The role of agroforestry practices in a healthy farm

Paper presented at the 11th North American Agroforesty Conference, which was held May 31-June 3, 2009 in Columbia, Missouri.In Gold, M.A. and M.M. Hall, eds. Agroforestry Comes of Age: Putting Science into Practice. Proceedings, 11th North American Agroforestry Conference, Columbia, Mo., May 31-June 3, 2009.The University of Nebraska-Lincoln is developing a Healthy Farm Index that reflects a vision of sustainable farming. The index uses multiple indicators within ecological, environmental, and socio-economic categories to assess production, biodiversity, and ecosystem services provided by sustainable farm systems. The value of various agroforestry practices is reflected in these indicators as a component that improves farm profitability, conserves biological diversity, and enhances ecosystem services to and from agroecosystems. Agricultural systems are typically managed to maximize the provision of food and fiber. In contrast, proponents of sustainable agricultural systems seek to optimize long-term outcomes that include multiple components of agroecosystems and rewards for farmers who use sustainable practices. Understanding how shape, arrangement, and management of agroforestry landscape features affect different components of the farm system is important, as is recognizing tradeoffs. Understanding tradeoffs requires whole farm analysis and management. Management objectives help plan the shape and arrangement of landscape features. In this paper we will discuss how the use and arrangement of woody landscape features will be included in the Healthy Farm Index. Four participating organic farms in eastern Nebraska provide examples of the influence of woody land cover on the index scores. The structure of the index allows for the integration of current and future components. The index will be a mechanism for communicating interdisciplinary data toward farm practices and policy that optimize food production, biodiversity, and ecosystem services.James R. Brandle (1), Ron. J. Johnson (2), and John E. Quinn (1) ; 1. School of Natural Resources, University of Nebraska Lincoln, Lincoln, NE. 2. Department of Forestry & Natural Resources, Clemson University, Clemson, SC.Includes bibliographical references

A farm-scale biodiversity and ecosystem services assessment tool: The healthy farm index

Farm management focused on maximizing biomass production results in biological simplification and ultimately a degraded production potential for the future. Despite the large and growing body of evidence pointing to the need to restore biodiversity to farm systems, incorporation of biodiversity and ecosystem services into local agricultural land use decision- making remains limited. The lack of planned and associated biodiversity may reduce resiliency of local managed ecosystems and add management costs; however, the trade-off for individual landowners of greater diversity is increased management complexity and uncertainty. To assist farmers in managing biodiversity and to encourage ecological thinking, we developed the Healthy Farm Index, a farm-scale tool that complements existing farm assessment tools by integrating multiple metrics and outputs suitable for applied decision-making and annual evaluation. In this article, we describe the impetus for the index development and the structure of the index and through a case study apply the index and discuss its varied outputs and applications

Biotic interactions in organic farm systems

Paper presented at the 11th North American Agroforesty Conference, which was held May 31-June 3, 2009 in Columbia, Missouri.In Gold, M.A. and M.M. Hall, eds. Agroforestry Comes of Age: Putting Science into Practice. Proceedings, 11th North American Agroforestry Conference, Columbia, Mo., May 31-June 3, 2009.Fire, drought, and grazing were primary ecological drivers of the historical Great Plains' prairie ecosystem. The suppression of fire, a shift in grazing and cropping systems, and the introduction of windbreaks and other woody vegetation altered the landscape. The abundance, vertical diversity, and composition of woody species have noticeably increased. A subsequent shift has been documented in relative abundance of bird species in the state, with shrubland and edge species filling the ecological niche created with the conversion of many cropland acres to woodland. Shrubland and edge birds may fill an important functional role in agroecosystems. Organic farms frequently have greater habitat heterogeneity then other farm types. Agroforesty is an important component of this habitat diversity. To quantify the effect of woody land-use and land-cover on biodiversity and to assess the functionality of avian species as predators in organic farm systems, avian and insect diversity were sampled on 23 organic farms in eastern Nebraska and Kansas in 2007 and 2008. Species response to the presence and arrangement of woodland cover on farms is of great interest. An N-mixture model was used to estimate abundance and detectability of farmland bird species. Results from these analyses will be used to assess the functional role of birds and explore relationships between insect and bird communities to determine whether woodland edge bird species have the potential to effectively suppress crop pests on organic farms.John E. Quinn (1), Ron. J. Johnson (2), and James R. Brandle (1) ; 1. School of Natural Resources, University of Nebraska Lincoln, Lincoln, NE. 2. Department of Forestry & Natural Resources, Clemson University, Clemson, SC.Includes bibliographical references

Avian Foraging Patterns in Crop Field Edges Adjacent to Woody Habitat

As natural predators of pest insects, woodland birds provide biological pest suppression in crop fields adjacent to woody edges. Although many birds using these habitats forage widely, earlier studies have found that most foraging activity occurs within 50 m of the woody edge. The goals of this study were to determine the primary area of use, or functional edge, for birds foraging in crop fields adjacent to woody edges, and to evaluate their foraging distance patterns. During the summers of 2005 and 2006, avian foraging behavior was observed at 12 research sites in east central Nebraska that contained either a shelterbelt or woody riparian edge. At each site, perches were provided at 10 m intervals out from the edge and insect larvae were placed in feeders at random locations to simulate a pest insect food resource. Birds were recorded foraging in five distance categories out from the edge (0–10, 10–20, 20–30, 30–40, and 40–50 m). Seven species foraged primarily within 20 m of the edge (72% all observations; 79% without perch or feeder observations). Ten species foraged throughout the plots but six of these generally foraged more often (45% and 49%) and four less often (30% and 30%) within 20 m of the edge. The 13 species that tended to forage more often within 20 m of the edge, with 56% of their foraging overall in this area, also tended to forage farther when perch and feeder observations were included, indicating willingness to forage farther when food resources were available. Based on a repeated measures analysis of variance, foraging distances appeared to be greater at sites with soybean as the planted crop, although this apparent trend was significant for only some species. There was no clear difference in foraging distances outward from shelterbelt versus riparian sites. These results indicate that conservation efforts within the 20 m functional edge offer potential to enhance the sustainability of both birds and crops in agricultural

Avian Foraging Patterns in Crop Field Edges Adjacent to Woody Habitat

As natural predators of pest insects, woodland birds provide biological pest suppression in crop fields adjacent to woody edges. Although many birds using these habitats forage widely, earlier studies have found that most foraging activity occurs within 50 m of the woody edge. The goals of this study were to determine the primary area of use, or functional edge, for birds foraging in crop fields adjacent to woody edges, and to evaluate their foraging distance patterns. During the summers of 2005 and 2006, avian foraging behavior was observed at 12 research sites in east central Nebraska that contained either a shelterbelt or woody riparian edge. At each site, perches were provided at 10 m intervals out from the edge and insect larvae were placed in feeders at random locations to simulate a pest insect food resource. Birds were recorded foraging in five distance categories out from the edge (0–10, 10–20, 20–30, 30–40, and 40–50 m). Seven species foraged primarily within 20 m of the edge (72% all observations; 79% without perch or feeder observations). Ten species foraged throughout the plots but six of these generally foraged more often (45% and 49%) and four less often (30% and 30%) within 20 m of the edge. The 13 species that tended to forage more often within 20 m of the edge, with 56% of their foraging overall in this area, also tended to forage farther when perch and feeder observations were included, indicating willingness to forage farther when food resources were available. Based on a repeated measures analysis of variance, foraging distances appeared to be greater at sites with soybean as the planted crop, although this apparent trend was significant for only some species. There was no clear difference in foraging distances outward from shelterbelt versus riparian sites. These results indicate that conservation efforts within the 20 m functional edge offer potential to enhance the sustainability of both birds and crops in agricultural

Improving the validation of model-simulated crop yield response to climate change: an application to the EPIC model* Jour. Ser. No. 11339 Nebraska Ag. Res. Div.

Crop models have been used extensively to simulate yield response to various scenarios of climate change. Such simulations have been inadequately validated, limiting their utility in policy analysis. In this research, it is argued that the performance of crop models during recent years of extreme weather conditions relative to current normals may give a better indication of the validity of model simulations of crop yields in response to climate change than performance during the full range of climate conditions (as is done now). Twenty years of the climate record (1971-1990) are separated into different growing season temperature and precipitation classes (normal years, hot/cold extremes, wet/dry extremes) for 7weather stations in eastern Nebraska, USA. The Erosion Productivity Impact Calculator (EPIC), a crop growth model, is used to simulate crop yields with each of the above weather classes. Statistical comparisons are made between simulated yields, observed yields and observed yields detrended of technology influences. Based on these comparisons, we conclude that EPIC reliably simulates crop yields under temperature extremes, some which approach the types of climate conditions that may become more frequent with climate change. Simulations with precipitation extremes are less reliable than with the temperature extremes but are argued still to be credible. Confidence in crop simulations during years mimicking climate warming scenarios appears warranted

Variation in Avian Vocalizations during the Non-Breeding Season in Response to Traffic Noise

Low-frequency traffic noise that leads to acoustic masking of vocalizations may cause birds to alter the frequencies or other components of their vocalizations in order to be heard by conspecifics and others. Altering parts of a vocalization may result in poorer vocal performance or the message contained in the vocalization being received incorrectly. During the winters of 2011–2012 and 2012–2013, we recorded and measured the “chick-a-dee” call of Black-capped Chickadees (Poecile atricapillus) and the “po-ta-to-chip” call of American Goldfinches (Spinus tristis) to determine whether components of the calls produced in areas of high traffic noise and low traffic noise differed in any way. We found that both chickadee and goldfinch calls had higher minimum frequencies in areas with high traffic-noise than in low traffic-noise areas. The maximum frequencies showed no differences in either species’ calls. This suggests that chickadees and goldfinches alter the part of their calls that are acoustically masked by traffic noise in effort to better transmit the vocalization. These differences suggest that increasing anthropogenic noise may influence avian communication and that noise management should be included in conservation planning

Expressed sequence tags from Madagascar periwinkle (Catharanthus roseus)

AbstractThe Madagascar periwinkle (Catharanthus roseus) is well known to produce the chemotherapeutic anticancer agents, vinblastine and vincristine. In spite of its importance, no expressed sequence tag (EST) analysis of this plant has been reported. Two cDNA libraries were generated from RNA isolated from the base part of young leaves and from root tips to select 9824 random clones for unidirectional sequencing, to yield 3327 related sequences and 1696 singletons by cluster analysis. Putative functions of 3663 clones were assigned, from 5023 non-redundant ESTs to establish a resource for transcriptome analysis and gene discovery in this medicinal plant

Estimating carbon storage in windbreak trees on U.S. agricultural lands

Assessing carbon (C) capture and storage potential by the agroforestry practice of windbreaks has been limited. This is due, in part, to a lack of suitable data and associated models for estimating tree biomass and C for species growing under more opengrown conditions such as windbreaks in the Central Plains region of the United States (U.S.). We evaluated 15 allometric models using destructively sampled Pinus ponderosa (Lawson & C. Lawson) data from field windbreaks in Nebraska and Montana. Several goodness-of-fit metrics were used to select the optimal model. The Jenkins’ et al. model was then used to estimate biomass for 16 tree species in windbreaks projected over a 50 year time horizon in nine continental U.S. regions. Carbon storage potential in the windbreak scenarios ranged from 1.07 ± 0.21 to 3.84 ± 0.04 Mg C ha-1 year-1 for conifer species and from 0.99 ± 0.16 to 13.6 ± 7.72 Mg C ha-1 year-1 for broadleaved deciduous species during the 50 year period. Estimated mean C storage potentials across species and regions were 2.45 ± 0.42 and 4.39 ± 1.74 Mg C ha-1 year-1 for conifer and broadleaved deciduous species, respectively. Such information enhances our capacity to better predict the C sequestration potential of windbreaks associated with whole farm/ranch operations in the U.S