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1.
Front Plant Sci ; 15: 1423703, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39220007

RESUMEN

Investigating the quantity and spatiotemporal dynamics of metabolite release from plant roots is essential if we are to understand the ecological significance of root exudates in the rhizosphere; however, this is difficult to quantify. In the present study, we quantified in situ root exudation rates during three incubation periods (0-24, 24-48, and 48-72 h) and fine roots within four diameter ranges (<0.8, 0.8-1.0, 1.0-1.2, and 1.2-2.0 mm), and also measured nine morphological traits in the fine roots of Pinus massoniana. Higher root carbon (C) exudation rates were detected during the 0-24 h period. During the 0-24 h and 24-48 h periods, nitrogen (N) uptake rates were higher than N exudation rates, while during the 48-72 h period, N exudation rates exceeded uptake rates. As C exudation increased during 0-48h incubation period, the uptake of N tended to level out. We concluded that the 24-48 h incubation period was the most suitable for capturing root exudates from P. massoniana. The exudation of C from the roots was positively associated with root mass, length, surface area, volume, the number of root tips, and the root tissue density, when incubated for 0-24 h and 24-48 h. Furthermore, length-specific C exudation rates, along with N exudation and uptake rates, all increased as the diameter of the fine roots increased. The release of root exudates could be efficiently predicted by the fine root morphological traits, although the accuracy of prediction depended on the incubation period. Higher values for fine root morphological traits were generally indicative of higher nutrient requirements and tissue investment, as well as higher C exudation rates.

2.
Sci Rep ; 13(1): 20659, 2023 11 24.
Artículo en Inglés | MEDLINE | ID: mdl-38001125

RESUMEN

Traditional villages have received widespread attention from all walks of life based on important carriers of Chinese rural culture. The mutual superposition of natural and cultural factors may exacerbate the evolution of traditional village geographical patterns. To understand such relationships and effects, factors and degrees influencing traditional villages need to be determined. Here, we analysed the data of 724 traditional villages in Guizhou recognised by relevant national ministries and commissions in China using average nearest neighbour analysis, Tyson polygon analysis, nuclear density analysis and Geodector. The geographic pattern feature revealed that traditional villages, in general, are highly clustered regionally and have significant edge effects on administrative units. Different substrate environments result in significant spatial heterogeneity in village spatial density, clustering, surface undulation, sun exposure, and waterfront. The geographic pattern of traditional villages is mostly affected by the closest distance to river valleys, the types and number of intangible cultural heritage resources in the county, river gorge density, edge effect index, degree of county ethnic language use, and proportion of paddy fields to the regional area; and their combined effects influence and control the community structure. The results highlight the impact of nature and culture on the distribution of traditional villages, which helps traditional village conservation and scientific exploration of human-land relationship issues in the mountainous areas of Southwest China.


Asunto(s)
Sistemas de Información Geográfica , Población Rural , Humanos , China , Ríos , Análisis por Conglomerados
3.
Sci Total Environ ; 793: 148387, 2021 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-34175605

RESUMEN

Southwest China gets abundant rainfall, but in its rural areas, there is a severe shortage of water resources for irrigation and drinking. A case study was conducted in the Guizhou Province, which has the most concentrated karst distribution worldwide. The rural water security index was constructed, and Geodetector and ArcGIS were employed to systematically analyze the status quo, spatial differentiation, and driving mechanism of water security in rural areas of Guizhou in 2016. The results showed that (1) there was obvious spatial variation in the rural water security index in the study area, with only 3.85% of areas being maximally safe, and 20.51%, 35.89%, 15.38%, and 24.36% being sub-optimally safe, moderately safe, unsafe, and extremely unsafe, respectively. The spatial distribution of the rural water security index, it generally coincides with a gradual decay from the economically developed areas to the periphery. The water security of the geographical environment is inferior to those of domestic water and water for agricultural production. (2) For Guizhou Province, economic and social factors, such as the disposable income of rural residents and the incidence of impoverishment, were critical factors influencing rural water security. The critical influencing factors vary greatly among prefectures; however, there are some common factors that affect rural water security, such as the incidence of impoverishment, the penetration rate of rural piped water, the percentage of primary industry, and the percentage of karst area. The maximum value of the interactive driver of the percentage of groundwater and the disposable income of rural residents was 0.812, indicating that the interaction between the high percentage of groundwater caused by karst development and the low disposable income of rural residents was the primary reason for the low rural water security. (3) Rural water security was largely influenced by poor socioeconomic development, resulting in a low level of security and the availability of public water facilities and domestic water in rural areas. Significant improvements in rural water security depend on ameliorating the water security of agricultural production and domestic water, rather than improving the geo-environmental conditions of water resources at extremely high costs.


Asunto(s)
Agua Subterránea , Agua , Agricultura , China , Abastecimiento de Agua
4.
Ying Yong Sheng Tai Xue Bao ; 25(1): 99-110, 2014 Jan.
Artículo en Chino | MEDLINE | ID: mdl-24765848

RESUMEN

Based on high-resolution SPOT-5 images, combined with topographic (1:10000) calculating terrain-bit index, the distribution characteristics of woodlands in different terrain niches, and the buffer radii of different roads, water bodies and settlements were identified by using ArcGIS space overlay and buffer analysis function. Results showed that woodland resources were abundant, and arbor woodland and shrub land were the main species, which mainly distributed in two mountain areas (Fangdou Mountain, Qiyao Mountain) affected by topographic restriction and woodland natural basis. The woodland terrain niche distribution index showed an overall upward trend with increasing terrain niche gradient, especially for the arbor woodland and shrub land, while the other woodland types presented an opposite trend. The percentage of woodland area occupying the corresponding buffer radius around the roads, waterbodies and settlements had a strong similarity with the woodland terrain niche distribution index. Only around the settlements, bamboo forest, sparse woodland and immature woodland occupied higher percentages of the woodland area of the corresponding buffer radius than that of arbor woodland and shrub land. Woodland distribution was mainly controlled by large landform patterns of mountain features, while the distribution of woodlands in the different terrain niches and the different buffer radii of roads, waterbodies and settlements were driven mainly by duress of human activities under the auspices of the large landform patterns.


Asunto(s)
Restauración y Remediación Ambiental , Bosques , Tecnología de Sensores Remotos
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