Expenditures on salaries act as an incentive system to make the current advisor FTE more productive, which enhances productivity, as is indicated by our results. Expenditures on infrastructure have a positive impact on knowledge production before the threshold level is reached, beyond which the impact becomes negative. In this respect, our findings for the extension system in California suggest that the research and dissemination by agricultural extension is similar to that of a research only system. The quadratic behavior of the expenditures on infrastructure was found significant, with a negative sign for the quadratic term. This finding is similar to the results in Roper and Hewitt-Dundas , Jordan and O’Leary , and Charlot et al. . Such results suggest an inverse U-shaped relationship between knowledge production and fixed infrastructure investment. The support in findings on the inverse U-shaped impact of research infrastructure on knowledge production we get from literature on non-agricultural research, is very helpful for validating the results in our analysis with focus on agricultural research and extension in California.We found that expenditures on infrastructure per-unit FTE as a research input has diminishing marginal effects on knowledge production. Marginal product of advisor FTE calculated at the mean value of the input and knowledge index equals 106.33; this implied that one unit increase in county FTE led to nearly 106 additional counts of knowledge production. Marginal products of expenditures on salaries per FTE and infrastructure per FTE are 0.003and −0.0003,respectively. Marginal products values calculated at the mean emphasized the importance of advisor FTE as a research input.

hey also brought forward the issue of diminishing returns on investments in incentives and infrastructures. We conducted several robustness checks by running regression for models using each of the three broad categories of knowledge production and dissemination instead of the calculated knowledge index. The three broad categories are: direct contacts, indirect contact, and publications and research projects as dependent variables. The results of the robustness checks are reported in Appendix Tables A2, A3, and A4. The results suggest similar range of coefficients for each of the variables,hydroponic bucket similar signs and significance levels across the various estimated models. Thus, these results suggest that the empirical knowledge function we use is robust. Endogeneity, if exists, could be found in the sphere of budget allocation for extension work at the county level. It could be argued that level of budget allocation is a function of the agricultural performance of the county, and thus introducing endogeneity biases in our estimates. However, following interviews with county directors, decisions on budget allocations among the counties in California are made based on political negotiations between the county directors and the UCCE system. Furthermore, as suggested by Guttman , Rose-Ackerman and Evenson , Pardey and Pardey and Craig , political rather than just economics efficiency criteria influence the allocation of public agricultural research and extension resources.We have estimated the contemporaneous impact of UC Cooperative Extension on the production of knowledge through research and extension work that is conducted in all California counties. Available data on R&D expenditures and knowledge products was used to construct a unique data set for seven years, spanning from 2007 to 2013. The data contained information on extension advisor FTE, expenditures on advisor FTE salaries, and on advisor FTE infrastructure. We obtained data on a number of knowledge production and dissemination methods. They are categorized into 11 subcategories, and three broad categories.

We computed a weighted average knowledge index variable with the weights provided by UCCE county directors via an electronic survey. The contribution of this work is the quantification of extension research input and in the fact that the trends and relative importance of research variables found in an extension research and dissemination system in California are similar to previous results of the agricultural research system in the USA, and previous results from several industrial research and development activities around the world. Both these similarities suggest that a research and dissemination agricultural extension behaves similarly to industrial research systems. One limitation of the study is that we were able to capture only the contemporaneous impact of research inputs on the production and dissemination of knowledge, due to data constraints. With further availability of data, analysis of long-run impact will enable policymakers to make informed decisions on investments in research inputs. This will enable sustained knowledge production and dissemination. Another limitation of the study is the lack of information on components of the research inputs, such as attributing research outcomes and extension impact to advisors, rather than distinguishing among advisors, based on seniority and experience. Such a distinction related to university research was performed in a study by Gurmu et al. . Some potential issues with the variable specifications deserve a mention. The variable FTE includes UCCE county advisors. Incorporation of detailed data on knowledge produced and disseminated by UCCE specialists at the county level would provide a more complete picture of the knowledge production mechanism. Data on FTE experience and expertise could also refine our results and understanding of the input-output relationship. Research-based agricultural knowledge is one of the most important inputs in the enhancement of agricultural productivity , and evidence suggests significant impacts on current productivity from the past 35 years of research-based knowledge . Therefore, better understanding of relevant research inputs, environments in which substitution between inputs is viable, and long-term impact of shifts in investments in research inputs have a great deal of importance for policy purposes.

This paper poses and provides answers to some of these questions and indicates possible directions for future study on this issue. Another point to address is the international and national relevance of this work to the literature and to policy practitioners. California is a leader in agricultural production. California extension system is a leader in extension knowledge that feeds into the agricultural production in the state. Therefore, understanding the process of knowledge creation by agricultural extension in California is of interest to researchers and practitioners in other states and countries. The finding in this study suggests that data collection and analysis for public extension activities are essential for proper policy consideration of a public knowledge system, which faces budget pressure world-wide. While the coefficients estimated for the case of California represent California situation, the trends of the coefficients are general and relevant to other states and countries around the world. With the data challenges we faced in this study, our results indicate the importance of the policymaker to be able to quantify the process of knowledge production in the agricultural extension systems. California ranks first among the top five national agricultural producers,stackable planters according to the California Statistical Review 2014–15 , with crop cash receipts amounting $53.5 billion . Irrigated agriculture in California consumes on average about 85% of the available renewable water resources in the state . Agricultural extension plays a major role in keeping agriculture sustainable and profitable . Therefore, the need for a reliable system of data collection on agricultural extension activities and knowledge produced at the state and county levels would enhance the ability to identify the determinants of knowledge production by the extension system. Finally, we observed, as Pardey and Alston et al. also did, that the public budget allocated to agricultural and extension has declined over time. The lesser funding allocated to UCCE over time is not because knowledge has decreased; in fact, we claim that it is the opposite, knowledge production has declined because there was less funding due to recession or/and budgetary constraints in the University of California system as a result of financial difficulties faced by the state of California during the years we analyze.Human-altered landscapes are expanding globally and are often associated with declining natural habitat, non-native species, fragmentation, and transformations in structure, inputs, climate, and connectivity. These changes collectively have resulted in shifts in both spatial distributions and species diversity across many taxa including birds, mammals, reptiles, amphibians, invertebrates, and plants.

One common driver of global change is urbanization, which in the extreme is associated with a reduction in biodiversity compared to habitats in their more natural state. However, in moderately urbanized areas, the effects of urban impacts on species distribution and diversity can vary greatly and depends on region, type of change, and taxonomic group, among other factors. Documenting the effects of urbanization compared to natural communities has proven problematic, making predictions of community change associated with urbanization difficult. Human-altered landscapes are often associated with many non-native species which add to species diversity but also can obscure changes in community dynamics. Thus, to assess accurately the complex impacts of land use change on ecological communities, one must look beyond species richness to investigate ecological processes themselves. Ecological processes are the links between organisms in a functioning ecosystem, and are critical in understanding how altered biodiversity can lead to changes in ecosystem functioning. Global environmental change has been found to have a wide variety of impacts on ecological processes in different systems. Pollinator-plant relationships in particular are found to be particularly vulnerable to land use change, resulting in decreases in interaction strength and frequency. Pollination services are crucial ecosystem processes in natural systems, but also in agricultural and urban areas. Bees provide the majority of animal-mediated pollination services on which it is estimated 87.5% of flowering plants depend. The value of pollination in agriculture is estimated at $200 billion worldwide, largely due to many foods that are essential for food security and a healthy human diet, including numerous fruits, vegetables, and nuts that require bee pollination. As urban areas expand, there has been increasing interest in urban agriculture to ensure food security and access to healthy foods for growing populations, and these systems also depend on pollination. For example, Kollin estimated that the economic value of urban fruit trees to be worth $10 million annually in San Jose, California. Despite the important role of pollinators and concerns about bee declines, there remain many uncertainties regarding the impact of land use change on pollinators. Urbanization has resulted in more interfaces with both natural and agricultural landscapes, creating new transitional zones of peri-urbanization. While there has been extensive pollinator research in agricultural and natural systems, less attention has focused on pollination in neighboring urban areas and how the changing landscape has impacted pollination. In addition, very few studies of urban areas have looked beyond changes in bee diversity to understand explicitly the effect of urbanization on pollinator-plant interactions. Here, we investigate the effect of land use change on pollinator plant ecosystem processes. We make use of a ‘‘natural experimental design’’ in which urban, agricultural, and natural areas intersect. Bees visit flowers for both pollen and nectar resources, and floral visitation is a commonly used as an index of pollination services. However, depending on the flower, certain bee groups are much more effective pollinators than others. Thus, while visitation is important, it alone does not definitively indicate whether pollination services were received by the plant. When pollen is limited by other factors, consequences for plant fitness can include failure to set seed, production of smaller fruits, and even complete lack of reproduction. By looking at rates of bee visitation and comparing this with other measures of plant fitness, such as seed set, we can develop a more complete understanding of how shifts in bee distributions between areas that differ in land use are impacting pollination services. To study the impact of changing land use on pollinator-plant interactions, we focus on bee pollination of a widespread plant, yellow starthistle , a common weed found in natural, agricultural, and urban habitats. Using standardized observations of floral visitation and seed set measurements of yellow starthistle, we test the hypotheses that increasing urbanization decreases 1) rates of bee visitation, 2) viable seed set, and 3) the efficiency of pollination . In addition to contributing to a better understanding of how change in landscape use, particularly urbanization, affects pollination-plant interactions, the study illustrates the importance of use of neighboring lands for pollination services.We observed visits by all bee species to yellow starthistle at all sites 3 times for a 30 min period for a total of 90 min of total observation time per site within the same 2 wk period in August 2011.