Search results for "forest"
showing 10 items of 3780 documents
Soil and organic carbon redistribution in a recently burned Mediterranean hillslope affected by water erosion processes
2022
Forest fires cause many changes in the physical, chemical and biological soil properties such as aggregation and soil organic carbon contents (SOC) as well as on soil hydrology and erosion processes. Most studies on post-fire soil erosion in Mediterranean environments have been plot-based and research at hillslope or broader scale is scarce. Understanding SOC nature, distribution and modifications, as produced by forest fires and erosion, has become crucial to model and define the role of soil erosion as source or sink of C, and to sustainably manage ecosystem services related to the soil resource. This research provides data about the loss and redistribution of soil and SOC in a Mediterran…
Paléoenvironnements et caractérisation des roches mères pétrolières des séries pré-salifères du bassin intérieur du Gabon
2003
Resume Le bassin interieur du Gabon, dont l'histoire est liee a la separation des continents Sud-Americain et Africain, comprend des depots continentaux fluvio-lacustres, localement glaciaires, dates du Precambrien superieur a l'Aptien p.p., surmontes par des facies marins aptiens et albiens. L'analyse par pyrolyse Rock–Eval d'echantillons d'affleurements et de forages preleves dans ce bassin met en evidence la presence de facies siliciclastiques riches en matiere organique (jusqu'a 25 % de carbone organique total) de types I et II. Ces niveaux, qui se rencontrent dans le Permien, le Neocomien-Barremien ainsi que dans l'Aptien, constituent d'excellentes roches meres et sont a l'origine des …
Impact of woody encroachment on soil organic carbon and nitrogen in abandoned agricultural lands along a rainfall gradient in Italy
2011
Land use changes represent one of the most important components of global environmental change andhave a strong influence on carbon cycling. As a consequence of changes in economy during the last century, areas of marginal agriculture have been abandoned leading to secondary successions. The encroachment of woody plants into grasslands, pastures and croplands is generally thought to increase the carbon stored in these ecosystems even though there are evidences for a decrease in soil carbon stocks after land use change. In this paper, we investigate the effects of woody plant invasion on soil carbon and nitrogen stocks along a precipitation gradient (200–2,500 mm) using original data from pa…
Prediction of organic carbon and total nitrogen contents in organic wastes and their composts by Infrared spectroscopy and partial least square regre…
2017
Middle and near infrared (MIR and NIR) were employed to determine organic carbon (OC) and total nitrogen (TN) in different soil organic amendments including wastes, composts and mixtures of composts and organic wastes. Prediction models based on partial least squares (PLS) regression from the spectra of untreated samples were built. Different spectra preprocessing strategies were adopted and the best number of latent variable was evaluated using leave-one-out cross-validation. Attenuated total reflectance (PLS-ATR-MIR) and diffuse reflectance (PLS-DR-NIR) models were built and evaluated from root mean square error of cross validation and prediction (RMSECV and RMSEP), coefficients of determ…
Impact of wheeled and tracked tractors on soil physical properties in a mixed conifer stand
2016
Abstract: Damage to forest soil caused by vehicle traffic mainly consists of soil compaction, displacement, and rut formation. Severity of the damage depends on vehicle mass, weight of the carried loads, ground morphology, and soil properties, such as moisture. This paper investigates the impacts of two types of vehicles (tracked or wheeled tractor), traffic intensities (one or five skidding cycles) and soil moisture (24% or 13% by weight) on compaction of a loam textured soil in a mixed conifer stand of central Italy. Changes in porosity, bulk density, shear and penetration resistances were analyzed. The latter three parameters were significantly higher in the trafficked soil portions than…
An open-source instrumentation package for intensive soil hydraulic characterization
2020
International audience; We present a new open-source and modular instrumentation package composed of up to ten automatic in- filtrometers connected to data acquisition systems for automatic recording of multiple infiltration experiments. The infiltrometers are equipped with differential transducers to monitor water level changes in a Mariotte re- servoir, and, in turn, to quantify water infiltration rates. The data acquisition systems consist of low-cost components and operate on the open-source microcontroller platform Arduino. The devices were tested both in the laboratory and on different urban and agricultural soils in France and India. More specifically, we tested three procedures to t…
A Trans-amplifying RNA Vaccine Strategy for Induction of Potent Protective Immunity
2019
Here, we present a potent RNA vaccine approach based on a novel bipartite vector system using trans-amplifying RNA (taRNA). The vector cassette encoding the vaccine antigen originates from an alphaviral self-amplifying RNA (saRNA), from which the replicase was deleted to form a transreplicon. Replicase activity is provided in trans by a second molecule, either by a standard saRNA or an optimized non-replicating mRNA (nrRNA). The latter delivered 10- to 100-fold higher transreplicon expression than the former. Moreover, expression driven by the nrRNA-encoded replicase in the taRNA system was as efficient as in a conventional monopartite saRNA system. We show that the superiority of nrRNA- ov…
The Italian TREETALKER NETWORK (ITT-Net): continuous large scale monitoring of tree functional traits and vulnerabilities to climate change
2020
<p>The  <strong>Italian TREETALKER NETWORK (ITT-Net) </strong>aims to respond to one of the grand societal challenges: the impact of climate changes on forests ecosystem services and forest dieback. The comprehension of the link between these phenomena requires to complement the most classical approaches with a new monitoring paradigm based on large scale, single tree, high frequency and long-term monitoring tree physiology, which, at present, is limited by the still elevated costs of multi-sensor devices, their energy demand and maintenance not always suitable for monitoring in remote areas. The ITT-Net network will be a unique and un…
KARAKTERISTIK MORFOLOGI KANGURU POHON CENDERAWASIH (Dendrolagus ursinus) DI KAWASAN PEGUNUNGAN ARFAK MANOKWARI
2008
<em>This research was carried out to study the morphological charachteristics of the tree kanguroo in the Arfak Mountains, especially in the village of Mokwam and Umbui. Observation was done on the qualitative and quantitative charachters. Four kanguroo tree was observed during the study</em>
What is a tree in the Mediterranean Basin hotspot? A critical analysis
2019
Background: Tree species represent 20% of the vascular plant species worldwide and they play a crucial role in the global functioning of the biosphere. The Mediterranean Basin is one of the 36 world biodiversity hotspots, and it is estimated that forests covered 82% of the landscape before the first human impacts, thousands of years ago. However, the spatial distribution of the Mediterranean biodiversity is still imperfectly known, and a focus on tree species constitutes a key issue for understanding forest functioning and develop conservation strategies. Methods: We provide the first comprehensive checklist of all native tree taxa (species and subspecies) present in the Mediterranean-Europ…