197 research outputs found
Designing a Regional System of Social Indicators to Evaluate Nonpoint Source Water Projects
A collaborative team has developed a system to measure the social outcomes of nonpoint source
water projects as indicators of progress towards environmental goals. The system involves a set of core
indicators, additional supplemental indicators, and a process for collecting and using the indicators. This
process is supported by methodologies and instruments for data collection, analysis, and reporting that are
coordinated and supported through detailed written guidance and an on-line data management tool. Its
multi-state scope and application offer a unique opportunity to target, measure, and report interim resource
management accomplishments consistently at multiple levels
Adoption of agricultural conservation practices in the United States: Evidence from 35 years of quantitative literature
Copyright © 2019 Soil and Water Conservation Society. All rights reserved. This is a comprehensive review of all published, quantitative studies focused on adoption of agricultural conservation practices in the United States between 1982 and 2017. This review finds that, taken as a whole, few independent variables have a consistent statistically significant relationship with adoption. Analyses showed that variables positively associated with adoption include the farmer self-identifying primarily as stewardship motivated or otherwise nonfinancially motivated, environmental attitudes, a positive attitude toward the particular program or practice, previous adoption of other conservation practices, seeking and using information, awareness of programs or practices, vulnerable land, greater farm size, higher levels of income and formal education, engaging in marketing arrangements, and positive yield impact expected. Some variables often thought to be important, such as land tenure, did not emerge as consistently important in this cross-study review. Other variables, such as farmers’ sense of place, training, presence of institutional conditions supporting adoption, and the role of collective decision making are not measured in enough studies to draw conclusions but potentially have a relationship with adoption decisions. Implications for how to promote conservation adoption and directions for future research are discussed. Because positive attitudes and awareness of conservation programs or practices are positive predictors of adoption, practitioners should share benefits of specific practices and programs and leverage existing practice adoption. Further work to explore relationships between conservation adoption and the role of farmer identity, nuances of land tenure, and the influence of structural factors is needed. Moreover, we suggest that future research should focus on the impact of different messages and avenues of reaching farmers in order to continue to inform conservation practices. Future research should consider both individual and institutional factors that facilitate and constrain adoption
Adoption of agricultural conservation practices in the United States: Evidence from 35 years of quantitative literature
This is a comprehensive review of all published, quantitative studies focused on adoption of agricultural conservation practices in the United States between 1982 and 2017. This review finds that, taken as a whole, few independent variables have a consistent statistically significant relationship with adoption. Analyses showed that variables positively associated with adoption include the farmer self-identifying primarily as stewardship motivated or otherwise nonfinancially motivated, environmental attitudes, a positive attitude toward the particular program or practice, previous adoption of other conservation practices, seeking and using information, awareness of programs or practices, vulnerable land, greater farm size, higher levels of income and formal education, engaging in marketing arrangements, and positive yield impact expected. Some variables often thought to be important, such as land tenure, did not emerge as consistently important in this cross-study review. Other variables, such as farmers\u27 sense of place, training, presence of institutional conditions supporting adoption, and the role of collective decision making are not measured in enough studies to draw conclusions but potentially have a relationship with adoption decisions. Implications for how to promote conservation adoption and directions for future research are discussed. Because positive attitudes and awareness of conservation programs or practices are positive predictors of adoption, practitioners should share benefits of specific practices and programs and leverage existing practice adoption. Further work to explore relationships between conservation adoption and the role of farmer identity, nuances of land tenure, and the influence of structural factors is needed. Moreover, we suggest that future research should focus on the impact of different messages and avenues of reaching farmers in order to continue to inform conservation practices. Future research should consider both individual and institutional factors that facilitate and constrain adoption
Expressed Sequence Tags from Cephalic Chemosensory Organs of the Northern Walnut Husk Fly, Rhagoletis suavis, Including a Putative Canonical Odorant Receptor
Rhagoletis fruit flies are important both as major agricultural pests and as model organisms for the study of adaptation to new host plants and host race formation. Response to fruit odor plays a critical role in such adaptation. To better understand olfaction in Rhagoletis, an expressed sequence tag (EST) study was carried out on the antennae and maxillary palps of Rhagoletis suavis (Loew) (Diptera: Tephritidae), a common pest of walnuts in eastern United States. After cDNA cloning and sequencing, 544 ESTs were annotated. Of these, 66% had an open reading frame and could be matched to a previously sequenced gene. Based on BLAST sequence homology, 9% (49 of 544 sequences) were nuclear genes potentially involved in olfaction. The most significant finding is a putative odorant receptor (OR), RSOr1, that is homologous to Drosophila melanogaster Or49a and Or85f. This is the first tephritid OR discovered that might recognize a specific odorant. Other olfactory genes recovered included odorant binding proteins, chemosensory proteins, and putative odorant degrading enzymes
Long-Term Functionality of Rural Water Services in Developing Countries: A System Dynamics Approach to Understanding the Dynamic Interaction of Causal Factors
Research has shown that sustainability of rural water infrastructure in developing countries is largely affected by the dynamic and systemic interactions of technical, social, financial, institutional, and environmental factors that can lead to premature water system failure. This research employs systems dynamic modeling, which uses feedback mechanisms to understand how these factors interact dynamically to influence long-term rural water system functionality. To do this, the research first identified and aggregated key factors from literature, then asked water sector experts to indicate the polarity and strength between factors through Delphi and cross impact survey questionnaires, and finally used system dynamics modeling to identify and prioritize feedback mechanisms. The resulting model identified 101 feedback mechanisms that were dominated primarily by three and four-factor loops that contained some combination of the factors: Water System Functionality, Community, Financial, Government, Management, and Technology. These feedback mechanisms were then scored and prioritized, with the most dominant feedback mechanism identified as Water System Functionality – Community – Finance – Management. This research offers insight into the dynamic interaction of factors impacting sustainability of rural water infrastructure through the identification of these feedback mechanisms and makes a compelling case for future research to longitudinally investigate the interaction of these factors in various contexts
Post-Construction Support and Sustainability in Community-Managed Rural Water Supply
Executive Summary This volume reports the main findings from a multi-country research project that was designed to develop a better understanding of how rural water supply systems are performing in developing countries. We began the research in 2004 to investigate how the provision of support to communities after the construction of a rural water supply project affected project performance in the medium term. We collected information from households, village water committees, focus groups of village residents, system operators, and key informants in 400 rural communities in Bolivia, Ghana, and Peru; in total, we discussed community water supply issues with approximately 10,000 individuals in these communities. To our surprise, we found the great majority of the village water systems were performing well. Our findings on the factors influencing their sustainability will, we hope, be of use to policy makers, investors, and managers in rural water supply
Visual ecology of aphids – a critical review on the role of colours in host finding
We review the rich literature on behavioural responses of aphids (Hemiptera: Aphididae) to stimuli of different colours. Only in one species there are adequate physiological data on spectral sensitivity to explain behaviour crisply in mechanistic terms.
Because of the great interest in aphid responses to coloured targets from an evolutionary, ecological and applied perspective, there is a substantial need to expand these studies to more species of aphids, and to quantify spectral properties of stimuli rigorously. We show that aphid responses to colours, at least for some species, are likely based on a specific colour opponency mechanism, with positive input from the green domain of the spectrum and negative input from the blue and/or UV region.
We further demonstrate that the usual yellow preference of aphids encountered in field experiments is not a true colour preference but involves additional brightness effects. We discuss the implications for agriculture and sensory ecology, with special respect to the recent debate on autumn leaf colouration. We illustrate that recent evolutionary theories concerning aphid–tree interactions imply far-reaching assumptions on aphid responses to colours
that are not likely to hold. Finally we also discuss the
implications for developing and optimising strategies
of aphid control and monitoring
Morphology of olfactory sensilla and its role in host plant recognition by Neomegalotomus parvus (Westwood) (Heteroptera: Alydidae)
Multimodal Stimulation of Colorado Potato Beetle Reveals Modulation of Pheromone Response by Yellow Light
Orientation of insects to host plants and conspecifics is the result of detection and integration of chemical and physical cues present in the environment. Sensory organs have evolved to be sensitive to important signals, providing neural input for higher order multimodal processing and behavioral output. Here we report experiments to determine decisions made by Colorado potato beetle (CPB), Leptinotarsa decemlineata, in response to isolated stimuli and multimodal combinations of signals on a locomotion compensator. Our results show that in complete darkness and in the absence of other stimuli, pheromonal stimulation increases attraction behavior of CPB as measured in oriented displacement and walking speed. However, orientation to the pheromone is abolished when presented with the alternative stimulation of a low intensity yellow light in a dark environment. The ability of the pheromone to stimulate these diurnal beetles in the dark in the absence of other stimuli is an unexpected but interesting observation. The predominance of the phototactic response over that to pheromone when low intensity lights were offered as choices seems to confirm the diurnal nature of the insect. The biological significance of the response to pheromone in the dark is unclear. The phototactic response will play a key role in elucidating multimodal stimulation in the host-finding process of CPB, and perhaps other insects. Such information might be exploited in the design of applications to attract and trap CPB for survey or control purposes and other insect pests using similar orientation mechanisms
Leaf colour as a signal of chemical defence to insect herbivores in wild cabbage (Brassica Oleracea)
Leaf colour has been proposed to signal levels of host defence to insect herbivores, but we lack data on herbivory, leaf colour and levels of defence for wild host populations necessary to test this hypothesis. Such a test requires measurements of leaf spectra as they would be sensed by herbivore visual systems, as well as simultaneous measurements of chemical defences and herbivore responses to leaf colour in natural host-herbivore populations. In a large-scale field survey of wild cabbage (Brassica oleracea) populations, we show that variation in leaf colour and brightness, measured according to herbivore spectral sensitivities, predicts both levels of chemical defences (glucosinolates) and abundance of specialist lepidopteran (Pieris rapae) and hemipteran (Brevicoryne brassicae) herbivores. In subsequent experiments, P. rapae larvae achieved faster growth and greater pupal mass when feeding on plants with bluer leaves, which contained lower levels of aliphatic glucosinolates. Glucosinolate-mediated effects on larval performance may thus contribute to the association between P. rapae herbivory and leaf colour observed in the field. However, preference tests found no evidence that adult butterflies selected host plants based on leaf coloration. In the field, B. brassicae abundance varied with leaf brightness but greenhouse experiments were unable to identify any effects of brightness on aphid preference or performance. Our findings suggest that although leaf colour reflects both levels of host defences and herbivore abundance in the field, the ability of herbivores to respond to colour signals may be limited, even in species where performance is correlated with leaf colour
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