Opinion ID: 793847
Heading Depth: 4
Heading Rank: 1

Heading: Tree Mortality Guidelines

Text: 46 Earth Island argues that the FEISs' guidelines for cutting burned and scorched trees substantially overpredict tree mortality, with the result that many more trees will be cut than are necessary to meet the legitimate objectives of the Power and Freds Projects. Earth Island argues that by cutting many trees that will not die, the USFS will unnecessarily destroy valuable habitat for the California spotted owl and certain MIS bird species. 47 The tree mortality guidelines contained in the FEISs are based upon the 2005 draft Hood Study. That study predicts post-fire mortality for trees burned or scorched in forest fires. The guidelines for both projects are keyed to the percentage of the tree's green crown that has been scorched by the fires. 48 Based on data contained in the Hood Study, the USFS chose two different marking guidelines, one for areas to be logged by tractor and one for areas to be logged by helicopter or skyline. Table 3-5 of both of the FEISs is entitled Mortality Guidelines for marking as applied to [various alternatives]. For simplicity of explanation, we will describe the guidelines only as they apply to yellow pine and white fir, and only as to helicopter and skyline logging. Yellow pine with 65% or more of the length of their crown scorched are considered dead, and are to be marked for cutting. The same crown length scorch percentages apply to white fir over 20 in diameter. 49 For the convenience of the reader, we reproduce Table 3-5: 50 PP/JP/SP White White [yellow Fir Fir Incense Red Douglas pine] &20 >20 Cedar Fir Fir Tractor Logging System Crown Scorch  75% 95% 80% 100% ? ? Crown Scorch + RTB or Ambrosia Beetle ? Helicopter and Skyline Logging Systems Crown Scorch  65% 85% 65% 95% ? ? Crown Scorch + RTB or Ambrosia Beetle ? 51 Table 3-6 of the FEISs is entitled Probability of Tree Mortality. Both FEISs state, Table 3-6 indicates the probability of tree mortality to individual trees meeting the Power [and Freds] Fire marking guidelines (Correctly Predicted Mortality) and the predicted survival of trees with less fire damage than the minimum requirements of the marking guidelines (Correctly Predicted Survival). According to Table 3-6, a yellow pine cut in accordance with the 65% crown length scorch guideline of Table 3-5 has a 90% Correctly Predicted Mortality. A white fir over 20 in diameter cut in accordance with the guidelines has a 87% Correctly Predicted Mortality. 52 For the convenience of the reader, we reproduce Table 3-6. We have italicized the numbers 90 and 87 to indicate the correctly predicted mortality percentages for yellow pine and white fir cut in accordance with the 65% crown length scorch guideline: 53 PP/JP/SP Incense Douglas [yellow pine] White Fir Cedar Red Fir Fir Tractor Logging System Correctly Predicted Mortality (%) 96 95 100 100 -- Correctly Predicted Survival (%) 51 63 88 -- -- Helicopter and Skyline Logging Systems Correctly Predicted Mortality (%) 90 87 85 100 -- Correctly Predicted Survival (%) 65 74 89 -- -- 54 Earth Island contends that the findings contained in the draft Hood Study, as well as in other studies, have substantially different percentage estimates of tree mortality from the percentages contained in Table 3-6. Earth Island relies upon the declaration of Dr. Edwin B. Royce in support of its contention. Royce has a Ph.D. in Botany with a specialization in Forest Plant Ecology from the University of California at Davis, and a Ph.D. in Applied Physics from Harvard University. Royce has had twelve years of experience in the characterization of forest vegetation. 55 The USFS challenges the admissibility of Royce's declaration, as well as other expert declarations offered by Earth Island, because they were not before the agency during the administrative review process. We allow extra-record materials if necessary to determine whether the agency has considered all relevant factors and has explained its decision. Sw. Ctr. for Biological Diversity v. U.S. Forest Serv., 100 F.3d 1443, 1450 (9th Cir.1996). Because Earth Island's expert declarations are offered for this purpose, they were properly before the district court and are properly before this court on review. 56 According to Royce, yellow pine and white fir are both thick bark trees whose bark provides significant protection of the living tissue beneath the bark. According to Royce, [c]rown kill is commonly the dominant source of fire-induced mortality in large trees having thick bark, such as white fir or yellow pine. However, [f]all fires, such as the Power and Fred's fires, are least damaging to conifers. In part this is because reserves of stored products of photosynthesis are high and because new growth throughout the trees is less vulnerable to damage then, as compared to that same growth during the summer growing season. A low-intensity surface fire commonly produces only partial crown kill and only minimal mortality in larger trees. Trees tolerate partial crown kill in a surface fire in part because only the lower part of the crown is normally killed. The lower part of the crown is less photosynthetically productive than is the upper part. 57 For yellow pine, Royce states, [t]he mortality guidelines for yellow pine (ponderosa and Jeffrey pine) will permit the harvest of trees with a substantial probability of surviving if they were not harvested. The Royce declaration contains tables showing predicted tree mortality in the Hood Study, as well as in three other studies. Those other studies were by Ryan and Reinhardt, by Stephens and Finney, and by McHugh and Kolb. Royce states as to yellow pine, [f]or helicopter and skyline logging, mortalities from the[Hood Study] models are 60% and 70%, as compared to a 90% mortality claimed in the FEIS and ROD. Mortalities predicted by the three other studies are even more at variance from the mortality predicted in the FEISs. Royce states, 58 [T]he guidelines for helicopter and skyline logging will allow the cutting of small trees that have probabilities of mortality between 12% and 57% and large trees with mortality probabilities between 11% and 32% (compared with 90% mortality claimed by the FEIS's). Even if one accepts only the largest of the probabilities of mortality—that given by the Ryan and Reinhardt paper— this still translates into a worst case probability of survival of up to 68% for trees that could be cut (meaning 68% of the trees logged would otherwise survive). (emphasis in original.) 59 In addition, Royce states that he personally evaluated 39 yellow pine that were part of the data base for the Hood Study, and found evidence of measurement errors that would lead to the development of models that over predict mortality. According to Royce, 60 I measured the average amount of crown kill on these trees to be 88%, whereas, the [Hood Study] field workers evaluated the same damage to average 64%. A small part of this difference may be due to the fact that my measurements were crown volume measurements, whereas, the [Hood Study] measurements were linear measurements. However, as discussed [earlier in my declaration], this should produce only a few percent difference between the two measurements. I suggest that at least a substantial part of the difference between the two measurements is a result of the [Hood Study] field workers underestimating crown kill. This will result in a model that over predicts mortality when correct crown kill values are used. A corrected [Hood Study] model yielding lower mortality predictions would make the proposed guidelines even less defensible. 61 For white fir, Royce states, [t]he mortality guidelines for large white fir will permit the harvest of trees with a substantial probability of surviving if they were not harvested. As he does for yellow pine, Royce presents tables showing predicted tree mortality in the Hood Study, as well as in the three other studies. He states as to white fir, [f]or the helicopter and skyline logging of large trees, mortalities from the[Hood Study] models are between 25% and 45%, as compared to an 87% mortality claimed in the FEIS and ROD. Just as with yellow pine, mortalities predicted by the three other studies are even more at variance from the mortalities predicted in the FEISs. Royce states, 62 the guidelines for helicopter or skyline logging will allow the cutting of large trees with mortality probabilities between 7% and 50%, as compared to the 87% mortality claimed in the FEIS's. Even if one accepts only the largest of these predictions of mortality—that given by the Ryan and Reinhardt paper— this still translates into a worst case probability of survival (in helicopter units) of up to 50% for trees that could be cut. (emphasis in original). 63 In response, the USFS relies on a declaration of Sheri L. Smith. Smith is one of the three co-authors of the draft Hood Study. She has B.S. and M.S. degrees in Biology and Entomology from Utah State University. She has been an USFS employee for 15 years. She has been involved in evaluating fire-injured trees in California since 1991. 64 Smith makes three points in response to the Royce declaration. First, she contends that Royce misunderstood Table 3-6. As noted above, that table is entitled Probability of Tree Mortality. Royce understood the percentages contained in that table as indicating the probability that a tree will die. For example, Table 3-6 indicates that a yellow pine with a minimum of 75% scorched crown (the guideline for tractor logging) has a correctly predicted mortality of 96%, and a correctly predicted survival of 51%. Royce understood the table to mean that 96% of yellow pine with a minimum of 75% scorched crown will die. 65 Smith responds, 66 The marking guidelines used for the Power and Freds fire are based on models that use percent crown kill.... I attach a true and correct copy of an excerpt of the models which are the basis for the Power and Freds marking guidelines (Attachment A). 67 Mr. Royce states that Table 3-6 represents that 96% of trees with 75% crown kill will die. This is simply incorrect. The 96% in Table 3-6 (classification table) shows that the marking guideline model used by the Forest Service is correct in predicting mortality 96% of the time when our individual study trees are run through the model. In other words, the 96% is an estimate of the accuracy of the model, not of the percentage of mortality as Mr. Royce states. Both FEISs accurately interpret the findings of our paper in light of the specific marking guideline model selected by the Forest Service. 68 The percentages shown in Table 3-6 (classification table) of both the Power and Freds FEIS are derived from the entire [Hood Study] dataset, which, for yellow pine, is based on measurements of 1,969 trees. The models in our paper take these percentages to arrive at a statistical probability of mortality for an individual tree. The probability of mortality (Pm) ranges from 0.0 to 1.0, with 1.0 being certain mortality. The Forest Service selected a Pm of 0.90 for all ground-based harvest units. For yellow pine, a Pm of 0.90 corresponds to a crown length kill of 75%. Using this criterion, the marking guideline model correctly predicted mortality for yellow pine trees in the [Hood Study] dataset 96% of the time and correctly predicted survival 50% of the time. In other words, using a Pm of 0.90 (75% crown kill), only 4% of the trees the model predicts will die, actually survived, but 50% of the trees predicted to survive eventually died.... 69 This means that there is a high likelihood of correctly predicting mortality, but a lower likelihood of correctly predicting survival using the 75% crown scorch model, which means that it is much more likely that the Forest Service is leaving trees behind that will later die, than it is taking trees that would have survived. This is directly contrary to Mr. Royce's assertions[.]... The same misinterpretation of the data is true for Mr. Royce's discussion of yellow pine on helicopter and skyline harvest units and all white fir, all of which misinterpret the percentages in Table 3-6 to be something other than what they are—a verification of the accuracy of the marking guideline model using the [Hood Study] dataset. 70 (emphasis in original). 71 Second, Smith responds that Royce estimated the probability that a tree will die based on the percentage volume of crown kill. By contrast, the Hood Study estimated the probability based on the percentage length of crown kill. Therefore, according to Smith, Royce's comparisons are problematic. 72 Third, Smith responds that two of the three other studies upon which Royce relies for his comparison—the studies of Stephens and Finney, and of McHugh and Kolb—are based on prescribed fires. According to Smith, [m]ost often, the objective of a prescribed fire is to limit the mortality of the overstory while reducing fuel loadings and ingrowth of smaller trees. Our model is more appropriate to the type of fire represented by the Freds and Power fires, which killed not only the ingrowth of smaller trees, but also resulted in high levels of crown kill of larger trees. 73 We analyze Smith's three points in turn. First, Smith contends Royce has misunderstood Table 3-6. According to Smith, the percentage figures given for correctly predicted mortality—such as 96% for yellow pine with a minimum of 75% crown length scorch—do not predict the percentage of trees that will die. Rather, these figures predict the accuracy of the prediction of the percentage of these trees that will die. Similarly, according to Smith, the percentage figures for correctly predicted survival—such as 51% for yellow pine with a minimum of 75% crown length scorch—do not predict the percentage of trees that will live. Rather, they predict the accuracy of the prediction of the percentage of these trees that will live. Smith may well be correct. Indeed, it appears from the face of Table 3-6 that she may be, for if the table predicted the percentage of trees that will die or live, as distinct from predicting the accuracy of the predictions of these percentages, the percentages given in the table should add up to 100%. Instead, in the example given for yellow pine with 75% crown length scorch, they add up to 147% (96% plus 51%). 74 But even if Smith is correct, this does not solve the problem. Table 3-6 is, to say the least, misleading. Its title is Probability of Tree Mortality, rather than Probability that Predictions of Probability of Tree Mortality and Survival are Correct. Second, there is no other table in the FEISs providing the probability of tree mortality. The absence of such a table is significant. The single most important aspect of the FEISs is their estimate of the likelihood that trees with certain amounts of fire damage will die. This is so for the obvious reason that the justification for cutting burned or scorched trees is the likelihood that they will die. Any reader of the FEISs will therefore look for a table providing probability of tree mortality. The only table in the FEISs that appears to provide that information is Table 3-6. It is not unforeseeable that a reader—even an expert reader such as Royce—would misunderstand the table. Further, the explanation for Table 3-6 provided by Smith's declaration in the district court is nowhere provided in the FEISs. For example, Attachment A to Smith's declaration is not provided, or even referred to, in the FEISs. The absence of such an explanation in the FEISs obviously increases the chance that the table will be misunderstood. 75 Further, the Royce declaration provides tree mortality percentages given in the draft Hood Study, and he compares those percentages to those given in Table 3-6. The Hood Study percentages provided by Royce are not contested by Smith. (This is not surprising, given that Smith is a co-author of the Hood Study.) The Hood Study mortality percentages are substantially lower than the percentages given in Table 3-6. Yet those percentages are not provided in the text of the FEISs. If the USFS had been truly interested in educating the reader as to the actual percentages of trees likely to die from scorch damage, it would have provided those percentages in the FEISs. Instead, it provided Table 3-6 (entitled Probability of Tree Mortality) giving percentages of correctly predicted mortality. Even if the USFS could properly rely on the draft Hood Study instead of other tree mortality studies—a question we do not here decide—it should have provided the mortality percentage figures in the Hood Study rather than, or in addition to, the figures in Table 3-6. 76 Second, Smith responds that the comparisons used by Royce to estimate tree mortality are based on percentage volume of crown kill rather than percentage length of crown kill. We note initially that Smith's response has no application to the comparison between the percentage numbers given in Table 3-6 and those given in the Hood Study. Both Table 3-6 and the Hood Study were based on the same methodology—correlating percentage length of crown kill with likelihood of tree death. Further, we note that with respect to studies that relied on percentage volume rather than percentage length of crown kill, Royce had explained in his declaration why the FEISs' emphasis on the difference in the two type of crown kill measurements is misleading. He wrote: 77 Tables 3-4 in both the Power and Fred's fire FEIS's show a relationship between these two measures of crown kill in which the volume measure is much larger than the linear measure for the same amount of damage. However, these tables are valid only for young trees with a tapered shape, similar to the classic conical Christmas tree shape shown in figure F-1 of the Powers FEIS or figure A-1 of the Fred's FEIS. Large, mature trees growing in a forest surrounded by other trees have a shape more like a cylinder, tapered only in the topmost branches.... It is to mature trees that the guidelines [in the FEIS's] are to be applied to determine if the trees are dying and hence subject to salvage harvest. In the context of the salvage of mature trees, the inclusion of these tables and figures in the FEIS's is completely misleading. 78 My experience measuring mature trees on the Eldorado-Star fire site ... was that, within the uncertainty with which these determinations can be made in the field, the two measures give the same numerical value for crown kill. 79 Third, Smith responds that two of the three other studies used by Royce for comparison were based on prescribed fires. According to Smith, reliance on these two studies—the Stephens and Finney study and the McHugh and Kolb study—was inappropriate because the Power and Freds Fires resulted in high levels of crown kill of larger trees compared with the levels of crown kill in the prescribed fires. It may well be that, as Smith says, the prescribed fires resulted in lower levels of crown kill in larger trees. But Smith does not explain why that makes a difference. As those two studies are described by Royce, they predict tree mortality based on the actual percentage of crown kill in particular trees. The fact that fewer trees have that degree of crown kill in a prescribed fire should not make any difference in the predicted mortality of those trees that actually have a high level of crown kill. 80 Further, Smith does not mention the third study upon which Royce relies—the Ryan and Reinhardt study. Of the three studies, this one gives the highest probability of tree mortality. Royce explicitly discusses and relies on the Ryan and Reinhardt study in his conclusion that the FEISs overpredict tree mortality. For example, as indicated above, Royce writes with respect to yellow pine, [e]ven if one accepts only the largest of these probabilities of mortality—that given by the Ryan and Reinhardt paper—this still translates into a worst case probability of survival of up to 68% for trees that could be cut[.] 81 We recognize that the FEISs discount two of the studies—those by Stephens and Finney and by Ryan and Reinhardt. The Power and Freds FEISs both discount the Stephens and Finney study on the ground that its purpose was not to provide salvage guidelines, and that some of its data were obtained pre-rather than post-fire. The Powers FEIS discounts the Ryan and Reinhardt study as involving only one of the species (Douglas fir) that occurs in the Power Fire area. The Freds FEIS discounts that study in slightly different terms, stating, [r]esults from the Ryan and Reinhardt 1988 study were obtained mostly for tree species not found in, and geographic regions not related to, the Sierra Nevada. But even if we must discount both of these studies—a question we do not decide—the McHugh and Kolb study remains. That study was not discussed, or discounted, in either of the FEISs. 82 In the end, we conclude that the USFS abused its discretion in its estimates of likely tree mortality in both the Power and Freds FEISs. We will assume, for purposes of our analysis, that the Smith declaration correctly states what the percentage numbers in Table 3-6 really mean. But even if the Smith declaration is correct, Table 3-6 is, for the reasons given above, extremely misleading. A casual, or even a careful, reader of the FEISs and of Table 3-6 could easily conclude that 96% of yellow pine with a minimum of 75% crown length scorch will die, or that 90% with a minimum of 65% crown length scorch will die. If those were, in fact, the percentages of yellow pine with that degree of fire damage that will die, it would be easy to conclude that the USFS is justified in cutting all yellow pine that satisfy those criteria. But those are not the percentages of trees that will die. 83 The Hood Study itself estimates a substantially lower tree mortality than the percentage numbers provided in Table 3-6. The other three studies estimate even lower tree mortalities. It is possible that those who prepared the FEISs, and the Forest Supervisor who signed the RODs based on the FEISs, understood Table 3-6 in the way Royce understood it. If this is so, the USFS abused its discretion, for it failed to take the requisite hard look at the data underlying their analysis and decision. Kern, 284 F.3d at 1066. It is also possible that those who prepared the FEISs, and the Forest Supervisor, understood Table 3-6 in precisely the way Smith described it in her declaration. If this is so, the USFS also abused it discretion, for it failed to reveal the actual percentages upon which it relied and it drafted highly misleading FEISs. Native Ecosystems Council, 418 F.3d at 965. Under the first alternative, the USFS misunderstood the data; under the second, it understood but concealed and misrepresented the data. Under either alternative, it abused its discretion. 84