In less then a month it will be time for our annual effort at accomplishing our prescribed burns here at Fish Springs. These burning efforts are critical to how we manage the wetlands here and are a core part of keeping the marshes healthy and the wildlife that uses them well provided for.
Burning accomplishes a number of beneficial outcomes. At the top of our list is to release the nutrients that are tied up in the dense residual vegetation that characterizes our wetlands after several growing seasons. Most of these nutrients will remain in the basin after a burn and when we re-flood, they provide a big boost to the aquatic insects that quickly re-colonize. We have several years of study results to support that the first spring after burning and re-floodinging, the number of species and the total numbers of these aquatic insects make an incredible leap in productivity. These "water bugs" are the critical food for nearly all of the young of virtually all of the waterbirds that nest here at Fish Springs. Many will switch to a largely vegetarian diet when they are a bit older but the young forage almost exclusively on aquatic insects in the early stages when high protein levels are critical to fuel the rapid growth. We have seen that the waterfowl hens know where these prime brooding areas are and often move their busy broods some distance to take advantage of this smorgasbord!
Burning also reinvigorates the growth of the wetland vegetation in these impoundments. Much like a lawn that has not been mowed for sometime and then is mowed, and then given a big boost of fertilizer, in in this case in the form of all of these burn released nutrients, the plants grow back robust and higher in nutrient levels. This, in turn, attracts those of our wildlife constituency who are herbivores.
As a practical matter, burning also exposes dikes and ditches that have been obscured for a few years and give us a chance to perform any needed inspections and maintenance. More than once I have had a water control structure disappear in the vegetation only to starkly re-appear after a burn!
This year we will be burning Avocet Unit, our largest single burn in our five year burn cycle. At over 1,000 acres, it is quite a sight. While we do close much of the Refuge on burn day, we do invite any and all to come and observe from the Headquarters area or from up on the hill by the Pony Express monument. There will be flames in excess of 30' high and a smoke column that will probably be visible from quite far away. The exact date is not set but we are planning to burn during the week of March 16-20 if conditions are sufficient.
When one visits Fish Springs and see the incredible volume of water and the verdant wetlands, it is easy to forget that it sit in the middle of the desert. While I suspect that most folks define deserts by what they see in the form of vegetative cover, they are actually defined by precipitation. Generally speaking, deserts are defined at areas that receive less than 10" of precipitation each year. Certainly the eastern Great Basin meets that definition.
Our long term annual precipitation average here at Fish Springs is just over 8". However, the extended drought cycles of the last decade or more are working towards reducing that total in a rather precipitous manner. We have not had a year for over a decade where we reached that total. Our long term average annual snowfall at the Refuge is 15" and it has been nearly 15 years since we had a year where we reached or exceeded that average.
This past year, we were particularly hard hit during the critical spring and early summer period. Normally during this time period, the environs of around the Refuge would receive about 3-3.25" of rain. This past year from the beginning of April to late July we only had about 1.3". Normally these will come as smaller .25-.35" events with an occasionally gully washer.
These spring and summer rains are vital in the survival of our upland and salt desert scrub nesting bird species. These smaller but recurrent rains are often a critical trigger for egg and larval hatching for many desert insects. Just like the birds that nest on the Refuge wetlands, the birds who nest in these other habitats, regardless of what they might forage on as adults, are entirely depended on having an abundance of insects to raise young. This past year we saw very poor production due to the fact that many broods simply could not find enough insects to thrive and reach adult stage.
Let's hope for a wet spring. Because it does not matter if you need it for raising a crop of hay, raising a garden, keeping the flow going to a favorite trout stream, of for precipitating an insect hatch for raising young birds, it is critical to the life blood of the desert. As my beloved friend Leah Layland always reminded me, "There is never a bad time for rain in the West Desert. Sometimes it sure isn't very convenient but it is never bad!"
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Your prescribed fire program sounds great. The natural wildfire program has been lost in so much of the world, but as you point out, it has so many benefits.
ReplyDeleteI hope we have a wet spring, too. Without any streams flowing from the surrounding mountains onto the wildlife refuge, you are particularly reliant on what falls out of the sky.