Historical Forests  Bob Leverett Jun 08, 2003 15:25 PDT  Mike:          Your earlier post set me to thinking about data collection, analysis, and presentation. Charlie and the Harvard Forest Scientists have almost certainly seen more historical data on witness trees than any humans alive and as the highly capable scientists that they are, we can conclude that their interpretations within the limits of the data are as good as we're going to get. The operative caveat is 'within the limits of the data'. Their conclusions about what the data show with respect to species abundance/distribution are likely to be as good as we'll get. If the witness tree data show the same species then as now, but different relative abundances, should we conclude that overall the forest of yesteryear looked fairly similar to that which we see today -because we see the same species? Or should we conclude that it looks different because of the difference in relative abundances. Suppose things even out over larger areas. Then the no difference hypothesis would seem correct just based on species. This conclusion might not be reasonable, though, if tree condition is factored in. Do we have enough data on the condition of trees in the forests of the past to judge condition? We have lots of general information about forest conditions. We also have lots of old photographs of log jams from the great timber moves off the past. Can we judge from the photos whether or not the average tree size was significantly larger than today. We also have lots of photos of surviving OG. We've got lots of fragments so that putting together all the pieces requires lots of good detective work. Even with the fragments, I suppose if one worked at it long enough one could draw some pretty good conclusions. It would be the presentation of those conclusions to the general public that would worry me most.     Scientists don't like to use emotionally charged terms. A word like 'change' is preferred to 'trashed'. I'm comfortable with both, but don't want 'changed' used to disguise what most of us might agree was 'trashed' if substantial misunderstanding could take place on the part of the public. So let's say that you look at a woodland along with Charlie. He concludes that it is either changed or unchanged with respect to species mix and you conclude that it is either trashed or untrashed relative to what has been removed and what remains. Relative to what was once there, the quality has changed from silvicultural perspective (big tree lovers would likely be in full agreement). Over a large region, the species mix might not be much different from past to present based on witness tree inventories, but the condition of the woodlands could be very different.     With the myriad of diseases attacking trees today, the invasives, poor forest practices that impact distribution, such as the intentional high grading of large areas of forest, it is very tempting to conclude that the forests of yesteryear would have been in much better shape, overall, than those of today. The timbers in old buildings suggest that there was lots of fine timber around. I would be very interested in knowing if data exists to the contrary and whether or not those data were considered in the analysis that Charlie and the Harvard Forest team did. Hopefully, if Charlie reads this he will explain the limits of the teams conclusions. Bob Pre vs post-settlement forests Bob Leverett Jun 09, 2003 07:40 PDT   The early dominance of the oak is striking, but by 1800 southern New England had up to 180 years of European American presence. Do we have good reason to believe that the 1800s distribution was very similar to the 1600s distribution? Interestingly the 1800s percentage of chestnut refutes the memories of lots of old-timers who think of chestnut as comprising a greater percentage than 4.5%. I'm not that surprised. Human memories of climate (notoriously inadequate) are often swayed by memories of distinct weather events like hurricanes and big snowfalls. Very infrequent events become recalled as common occurrences.      It is my understanding that the period of greatest land clearing in New England occurred between 1830 and 1850. I think it reached a maximum between 1840 and 1850. So what was the state of New England's woodlands in 1800?      In terms of big versus small trees, higher average age versus younger, less open land versus more, what can we conclude in terms of overall appearance? Would only big tree afficianados and foresters notice the differences? Where does individual condition of the trees actually fit in? Does the fall of oak and the ascendency of maple, especially red maple, create a strikingly different forest appearance? Are we dealing with a highly subjective idea, i.e. appearance, as with beauty being in the eye of the beholder? Are there cases where modest changes is species distribution manifest as a major changes in appearance? Do the use of witness trees as a population introduce a bias in computing overall species composition and distribution?      What can we learn by studying forests that have been changed from their pre-settlement compositions in much more recent times, such as in the upper Mid-west? Lee, HELP!!! Do the upper Mid-west forests of today look like would have in say the late 1800s? Can such comparisons between New England and the upper Mid-west be fairly made?      Lots to discuss. Bob Re: Pre vs post-settlement forests    Lee E. Frelich    Jun 09, 2003 07:40 PDT  Bob: To answer you questions in the last paragraph below: I don't think the Porkies and Sylvania and a few other places, especially peatland forests, look much different now than 150 years ago. Most of the rest of the landscape looks quite a bit different in terms of age structure, composition, and proportion of the landscape covered by forest. Even the 375,000 acre remnant of boreal forest in the Boundary Waters is much different today, since it is mostly spruce, fir and birch, rather than jack pine. Regarding your question about analogies between the Midwest now and New England during the 1800s, that may not be as fruitfull as you might think. The southern Midwest and some northern areas near the Great Lakes were settled almost as early as New England. The city of Green Bay, for example, celebrated its 350th birthday during the 1990s, and many other areas were settled only 20-40 years after Boston. Widespread land clearing in eastern WI and most of MI peaked in the 1840s, so it is not necessarily much different than New England. Some parts of northern WI and MN, and Upper MI, on the other hand, were settled from the late 1800s up to the 1940s, but these areas have such different climate and species composition than New England that comparisons would not yield much insight. MN is a different universe and perhaps more analogous to Iowa and Alaska than New England. Lee RE: Pre vs post-settlement forests   Gary A. Beluzo   Jun 09, 2003 17:36 PDT  Bob, Is this similar to what Lee has described…that because of altered land use and fire suppression oaks have given way to maples (more shade tolerant) over the past 150 years or is it because the land that was cleared in the 1800s (rich well drained soil) for pasture and crops had previously harbored many of the maples and over the last 150 years that abandoned land has reverted back to maple dominant forest? Perhaps both? Gary   Home