Understanding how land cover and seasonal variations influence soil microbial communities and nutrient cycling is crucial for sustainable land management in tropical forests. However, such investigations are limited in Madagascar's tropical ecosystems. This study investigated the impacts of land cover types and seasonal variations on soil properties and microbial communities in the tropical forest region of Andasibe, Madagascar. Soil samples were collected from four land cover types-tree fallow (TSA), shrub fallow (SSA), eucalyptus forest (EUC), and degraded land (TM)-across three seasonal periods: the dry season, the start of the rainy season, and the end of the rainy season. Both land cover and sampling season affected soil pH and available P, whereas total nitrogen, soil organic carbon, and the C/N ratio were affected only by land cover. The soil organic carbon and total nitrogen concentrations were greater in TM. NextSeq sequencing of the 16S rRNA gene and ITS regions of the nuclear rRNA operon revealed distinct microbial community compositions across land covers, with greater diversity in the TSA and SSA. Bacteria are more sensitive to seasonal changes than are fungi, with phosphate-solubilizing (gcd) and phosphate-mineralizing (phoD) genes being more abundant in the rainy season, emphasizing the role of microbes in nutrient availability under different climatic conditions. Principal component analysis highlighted SSA as a hotspot for microbial activity, reinforcing the potential of shrub ecosystems in soil restoration. These findings reveal strong land cover and seasonal effects on soil microbial functions, with implications for nutrient cycling, ecosystem resilience, and sustainable land management in tropical forest landscapes.

Ground-borne vibrations resulting from construction activity or road traffic may set vibrations in buildings. The effects of these induced vibrations on buildings may range from no effect to minor cosmetic damage to serious damage, depending on factors such as the amplitude and time-dependence of the vibration, the building structure and the type of soil it rests on, and the duration of exposure. Various codes and standards from various countries set recommendations regarding the exposure of buildings to soil-induced vibrations with emphasis on the characteristics of the vibration signals for limiting their effects on the building structure and for not reducing the comfort of their tenants. These facts are shortly reviewed in this presentation in conjunction with the effects of vibrations on the human body.

The main theoretical principles used in the mathematical modeling of the interaction of the soil mass and the lining of a tunnel of circular cross-section, constructed under the protection of a shield made of pipes in a closed way in close proximity to the earth's surface. A formulation has been made and an analytical solution has been obtained for a plane elasticity theory problem on the equilibrium of a geomechanical system, including a weighty semi-infinite region containing arbitrarily located solid washers and a circular hole supported by a ring, simulating a soil mass, cross-sections of protective shield pipes and the lining of a tunnel. The boundary conditions of the problem reflect the action of gravitational forces in the mass and the presence of full contact at the boundaries of regions with different deformation characteristics. To solve the problem, the theory of functions of a complex variable, the mathematical apparatus of complex Kolosov-Muskhelishvili potentials and Laurent series were used. This solution, which makes it possible to determine the components of the stress tensor at any point in each of the considered areas, is the basis for the method of lining a tunnel constructed using a protective shield made of pipes.

Global warming has significantly impacted the hydrological processes in alpine cryosphere region. Water age is an essential descriptor of the hydrological function within a catchment. However, the mechanism of streamwater age variability remains unclear due to limited observational data and high altitudes of alpine catchment. In this study, long-term stable isotopic data on streamwater in a catchment in the central Tibetan Plateau (TP) were collected to assess the water age using the sine-wave approach and gamma distribution. Results showed that the mean streamwater age was 77 days, and that 30 % of streamwater was less than 41 days old on average. The streamwater age in this study was relatively younger than that in low-elevation natural catchments, indicating that the rapid drainage process occurs within the glacier and permafrost catchment. The fraction of young water (Fyw) of the streamwater decreased from 39 % at an upstream site to 28 % at the outlet, revealing the impact of permafrost (low Fyw: 25 %) on streamwater age. These variabilities were related to glacier and permafrost coverage, specifically in catchments with higher glacier coverage that are prone to have a lower water age. Temporally, the streamwater age was significantly influenced by precipitation, relative humidity, and glacier change and, to a lesser extent, permafrost change. Mechanically, glacier and permafrost changes influenced the water age by increasing the vertical flowpath length. This study provides new insights into the change in hy-drological processes in alpine headwater catchments under global warming.

特征跟踪是利用光学遥感影像量测冰川表面流速的主要方法,影像的太阳高度角、时间间隔和纹理特征等因素都会影响特征点匹配的精度,产生误匹配点对。本文拟选择Jutulstraumen冰川作为研究区域,采用基于三角网约束的分层匹配方法获取特征匹配点数据,结合阈值方向和绝对标准差均值(MAD)提出了识别和剔除误匹配点对的方法,最终得到连续、一致的冰流速度场。结果表明,该方法与基于相关系数的误匹配剔除方法相比,能够识别和剔除与邻域中流速方向有明显偏差的匹配点对,获取流速方向统一,流速连续的冰流场结果。

The warming of Arctic region has recently gained worldwide attention due to its projected impacts on global climate system. The effect of anthropogenic black carbon (BC) aerosol on snow is of enduring interest due to its role in aerosol radiative forcing and further consequences for Arctic and global climate change. Using an A ethalometer, measurements of BC aerosols were continuously carried out over the Indian Arctic Station, Himadri during the Arctic Summer (23 July to 19 August) of 2012. Monthly mean BC mass concentration during July and August was found to be 0.093 +/- 0.046 and 0.069 +/- 0.050 mu g/m(3), respectively. BC mass concentration showed maximum loading during 0800-1600 LT. Transport from distant sources (as observed from air mass back trajectories) apart from some local anthropogenic activities (emissions from shipping and power plant) could be the possible sources for observed BC concentration at Himadri. Using the OPAC and SBDART models, optical properties and aerosol radiative forcing (ARF) in the spectral range 0.2 to 4 mu m for composite aerosol and without-BC aerosol at the top of the atmosphere, surface and atmosphere were computed. The presence of BC resulted in positive radiative forcing in the atmosphere leading to warming effect (+2.1 W/m(2)) whereas cooling was observed at the top of the atmosphere (-0.4 W/m(2)) and at surface (-2.5 W/m(2)). BC formed about 57% of atmospheric ARF. (C) 2015 Elsevier B.V. All rights reserved.

The area of desertified land has increased by 27.3% from 1987 to 2000 in Maduo County, northeastern Qinghai-Tibet Plateau. Driving forces of land degradation has been extensively studied in the region. Using Factor Analysis (FA), we evaluate contribution of human activity and natural environmental change to land degradation. Four common factors were extracted in this study. The result shows that climate related other than human-related factors, are the major inducing factors of land degradation in Maduo County. Climate change and consequent change of permafrost account for 70% to the land degradation. Increasing evaporation and declining precipitation in the beginning of the growing season hamper seedling establishment. Decreasing frozen days and rising active layer lower bound make surface soil loose and less soil moisture available for plant.