Switchgrass (Panicum virgatum) Intercropping within Managed Loblolly Pine (Pinus taeda) Does Not Affect Wild Bee...

Area of Science:

• Ecology
• Entomology
• Forestry

Background:

• Intensively managed pine (Pinus spp.) plantations are known to support vertebrate diversity.
• The impact of these plantations on invertebrate communities, particularly wild bees, remains understudied.
• Intercropping switchgrass (Panicum virgatum) in loblolly pine (P. taeda) plantations is being explored for cellulosic biofuel production.

Purpose of the Study:

• To investigate the effects of intercropping switchgrass on wild bee communities within loblolly pine plantations.
• To compare bee visitation and abundance in relation to plantation age and the presence of intercropped switchgrass.

Main Methods:

• Study conducted in loblolly pine plantations in Mississippi, USA, with four treatments: 3-4 year old plantations and 9-10 year old plantations, with and without intercropped switchgrass.
• Colored pan traps were used to collect bees over the 2013 and 2014 growing seasons.
• Captured bees were identified to genus level.

Main Results:

• A total of 2507 bees from 18 genera were captured.
• The most common genera were Lasioglossum and Ceratina.
• Bee abundance was significantly influenced by plantation age, but not by the presence or absence of intercropped switchgrass.

Conclusions:

• Switchgrass intercropping does not appear to negatively impact or promote wild bee communities in intensively managed loblolly pine plantations.
• Plantation age is a more critical factor than switchgrass presence in determining bee abundance in these systems.
• Findings suggest that intercropping switchgrass for biofuels may be compatible with supporting existing wild bee communities in pine plantations.