Lonicera maackii (Amur honeysuckle).

A datasheet on Lonicera maackii covering, as an economically important tree, its taxonomy, importance, silviculture, distribution, biology and ecology, uses, products and pests.

White-tailed deer browse preference for an invasive shrub, Amur honeysuckle (Lonicera maackii), depends on woody species composition

Selective browsing by abundant, generalist herbivores on preferred species could allow less-preferred invasive species to flourish. We tested such an effect by examining rates at which white-tailed deer (Odocoileus virginianus Zimmermann) consume Amur honeysuckle [Lonicera maackii (Rupr.) Herder], an invasive shrub, relative to native woody species across eight forested sites in southwestern Ohio. We tested three hypotheses: (1) deer prefer to browse on L. maackii versus other woody plants; (2) L. maackii is not a preferred source of browse, but is consumed where preferred foods are scarce; and (3) L. maackii provides an important food resource for deer in early spring when other foods are scarce. We used counts of browsed and unbrowsed twigs of each species to calculate, for each site, both the proportion of each species’ twigs browsed and the degree to which deer selectively favor each species (“electivity”) during early to mid-growing season. Across the eight sites, electivity of L. maackii correlated with the proportion of its twigs browsed, and both measures were negatively associated with the density of L. maackii twigs. Lonicera maackii electivity was negative at most sites, indicating it is generally not preferred, undermining hypothesis 1. The hypothesis that deer consume L. maackii when more-preferred foods are depleted was not supported, as there was no negative relationship between L. maackii browse and the density of twigs of more-preferred species. We found a negative relationship between the proportion of L. maackii twigs browsed and the density of L. maackii among sites, which supports the third hypothesis. This finding, combined with seasonal patterns of deer browse on L. maackii, indicates that this invasive shrub is an important source of browse for deer during early spring, regardless of its abundance.

Management of the Invasive Shrub Amur Honeysuckle (Lonicera maackii) for the Endangered Perennial Wild Dill (Perideridia americana)

Radnor Lake State Natural Area in Nashville, TN, has cedar glades that contain the endangered perennial herb wild dill [Perideridia americana (Nutt. ex DC.) Rchb.] and the invasive shrub Amur honeysuckle [Lonicera maackii (Rupr.) Herder]. This research examined whether L. maackii treatment in the Radnor Lake State Natural Area cedar glades is followed by an increase in P. americana plants. A grid of 60 adjacent 2 m by 4 m plots was placed in five cedar glades to encompass the P. americana population. With great care to protect P. americana, the annual treatment for L. maackii was to pull plants ≤1-m tall from the ground; and to cut stems >1-m tall and then treat the stumps with glyphosate. The t-tests of means for the log natural of the number of plants in the 60 plots (significance level of P-value = 0.05) were used to compare pretreatment L. maackii and P. americana counts with posttreatment counts in 2018 and P. americana counts at leaf out and flowering in 2018. The L. maackii population was significantly smaller (P-value < 0.001) in 2018 than pretreatment at all five sites. When pretreatment in 2014 and 2015 was compared with posttreatment in 2018 for the P. americana populations, the increases were significant at the Cheek, Harris 2, Hideaway, and Norfleet sites, but the increase at East Hall Farm was not significant. White-tailed deer (Odocoileus virginianus Zimmermann) trampling was the explanation given for the decreases in P. americana from leaf out to flowering at all five sites in 2018. Browsing was evident only at Hideaway, which had a greater loss for P. americana from leaf out to flowering in 2018 than the combined losses for the Cheek, East Hall Farm, Harris 2, and Norfleet sites. The research informed the creation of adaptive management decisions regarding monitoring and treatment of the invasive species L. maackii for an endangered species.