Search results for "forest"
showing 10 items of 3780 documents
Human settlement dynamics and alluvial dynamics of the Rhine River during the Holocene: Geoarchaeology of the site of Oedenburg (Haut-Rhin, France).
2007
The relationship between alluvial dynamics and control parameters such as climate are well known and understood at plurimillennial and pluriannual time-scales. But it is not really the case at multicentennial and multidecennal time-scales compatible with human society settlement time-scales. In a present and near future context, when human settlement may be affected by strong climatic variation, alluvial dynamics understanding is however a major centre of attention to the development of efficient models. To approach this scale-related question, a segment of the Upper Rhine River presenting both anastomosed and braided was investigated. This area also gives us the opportunity to study settle…
Impacts of oak deforestation and rainfed cultivation on soil redistribution processes across hillslopes using 137Cs techniques
2021
Abstract Background As one of the main components of land-use change, deforestation is considered the greatest threat to global environmental diversity with possible irreversible environmental consequences. Specifically, one example could be the impacts of land-use changes from oak forests into agricultural ecosystems, which may have detrimental impacts on soil mobilization across hillslopes. However, to date, scarce studies are assessing these impacts at different slope positions and soil depths, shedding light on key geomorphological processes. Methods In this research, the Caesium-137 (137Cs) technique was applied to evaluate soil redistribution and soil erosion rates due to the effects …
Carbon stock increases up to old growth forest along a secondary succession in Mediterranean island ecosystems.
2019
The occurrence of old-growth forests is quite limited in Mediterranean islands, which have been subject to particularly pronounced human impacts. Little is known about the carbon stocks of such peculiar ecosystems compared with different stages of secondary succession. We investigated the carbon variation in aboveground woody biomass, in litter and soil, and the nitrogen variation in litter and soil, in a 100 years long secondary succession in Mediterranean ecosystems. A vineyard, three stages of plant succession (high maquis, maquis-forest, and forest-maquis), and an old growth forest were compared. Soil samples at two soil depths (0-15 and 15-30 cm), and two litter types, relatively undec…
Comparison of neophyte communities of Robinia pseudoacacia L. and Acer negundo L. in the eastern Baltic Sea region cities of Riga and Kaunas
2015
Abstract In this study, we examined the species composition of neophyte communities of Robinia pseudoacacia and Acer negundo and compared the site conditions of the urban environment of two cities—Riga and Kaunas. Eighty-five plots of A. negundo and R. pseudoacacia communities were selected. Within each plot, all of the vascular plant species were recorded, and their abundance was estimated in 2014. Composite soil samples of the 0–10 cm mineral topsoil were collected for the estimation of the soil chemical properties at nine systematically distributed points in each sample plot. The soil pH KCL , exchangeable bases, total nitrogen, total organic matter, C/N ratio, and concentrations of the …
Pore water velocity and ionic strength effects on DOC release from peat-sand mixtures: Results from laboratory and field experiments
2017
Organic soils are the most important source of dissolved organic carbon (DOC) in surface water. To date, most studies have focused on natural and re-wetted peatlands, but in Central Europe a large proportion of organic soils are drained and under agricultural use. Furthermore, measures such as deep ploughing or sand addition have been conducted to improve trafficability and have resulted in topsoil horizons consisting of a peat-sand mixture. Very little is known about DOC losses from such soils. Moreover, peat soils frequently feature both mobile zones, characterised by active water and solute transport, and immobile zones, which exchange solutes with the mobile zone by diffusion. Surprisin…
Assessment of the soil organic carbon stock in Spain
2016
p.- 4 Tabls.- 6 Figs.
Response of Vertisols, Andosols, and Alisols to paddy management
2016
Abstract Interchanging submergence and drainage in paddy soils induce alternating redox conditions. It is known that this causes changes in organic carbon stocks, in amounts and crystallinity of Fe oxides as well as transformation of clay minerals and subsequent changes in cation exchange capacity (CEC). However, the influence of the initial soil type on the extent of these changes is not yet well understood. Therefore, we studied paddy soils that derived from three different soil types (Vertisols, Andosols, Alisols) on volcanic parent material in Java (Indonesia). To account for the variability in parent materials, we additionally sampled sandstone-derived Alisols in China. Adjacent non-pa…
Changes in soil organic matter and soil humic substances following the afforestation of former agricultural lands in the boreal-nemoral ecotone (Latv…
2019
Abstract Abandonment of agricultural land is a widespread process in Northern Europe, which is associated with changes in content and distribution of organic matter in soil, including C stocks. There is insufficient information on changes in soil organic matter properties during afforestation of these lands. The aim of the study was to determine and describe the influence of afforestation on organic carbon (CORG) content and properties of soil organic matter (SOM) in mineral topsoil in the boreo-nemoral ecotone in Latvia. We studied soils in 4 model territories that represented abandoned farmlands and territories where mixed or coniferous forests were established at different times on forme…
Soil moisture influences sorptivity and water repellency of topsoil aggregates in native grasslands
2017
Abstract Water repellency is associated to coating of soil particles by hydrophobic substances, usually of organic origin, affecting water dynamics in soil matrix. We analyzed the effect of water repellency on water sorptivity of topsoil aggregates of six soil types under three initial moisture conditions (10 kPa, 100 kPa, and air-dried). Undisturbed soil samples were collected to evaluate sorptivity in the 0–5 cm soil layer at different locations in Pampa Biome in southern Brazil. Disturbed soil samples were also collected for soil particle size distribution, particle density and organic matter content. Sorptivity test was conducted in a tension micro-infiltrometer, using distilled water a…
Connectivity assessment in Mediterranean vineyards using improved stock unearthing method, LiDAR and soil erosion field surveys
2018
The interaction between processes and landforms is accelerated in vineyards due to bare tilled soils that enhance splash, runoff, and erosion. Traditionally, in order to assess these processes, the stock unearthing method (SUM) is considered a useful methodology that uses the graft union of the vine plant as passive bio-indicator of the topsoil level changes. However, SUM assumes that the topography between the rows is planar when development of a model of the current micro-topography is performed. Thus, we consider that there is a need to develop a new methodology (ISUM: improved SUM) that, by adding new measurements in the inter-row areas (at least 3), allows inclusion of the absent micro…