Search results for "forest"

Soil erosion and agriculture

2009

Role of rock fragment cover on runoff generation and sediment yield in tilled vineyards

2017

Summary The soil in conventional Mediterranean vineyards is an active and non-sustainable source of sediment and water. Lack of vegetation cover, small soil organic matter content and intense ploughing result in large rates of erosion in a millennia-old tillage system. There is a need for soil conservation strategies that enable sustainability of wine and grape production; therefore, it is essential to measure the rates and to investigate the processes and factors of soil erosion. This study evaluated factors that can reduce soil losses in traditional Mediterranean vineyards. The investigation was carried out with 96 rainfall simulation experiments at the pedon scale (0.24 m2) to measure so…

Developing an erodibility triangle for soil textures in semi-arid regions, NW Iran

2016

Abstract There is a strong need to develop a simple method for rapid estimation of erodibility using readily available data. In this study, soil erodibility was measured using eleven soil textures at the plot scale (60 cm × 80 cm) on a slope of 9% in a semi-arid region. A total of 110 soil erosion experiments were conducted using ten simulated rainfalls (50 mm h− 1 for 30 min). A regression model was developed based on silt and clay content (R2 = 0.82, p

Comparing different application procedures of the water drop penetration time test to assess soil water repellency in a fire affected Sicilian area

2019

Abstract The Water Drop Penetration Time (WDPT) technique was applied in two subsequent years (2016 and 2017) to check surface soil water repellency (SWR) in a Sicilian mountain area affected by a wildfire on June 2016. A total of 93 sites were sampled and from 3 to 100 droplets were used to characterize a site. The detected SWR varied with the severity of the wildfire, being practically absent in the unburnt control area and slight to extreme in the burnt areas. The percentage of extremely repellent sites increased with wildfire severity. SWR vanished one year after the passage of the fire in sites where fire severity was moderate but it persisted in the case of a severe wildfire. In gener…

Particularities of Grey Alder (Alnus incana) Stands in Riparian Galleries Along Streams of the Southern Transylvanian Tableland (Romania)

2019

Abstract Grey Alder (Alnus incana (L.) Moench.) stands are distributed in the Carpathian area on alluvial deposits with sediments of different grain size as galleries along rivers and streams of the sub-montane to the middle montane level. The geological structure (Tertiary sedimentary deposits) in relation to the hydromorphological processes is the base for the structure of the stream valleys, which are in part very deep. Under the special microclimate of these deeper stream stretches with lower temperatures there are favourable conditions for the development of grey alder stands.

A new windstorm proxy from lake sediments: A comparison of geological and meteorological data from western Germany for the period 1965–2001

2009

[1] The feasibility of detecting windstorm layers in lake sediments is explored by comparing quartz grain size data from a freeze core obtained from the Schalkenmehrener Maar (Eifel region, western Germany) to recent meteorological wind data. The Schalkenmehrener Maar is appropriate for such a calibration study because the morphological settings of the lake allow the conservation of windstorm layers (in particular, there is no fluvial sediment inflow) and long-term wind measurements are available from nearby stations. The age model for the uppermost 30 cm of the sediment core is based on measurements of 137Cs and 210Pb concentrations. An ultra-high-resolution grain size analysis is performe…

Prospective use of collected fog water in the restoration of degraded burned areas under dry Mediterranean conditions

2009

Abstract A mountainous plot located in the interior of the Valencia region (east coast of the Iberian Peninsula) was identified for reforestation using the fog-water collection potential prevailing in the area. Fog data were obtained by means of an instrument ensemble consisting of a passive cylindrical fog-water collector, a rain gauge, a wind direction and velocity sensor and a temperature and humidity probe. Preliminary results gave rise to the additional deployment of a low-cost 18-m 2 flat-panel collector connected to three 1000-l tanks for larger scale fog-water collection and storage. The 2007 annual rate of fog water that could be derived from the instrument ensemble amounted to 3.3…

Climatic changes in yield index and soil water deficit trends in China

2000

Long-term trends of the combined effects of evapotranspiration and precipitation effect surface hydrology and soil water and consequently natural and agricultural ecosystems. This paper analyses yield index and soil water deficit time series derived from water balance calculations for multiple cropping systems with FAO methodology. The analysis shows that yield index values have increased and soil water deficits have consequently decreased over much of China during 1954‐1993. The likely parameters contributing to this trend are precipitation changes north of 35 N and maximum evapotranspiration as well as available soil water trends south of this line. Increasing the assumed maximum soil wat…

Wheat growth simulation and yield prediction with seasonal forecasts and a numerical model

2007

Abstract Wheat is a major winter crop in northern Italy. Italian agricultural markets and government agencies would undoubtedly benefit from the early availability of wheat yield forecasts at the regional and national scales as useful support in decision making. In this study we tested the skill of seasonal weather forecasts, in combination with observed weather data, as input to a crop model working in water limited conditions. The observations were used to simulate wheat growth from sowing up to 2 months before harvest, while seasonal forecasts were used afterwards to predict final yields. Observations included climatic variables and water table levels from a location in the Po river plai…

Tropical Andean forest derives calcium and magnesium from Saharan dust

2008

[1] We quantified base metal deposition to Amazonian montane rain forest in Ecuador between May 1998 and April 2003 and assessed the response of the base metal budget of three forested microcatchments (8–13 ha). There was a strong interannual variation in deposition of Ca [4.4–29 kg ha−1 a−1], Mg [1.6–12], and K [9.8–30]). High deposition changed the Ca and Mg budgets of the catchments from loss to retention, suggesting that the additionally available Ca and Mg was used by the ecosystem. Increased base metal deposition was related to dust outbursts of the Sahara and an Amazonian precipitation pattern with trans-regional dry spells allowing for dust transport to the Andes. The increased base…