Green Roofs and Pest Control Presented by Patrick T. Copps, BCE Technical Services Manager Orkin Pest Control
Agenda Introduction & Overview History Why Green Roofs? Basic Plans for Green Roof Construction Types of Green Roofs Vegetative Design & Maintenance Green Roof Usage Pest Management Considerations Case Studies Conclusions
Green Roofs Introduction and Overview
Green Roofs Introduction and Overview
Green Roofs Introduction and Overview
History Technology developed in Germany in the 1960s In 1990 the FBB Fachvereinigung Bauwerksbegrunung was formed as a trade organization promoting green roofs Today, there is an EU group EFB Europaische Foderation der Bauwerksbegrunungsverbande the European Federation of Green Roof Associations (formed in 1997) Green roofs are becoming increasingly popular in the United States, although they are not as common as in parts of Europe
Water Quality Large impervious surfaces result in rapid rainwater run off and overloading of storm drains, which increases the tendency of rivers to overtop their banks and flood surrounding land Aesthetics & Quality of Life Reduced contact with nature negatively affects the health and well being of communities Why Green Roofs? Energy Urban heat island effect and problems with air quality, energy use and ambient temperatures
Basic Plans for Green Roof Construction
Types of Green Roofs Intensive Supports 80-150 lbs of vegetation per square foot of roof surface area Labor-intensive Irrigation Fertilizer (feeding) Pruning Foot traffic encouraged Extensive Supports 10-25 lbs of vegetation per square foot of roof surface area Minimal maintenance Accessed only for that purpose
Gardens and Decorative Features
Gardens and Decorative Features
Unintentional Green Roofs
Vegetative Design & Maintenance Success starts with good design and properly selected vegetation Most green roof problems result from poor initial design and lack of post-installation care and maintenance A routine and consistently executed maintenance protocol should include: Watering Weeding Fertilizing Replanting Replacing eroded materials Must be executed by a designated facility grounds manager or other on-site personnel
Vegetative Design & Maintenance A green roof is a highly engineered living system, and living systems need care and maintenance Don t confuse low maintenance with no maintenance No different than other complicated systems or machinery Routine care and maintenance is critical and must be performed to ensure long-term viability and performance
Green Roof Usage Increased use of rooftops as recreational spaces: Patios Parks Bars Restaurants New threat from food pests
Pest Management Considerations Niche Theory Build it and they will come Organismal/population response to distribution of resources and competitors Urban habitats are well known for providing resources for a variety of arthropod & vertebrates that end up being classified as pests. Problematic pests for green roof systems include: Plant feeders (e.g. beetles) Cockroaches Ants Flies Rodents Spiders Other arthropods
Pest Management Considerations Roof Rats Recent population increase Nest inside structural voids Excellent climbers Highly adaptable Year-round breeding Within a year, one female can give birth to 40 new rodents Disease carriers Signs of an Infestation Live or dead rodents; noise Droppings (12-13mm with pointed ends) Grease marks along surfaces Nests Damage Prevention Tips Make sure all windows and vents are screened Trim all overhanging tree branches Limit access from below
Pest Management Considerations Green roof installers and maintainers must be able to: Recognize the early signs of pest infestations Know how to control pest populations first through non-chemical methods and finally with a targeted plantbased, non-toxic pesticide if necessary
Case Studies Swarthmore College White grub infestation Organic pest control methods U.K. School Red spider mite infestation Entered school through air ducts School closure due to bites
Conclusions Green roof systems are a growing trend in urban centers in the U.S. Increased pest pressure is a byproduct of green roofs Routine maintenance and monitoring are key to minimizing pest threats
THANK YOU Questions? Pcopps@orkin.com
Appendix Green Roofs An Introduction and Overview. Brian T. Forschler, University of Georgia, Athens, GA. Stormwater Runoff and Heat Island effects Reviewed by K.L. Getter and D.B. Rowe 2006. HortScience. 41: 1276-1285. Energy Usage Reviewed by H. F. Castelton et al. 2010. Energy and Buildings. 42: 1582-1591. Potential Ecological Sociological benefits - R. A. Francis and J. Lorimer. 2011. J. Environ. Mgt. 92: 1429-1437. Costs & Societal benefits Mullen, J.D., M. Lamsal, G. Colson. 2013. Environ. Sci. & Tech. 47: 10824-10831.
Appendix Real Benefits? A. Henry and N. Frascaria-Lascoste. J. Envir. Mgt. 2012. 104: 91-92. Schindler et al. 2011. Cities & Environ. Vol. 4, Issue 1, Article 5. (no effect of roof size or height but diversity dependent on vegetation Boston). Braaker, S. et al. 2014. Ecology 95: 1010-1021. (no effect of roof size or height but diversity dependent on vegetation Switzerland).