Tuesday, September 6, 2016

Letting the Light In for Rare Plants!

Submitted by Michael R. Jenkins, Magnolia Chapter. Plant Conservation Program Biologist, Florida Forest Service, Florida Department of Agriculture and Consumer Services

Sometimes sun-loving (usually pyrophytic) plant populations are in heavy competition with taller, woody plants and in need of help from an outsider. Here, someone with a pair of loppers, work clothes, water, and a few hours can really help. How about an 80% increase-in-stems kinda help? This situation was encountered where a nice population of White Birds-In-A-Nest (Macbridea alba) highly benefited from hand removing competing small trees and shrubs from around the plants, done to open up the habitat and to mimic fire (somewhat). This was done by one person working for just four hours. This person is the "fuel buster." 

White-Birds-In-A-Nest: Macbridea alba, Mint Family, Lamiaceae G2 S2, Federal Threatened, State Endangered,
Endemic to well-burned/mowed, pine dominated habitats adjacent to the lower Apalachicola River) 
 Photo: Michael R. Jenkins

This particular “White Birds” population covers about a quarter of an acre in a habitat classified by Florida Natural Areas Inventory (FNAI) 2010 Natural Community Guide as a Wet Prairie but within a matrix of Wet and Mesic Flatwoods, and Bottomland Forest. Interestingly and untypically, White Birds here grow up to the edge of a small stream. The population has been periodically monitored since it was first found by botanist Wilson Baker in 2003 and documented in the FNAI Florida Element Occurrence database of rare plants, animals, and natural communities.

White-Birds-In-A-Nest bloom in late June and July.
Photo: Michael R. Jenkins
 
The White Birds bloom in late June and July and in 2015, were in serious competition with smaller Red Maples, Water Oaks, Silver Bay Magnolias, Wax Myrtles, tytys (White and Black), Gallberries, and several species of St. John’s worts, over head high. This competing, woody vegetation is known by Florida biologists as “heavy fuels” because they grow in the absence of fire and when they do burn, they burn really hot because of their biomass, sometimes killing native pine trees that grow in the Wet Prairies.

The population was surveyed for the year and flags were placed around all points that had ever been taken there since 2003. To remove the heavy fuels, the site was revisited in March, when superterranean portions of the White Birds were not visible. All heavy fuels were cut and cleared out over the flagged population with a pair of loppers, cutting them to ground-level and removing the cut plants away from the population to increase sunlight. The cuttings were placed in areas outside of the Wet Prairie in thicker areas of the Bottomland Forest and on top of large briar patches.

  Picture of east portion of White Birds-In-A-Nest population (large, white flowers)
 where heavy fuels were removed and plant reacted very positively.
Photo: Michael R. Jenkins
The population responded so well (estimated an 80% increase in stems) that it was just too hard to walk into the population without stepping on them and crushing them! So I didn’t. 

They had formed quite a groundcover in some places! Flowering increased also with the increase in stems but what was really eye-popping was the stem-density and vigor of the plants in the area where the heavy fuels were removed. The plants also came up into new areas that were not cut but adjacent to the cut site, enlarging the population. They obviously had a very positive response to this management technique that is easy and fun to do. The same effort will be done each year.

This was the best response we have had by a species to this “fuel busting” technique, similar to ones done in the Panhandle by past Florida Park Service biologist, Tova Spector in pitcherplant bogs that increased pitcherplant and terrestrial orchid populations. These are now being continued by Atlanta Botanical Garden and several other organizations and individuals throughout Florida. We have had increased flowering in all fuel buster areas for Pot-of-Gold Lily, Florida Beargrass, Lewton’s Polygala, Godfrey’s Butterwort, and other pitcherplant and butterwort species. It is important to note that you must be committed to follow up treatments of a site for successive years because of the heavy resprouting from the cut woody plants that occurs soon after cutting.

Editor's Note: I asked Michael about the term "Fuel Buster" because I had never hear it to refer to a person. Here is his response: "When I was out in field with Florida Park Service’s Tova Spector (now gone and in the West) at her sites where they had removed competing woody vegetation over pitcherplant bogs, we used to say “bust up the fuels”. Since saying “removal of competing woody vegetation” is such a mouthful, I am just saying Fuel Buster. I have heard it used by other folks in different organizations (e.g., fire suppression) but doing the same activity. Anyway, it would help if it were a more common activity because it works so well for the plants!"

I agree! Where rare native plants are in similar harms way, we need more "Fuel Buster" patrols. 




1 comment:

John Lampkin said...

Heavy resprouting and the need for extensive followup treatment is easily prevented by IMMEDIATELY painting the stump with triclopyr concentrate as per label directions for stump treatment. It's fast and easy as a three-person job: one to lop, one to pile up the cuttings and one to paint the stump. We are using this technique in lieu of fire in a small natural area in Hillsborough County. Thanks for the term, "Fuel Buster." Now we know what we are!