Targeting perennial vegetation in agricultural landscapes for enhancing ecosystem services

Abstract

Over the past century, agricultural landscapes worldwide have increasingly been managed for the primary purpose of producing food, while other diverse ecosystem services potentially available from these landscapes have often been undervalued and diminished. The incorporation of relatively small amounts of perennial vegetation in strategic locations within agricultural landscapes dominated by annual crops-or perennialization-creates an opportunity for enhancing the provision of a wide range of goods and services to society, such as water purification, hydrologic regulation, pollination services, control of pest and pathogen populations, diverse food and fuel products, and greater resilience to climate change and extreme disturbances, while at the same time improving the sustainability of food production. This paper synthesizes the current scientific theory and evidence for the role of perennial plants in balancing conservation with agricultural production, focusing on the Midwestern USA as a model system, while also drawing comparisons with other climatically diverse regions of the world. Particular emphasis is given to identifying promising opportunities for advancement and critical gaps in our knowledge related to purposefully integrating perennial vegetation into agroecosystems as a management tool for maximizing multiple benefits to society. AbstractOver the past century, agricultural landscapes worldwide have increasingly been managed for the primary purpose of producing food, while other diverse ecosystem services potentially available from these landscapes have often been undervalued and diminished. The incorporation of relatively small amounts of perennial vegetation in strategic locations within agricultural landscapes dominated by annual crops-or perennialization-creates an opportunity for enhancing the provision of a wide range of goods and services to society, such as water purification, hydrologic regulation, pollination services, control of pest and pathogen populations, diverse food and fuel products, and greater resilience to climate change and extreme disturbances, while at the same time improving the sustainability of food production. This paper synthesizes the current scientific theory and evidence for the role of perennial plants in balancing conservation with agricultural production, focusing on the Midwestern USA as a model system, while also drawing comparisons with other climatically diverse regions of the world. Particular emphasis is given to identifying promising opportunities for advancement and critical gaps in our knowledge related to purposefully integrating perennial vegetation into agroecosystems as a management tool for maximizing multiple benefits to society.

Using biodiversity to link agricultural productivity with environmental quality: Results from three field experiments in Iowa

“…Schulte et al 18 suggested that the strategic integration of perennial vegetation into agricultural landscapes dominated by annual crops could help reconcile agricultural productivity with environmental quality. Increasing crop and non-crop diversity in agroecosystems with perennial species may be especially important because perennial plants perform many key ecological functions more effectively than annuals, including (1) regulating the flow and storage of water, (2) reducing soil erosion, (3) storing and cycling nutrients and carbon, and (4) providing habitat for natural enemies of crop pests and for native plants and animals of conservation concern 18,19 . Many options exist for diversifying agroecosystems with perennial vegetation, including forage crops that are alternated with row crops in rotation sequences; riparian buffers of trees, shrubs and grasses that separate crop fields from streams; in-field strips of herbaceous species that filter runoff water; trees and shrubs on field margins that reduce wind movement; reconstructed wetlands that receive drainage water from crop fields; agroforestry plantations that supply a variety of economic products; and woody and herbaceous plants that are harvested as biofuel feedstocks 18 .…”

Supporting Agricultural Ecosystem Services through the Integration of Perennial Polycultures into Crop Rotations

“…Perennial crops contribute to a mixture of population communities with different "ecological ages", which was proposed by Odum [147] for nature conservation in landscape planning [153]. A strategic placement of perennial plants in agricultural landscapes, either on-field or adjacent, likely provides greater benefits than their spatial extent suggests [11,122].…”

Enhancing agroecosystem performance and resilience through increased diversification of landscapes and cropping systems

“…Much of the dysfunction of industrial agriculture in the Corn Belt derives from the low levels of biological diversity now present across landscapes and within farming systems in the region (Broussard and Turner, 2009;Liebman et al, 2013;Asbjornsen et al, 2014). Of particular importance is the fact that shallow-rooted, short-season crops like corn and soybean have replaced native, perennial species whose deep roots and long growth period from early spring to late fall are much more effective in holding soil in place, promoting water infiltration into soil and transpiration into the atmosphere, fostering carbon sequestration and nutrient retention, and providing habitat for pollinators, biological control agents, and a host of other organisms .…”

“…Although we have presented just two case studies of how diversification might be used to enhance agroecosystem performance and resilience in the U.S. Corn Belt, studies conducted in other regions also support diversification as a key principle underpinning the design of multifunctional agroecosystems that provide a wide range of goods and services while protecting environmental quality (Altieri, 1995;Kremen and Miles, 2012;Asbjornsen et al, 2014). Additional options for diversifying landscapes and cropping systems include the use of mixed species pastures for dairy and beef production (Sulc and Tracy, 2007); perennial grains for food and feed production (Cox et al, 2006); cover crops to fill otherwise unoccupied temporal niches (Snapp et al, 2005); dedicated perennial grasses and native mixed-species communities for biofuel feedstock production (Heaton et al, 2013); herbaceous and woody species for reconstructing wetlands (Zedler, 2003) and riparian corridors (Schultz et al, 2004); and trees for agroforestry plantations ( Jose et al, 2012).…”

“…Diversification of agricultural landscapes and cropping systems offers one of the best and most accessible strategies for resolving the seemingly intractable tension between agricultural production and environmental quality (Boody et al, 2005;Jordan and Warner, 2010;Liebman et al, 2013;Asbjornsen et al, 2014;McGranahan, 2014).…”