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61.
62.
Sven Günter Paul Gonzalez Guido Álvarez Nikolay Aguirre Ximena Palomeque Frank Haubrich Michael Weber 《Forest Ecology and Management》2009
The Andes of Ecuador are known for their outstanding biodiversity but also as the region with the highest deforestation rate in South America. This process is accompanied by accelerating degradation and loss of environmental services. Despite an extraordinary richness in native tree diversity, more than 90% of all forest plantations established in Ecuador consist of exotic species, primarily Eucalyptus spp. and Pinus spp. This is mainly due to the lack of information about the autecological and synecological requirements of the native species. 相似文献
63.
Delphine Sciama Laurent Augusto Jean-Luc Dupouey Maya Gonzalez Concepción Moares Domínguez 《Forest Ecology and Management》2009
The aim of this work was to investigate differences in soil chemistry and understory composition between recent forests (sites afforested in the last 170 years) and ancient forests growing on non-acidic soils. The study was carried out on hardwood forests at moderate elevation (400–600 m asl) in the Jura Mountains (N.E. France) on four main pedological substrates with different characteristics. The floristic composition of 127 stands from recent forests (n = 65) or ancient forests (n = 62) was surveyed. Some functional traits and the Ellenberg indicator values of the surveyed species were recorded. In addition, the topsoil from 30 stands was analysed. The composition of the flora was analysed by Detrended Correspondence Analysis and the species which were typical of one class of forest age were identified using a chi-square (χ2) test. The difference between forest classes for plant traits, their indicator values, or soil chemistry was tested using the generalized linear model and Bonferroni t-tests (or Kruskall–Wallis tests). The floristic composition of the ancient forests was significantly different from that of the recent forests and was characterized by a high occurrence of shrub species in recent forests. These differences were associated with higher specific leaf area, low-range seeds dispersal, and some life forms like geophytes. There was no clear difference in soil chemistry between the two classes of forests, except for δ15N values. The weakness of the difference in the soil between ancient and recent forests suggested that changes in soil chemistry caused by a former agricultural land use were not responsible for the differences in understory composition recorded. The differences in functional traits between the two forest classes supported this conclusion. We finally concluded that (i) past land use modifies the vegetation composition of current forests, even on neutral soils and that (ii) in our context, biological filters were probably responsible for these changes. 相似文献
64.
F. Abderrahim E. Huanatico R. Repo-Carrasco-Valencia S.M. Arribas M.C. Gonzalez L. Condezo-Hoyos 《Journal of Cereal Science》2012
Germination of cereals/pseudo-cereals has been suggested as an effective method to increase antioxidant compounds. However, this process could also lead to high reducing sugar levels and subsequent Maillard reaction products. The aim of this work was to determine the time course effect of canihua (Chenopodium pallidicaule) germination on: 1) antioxidant capacity, 2) extractable and non-extractable phenolic compounds content, 3) Maillard reaction products and 4) oxidative stress markers. Germination increased antioxidant capacity, phenolic compounds and Maillard reaction products, including advanced glycated end products while it decreased oxidative stress markers. All parameters exhibited a similar time course pattern with a maximum at 72 h. In addition to the increase in phenolic compounds and antioxidant capacity, canihua germination produced advanced glycated end products. The impact on human health of these compounds in germinated seeds deserves future attention. 相似文献
65.
RNAseq analysis reveals the role of secondary metabolism in the response of URS 21, a race‐nonspecific resistant cultivar,to crown rust 下载免费PDF全文
66.
This report describes a suspect case of West Nile virus (WNV) encephalomyelitis, reported for the first time in a horse in the UK. The affected gelding had been imported from the Republic of Cyprus and travelled through several WNV endemic areas in Europe before arriving at the premises in Lincolnshire. Clinical signs included muscle fasciculations, weakness of the hindlimbs and transient lip twitching that quickly progressed to depression and recumbency. West Nile virus specific antibodies were detected by serological tests in the absence of a previous history of vaccination. The horse improved clinically 10 days after the onset of disease and fully recovered in 12 weeks. Follow‐ups at 12 and 20 months post event did not reveal any sequela and the horse was performing adequately at novice level. This article refers to the same horse mentioned by Fooks et al. (2014) and it is an extension of the previous published work. 相似文献
67.
SM Gonzalez CB da Silva AG Lindquist I Bufalo F Morotti LA Lisboa M Seneda 《Reproduction in domestic animals》2017,52(5):836-841
The goal of this study was to determine the distribution of pre‐antral follicles in the ovarian parenchyma of mares. For Experiment 1, each ovary was cut longitudinally at the greater curvature, performing two hemiovaries. After that, six fragments from each hemiovary were obtained, resulting in 12 fragments, which were divided into the innermost region of the parenchyma, the middle region and the outermost region. All the three obtained sections were cut transversally to obtain two fragments from each one. For Experiment 2, each ovary also submitted to a longitudinal cut on the greater curvature, forming two hemiovaries. Each hemiovary was sectioned into four symmetrical fragments, resulting in eight fragments per ovary. The fragments were related as being near to or far from the ovulatory fossa. The fragments of both experiments were immediately fixed in Carnoy for 12 hr and kept in 70% ethanol for 24 hr. Follicles were classified according to the stages of development and for morphological integrity according to oocyte morphology and granulosa cells. After the histological assessment, a total of 1,130 follicles were visualized from Experiment 1, being 1,054 (93.3%) primordial follicles and 76 (4.7%) follicles in development. The innermost region had the highest percentage of pre‐antral follicles compared to the other regions (p < .05). The middle and outermost regions showed higher percentages of intact primordial and developing follicles than the innermost region (p < .05). Considering Experiment 2, 938 follicles were found, being 894 (95.3%) primordial and 44 (4.7%) follicles in development. The region near the ovulatory fossa presented higher (58.7%; 551 of 938) follicular concentration compared to the region far from the ovulatory fossa (41.3%; 387 of 938; p < .05). As a conclusion, distribution of pre‐antral follicles in the equine ovary has a specific pattern through the parenchyma. Also, the follicular integrity differed in the studied ovarian areas. 相似文献
68.
Leonel Lopez-Toledo Margarita Heredia-Hernández Dante Castellanos-Acuña Arnulfo Blanco-García Cuauhtémoc Saénz-Romero 《New Forests》2017,48(6):867-881
Climate varies along altitudinal gradients and species performance may be affected in response to these variations. Climate change can modify these gradients and, at the lower limit of species distributions, individuals may become stressed and their general health and reproductive performance may decrease. Study and prediction of the effects of climate change on the distribution of species along these gradients is therefore necessary. Our model study species, Pinus pseudostrobus, is a widely distributed pine in Mexico, ranging from 1600 to 3200 masl in altitude. In order to explore changes in health condition and reproductive investment along an altitudinal gradient, ten reproductive trees were selected in each of four populations (at 2300, 2400, 2700 and 2900 masl). As a proxy of individual health, we conducted a rapid visual assessment for each tree, based on crown defoliation, dead branches and foliage discoloration. This stress condition index (SCI) ranges from zero to fifteen, and lower values indicate low stress and therefore better health conditions. We also evaluated reproductive (cone weight, number/weight of seeds) and progeny (germination/seedling growth) traits. In addition, the relationships between SCI and the reproductive/progeny traits were assessed. The lowest altitude population presented poor health, with higher values of SCI (mean ± SE = 6.3 ± 0.9) that reduced up to 4.8-fold in higher-altitude populations. Cone weight also differed among altitudes, with lighter cones in the lower population (mean ± SE = 38.2 ± 4.3 g), and 1.5-fold heavier cones found in the higher populations. In general, all of the reproductive/progeny traits differed among altitudes. The population of intermediate altitude (2700 masl) presented the highest values for all traits evaluated, indicating higher performance at this altitude. Finally, a negative relationship was found between stress condition and cone weight. Based on our results and climate change models and their predictions, an increase in physiological stress can be expected in individuals of low altitude populations. Furthermore, possible increases in pests and pathogens are likely to contribute to the decline of this population. It is therefore necessary to maintain efforts of stress condition assessment and population dynamics, as well as to permanently monitor the climate along altitudinal gradients. 相似文献
69.
Adalton Mazetti Fernandes Bruno Gazola Jesion Geibel da Silva Nunes Emerson Loli Garcia Magali Leonel 《Journal of plant nutrition》2017,40(20):2785-2796
Potassium (K) is one of the most absorbed nutrients by cassava because it acts on the synthesis and starch accumulation in the storage roots. Here, we show that K application at the beginning of the second vegetative cycle of cassava submitted to shoot pruning increased the yield of roots and starch, and the nutrient demand of plants. Application of 45–89 kg ha?1 dipotassium oxide (K2O) in the second cycle increased the yield of storage roots and starch from 36–49% and K applied at this time had a greater effect on the synthesis and allocation of starch in the storage roots. K supply increased the accumulation of N and S by 2.0- to 3.0-fold and the accumulation of other nutrients by 1.4- to 1.7-fold. The removal of phosphorus (P), manganese (Mn), and zinc (Zn) by storage roots was not affected by K application, whereas the removal of other nutrients increased by 1.3- to 4.3-fold. 相似文献
70.
Shikha Singh Nathan Brandenburg Laurent Ahiablame Arturo Gonzalez Jeppe Kjaersgaard Todd P. Trooien Sandeep Kumar 《Water, air, and soil pollution》2017,228(10):389
Manure application on frozen soil, which is a common practice in the upper Midwest of USA, results in degraded soil and water quality. During snowmelt or precipitation events, water runoff carries nutrients into nearby streams and impairs the water quality. There is a need, therefore, to identify improved management of manure application in the soils. This study was conducted to assess water quality impacts associated following manure application during winter months when soil is completely covered with snow. The study site included three watersheds, named south (SW), east (CW), and north (NW) managed with a corn (Zea mays L.)-soybean (Glycine max L.) rotation located in South Dakota. The SW and NW were used as treatment, and CW as the control watershed. The treatments included manure application on the upper half of the SW and lower half of the NW, and CW received no manure application. This study showed that manure improved soil properties including infiltration rate and organic matter. Nitrogen and phosphorus losses in the surface runoff were higher from NW compared to that of SW. The CW had similar nutrient losses compared to the NW with slight differences. It can be concluded that maintaining a setback distance can help in improving the environmental quality as well as managing the agricultural wastes during the winter months. 相似文献