TITLE:
Invertebrate Abundance, Biomass, and Richness Associated with an Exotic Invasive Shrub (Lonicera morrowii A. Gray)
AUTHORS:
Jason P. Love, James T. Anderson
KEYWORDS:
Invertebrate Biomass, Lonicera morrowii, Morrow’s Honeysuckle, Southern Arrowwood, Terrestrial Invertebrates, Viburnum recognitum
JOURNAL NAME:
Natural Resources,
Vol.11 No.7,
July
17,
2020
ABSTRACT: Exotic
bush honeysuckles (Lonicera spp.) are
becoming increasingly common in the eastern and mid-western United States, but
little is known about their impacts on invertebrates. We used a modified leaf
vacuum to sample invertebrates in the shrub strata and understory of three
shrub types (and open plots in the
understory): single Morrow’s honeysuckle (L. morrowii A. Gray) shrubs, single
native southern arrowwood (Viburnum recognitum Fernald) shrubs, and dense thickets of Morrow’s honeysuckle, in
southwestern PA, USA during 2004 and 2005. We also assessed the degree of herbivory on the two species of shrubs. Within the shrub strata, invertebrate biomass was
lower in southern arrowwood shrubs, but there was no difference in invertebrate
abundance or family richness. Invertebrate abundance and richness were lowest in August, but there was no difference in biomass
among the months. Invertebrate abundance, biomass, and family richness
were lowest in the understory below dense thickets of Morrow’s honeysuckle.
Overall, the percent cover of herbs was the proximate factor responsible for
driving patterns of invertebrate abundance, though ultimately these patterns
were being driven by shrub type. Abundance and biomass of larval leaf chewers
were highest in the native shrub; Morrow’s honeysuckle had a mean of 29.7 cm2 of leaf area consumed per 1 m2 of leaf area, while the native shrub
had a mean of 284.3 cm2 of leaf area consumed. Our results suggest
that areas dominated by the exotic shrub negatively impact invertebrate
biomass, which may in turn affect organisms at higher trophic levels.