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Ivette Perfecto – One of the best experts on this subject based on the ideXlab platform.
review do polycultures promote win wins or trade offs in Agricultural Ecosystem services a meta analysisJournal of Applied Ecology, 2014Co-Authors: Aaron L Iverson, Linda Marin, Katherine K Ennis, David J Gonthier, Benjamin T Connorbarrie, Jane L Remfert, Bradley J Cardinale, Ivette PerfectoAbstract:
Agriculture comprises the largest global land use, makes it a leading cause of habitat loss. It is therefore critical to identify how to best construct Agricultural systems that can simultaneously provide food and other Ecosystem services. This challenge requires that we determine how to maximize win-win relationships and minimize trade-offs between services.
Through meta-analysis, we tested whether within-field crop diversification (polyculture) can lead to win-win relationships between two Ecosystem services: yield of a focal crop species and biocontrol of crop pests. We selected only studies that recorded both services (N = 26 studies; 301 observations), allowing us to better determine the underlying mechanisms of our principal findings. We calculated log-response ratios for both Ecosystem services in mono- and polycultures.
We found win-win relationships between per-plant yield of the primary crop and biocontrol in polyculture systems that minimized intraspecific competition via substitutive planting. Additionally, we found beneficial effects on biocontrol with no difference in per-unit area yield of the primary crop in polyculture fields at high cropping densities (additive planting) where legumes were used as the secondary crop. These results suggest that there is a strong potential for win-win relationships between biocontrol and per-unit area yield under certain scenarios. Our findings were consistent across geographical regions and by type of primary crop. We did not find evidence that biocontrol had an effect on yield, but rather, both were independently affected by polycultural cropping.
Synthesis and applications. We show that well-designed polycultures can produce win-win outcomes between per-plant, and potentially per-unit area, primary crop yield and biocontrol. Biocontrol services are consistently enhanced in polycultures, so polyculture management that focuses on yield optimization is likely to be the best strategy for maximizing both services. In doing so, we suggest that practitioners utilize polycultures that decrease plant–plant competition through a substitution of relatively large quantities of the primary crop for compatibly harvestable secondary crops. Additionally, if planting at high cropping densities, it is important that legumes be the secondary crop.
Ellen Kandeler – One of the best experts on this subject based on the ideXlab platform.
field scale manipulation of soil temperature and precipitation change soil co2 flux in a temperate Agricultural EcosystemAgriculture Ecosystems & Environment, 2013Co-Authors: Christian Poll, Sven Marhan, Florian Back, Pascal A Niklaus, Ellen KandelerAbstract:
Abstract Modifications in temperature and precipitation due to climate change will likely affect carbon cycling and soil respiration in terrestrial Ecosystems. Despite the important feedback mechanism of Ecosystems to climate change, there is still a lack of experimental observation in Agricultural Ecosystems. In July 2008, we established the Hohenheim Climate Change (HoCC) experiment to investigate effects of elevated temperature and altered precipitation on soil respiration in an arable soil (mean annual temperature and precipitation 8.7 °C and 679 mm, respectively). We elevated soil temperature to 4 cm depth by 2.5 °C, reduced the amount of summer precipitation by 25%, and extended dry intervals between precipitation events. For two years, CO 2 fluxes were measured weekly and aboveground plant biomass and soil microbial biomass was determined. The results of the two-year study underline the importance of soil moisture as a driving factor in Ecosystem response to climate change. Soil warming did not increase soil respiration in the first year; in the second year, a 27% increase was measured. The differential response of soil respiration to warming was most likely driven by soil moisture. In summer 2009, water limitation reduced microbial biomass in the heated plots thereby suppressing the stimulatory effect of elevated temperature on soil microorganisms. In summer 2010, the reduction in soil moisture was less pronounced and microbial biomass and respiration were not affected by water limitation. Temperature elevation significantly reduced Q 10 values of soil respiration by 0.7–0.8. Altered precipitation showed only minor effects during the first two years of the experiment. We conclude from our study that the moisture regime of soils under elevation of temperature will largely determine whether different soils will serve either as carbon sources or as carbon sinks.
Jianguo Wu – One of the best experts on this subject based on the ideXlab platform.
how do climatic and management factors affect Agricultural Ecosystem services a case study in the agro pastoral transitional zone of northern chinaScience of The Total Environment, 2018Co-Authors: Jianmin Qiao, Jianguo Wu, Deyong YuAbstract:
Abstract Agricultural Ecosystem management needs to ensure food production and minimize soil erosion and nitrogen (N) leaching under climate change and increasingly intensive human activity. Thus, the mechanisms through which climatic and management factors affect crop production, soil erosion, and N leaching must be understood in order to ensure food security and sustainable Agricultural development. In this study, we adopted the GIS-based Environmental Policy Integrated Climate (EPIC) model to simulate crop production, soil erosion, and N leaching, and used a partial least squares regression model to evaluate the contributions of climate variables (solar radiation, precipitation, wind speed, relative humidity, and maximum and minimum temperature) and management factors (irrigation, fertilization, and crop cultivation area) on Agricultural Ecosystem services (AES) in the agro-pastoral transitional zone (APTZ) of northern China. The results indicated that crop production and N leaching markedly increased, whereas soil erosion declined from 1980 to 2010 in the APTZ. Management factors had larger effects on the AES than climate change. Among the climatic variables, daily minimum temperature was the most important contributor to the variations in Ecosystem services of wheat, maize, and rice. Spatial changes in the cultivated area most affected crop production, soil erosion, and N leaching for majority of the cultivated areas of the three crops, except for the wheat-cultivated area, where the dominant factor for N leaching was fertilization. Although a tradeoff existed between crop production and negative environmental effects, compromises were possible. These findings provide new insights into the effects of climatic and management factors on AES, and have practical implications for improving crop production while minimizing negative environmental impacts.