Supporting U.S. Agricultural Landscapes Under Changing Conditions With Agroforestry

68 Pages·2017·2 MB·English

United States Department of Agriculture
Supporting U.S.
Agricultural
Landscapes
Under Changing
Conditions With
Agroforestry
An Annotated Bibliography
Forest Service Bibliographies and Literature of Agriculture 137 May 2018
Cover Photos (left to right): A shelterbelt around a Great Plains farm, a silvopasture system in Georgia, blueberries growing in
an agroforestry practice, alley cropping with soybeans and walnuts, and a riparian forest buffer in Iowa; (background): shiitake
mushrooms grown on logs under a forest canopy. Shelterbelt photo courtesy of the U.S. Department of Agriculture (USDA) Natural
Resources Conservation Service; all other photos courtesy of the USDA National Agroforestry Center.
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United States Department of Agriculture
Supporting U.S.
Agricultural
Landscapes
Under Changing
Conditions With
Agroforestry
An Annotated Bibliography
Gary Bentrup, Ina Cernusca, and Michael Gold
Forest Service Bibliographies and Literature of Agriculture 137 May 2018
Gary Bentrup is a research landscape planner, U.S. Department of Agriculture (USDA), Forest Service, USDA
National Agroforestry Center; Ina Cernusca is a research specialist, Center for Social Research, North Dakota
State University; Michael Gold is the Interim Director of the Center for Agroforestry, University of Missouri.
Abstract
Agroforestry can reduce risks and promote sustainable agricultural production under shifting climate and weather
extremes by (1) reducing threats and enhancing agricultural landscape resiliency, (2) facilitating species movement to
more favorable conditions, (3) sequestering carbon, and (4) reducing greenhouse gas emissions. Although agroforest-
ry practices can provide these positive adaptation and mitigation services, they in turn can be vulnerable to the same
forces. The design and management of agroforestry systems must therefore take into account how these systems can
incorporate resiliency into agriculture in ways that the systems are more resilient to these changing conditions. As a
key step in this process, the authors conducted a search of the scientific literature on agroforestry’s role in adaptation
and mitigation under climatic variability and change, as well as on the effects of these stressors on agroforestry. The
temporal scope of the literature search focused on the period of 1992 to 2017, and the geographical scope concen-
trated on temperate agricultural regions. This publication is available at http://www.treesearch.fs.fed.us/ as a printable
and searchable document. The references and annotations are also available from an online ZoteroTM database that
will be periodically updated as new literature becomes available. The public database is accessible at https://www.
zotero.org/groups/1738910/agroforestry__climate_change.
Keywords: climate variability, climate change, mitigation, adaptation, carbon sequestration, greenhouse gas emis-
sions, resiliency
Introduction
U.S. agricultural operations and landscapes are already Agroforestry and Climate Variability and
impacted by changes in climate patterns and weather Change
variability, with impacts expected to increase through-
Agroforestry is a suite of tree-based management
out the 21st century. Future growing conditions across
practices that farmers and ranchers can use to enhance
the temperate zone of the United States are predicted
the capacity of their agricultural operations and lands to
to include longer growing seasons that could potential-
adapt to climatic variability and change. These practic-
ly increase crop yields but also increase heat waves,
es blend trees and shrubs into agricultural settings to
floods, droughts, and insect and weed issues deleterious
modify landscape structure in specific ways to produce
to production (Walthall et al. 2012). Other ecosystem
desired ecosystem services and human benefits (fig. 2).
services that we, as a society, derive from farms and
Structure provided by agroforestry practices can be
ranches—such as clean water, soil and air quality, and
designed to modify microclimate to ameliorate direct
wildlife habitat—can also be negatively impacted (Melillo
impacts of weather extremes on production systems; to
et al. 2014). Enhancing food security and preserving oth-
provide additional benefits for crop production; and to
er vital ecosystem services from U.S. agricultural lands
protect and enhance key resources—such as soil, water,
under current and future shifting weather and climate
and biodiversity—on which agricultural production and
conditions will require a transition to production systems
other ecosystem services depend.
that are more productive, use inputs more efficiently,
have greater stability, and are more resilient to risks, Based on available evidence, agroforestry has the po-
shocks, and long-term climate variability (Scherr et al. tential capacity to contribute to climate change mitigation
2012). Approaches will need to be based on agroeco- and adaptation by (1) reducing threats and enhancing
logical principles and the availability of many practices in agricultural landscape resiliency, (2) facilitating species
order to attain and capitalize on greater multifunctionality movement to more favorable conditions, (3) sequestering
within the agricultural system (Beddington et al. 2012, carbon, and (4) reducing greenhouse gas emissions (ta-
Tomich et al. 2011, Wall and Smit 2005). ble 2; Matocha et al. 2012, Schoeneberger et al. 2012).
One of the strengths of agroforestry is the opportunity
Agroforestry—the intentional integration of trees and
it affords to provide these services in an integrated and
shrubs into crop and animal production systems to
synergistic manner (Duguma et al. 2014). Often, an en-
create productive, healthy, and resilient agricultural
hanced outcome results when the components interact
operations and lands—is one of these potential practices
with each other, increasing effectiveness, minimizing
(Jose et al. 2012, Schoeneberger et al. 2012, Smith et al.
costs, and ensuring continuity of production and service
2013). As defined within the United States, agroforestry
provision by minimizing risks (Duguma et al. 2014).
is “intensive land-use management that optimizes the
benefits (physical, biological, ecological, economic, and The use of agroforestry to address extreme weather
social) from biophysical interactions created when trees events on agricultural lands in the United States is not a
and/or shrubs are deliberately combined with crops and/ new idea. To mitigate one of the largest North American
or livestock” (Gold and Garrett 2009). Brief overviews wind-erosion events in history—the 1930s Dust Bowl—
of agroforestry practices used in the United States are the Prairie States Forestry Program planted windbreaks
presented in fig. 1 and table 1.
Supporting U.S. Agricultural Landscapes Under Changing Conditions With Agroforestry: An Annotated Bibliography 1
Figure 1. Five main categories of agroforestry practices are used in the United States: (A) alley cropping, (B) windbreaks, (C) riparian
forest buffers, (D) silvopasture, and (E) forest farming. An emerging sixth category is (F) special applications (e.g., short-rotation woody
crops). Photos by the U.S. Department of Agriculture, National Agroforestry Center (A, B, D, F), Ben Fertig, Integration and Application
Network, University of Maryland, Center for Environmental Science (ian.umces.edu/imagelibrary/) (C), and Catherine Bukowski, Virginia
Tech (E).
across the length of the Great Plains (fig. 3). Nearly 220 Some potential impacts include tree mortality or reduced
million seedlings were planted, creating 18,600 miles of production due to increasing droughts and floods, pests
windbreaks occupying 240,000 acres on 30,000 farms and diseases, or lack of chilling requirements. Where-
(Williams 2005). as impacts on monoculture crops or simple livestock
production systems can be reasonably predicted with
Although agroforestry practices can help address the
process-based models, robust models for agroforestry
negative impacts of climatic variability, they in turn can
systems are not yet available (Luedeling et al. 2014).
be vulnerable to the same forces. Agroforestry systems
This lack is a serious concern given the long planning
are complex assemblages of ecosystem components,
horizons required for implementing and managing tree-
each responding to changes in weather and climate.
based practices.
2 Supporting U.S. Agricultural Landscapes Under Changing Conditions With Agroforestry: An Annotated Bibliography
Table 1. Categories of agroforestry practices used in the United States
Practice Descriptiona Primary benefits and usesb
Alley cropping Trees or shrubs planted in sets of single • Produce annual and higher value but longer term crops.
(also called or multiple rows with agronomic, horticul- • Enhance microclimate conditions to improve crop or forage quality and quantity.
tree-based tural crops, or forages produced in the • Reduce surface water runoff and erosion.
intercropping) alleys between the trees that can also • Improve soil quality by increasing utilization and cycling of nutrients.
produce additional products. • Enhance habitat for wildlife and beneficial insects.
• Decrease offsite movement of nutrients or chemicals.
Windbreaks Single or multiple rows of trees or shrubs • Control wind erosion.
(also includes that are established for environmental • Protect wind-sensitive crops.
shelterbelts) purposes. Depending on the primary • Enhance crop yields.
use, may be referred to as crop or field • Reduce animal stress and mortality.
windbreak, livestock windbreak, living • Serve as barriers to dust, odor, and pesticide drift.
snow fence, farmstead windbreak, or • Conserve energy.
hedgerow. • Manage snow dispersal to keep roads open or harvest moisture.
Riparian forest Areas of trees, shrubs, and herbaceous • Reduce nonpoint source pollution from adjacent land uses.
buffersc vegetation established and managed • Stabilize streambanks.
adjacent to streams, lakes, ponds, and • Enhance aquatic and terrestrial habitats.
wetlands. • Increase C storage in plant biomass and soils.
• Diversify income either through added plant production or recreational fees.
Silvopasture Trees combined with pasture and live- • Produce diversification of livestock and plant products in time and space.
stock production. • Produce annual and higher value but longer term products.
• Reduce nutrient loss.
Forest farming Existing or planted stands of trees and/or • Improve crop diversity by growing mixed but compatible crops having different
(also called shrubs that are managed as an oversto- heights on the same area.
multistory ry, with an understory of plants grown for • Improve soil quality by increasing utilization and cycling of nutrients.
cropping) a variety of products. • Increase C storage in plant biomass and soil.
Special Use of agroforestry technologies to help • Treat municipal and agricultural wastes.
applications solve special concerns, such as disposal • Manage stormwater.
of animal wastes or filtering irrigation • Produce biofeedstock.
tailwater, while producing a short- or
long-rotation woody crop.
C = carbon.
a Descriptions follow USDA Natural Resources Conservation Service Practice Standards.
b All agroforestry plantings add diversity within the agricultural landscape. In general, such plantings will enhance wildlife habitat in agricultural settings and are
often designed or managed with doing so as a secondary benefit.
c Riparian forest buffers refers to the planted practice. This category does not include naturally established riparian forests.
Figure 2. Agroforestry reduces climate-related threats to agriculture by modifying the structure of agricultural landscapes. Through land-
scape structure, agroforestry practices modify microclimate, stabilize soil, protect water and air quality, and provide for biological diversity,
including the diversity of agricultural crops. Each general type of agroforestry practice (table 1) represents a different structural template
for emphasizing certain benefits over others. Figure from Dosskey et al. (2012) as modified from MEA (2005).
Supporting U.S. Agricultural Landscapes Under Changing Conditions With Agroforestry: An Annotated Bibliography 3
Table 2. Agroforestry functions that support climate change adaptation and mitigation
Climate change Major climate change Agroforestry functions that support climate change
activity functions mitigation and adaptation
Adaptation Reduce threats and enhance • Alter microclimate to reduce impact of extreme weather events on crop production.
resilience. • Alter microclimate to maintain quality and quantity of forage production.
Actions that re- • Alter microclimate to reduce livestock stress.
duce or eliminate • Provide greater habitat diversity to support organisms (e.g., native pollinators, benefi-
the negative cial insects).
effects of climate • Provide greater structural and functional diversity to maintain and protect natural
change or take resource services.
advantage of the • Create diversified production opportunities to reduce risk under fluctuating climate.
positive effects
Facilitate species movement to • Assist in plant species movement through planting decisions.
more favorable conditions. • Provide travel corridors for species migration.
Mitigation Sequester C. • Accumulate C in woody biomass.
• Accumulate C in soil.
Activities that re-
Reduce GHG emissions. • Reduce fossil fuel consumption:
duce GHGs in the
◊ With reduced equipment runs in areas with trees.
atmosphere or en-
◊ With reduced farmstead heating and cooling.
hance the storage
• Reduce NO emissions:
of GHGs stored in 2
◊ By greater nutrient uptake through plant diversity.
ecosystems
◊ By reduced N fertilizer application in tree component.
• Enhance forage quality, thereby reducing CH.
4
C = carbon. CH = methane. GHG = greenhouse gas. N = nitrogen. N0 = nitrous oxide.
4 2
Source: Modified from Schoeneberger et al. (2012).
Figure 3. (A) A giant dust storm rolls across eastern Colorado during the 1930s. (B) Landowners tending to their windbreak planted with
the Prairie States Forestry Project. Photos by the U.S. Department of Agriculture, Natural Resources Conservation Service (A) and Forest
Service (B).
The Bibliography climatic variability and change and associated stressors
on agroforestry. This annotated bibliography is intended
Purpose primarily as a reference for researchers, planners, and
managers. The temporal scope of the literature search
A pressing need exists to design and manage agrofor-
is the period from 1992 to 2017. Although useful liter-
estry systems that offer resiliency under climatic vari-
ature exists prior to this time period, we concentrated
ability and change that are themselves resilient. A better
on recent material that was framed within a climatic
understanding of the scientific basis for these services,
variability and change context. References and informa-
identification of knowledge gaps, and translation of the
tion prior to the surveyed time period are found in other
knowledge into planning and design tools are needed.
publications (e.g., Brandle et al. 1988, Buck et al. 1998,
As a critical step in this process, we—as authors of this
Garrett 2009, Gordon and Newman 1997, Nair 1993,
document—conducted a search of the scientific liter-
Smith 1950, Young 1989). The geographical scope of
ature on agroforestry’s role in climate change adapta-
this bibliography was primarily temperate agricultural
tion and mitigation, as well as the potential impacts of
regions, although we included some studies involving
4 Supporting U.S. Agricultural Landscapes Under Changing Conditions With Agroforestry: An Annotated Bibliography
tropical regions if they were relevant to U.S. agricultural Brandle, J.R.; Hintz, D.L.; Sturrock, J.W., eds. 1988.
production and food security concerns (i.e., Hawaii and Windbreak technology. Amsterdam, Netherlands: Elsevi-
other U.S.-affiliated tropical islands). Each study listed in er. 608 p.
the bibliography is followed by a concise summary of its
Buck, L.E.; Lassoie, J.P.; Fernandes, E.C., eds. 1998.
methods and primary results. At the time of publication,
Agroforestry in sustainable agricultural systems. Boca
this bibliography contains 206 publications.
Raton, FL: CRC Press. 432 p.
Using This Bibliography Dosskey, M.; Wells, G.; Bentrup, G.; Wallace, D. 2012.
Enhancing ecosystem services: designing for multifunc-
This annotated bibliography is available as a download-
tionality. Journal of Soil and Water Conservation. 67(2):
able and printable document at http://www.treesearch.
37A–41A.
fs.fed.us/. The bibliography is published as a search-
able document, allowing for users to define keywords
Duguma, L.A.; Minang, P.A.; van Noordwijk, M. 2014.
of interest. To conduct a word search, use the Find
Climate change mitigation and adaptation in the land use
function in a pdf reader. Stable digital object identifier,
sector: from complementarity to synergy. Environmental
or DOI, links are provided for most publications. See the
Management. 54(3): 420–432.
appendix tables for descriptions of units of measure-
ment, names and abbreviations of chemical elements Garrett, H.E., ed. 2009. North American agroforestry: an
and compounds, and the definitions of abbreviations integrated science and practice. Madison, WI: American
and acronyms contained within the annotations. The Society of Agronomy. 400 p.
references and annotations are also available in an
Gold, M.A.; Garrett, H.E. 2009. Agroforestry nomenclature,
online Zotero1 database that will be periodically updat-
concepts and practices. In: Garrett, H.E., ed. North Amer-
ed as new literature becomes available. This database
ican agroforestry: an integrated science and practice.
is searchable based on keywords, authors, dates, and
Madison, WI: American Society of Agronomy: 63–78.
titles. Access the public database at https://www.zotero.
org/groups/1738910/agroforestry__climate_change. Gordon, A.M.; Newman, S.M. 1997. Temperate agro-
forestry systems. Wallingford, United Kingdom: CABI
A companion report, entitled Agroforestry: Enhancing
Publishers. 288 p.
Resiliency in U.S. Agricultural Landscapes Under Chang-
ing Conditions, provides a synthesis of the most current Jenkins J.C.; Chojnacky D.C.; Heat L.S. [et al.]. 2003.
science regarding how these tree-based practices can Comprehensive database of diameter-based biomass
impact agricultural production and resiliency and what regressions for North American tree species. Gen. Tech.
will be needed to successfully capitalize on agroforestry’s Rep. NE-319. Newtown Square, PA: U.S. Department
benefits under uncertain climate. The assessment report of Agriculture, Forest Service, Northeastern Research
is available at https://doi.org/10.2737/WO-GTR-96. Station. 45 p.
Jose, S.; Gold, M.A.; Garrett, H.E. 2012. The future of
Acknowledgments temperate agroforestry in the United States. In: Nair,
P.K.; Garrity, D., eds. Agroforestry—The future of global
The authors thank Hannah Hemmelgarn of University
land use. Advances in Agroforestry, Vol. 9. Dordecht,
of Missouri for her assistance with preparing a number
Netherlands: Springer: 217–245.
of the annotations. The U.S. Department of Agriculture,
Forest Service, Research and Development, National Luedeling, E.; Kindt, R.; Huth, N.I. [et al.]. 2014. Agro-
Agroforestry Center provided the funding support for this forestry systems in a changing climate—challenges in
project (grant number 13-JV-11330152-058). projecting future performance. Current Opinion in Envi-
ronmental Sustainability. 6: 1–7.
Literature Cited Matocha, J.; Schroth, G.; Hills, T. [et al.]. 2012. Integrat-
ing climate change adaptation and mitigation through
Beddington, J.R.; Asaduzzaman, M.; Clark, M.E. [et al.]. agroforestry and ecosystem conservation. In: Nair, P.K.;
2012. What next for agriculture after Durban? Science. Garrity, D., eds. Agroforestry—The future of global land
335(6066): 289–290. use. Advances in Agroforestry. 9 vol. Dordecht, Nether-
lands: Springer: 105–126.
1 Mention of product or trade names does not constitute endorsement by the Forest Service.
Supporting U.S. Agricultural Landscapes Under Changing Conditions With Agroforestry: An Annotated Bibliography 5
Melillo, J.M.; Richmond, T.C.; Yohe, G.W. eds. 2014. Smith, J.R. 1950. Tree crops: a permanent agriculture.
Climate change impacts in the United States: the Third New York: Island Press. 422 p.
National Climate Assessment. Washington, DC: U.S.
Tomich, T.P.; Brodt, S.; Ferris, H. 2011. Agroecology: a
Global Change Research Program. 841 p.
review from a global-change perspective. Annual Review
Millennium Ecosystem Assessment (MEA). 2005. Eco- of Environmental Resources. 36: 193–222.
systems and human well-being: current state and trends
Wall, E.; Smit, B. 2005. Climate change adaptation in
assessment. Washington, DC: Island Press. 948 p.
light of sustainable agriculture. Journal of Sustainable
Nair, P.K.R. 1993. An introduction to agroforestry. Dor- Agriculture. 27(1): 113–123.
drecht, Netherlands: Kluwer Academic Publishers. 505 p.
Walthall, C.J.; Hatfield, J.; Backlund, P. [et al.]. 2012. Cli-
Scherr, S.J.; Shames, S.; Friedman, R. 2012. From mate change and agriculture in the United States: effects
climate-smart agriculture to climate-smart landscapes. and adaptation. Washington, DC: U.S. Department of
Agriculture and Food Security. 1(1): 1–15. Agriculture, Technical Bulletin 1935. 186 p.
Schoeneberger, M.; Bentrup, G.; de Gooijer, H. [et al.]. Williams, G.W. 2005. The USDA Forest Service: first cen-
2012. Branching out: agroforestry as a climate change tury. Washington, DC: U.S. Department of Agriculture,
mitigation and adaptation tool for agriculture. Journal of Forest Service, Office of Communication. http://www.
Soil and Water Conservation. 67(5): 128A–136A. foresthistory.org/ASPNET/Publications/first_century/. (14
April 2017).
Smith, J.; Pearce, B.D.; Wolfe, M.S. 2013. Reconciling
productivity with protection of the environment: is tem- Young, A. 1989. Agroforestry for soil conservation. 4 vol.
perate agroforestry the answer? Renewable Agriculture Wallingford, United Kingdom: CABI Publishers. 276 p.
and Food Systems. 28(1): 80–92.
6 Supporting U.S. Agricultural Landscapes Under Changing Conditions With Agroforestry: An Annotated Bibliography