Forest fire, as a discontinuous ecological factor of forest, causes the changes of carbon storage and carbon distribution in forest ecosystem, and affects the process of forest succession and national carbon capacity. Taking the burned land with different forest fire interference intensity as the research object, using the comparison method of adjacent sample plots, and taking the combination of field investigation sampling and indoor test analysis as the main means, this paper studies the influence of different forest fire interference intensity on the carbon pool of forest ecosystem and the change and spatial distribution pattern of ecosystem carbon density, and discusses the influence mechanism of forest fire interference on ecosystem carbon density and distribution pattern. The results showed that forest fire disturbance reduced the carbon density of vegetation (P < 0.05). The carbon density of vegetation in the light, moderate and high forest fire disturbance sample plots were 67.88, 35.68 and 15.50 t∙hm-2, which decreased by 15.86%, 55.78% and 80.79% respectively compared with the control group. In the light, moderate and high forest fire disturbance sample plots, the carbon density of litter was 1.43, 0.94 and 0.81 t∙hm-2, which decreased by 28.14%, 52.76% and 59.30% respectively compared with the control group. The soil organic carbon density of the sample plots with different forest fire disturbance intensity is lower than that of the control group, and the reduction degree gradually decreases with the increase of soil profile depth. The soil organic carbon density of the sample plots with light, moderate and high forest fire disturbance is 103.30, 84.33 and 70.04 t∙hm-2 respectively, which is 11.670%, 27.899% and 40.11% lower than that of the control group respectively; the carbon density of forest ecosystem was 172.61, 120.95 and 86.35 t∙hm-2 after light, moderate and high forest fire disturbance, which decreased by 13.53%, 39.41% and 56.74% respectively compared with the control group; forest fire disturbance reduced the carbon density of eucalyptus forest, which showed a law of carbon density decreasing with the increase of forest fire disturbance intensity. Compared with the control group, the effect of light forest fire disturbance intensity on the carbon density of eucalyptus forest was not significant (P > 0.05), while the effect of moderate and high forest fire disturbance intensity on the carbon density of eucalyptus forest was significant (P < 0.05).
Introduction: The selection of genotypes with determinate growth habit in tomato should contemplate adequate selection criteria to increase the efficiency of the breeding program. Objective: The objective of this work was to estimate selection criteria for “chonto” type tomato lines with determined growth habit. Materials and methods: This work was carried out at the Universidad Nacional de Colombia (Palmira Campus), in 2016, with seven lines with determinate growth habit and a control with indeterminate growth. Heritability in a broad sense (h2 g), coefficient of environmental variation, coefficient of genetic variation, selection efficiency and genetic gain were determined in parameters of morphological, phonological, fruit quality, fruit shape and production, using the RELM/BLUP procedure of the SELEGEN software. Results: There were three ranges of h2 g, the first with values of h2 g greater than 0.76, the second between 0.53 and 0.38, and the third with a value less than 0.38. The highest values of h2 g were for final plant height with 0.92, plant height at harvest with 0.88, yield per plant with 0.83, days to flowering with 0.83, number of fruits per plant with 0.82, and days to harvest with 0.82. For genetic gain it was found that the control had the highest values for final plant height, plant height at harvest, internode length, days to harvest, harvest duration, soluble solids content, number of fruits per plant, fruit weight and yield per plant; however, in some parameters such as height and phenology for selection by determined growth habit, the lowest values were better. Conclusion: There was evidence of genetic parameters that could be considered as selection criteria for “chonto” type tomato lines with determinate growth habit.
Municipal authorities in industrialized and in developing countries face unceasingly the issues of congestion, insufficiency of transport means capacity, poor operability of transport systems and a growing demand for reliable and effective urban transport. While the expansion of infrastructure is generally considered as an undesirable option, in specific cases, when short links or ring roads are missing, new infrastructure projects may provide beneficial solutions. The upgrading and renewal of existing networks is always a challenge to the development of a modern city and the welfare of citizens. Central governance and management of transport systems, the establishment of smart and digital infrastructure, advanced surveillance and traffic monitoring, and intra-city energy-harvesting policy are some of the steps to be taken during the transition to a green and sustainable urban future.
Municipal authorities have also to consider other options and strategies to create a citizen-friendly setting for mobility: diminish the need for trips (digitalization of services, e-commerce, etc.), shift from private to public transport and transform the urban form to promote non-motorized transport in favor of the natural environment and public health. A citizen-friendly policy based on the anticipation of future needs and technological development seems to be a requisite for European cities searching for a smooth integration of their networks into urban space.
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