Discussion

Let us know what you think about any topic related to the Sierra Nevada Adaptive Management Project in the forums below. The Principal Investigators on the UC Science Team cannot answer every post, but they will read all comments in their areas, and respond to comments as a group at each quarterly meeting. We greatly value your input!

UC Science team response to SPLATs vs. DFPZs questions by Kim_Ingram, at 3:33 p.m. on 17 March 2010,

George,

The following is the response from the science team to your questions and comments re. SPLATs vs DFPZs. If you have any follow up questions/comments, please feel free to use this discussion board so all interested parties may be informed.

3/17/2010

Reply to questions from George Terhune from the SNAMP FFEH Team.

1) The Meta-analysis was unpersuasive, due to the great differences among sites and treatments, which cannot be papered over with statistical manipulations.

Answer: The objective of the fire integration project is to compare the performance of disparate treatments. Thus the challenge is to construct meaningful measures of comparison. One of our attempts at comparison was with the normalized impact metric where we controlled for the percent of area treated. The resulting index does not have the intuitive meaning of the raw measures (e.g., changes in fireline intensity) but it does allow us to compare across sites. The statistical manipulations are not meant to paper over differences but to provide a valid means of comparisons.

2) Why has nobody yet done a direct comparison of the SPLAT strategy vs the DFPZ strategy, using the same terrain, fuel, weather scenarios, area of treatment, type of treatment, and modeling techniques, but varying only the pattern of treatments on the ground? After all, the fundamental difference between the SPLAT and DFPZ strategies is the pattern of treatment, and DFPZs are an exception to the Regional policy specifying SPLATs, and that exception was specifically made by Congress to "demonstrate the effectiveness" of the DFPZ strategy. It isn't enough to say "it’s effective." You have to say "How effective," "Compared to what?," and "How efficient, in terms of cost-effectiveness, effect on suppression cost and firefighter safety, and effectiveness at different levels of implementation, from a few percent of the landscape treated in early years, to perhaps 30 percent of the landscape treated after 10 or 15 years. What effect would each strategy have on suppression effectiveness and safety? If these questions aren't important enough to be investigated directly, what is it that would be more important?

Answer: The suggestion for an evaluation of multiple forest management options for one site is a good one. However it is not the goal of SNAMP. The role of the UC Science Team was defined by the federal and state agencies who signed the MOU that stated the goals of the project. The focus is on the forest management alternative approved in the 2004 Record of Decision.

The UC Science Team and the Pacific Southwest Research Station did make a commitment to collaborate in order to gain the most insight from the research efforts underway in the Sierra Nevada. The Fire Integration Study is part of this commitment. While the insights may frustrate in what they don’t do, they do support the general principle behind all coordinated landscape-level treatments. In short, their impact on modifying fire behavior across the landscape is more than the sum of the individual treatments.

A more fruitful exercise would be to compare the implemented DFPZ network in Meadow Valley to a theoretical SPLAT design for the same area. This comparison would not be perfect, but it may be worthwhile. The problem is who would design the SPLATs? A totally theoretical design (regular, louvered, rectangular treatments) would never actually happen on the ground (Collins et al. 2010). As was the case with the DFPZs in Meadow Valley the planned network differed considerably from the actually implemented network. One could imagine a similar situation with a planned SPLAT design and actual implementation. So, if a more realistic SPLAT design could be developed perhaps PSW could take on the question.

Collins, B.M., S.L. Stephens, J.J. Moghaddas, and J. Battles. 2010. Challenges and approaches in planning fuel treatments across fire-excluded forested landscapes. J. Forest 108(1):24-31.

Re. the question of an email forum on "SPLATs vs DFPZs" by Kim_Ingram, at 11:12 a.m. on 11 March 2010,

George,

I spoke with Dr. Maggi Kelly, who designed and maintains the website. She suggested that most of the functions of an email or on-line forum such as you are suggesting, can be accomplished through the current SNAMP website. However,since the website, as currently designed, does not readily support the addition of documents or videos, participants could post a link to a particular document, photo, or movie within the body of their comment.

Unfortunately, the website also does not allow for a threaded discussion, or a continuous link from a particular discussion topic. Each new post is its own topic, though they are linked through key words. So a threaded discussion could be held if users search for a particular key word to view the history of the topic.

If you have any further comments/questions re. this area of your original comments, please feel free to contact me or use this discussion board. The Fire & Forest Ecosystem Health team is working on a response to your other questions/comments and I will let you know when they have been posted.

Thanks for your suggestions,

Kim Ingram, PPT Team

Cost-benefit of lidar by Maggi Kelly, at 1:18 p.m. on 13 July 2009,

This post is in response to the question: "Do the scientists find it is sufficiently accurate to give them measurements at the needed accuracy and at what cost?"

I will touch on the accuracy question first, and then the costs question.

First, the accuracy question. Tree attributes such as height, dbh (diameter at breast height), height to live crown, species, age, location, basal area, volume, biomass growth and leaf area index have been measured in the field in forest plots for over 100 years. Many of these attributes can be measured directly using LiDAR data, and some can be inferred from lidar data. Stand attributes such as age, trees per hectare, mean diameter and height, dominant height, volume per hectare, form factor, annual increment per hectare and growth have also been estimated from individual plot data for some time. Again many of these can be measured from processed LiDAR data. Accuracy, which is usually estimated by comparing ground data from a series of plots with lidar values, varies with species, density, topography, lidar equipment. For example, in our SNAMP project, preliminary analysis shows r2 of 0.78 for tree height, and 0.65 for dbh. A clear technical advantage of lidar is the ability to completely inventory the forest, instead of collecting a sample of plots that might not be representative of forest heterogeneity. The derived data products that come from lidar can easily be used at multiple scales (and resolutions) as direct inputs to fire models and environmental niche models. The field plot-based approach requires interpolating between these sampled plots to generate a continuous surface.

Second, the costs question. There is more information on the cost-benefits of lidar for topographic mapping and construction. For forestry applications, however, there is less information on the relative costs of lidar vs field capture. The cost of lidar includes acquisition, field data collection, and processing, which includes software and hardware as well as personnel. These can add up. Most comparisons of lidar vs. field alone concentrate on the technical advantages highlighted above. One exception is Renslow et al. (2000) who claim that for a typical even-aged, managed forest of 500,000 acres where in each year, 2% of 10,000 acres (200 acres) are sampled to determine what management steps are needed, cost savings with lidar would be $15,400 annually. I think this is overly optimistic, as it only includes 2 weeks for analysis. Our SNAMP analysis (albeit over a much larger area) takes considerably longer.

So, in proto-conclusion, I think the advantage of lidar is clearly in its accuracy and coverage, and these outweigh any cost savings that a fast and cheap field campaign might provide. Still, I will come back to this topic later with more analysis from our SNAMP project.

The value of LiDAR by Kim_Ingram, at 10:29 a.m. on 8 June 2009,

For those of you unable to attend out recent workshops on the use of LiDAR and other technologies, it has been asked if the spatial team can give a quick synthesis of the value of LiDAR.

Do the scientists find it is sufficiently accurate to give them measurements at the needed accuracy and at what cost?

Data Sharing by Shasta Ferranto, at 8:39 p.m. on 4 June 2009,

At the recent LiDAR workshops, Maggi Kelly talked about some of the publicly available data generated from the SNAMP project. This data can all be found on our data sharing website: https://snamp.ucmerced.edu/

If you'd like more information on which data we can and can't share, please check out our data sharing agreement.

Fuel build-up in the main control study area by Marek Jakubowski, at 4:27 p.m. on 29 October 2008,

N37 26 13.9 W119 34 34.0 in WGS84 Corresponding to photo "" on the photo page.

This shows an area of lots of downed fuel, encountered while approaching an FFEH plot.

US District Court Decision - Basin Project by Maggi Kelly, at 3:30 p.m. on 14 August 2008,

Judge M. C. England has found in favor of the Forest Service and HFQLG Pilot on 11 out of 12 points in the challenge of the 2004 Sierra Nevada Framework and the Basin Project on the Plumas National Forest. The Decision Document and some content from the document are posted on the discussion site.

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