Tuesday, November 1, 2011

November BMP Q&A

By: Chris Duncan, Water Resources Forester (Ret.), Texas Forest Service

Q: We own several hundred acres of timberland which were lost due to the recent wildfires in East Texas. We have spoken with our consulting forester and are planning on conducting some salvage harvesting operations. Our property has a fairly good sized stream which usually flows 3-4 months out of the year during the wetter months. Most of what we will be harvesting was completely or nearly completely killed by the fire, although there are some areas with higher survival. I would like to know if you have any recommendations on how we should conduct our harvesting so that we have as little impact to water quality as possible.
A: Sorry to hear about your loss of timber during this unprecedented fire season. I am glad to hear that you have consulted a professional forester to help you with the recovery of some of your timbers value. I would be happy to provide some recommendations for Best Management Practices which will help you reduce the risk of impacting your streams water quality during your operations. It appears you likely have an intermittent stream that flows through your property based on your description of the stream. Let’s start with the Streamside Management Zone (SMZ) along this stream.

SMZs provide several functions to help protect water quality. One of an SMZs primary functions is to provide shade to the water body. The shade provided by an SMZ helps regulate the water temperature, thereby protecting the thermal qualities of the stream. Many organisms have small tolerances to large thermal changes. Therefore, care should be taken during wildfire salvage operations not to remove more trees from the SMZ than absolutely necessary. Your forester should survey the SMZ, and make determinations of which trees will likely die from the fire, and which trees may survive. We recommend that any trees which may survive be left uncut to provide as much shade to the stream as possible. A good rule of thumb for hardwoods in the SMZ may be to leave any trees which still have at least 50% of their crown intact. As far as the pine trees go, if they are going to die from the fires we had this year, they have probably already turned brown and dropped their needles. Any pine trees which still have a majority of the crown in lush green needles should be saved if possible.

While selectively harvesting within the SMZ, care should be taken to disturb the ground as little as possible to maintain the SMZs protection of the stream from runoff. If the vegetation on the ground within the SMZ was completely consumed, efforts should be made to re-establish vegetation as soon as possible.

On rare occasion (flat terrain, lightly erodible soils, and cooler burned areas), a forester may use his professional judgment to determine if it is safe to narrow an SMZ so that it is less than the recommended 50’ on each side of a stream during salvage operations to recover some of the value. If it is determined that an SMZ will be narrower (maybe 30’– 40’ feet wide) than the 50’ recommendation, efforts should be made to disturb the soils and vegetation that would normally fall within the recommended SMZ as little as possible. Any mechanical or chemical site preparation or machine planting should be conducted outside the original 50’ buffer to reduce the risk of impairing water quality.

As far as the rest of the tract outside the SMZ; the harvesting, site preparation, and planting should all be conducted in accordance with all other BMP guidelines in the bluebook.

If you have any questions about wildfire salvage BMPs or any other BMPs please contact me.

* This article was published in the November 2011 issue of the Texas Logger

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