By: Todd Thomas, Water Resources Forester, Texas A&M Forest Service
Q: While conducting a complete harvest on a site with dense underbrush, my crew accidentally cut through an area that should have been reserved as an SMZ. Now that what’s done is done, what do you recommend as our next move?
A: While I hate to hear of the destruction of an SMZ, do not worry, not all is lost. First things first, in order to eliminate any confusion during site prep and planting, the area that would have been SMZ needs to be flagged off. This will avoid any intrusion of site prep or other management activities down the road that could cause any damage to water quality.
|Aerial view of Streamside Management Zones (SMZs) on a recent harvest in East Texas|
During site preparation and planting it is extremely important that any equipment on site stay out of the newly flagged off SMZ to avoid soil disturbance next to the stream. This will reduce erosion and the resulting sediment that could enter the stream. Remember, since you have harvested the timber off the tract, there will be more water wanting to enter the stream since those trees are no longer there to use it. This means that there will be more water in the soil, especially right next to the stream, making the area much more prone to rutting. If you do decide to plant this area when you are planting the rest of the tract, be sure and plant it by hand so you don’t rut up this sensitive area.
Going ahead and marking off the area that would have been SMZ will also be extremely beneficial if you plan on using herbicides during site prep. This will eliminate the possibility of any herbicide being directly applied to the stream. Also, not spraying here will allow vegetation to re-establish itself quickly, and reduce erosion potential. Not to mention this helps with maintaining biodiversity for wildlife habitat, one of the side benefits of SMZs.
It may not be a bad idea to go ahead and plant a mix of hardwood seedlings in this area, just to ensure that things begin to reestablish at a rapid pace. However, there is a good chance that there is enough seed already in the soil for seedlings and shrubs to grow in this area pretty densely. I have heard stories relating to similar scenarios where hardwoods were planted, but were eventually out-competed by seedlings that grew from the already existing seed bank. How you choose to approach this is totally up to your discretion.
If you plant anything, it is probably a good idea to at least put down some grass seed. There is chart that is extremely helpful in determining what to plant on page 67 and 68 of your blue book. This form of revegetation will hold the soil in place while any seedlings are getting established. Remember, per Texas BMPs, that it is not recommended to use fertilizer within an SMZ (page 66, blue book). This is because excessive nutrients entering the stream can greatly degrade water quality.
In conclusion, while it is never a good thing to slick off an SMZ, there are measures to restore the SMZ and to correct the mistake. Remember to delineate the area, keep out equipment, and to actively manage the area to reestablish vegetation so that it can return to a functioning SMZ. Keep the questions coming; you can call them in to me at 936-639-8180, or email me at firstname.lastname@example.org.
*This article was published in the November 2013 edition of the Texas Logger