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51.
Mercedes Uscola Juan A. Oliet Pedro Villar-Salvador Eugenio Díaz-Pinés Douglass F. Jacobs 《European Journal of Forest Research》2014,133(2):235-246
Most studies examining inorganic N form effects on growth and nutrition of forest trees have been conducted on single species from boreal or temperate environments, while comparative studies with species from other biomes are scarce. We evaluated the response of two Mediterranean trees of contrasting ecology, Quercus ilex L. and Pinus halepensis Mill., to cultivation with distinct inorganic N forms. Seedlings were fertilized with different NH4 +/NO3 ? proportion at either 1 or 10 mM N. In both species, N forms had small effects at low N concentration, but at high N concentration they markedly affected the plant performance. A greater proportion of NH4 + in the fertilizer at high N caused toxicity as it reduced growth and caused seedling death, with the effect being greater in Q. ilex than in P. halepensis. An increase in the proportion of NO3 ? at high N strongly enhanced growth relative to low N plants in P. halepensis but had minor effects in Q. ilex. Relatively more NH4 + in the fertilizer enhanced plant P concentration but reduced K concentration in both species, while the opposite effect occurred with NO3 ?, and these effects were enhanced under high N concentration. We conclude that species responses to inorganic N forms were related to their ecology. P. halepensis, a pioneer tree, had improved performance with NO3 ? at high N concentration and showed strong plasticity to changes in N supply. Q. ilex, a late successional tree, had low responsiveness to N form or concentration. 相似文献
52.
The life cycle of cuttlefish fed ad libitum exclusively on live grass shrimp (Palaemonetes varians) was studied during 5 consecutive generations. Different culture temperatures promoted different (P < 0.05) exponential growth for each life cycle, being summer generations shorter than those of winter. Higher temperatures promoted higher IGR’s and mortality, while lower temperatures promoted increased life span, reproduction stages, total fecundity and total egg biomass. Increased generations also seemed to increase fertility. A “hybrid” generation promoted the best results in terms of hatchling weight, individual fecundity and fertility. Mean egg weight was related to female size and embryonic development took longer at lower temperatures. Brood stock sex ratios seemed to be temperature related. All of these culture aspects were also compared between themselves in order to establish future brood stock methodologies. Grass shrimp proved to be a good diet for the culture of cuttlefish throughout the life cycle. The use of only one species reduces costs and labor associated to cuttlefish culture. 相似文献
53.
Concepts and methods for landscape multifunctionality and a unifying framework based on ecosystem services 总被引:2,自引:0,他引:2
Matias E. Mastrangelo Federico Weyland Sebastian H. Villarino María P. Barral Laura Nahuelhual Pedro Laterra 《Landscape Ecology》2014,29(2):345-358
The potential of landscapes to supply multiple benefits to society beyond commodities production has received increasing research and policy attention. Linking the concept of multifunctionality with the ecosystem services (ES) approach offers a promising avenue for producing scientific evidence to inform landscape planning, e.g., about the relative utility of land-sharing and land-sparing. However, the value for decision-making of ES-based multifunctionality assessments has been constrained by a significant conceptual and methodological dispersion. To contribute towards a cohesive framework for landscape multifunctionality, we analyse case studies of joint ES supply regarding ten criteria designed to ultimately answer four aspects: (i) the multifunctionality of what (e.g., landscapes), (ii) the type of multifunctionality (e.g., based on ES synergies), (iii) the procedure of multifunctionality assessments, and (iv) the purpose of multifunctionality. We constructed a typology of methodological approaches based on scores for criteria describing the evaluation method and the level of stakeholder participation in assessments of joint ES supply. Surveyed studies and underlying types of methodological approaches (spatial, socio-spatial, functional, spatio-functional) differed in most criteria. We illustrate the influence of methodological divergence on planning recommendations by comparing two studies employing contrasting approaches (spatial and functional) to assess the joint supply of wildlife habitat and agricultural production in the Argentine Chaco. We distinguish between a pattern-based and process-based multifunctionality, where the latter can only be detected through approaches considering the ecological processes (e.g., ES complementarities) supporting the supply of multiple ES (functional and spatio-functional). Finally, we propose an integrated approach for assessing a socially-relevant process-based multifunctionality. 相似文献
54.
Francisco Javier Estay Rodrigo Noriega Jose Pedro Ureta Werner Martín & Nelson Colihueque 《Aquaculture Research》2004,35(5):447-452
Data on reproductive traits in a cultured population of brown trout (Salmo trutta L.) in southern Chile were collected over three consecutive reproductive seasons: 1999, 2000 and 2001, corresponding to the first (at 3 years), second and third spawnings in females. Data were collected from individual females (n=238, 273 and 169 respectively). The reproductive season lasted mainly from June to August. The peak (July) tended to increase with each season (55.46%, 62.27% and 80.81% of total spawning fish respectively). Female body weight (470.8±102.5, 735.0±150 and 1263.9±263.4 g), total fecundity (1182±344, 1904±595 and 2744±605) and egg diameter (4.64±0.11, 4.67±0.27 and 5.24±0.12 mm) increased significantly (P<0.01) over successive reproductive seasons, particularly between the second and third spawnings. Relative fecundity, on the other hand, decreased significantly with each season (3577±471, 2591±900 and 2181±360). Following analysis of the variables over the three seasons, the correlation pattern of female body weight with total fecundity (r=0.91, n=458; P<0.001) and relative fecundity (r=?034, n=451; P<0.001) proved similar to that described in other salmonid females. Fertilization rate and survival to the eyed egg stage were also positively correlated (r=0.73, n=453; P<0.001). The systematically high values obtained for these latter variables over the seasons evaluated (consistently above 90%) are clearly greater than those we registered in other species of salmonids bred in Chile under similar conditions and suggest highly efficient biological variables that determine the gamete fertilization of this species. The brown trout is, therefore, an interesting potential aquaculture resource in Chile. 相似文献
55.
Carvalho Thayslan Brosinsky Arlena Foerster Saskia Teixeira Adunias Medeiros Pedro 《Journal of Soils and Sediments》2022,22(9):2557-2577
Journal of Soils and Sediments - Soil erosion by water yields sediment to surface reservoirs, reducing their storage capacities, changing their geometry, and degrading water quality. Sediment... 相似文献
56.
Effects of density on growth and survival of juvenile Red Swamp Crayfish, Procambarus clarkii (Girard), reared under laboratory conditions 总被引:2,自引:0,他引:2
Ricardo Oliveira Ramalho Alexandra Marçal Correia & Pedro Manuel Anastácio 《Aquaculture Research》2008,39(6):577-586
The aim of this study was to quantify the importance of population density on the growth and survival of juvenile red swamp crayfish, Procambarus clarkii (Girard), and to understand the effects of density on both the period between moults and the increment per moult at high densities without food limitation. A laboratory experiment was performed to determine growth and survival of juvenile crayfish at five densities (20, 40, 60, 80 and 100 crayfish m?2). Density clearly affected crayfish growth. The impact of density on final weight was higher than on total length increase, growth rate and final length (FL) (by decreasing order of effect). When comparing minimum and maximum densities, we observed that FL suffered a 34% reduction. Number of moults, mean intermoult period (IP) and survival were not significantly affected by density. Our results indicated that the IP and the percentage of increment per moult are affected by the size of crayfish before moult and we provide equations for these relations. Our findings are relevant both for crayfish aquaculture management and for the management of wild or harvested rice‐field crayfish populations. 相似文献
57.
San-José Miriam Arroyo-Rodríguez Víctor Jordano Pedro Meave Jorge A. Martínez-Ramos Miguel 《Landscape Ecology》2019,34(5):1069-1080
Landscape Ecology - Landscape structure can affect seed dispersal, but the spatial scale at which such effect is maximized (scale of effect, SoE) is unknown. We assessed patterns and predictors of... 相似文献
58.
Almy Junior Cordeiro de Carvalho Patrícia Soares Furno Fontes Marta Simone Mendonça Freitas Pedro Henrique Monnerat Alexandre Gomes Fontes 《Journal of plant nutrition》2013,36(4):614-626
This work was performed in the Rio de Janeiro State, Brazil, with the objective to evaluate the nutritional status of yellow passion fruit plants along different phenological stages, using the DRIS method. Fifty-four passion fruit cultivated areas with an annual yield productivity ranging from 6.95 to 33.8 t ha?1 year?1 and average productivity of 16.9 t ha?1 year?1 were selected in the region. The contents of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), chlorine (Cl), iron (Fe), zinc (Zn), manganese (Mn), and boron (B) were evaluated. The reference standards were established (mean and variation coefficient) for the values of the nutrient concentration ratios, two by two, on samples from high yield productivity plantations and analyzed by the DRIS index of nutrients for the medium and low yield productivity areas. The established standards differed according with the phenological stage of the culture. In a general way, the mean content of the evaluated nutrients did not differed between the two productivity levels into each phonological stage. There was a difference for the Nutritional Limitation Order between different phenological stages of yellow passion fruit plants. The most negative DRIS indexes and the highest absolute values for the Average Nutritional Balance on yellow passion fruit plants in the region, were found for potassium in May, phosphorus in October and iron in January. 相似文献
59.
Sclerotinia sclerotiorum infections on sunflower capitula produce white rot, one of the most dangerous diseases sunflower bears in all humid areas.
Therefore, disease quantification on developed genetic materials is a very important action in sunflower breeding. Given the
horizontal type of resistance these evaluations should be made in different environments. Several hybrids obtained after crossing
seven female × seven male sunflower inbred lines in a factorial mating design were evaluated for resistance to white rot in
two locations in the southeast of the province of Buenos Aires, Argentina. Disease incidence and the symptom appearance index
indicated significant genotypic effects and genotype × environment (G × E) interactions. Genotypic effects were a greater
source of variance than the G × E interaction effects. The G × E interactions only represented changes in magnitude. These
results were used to identify the best genotypes for both resistance factors. Four hybrids showed low disease incidence values
under both artificial and natural infections, of which only two had high values of the symptom appearance index at both locations.
These hybrids are considered to have adequate resistance attributes for the ascosporic penetration and the mycelium extension
in the capitulum tissue and could therefore be sown in the province of Buenos Aires without increasing risks of S. sclerotiorum attacks. 相似文献
60.
Andreia I. G. Raposo Susana M. F. Ferreira Rodolfo Ramos Pedro M. Santos Catarina Anjos Teresa Baptista Carla Tecelo Jos L. Costa Ana Pombo 《Aquaculture Research》2019,50(8):2023-2038
In this study, the effects of three diets were investigated to enhance Paracentrotus lividus production for commercial purposes. P. lividus were fed ad libitum for 80 days with: diet A—fresh Codium tomentosum Stackhouse, 1797; diet B—formulated using a jellified mix of macroalgae and vegetables, including C. tomentosum (20%), Coralina sp. Linnaeus, 1758 (17%), cabbage Brassica oleracea var. capitata Linnaeus, 1753 (30%), carrot Daucus carota Linnaeus, 1753 (30%) and agar (3%) as a gelling agent. Diet C consisted of maize Zea mays Linnaeus, 1753 (56%) and New Zealand spinach Tetragonia tetragonoides (Pallas, 1781) Kuntze, 1891 (44%). Their effects on the gonadal and somatic growths, gonadosomatic index (GI) and gametogenesis were evaluated, as well as on the total lipid content and fatty acid composition of sea urchin's gonads. Diet A provided high values of eicosapentaenoic acid (EPA). Gonads of sea urchins fed with diet A were found mostly in growth and maturation stages of gametogenesis and showed the lowest lipid content. Sea urchins fed with diet B presented their gonads in the reabsorption stage and had the highest values of omega‐3 polyunsaturated fatty acids (PUFAs). Sea urchins fed with diet C were in the early stages of gametogenesis and had the highest values of lipid content, plus omega‐6 PUFAs. Once as an ingredient in a balanced mix with vegetables, C. tomentosum can be a key factor to the development of new promising high‐quality and low‐cost feed for P. lividus roe enhancement. 相似文献