, in most regions, surprisingly few species went extinct during the Quaternary (from approximately 2.5 million years BCE to the present)—in North America, for example, only one tree species is known to have gone extinct (Bush and Hooghiemstra 2005). Large extinctions were reported mainly for tree species in northern Europe (68% loss of tree genera; Svenning and Skov 2004) and for large mammals (> 44 kg) in the Northern Hemisphere (MacPhee 1999).We refer to this contrast between the implications of modern forecasts and the observed fossil record as the “Quaternary conundrum.” The resolution of this conundrum is key to improving forecasts of climate-change effects on biodiversity. Among the possible explanations are that climate change during the Quaternary was greatly different from climate change forecasted for the future; that genetic and ecological mechanisms, not accounted for in formal forecasting methods, allow the persistence of many species even under rapid climate change; and that factors in addition to climate change could decrease rates of extinction.

Some recent ecological genetics research further deepens the puzzle. For example, the risk of extinction for a species in response to climate change depends on the demography and evolution of genetically differentiated populations across their geographic ranges. If populations are locally adapted, climate change will cause conditions to deteriorate across the species’ range, rather than just at the margins of the range. Modern reciprocal transplant experiments, in which spatial gradients in climate serve as proxies for temporal climate change in the future, show that these fitness losses can be large (Rehfeldt et al. 1999, Etterson 2004). For example, a reciprocal transplant experiment on lodgepole pine in Canada indicated that global warming would slow tree growth and increase mortality, resulting in a 20% loss of productivity (Rehfeldt et al. 1999). Likewise, a study of a prairie annual in the Great Plains of the United States showed a 30% reduction in seed production in climates similar to those predicted for future decades. Ecological genetic data, in each of these cases, predicted different rates of adaptive evolution in different parts of the species’ range (e.g., rear and leading edge; Hampe and Petit 2005) but generally suggested that evolutionary rates would be slower than the anticipated rate of climate change (Etterson and Shaw 2001, Rehfeldt et al. 2002).

Until recently, it was thought that past temperature changes were no more rapid than 1 degree Celsius (^oC) per millennium, but recent information from both Greenland and Antarctica, which goes back approximately 400,000 years,indicates that there have been many intervals of very rapid temperature change, as judged by shifts in oxygen isotope ratios. Some of the most dramatic changes (e.g., 7^oC to 12^oC within approximately 50 years; Macdougall 2006) are actually of greater amplitude than anything projected for the immediate future. Although these changes were probably not equally severe everywhere on the globe, a well-documented rapid warming did occur around the shores of the North Atlantic at the end of the last glaciation, when melting of the ice cover on the ocean suddenly allowed the Gulf Stream to reach the shores of northern Europe. There, temperatures rose rapidly, perhaps as rapidly as anticipated today for the next several decades (Huntley et al. 1997).

What could explain the Quaternary conundrum? One possibility is that migrations were faster than has been thought possible. A large literature examines late-Quaternary range shifts deduced from the pollen record, and recent papers consider models and seed-dispersal mechanisms that may account both for migration across geographic barriers and for rapid invasion of new territory. Sparse populations of several tree species are now known (from genetic and macrofossil evidence, supplemented by detailed analysis of mapped pollen data) to have persisted during the last glacial maximum in regions where very few, if any, pollen grains have been observed—regions that for this reason would be judged well outside the climate envelope for these species (Tomaru et al. 1998, Brubaker et al. 2005, McLachlan et al. 2005, Magri et al. 2006). These populations serve as advance colonists, allowing rapid population growth in newly available habitat.

A second explanation is that low extinction rates during Quaternary climate change may be partially attributable to ongoing adaptive evolution. Theoretical models suggest that adaptive evolution can enhance the persistence of populations in a changing environment even when migration is possible (Bürger and Lynch 1995). And rapid genetic adaptation to climate has already been documented for a few wild organisms for which long-term studies of field populations have been conducted (reviewed in Bradshaw and Holzapfel 2006). Invasive species have also evolved since their arrival in a new habitat in the 20th century, at surprisingly rapid rates of evolution (e.g., Huey et al. 2000).

A long-standing controversy regarding the role of people in Quaternary extinctions of large mammals speaks to the difficulty of quantifying impacts of multiple factors on species loss. The high extinction rate of large mammals has been widely recognized since the 19th century, and extinctions of large mammals and island birds over the past 100,000 years have been the subject of much conjecture. Paul Martin has made the now well-known case that the timing of extinctions followed human dispersal from Afro-Asia to other parts of the globe and that these extinctions resulted from human “blitzkrieg” overkill (Martin and Steadman 1999). But careful analysis of well-documented extinctions in Beringia suggests that human hunting was superimposed on a preexisting trend of diminishing animal population density (Shapiro et al. 2004, Guthrie 2006). These data suggest that the interaction of environmental change and human resource use can have a larger negative impact on biodiversity than either factor alone.

Copyright © American Institute of Biological Sciences, posted with permission.

The March, 2007, issue of the scientific journal, BioScience, has a new article by Daniel B. Botkin and colleagues titled Forecasting Effects of Global Warming on Biodiversity.

The news release from this journal’s parent organization, the American Institute of Biological Sciences, writes that “current mathematical models indicate that many species could be at risk from global warming, surprisingly few species became extinct during the past 2.5 million years, a period encompassing several ice ages. They suggest that this ‘Quaternary conundrum’ arises because the models fail to take adequate account of the mechanisms by which species persist in adverse conditions. Consequently, the researchers believe that current projections of extinction rates are overestimates.’ ”

There are 19 authors of this paper, from Australia, Denmark, France, Great Britain, Australia, and the United States; these include some of the world’s top scientists concerning ecological forecasting and the history, ecology, and genetics of extinction.

See the article at The American Institute of Biological Sciences.

One of the paper’s coauthors, Matthew J. Sobel of Case Western Reserve University, said, regarding this paper, that “The simultaneous widespread and justified alarm over global warming and changes in biodiversity has induced both outstanding scientific research and deplorable pseudoscientific work,”

According to a news release from Case Western Reserve, “Sobel raises concerns about the `blurring’ of scientific fact with public advocacy and wants public discussions to center around sound environmental facts. `Where the science has limitations that should be noted, too,’ added Sobel. His concern is that misinformation or poorly constructed forecasts may divert and reduce resources that could be better spent in other areas. Limits of scientific knowledge exist with current forecasting models, according to Sobel, and these need to be acknowledged when reporting global warming.”

Matthew Sobel is the William E. Umstattd Professor at the Weatherhead School of Management, Case Western Reserve University.

We still must be concerned about global warming and threats to the diversity of life on the Earth. There is not just one threat from human activities to the diversity of life; there are several major ones, including disruption of habitats, introduction of non-native species into new habitats, and many effects of technology. The good news is that species appear more resilient to rapid climate change than thought previously. The implication is that sound planning and policies to deal with biological diversity needs to include the multiple causes. The new article also calls for better methods of forecasting — better computer models — and better use of available data about past extinctions.

In the BioScience article, the researchers call for eight steps to better forecasting:

* Select one of the many meanings associated with the complex concept of biodiversity and target that meaning as the parameters in a specific forecast

* Evaluate and validate forecasting methods before applying them to general forecasts

* Consider the various factors that might impact biodiversity from climate change to pressures from humans on the native habitat of a species

* Obtain adequate information before making predictions about future outcomes

* Examine fossil records to aid in understanding how some plant and animal species have adapted to changes in their environments

* Improve four widely used techniques in forecasting that model individuals, groups,
integration of species and environmental factors and lastly groups or species based on theories

* Embed ecological principles in the forecasts based on air, water and animal and plant life.

* Develop better models that improve upon modeling forecasts called species-area curves that are based on specific number of species in relation to their habitat and how climate changes can modify the environment.

Copyright © Daniel B. Botkin 2007

Jim Welter lives in Brookings, Oregon, where he has spent his life as a fisherman. I first met Jim when he was in his eighties and blind in one eye — a wiry, thin, smallish man. He came to an open public meeting I ran for fishermen and fishing guides, which was part of a study I was doing for the state of Oregon about the relative effects of forest practices on salmon. I believed that as part of a democratic process in a democracy, we scientists should hear not only from other scientific experts but from the interested public as well — whomever wanted to speak, especially those who had spent their lives dealing with Oregon’s wonderful natural resources, and thought about them and loved them.

At this meeting, Jim made one of the most remarkable, insightful suggestions about salmon that I’d heard during the entire three-year study. But the meeting he attended hadn’t started off so well. To begin with, there was considerable distrust by the fishermen and fishing guides of some scientist from California, paid by the government, who arrived in Gold Beach and was probably going to tell them what to do about their salmon. Before the meeting, the small team of scientists I had organized to do the project ate lunch with a representative of the fishermen. One of my colleagues said to him, “There seems to be some considerably hostility toward the government of Oregon.”

“Darn right,”he said, “When they came down here and told us they could manage salmon, we thought they meant that we could manage to have salmon.”

When I opened the meeting, the audience of hardworking men sat stiffly upright in their chairs with their arms folded, looking hostile, until one of them said, “Professor Botkin, do you believe that the salmon are declining?”

I replied honestly “I’ve just started this project and don’t know much of anything about salmon and don’t have any preconceived ideas. I’m just here to find out what is known.”

The audience immediately relaxed and became very helpful. By the end of the meeting, the leader of the fishing guides got up and said that the guides knew the rivers better than anybody, they spent 360 days a year on them, and they would be willing to make any measurements that would be helpful to our study.”

That was a pleasant turn around. But most remarkable of all was Jim Welter. He got up to speak and said, “I don’t know much about science, but it just makes sense that if these salmon are born and reared in freshwater streams and spend about a year there, and then go to the ocean and return when they’re three or four, that the amount of water flowing in the stream where they were born ought to make a big difference in how many survive and return.”

That made a lot of sense to me, and it was refreshing to hear something constructive, especially when I had only recently learned that the Bonneville Power Administration, which built and ran the big dams on the Columbia and Snake rivers, had spent $2.5 billion on salmon research and restoration and, according to one of their top executives who spoke to me, those dollars hadn’t yielded a single sign of improvement in the salmon. How could a big agency spend that much money and have absolutely nothing to show for it? I wondered. I found out, but that’s the subject of another time, another story.

Jim Welter did more than provide us with a little verbal wisdom based on years of experience — in my career working on natural living resources, I had come across people who did provide that kind of insight, almost always interesting. But Jim took it several steps further. He went to the state of Oregon’s Department of Fish and Game and got the data for the counts of salmon crossing a dam on the Rogue and the Umpqua rivers — these were the only two rivers of the more than 20 rivers that flowed to the Pacific Ocean in Oregon south of the Columbia River, where the state actually counted salmon .

Discovering that the state didn’t know how many salmon it had on most of its rivers was pretty disconcerting to me, as I was hired to tell them what was happening to salmon and why, and this required basic information about changes in salmon numbers over time, which did not exist, I had only recently discovered, for most of the rivers.

Then Jim went to the U. S. Geological Survey and got the data for stream flow for each year on those rivers for the time that salmon had been counted. This was a remarkable step, especially because to my knowledge no agency of the state or federal government had done this comparison.

Even more remarkable was that Jim had gotten a friend who knew a little about science to help him graph the two kinds of data. He brought in a huge hand-drawn graph (this was in the days before PowerPoint, and anyway, Jim wouldn’t have used that). A nonscientist actually doing an analysis of data. Once again, no government agency had gone this far.

Sure enough, as Jim pointed out, if there was a high-water year, then four years later a lot of salmon swam upstream. If there was a low-water year, then four years later few salmon returned. Jim provided the first important insight into what might be a major factor influencing salmon abundance.

We were so impressed with Jim’s suggestion and his graph that we contracted with Ben Stout, a forester and statistician, to do a formal statistical analysis of these two data sets. And sure enough, it turned out that one could account for 80% of the variation in salmon abundance from water flow alone, and you could thereby forecast pretty well four years in advance whether or not there would be a good salmon year. Since the methods in use at the time set the catch sometimes a few months before the fishing season opened, and didn’t give the fishermen much chance to prepare, this seemed a remarkable advance.

We wrote this up as a scientific paper and proposed it to the state and to salmon fisheries scientists.

In the years since, once in a while I call Jim and ask how he’s doing. Sometimes he asks “Them government fellows ever listen to what you told them?” And I would have to admit that they hadn’t. Another time Jim said on the phone “If only we weren’t so greedy, everything would be all right.”

Although Jim wasn’t trained as a scientist, he was a natural at it. Gathering data, looking at it, thinking about it, graphing it, and coming up with insights. That was just good science. And sad to say, we had seen little like it, certainly not from the large staff of the Bonneville Power Administration. But as I said, that’s another story. If you want to hear about why BPA and other scientists did not think to plot water flow against salmon returns, write me and I’ll set that story down.

Jim Welter represents one kind of person we desperately need to help with our environmental problems: a good observer invested in natural resources without any ideological bones to pick, open to new ideas, willing to look at primary data in a fresh way, to construct graphs, and not jump to conclusions.

When I think about acting locally to help nature, I think about Jim Welter, who had more foresight with his one eye that many government employees with two.

A New Symbol For Our Times!

Copyright © 2004 Daniel B. Botkin

Is it just chance that people are about two meters tall, or is it a result of laws of nature?

Life comes in many sizes. The smallest creatures are bacteria. The smallest of these are about one millionth of a meter long and half that wide, and weigh less than a billionth of a billionth of a kilogram. The longest and widest creature is a surprise — not an elephant, not a whale, not a giant sequoia tree. It is a huge fungus that lives in soils in western North America, just under the ground. Some of these individuals stretch across two kilometers! If one of these giants were merely 10 cm thick, it would weight about 314,000 kilograms. These fungi live by digesting decaying vegetation in the soil, a vital role in the eternal cycling of life’s chemicals. Thank goodness, however, they have no sharp teeth or legs to walk on, or an interest in feeding on living flesh.

The heaviest organism is probably the largest of the giant Sequoia trees of California, known as the “Del Norte Titan” sequoia. It stands 94 meters high and is more than 7 meters in diameter, and weighs more than one million kilograms. (more…)

Restoration of nature and sustainability of natural resources have become popular terms these days. They sound straightforward enough, but they come with their own loaded meanings. If you restore a painting, you make it look exactly as it did when it was first painted – you put it back into its original state. So it is with restoring houses, gardens, antique cars. Restoration has always meant to bring back to a single original condition.

The idea that nature can be restored – and will restore itself – to a single, best, perfect state is ancient. It forms the basis of the great myth of the Balance of Nature – stated and believed by the ancient Greeks and part of Western civilization ever since. According to this belief, nature exists in a perfect balance that will persist forever, and, if disturbed by human action but then released from that disturbance, will return to that single perfect state. (more…)

Augusta, Maine: The taking down of Edwards Dam — the first intentional removal of a major hydropower dam in United States history, was scheduled for 9:00 am on a beautiful spring morning in 1999. We arrived early to find a parking place and watch preparations. As a crowd gathered along the east bluff, a great blue heron flew low above the Kennebec River, traveling downstream from where water still flowed smoothly over the 161 year-old structure. Soon out of view, the heron had been disturbed from its usual stalking territory, perhaps by the big diesel shovel digging bucketfuls of soil from a temporary dam across the river, or the large crowd on the opposite shore, a unique mass of white and bright colors in the heron’s habitat. Or perhaps it was the noise of a helicopter and a float-plane circling overhead carrying television crews.The dam was being removed to save migrating fish, restore the river’s habitat, and improve fishing and boating. If fish increased in the river, it might be a boon for the heron. Built in 1837, the dam was operating when Henry David Thoreau canoed Maine’s rivers in the 1840s. (more…)