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931.
Abdelfattah Z. M. Salem Mona M. Y. Elghandour Ahmed E. Kholif Secundino López Alberto B. Pliego Moisés Cipriano-Salazar Juan Carlos V. Chagoyán Roberto Montes de Oca Jiménez María U. Alonso 《Agroforestry Systems》2017,91(1):111-122
The study aimed to test the potential anthelmintic activity of Salix babylonica (SB) extract for the control of gastrointestinal and pulmonary parasites in sheep and goats under field conditions. A representative sample of 20 % of all animals reared in 8 sheep and 7 goat farms was used in the study. Animals from each farm were randomly selected for a total number of 93 sheep and 75 goats. Animals suffered a natural gastrointestinal nematode infection and had never been treated with chemical anthelmintic drugs. The SB extract (20 mL) was orally administered weekly before the morning feeding to each animal for 60 days. Fecal eggs or oocysts were counted at 0, 1, 20, 40, and 60 days after starting the extract administration. Differences (P < 0.01) in the fecal oocyst and egg output of Eimeria, Dictyocaulus, and Moniezia were observed between sheep and goats. In addition, the treatment influenced (P < 0.05) egg outputs of Cooperia, Dictyocaulus, and Trichuris. Fecal egg or oocyst counts of Haemonchus contortus, Eimeria, Cooperia, Chabertia, Dictyocaulus, Moniezia, and Ostertagia were time-dependent (P < 0.05). For sheep, administration of SB decreased (P < 0.05) the fecal eggs count of H. contortus, Cooperia, Chabertia, Dictyocaulus, Moniezia, and Trichuris. After 20 days of treatment, H. contortus, Cooperia, or Moniezia were not detected. For goats, SB reduced (P < 0.05) the fecal egg counts of H. contortus, Cooperia, Chabertia, and Moniezia. Moreover, decreases were observed (P < 0.05) for Chabertia, Trichostrongylus, and Ostertagia. Eggs of H. contortus and Moniezia were not present in the feces after 1 day of administration of the extract. It could be concluded that the weekly administration of SB extract at 20 mL per animal can be used to treat gastrointestinal and lung nematodes of small ruminants in organic and traditional farming systems of tropical regions. 相似文献
932.
Lorena Soto Pinto Manuel Anzueto Martínez Pablo Martínez Zurimendi Guillermo Jiménez-Ferrer 《Small-Scale Forestry》2017,16(1):103-118
Increasingly, plantations for food, fiber and wood, are necessary to provide a growing world population. Agroforestry systems become more and more important, however these systems usually develop in marginal conditions, limited land, restricted funding, occasional technical support and above this, there is limited documentation and evaluation of innovated traditional systems in indigenous and small-scale contexts, which challenge forest scientists. The aim of this research was to assess the quality of trees in plots managed by Mayan indigenous farmers who planted agroforestry systems with fine wood species to increase the value of land and labor in localities with highly-marginal social conditions in Northern Chiapas, México. Twenty oldest plots were selected within a group of previously established plots (eight with improved fallow, six with shaded coffee and six with maize crop associated to trees) where forest inventories were carried out in nested 100 and 1000 m2-circular plots. In all plots tree diameter, height, quality indicators and the incidence of the pest Hypsipyla grandella were measured. Trees in the maize-associated-to-trees system are favored by the practices applied to annual crop during the first 3rd–5th years, a period in which they are free from the interference of other trees and benefit from favorable light conditions, weeding and a higher intensive care from the farmer while shaded coffee and improved fallow have higher tree densities and a more closed canopy condition than maize associated to trees. In consequence, maize associated to trees shows 68.1 % stems with good form; shaded coffee and improved fallow averaged 40.5 and 39.7 % of good quality stems, respectively; improved fallow exhibited a greater number of suppressed trees than shaded coffee and maize associated to trees (p < 0.0001). In addition, maize associated to trees showed the highest proportion of trees with commercial value with 56.9 %, followed by improved fallow with 28.2 %, and shaded coffee with 11.8 % (p < 0.0001); the rest were trees with domestic uses. However, maize associated to trees significantly result with high incidence of H. grandella probably due to the crown exposure. Timber volume averaged 92.9 ± 68.9 m3 for improved fallow, 77.3 ± 24.8 m3 for shaded coffee, and 52.5 ± 39.7 m3 for maize associated to trees. The value of the fine wood represents increment in income, variety of products and self-employment for households. Nonetheless, improved fallow and coffee plantations might benefit from the elimination of competitors from larger trees to favor promising immature ones and pruning, while maize crop associated to trees might benefit from opportune pruning for controlling the stem borer as well as tree replacement to achieve long term replacement and harvesting. 相似文献
933.
José M. Fernández-Alonso José A. Vega Enrique Jiménez Ana D. Ruiz-González Juan G. Álvarez-González 《European Journal of Forest Research》2017,136(1):105-121
Fire is a major disturbance in forests and one of the most important carbon emissions sources, which contributes to climate change. Carbon emissions are directly correlated with the degree of organic matter consumption or fire severity. Gaining knowledge about the relative strength of the various explanatory variables is essential to mitigate its environmental impact. We tested an approach that combines wind modeling, light detection and ranging (LiDAR), remotely sensed vegetation indices and topography data for assessing the occurrence of high-severity fire using the random forests ensemble learning method. Data from four wildfires that occurred in Galicia (northwestern Spain) were used to exemplify the application of this approach. The models predicted high-severity occurrence with a classification accuracy ranging from 77 to 94%. High-severity fire occurred more frequently in areas of high simulated wind speed, and more pronouncedly, for cases reported as wind-driven fires. High severity also occurred more frequently in areas of high terrain roughness, on sunny slopes and in low canopy base height stands. This approach allowed predicting spatially explicit fire severity at a mean scale level (resolution of 25 m) with accuracy rates from 80 to 95%. This approach may be helpful for fire managers when delimiting and planning fuel treatments for severity mitigation or during fire suppression, and for post hoc case studies. 相似文献
934.
Diana E. Jiménez-de-Santiago Gonzalo Almendros Àngela D. Bosch-Serra 《Soil Use and Management》2023,39(4):1351-1363
Pig slurries are widely used on calcareous soils in European rainfed systems. Here we assess their impact on the amount of soil organic carbon (SOC) and on the composition of humic-type substances (HTS). Seven doses of slurry (five from fattening pigs and two from sows) ranging from 1.0 to 4.8 Mg ha−1 yr−1 of organic matter were evaluated after a period of 12 years and compared with mineral fertilizer treatment. At the end of the last annual cropping season (September), SOC was quantified, and HTS were isolated by alkaline extraction followed by acid precipitation, and studied by visible spectroscopy (800–400 nm) and Fourier-transformed infrared spectroscopy (4000–400 cm−1). Following the trend in the slurry organic matter applied rates, SOC increased from 9.5 g C kg−1 (mineral treatment) to 13.8 g C kg−1. This SOC increase was equivalent to c. 25.4% of the slurry organic carbon applied. The incorporation of aliphatic structures, mainly polyalkyl, from slurries into the HTS tends to modify the composition of the soil organic matter (SOM), which is reflected in a decrease in the intensity of FT-IR peaks related to aromatic structures. Despite the trend of significant increase in SOC with fattening slurries, mainly from the organic matter rate of 1.6 Mg ha−1 yr−1 (c. 185 kg N ha−1), the composition of the HTS showed an important aliphatic enhancement. The FTIR results showed that using exclusively the relative intensities of specific peaks (alkyl, carboxyl, aromatic and amide groups) as variables for the discriminant analysis, it is possible to identify HA between different groups of soils treated with progressive levels of slurry. Although the new aliphatic components could be considered important to improve soil physical quality, after the incorporation of additional SOM, the spectroscopic characteristics of HTS in soils treated with slurries suggested a weak effect in long-term C sequestration, as the newly incorporated OC forms are not qualitatively similar to the presumably stable native SOM. These potential changes in SOC and SOM composition at field level are constrained by the maximum allowed N rates from organic origin in some agricultural systems. 相似文献