Invasive Species Report USDA, FOREST SERVICE, SOUTHERN REGION KISATCHIE NATIONAL FOREST CATAHOULA RANGER DISTRICT
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Invasive Species Report USDA, FOREST SERVICE, SOUTHERN REGION KISATCHIE NATIONAL FOREST CATAHOULA RANGER DISTRICT Forest Health 2012, District-wide INTRODUCTION The proposed project description, alternatives, locations, and existing conditions are included in the botanical biological evaluation written for this project. USFS SOUTHERN REGION & KISATCHIE NATIONAL FOREST INVASIVE PLANTS Presidential Executive Order 13112, issued February 3, 1999 and amended by the National Invasive Species Management Plan of 2001, states: “A species is considered invasive if it meets two criteria: 1) it is nonnative to the ecosystem under consideration, and 2) its introduction causes or is likely to cause economic or environmental harm or harm to human, animal, and plant health.” The latter phrase contains recent modifications recommended to the National Invasive Species Council (USDA Forest Service Southern Regional Task Force). The Southern Region of the USDA Forest Service lists 384 plants as invasive exotic species of management concern (Nonnative Invasive Species in Southern Forest and Grassland Ecosystems). The Kisatchie National Forest maintains its own list of non-native invasive plants. The 1999 FEIS (Final Environmental Impact Statement) for the Forest’s (Kisatchie National Forest’s) Revised Forest Plan lists seven non-native invasive plants as occurring on its lands. The Forest’s invasive plant list was expanded to thirty-seven species in 2010 (Appendix C). SURVEYS Shannan Sharp, zone botanist for the Catahoula and Winn Ranger Districts, did not conduct field surveys for this project. She reviewed past field surveys and KNF Arcmap GIS records for invasive plants found on the District (Catahoula Ranger District), with the exception of species found only within the Old Camp Livingston area and aquatic plants. Those invasive are listed below: Table 1. Invasive Plants Possibly Within the Project Area Common name Scientific name habit silktree Albizia julibrissin tree English ivy Hedera helix vine Japanese lespedeza Kummerowia striata forb shrubby lespedeza Lespedeza bicolor shrub sericea lespedeza Lespedeza cuneata forb Chinese privet Ligustrum sinense shrub Common name Scientific name habit Japanese honeysuckle Lonicera japonica vine Japanese climbing fern Lygodium japonicum vine chinaberry Melia azederach tree sacred bamboo Nandina domestica shrub dallisgrass Paspalum dilatatum grass Vasey’s grass Paspalum urvillei grass chamber bitter Phyllanthus urinaria forb golden bamboo Phyllostachys aurea grass kudzu Pueraria montana var. lobata vine Cherokee rose Rosa laevigata vine Johnsongrass Sorghum halepense grass Chinese tallow Triadica sebifera tree Brazilian vervain Verbena brasiliensis forb tungoil tree Vernicia fordii tree Chinese wisteria Wisteria sinensis vine EFFECTS TO INVASIVE PLANTS BY SPECIES Silktree Description and Threat Silktree (Albizia julibrissin) is a small, deciduous tree that was introduced to the United States from Asia as an ornamental in the eighteenth century. It flowers from May to July. Its flowers have numerous, bright pink filaments that look like pom-poms. Abundant seeds are produced in beanlike pods from June to February. This tree prefers open conditions at dry to wet sites, but can persist in shade (Miller et al.). Silktree has become widespread in the United States. It is found throughout the southeast, but is also found in most of the eastern, midwestern, and southwestern states (USDA, NRCS). This species reproduces by forming colonies from root sprouts, but it can also spread its seeds along waterways or through animal dispersal. Seeds can remain viable for years. (Miller et al.). On the Catahoula RD, silktree is common at scattered locations, usually along roads and right-of- ways (personal observations). Few studies have been done on fire effects to silktree. However, existing evidence suggests that this tree is not suppressed by fire and that seed germination and resprouting increase after burning (Meyer 2009). Effects Analysis and Treatment Priority If Alternative 1 is implemented, silktree will continue to spread as usual. It will spread rather slowly along roads, firelines, and ROW’s (right-of-ways) and will invade disturbed sites If Alternative 2 is implemented, silktree will probably spread more rapidly. The proposed 1st thinnings are spread over a large area. Thinned stands will have disturbed habitat that this tree will be likely to invade. 2 It would be best to use herbicides to eradicate silktree infestations. But because of limited funding, other invasive plant infestations should be treated first. This tree spreads relatively slowly in comparison to other invasive plants found on the District. Distribution tends to be spotty with infestations remaining small and widely spaced. Silktree does not form dense stands that threaten forest habitat. Treating silktree should be a low priority. English Ivy Description and Threat English ivy (Hedera helix) is a woody, perennial vine native to Eurasia. Widely cultivated as an ornamental, it was brought to North America by colonial settlers. It was first documented in Virginia around 1800. It is still widely sold in the United States (Waggy 2010). This vine flowers from May to October and bears fruit from October to May, although it rarely produces fertile seed on the Gulf Coast. English ivy persists from cultivation and often spreads. It thrives in moist, open forests, but can adapt to a wide variety of conditions. Juvenile plants grow best in shady conditions, but adult plants become adapted to higher light levels (Allen et al. 2002, and Miller et al.) English ivy is widespread in the continental United States as well as in Hawaii. It is present in all but the northernmost states in the eastern half of the country and in all of the Pacific coast states, as well as in Texas, Idaho, Utah, and Arizona (USDA, NRCS). English ivy seeds can be spread by birds or it can spread vegetatively. This vine can resprout from stems, nodes, stumps, and roots. Once established, English ivy can grow aggressively, capable of covering and eventually smothering trees. It can persist once a tree has fallen to the ground, but typically does not spread (Diggs et al. 1999, Miller et al., and Waggy 2010). Little research has been done on effective ways of controlling this English ivy. Herbicide treatment, hand pulling, and fire can substantially reduce infestations. However, multiple treatments are probably necessary because it easily resprouts. English ivy may also reinvade sites, but mainly when conditions become shaded (Miller et al., and Waggy 2010). Effects Analysis and Treatment Priority If Alternative 1 is implemented, any English ivy within plantations will continue to grow slowly under shady conditions. It will probably spread vegetatively rather than by seeds since vines will be relatively small. If Alternative 2 is implemented, English ivy has the potential grow extremely rapidly in thinned stands where it is present. Vines could cover and smother trees, destroying timber and threatening habitat. With more growth, this vine may increase its reproduction. It could spread more rapidly by seeds. However, only one infestation has been recorded on the District, which is not near project stands. It is probably not much of a threat at present. Although English ivy may be a threat, it is not known if there are infestations of this vine within the project stands. Only one infestation of this species has been recorded on the District. The 3 best method of controlling the spread of this plant would be to monitor thinned sites. If it is present, infestations should be herbicide treated when small. Treatment priority should be medium. Although the potential threat is high, it is not known if it is even present within or near the project area. Japanese Lespedeza Description and Threat Japanese lespedeza (Kummerowia striata) is a perennial forb originally from Asia that has been planted in the United States since 1846. It has been used to control erosion, as a cover crop, and for hay and pasture. This species flowers from July to October and produces mature seed in late autumn. It is found in disturbed sites along roadsides, in old fields, and in waste places, as well as in open, dry woodlands and open, rocky sites (Diggs et al. 1999, and Gucker 2010a). Japanese lespedeza is common on the Winn RD, but is usually confined to dirt roads and road shoulders (personal observation). Japanese lespedeza is widespread throughout most of the eastern and central United States (USDA, NRCS). It has been widely planted and can naturalize in a number of habitats including open pinelands, mixed hardwood pine woodlands, and oak hickory woodlands. It is a pioneer species, rapidly invading disturbed sites, but it is usually crowded out by succeeding vegetation in a few years. Few studies have been done regarding fire effects on Japanese lespedeza. However, it appears that winter fires cause this plant to increase in abundance, while spring burns severely reduce or eliminate it (Gucker 2010a). Effects Analysis and Treatment Priority If Alternative 1 is implemented, Japanese lespedeza will continue to spread slowly, persisting along roadsides, firelines, and ROW’s. This plant may spread into temporarily disturbed sites on the Forest, but eventually dies out with the re-emergence of native vegetation. If Alternative 2 is implemented, Japanese lespedeza will likely spread into thinned stands from roadsides and ROW’s. However, since the disturbance will not be continuous, it will eventually die out.