Effect of Habitat Structure on the Reproductive Success and Prey Capture of Pinguicula lutea a Threatened Carnivorous Plant.

Habitat modification is one of the greatest threats to biodiversity worldwide and the main contributor to the decline of many carnivorous plant species. For carnivorous plants in the southeast US, including many Pinguicula species (butterwort, Lentibulariaceae), habitat modification via altered fire regime has been implicated in their decline. Despite this, limited empirical research has been conducted examining the influence of habitat structural changes on reproduction and prey capture. The objectives of our study are to assess the impacts of habitat structural changes on reproduction and prey capture for Pinguicula lutea (yellow butterwort) in the Florida Panhandle. Pinguicula lutea is a self-compatible, outcrossing, carnivorous plant that inhabits fire-dependent longleaf pine savannas of the southeast US and is threatened in the state of Florida. Its primary prey items are Collembola and small Diptera. In 2014 and 2015 a total of 13 populations were identified occupying a variety of habitat structure types including maintained (mowed), grassy (dense Aristida stricta var. beyrichiana), and woody (Hypericum/Ilex mix). Reproductive output was determined by assessing fruit and seed set at each population. Additionally, prey availability and prey capture were assessed at all sites. In general, habitat structural changes do not affect reproduction, but do affect the abundance of Collembola, Diptera, and all arthropods combined both in terms of availability and prey capture. Microclimatic conditions such as light availability and temperature associated with each habitat structure type could explain the observed arthropod abundance patterns. This study is the first comprehensive assessment of plant-insect interactions for Pinguicula species of the southeast US and highlights the need for additional research for this understudied group of carnivorous plants.