Article

Interception in a mountainous declining spruce stand in the Strengbach catchment (Vosges, France)

Centre d'Etudes et de Recherches Eco-Géographiques (CEREG), ULP, 3 rue de l'Argonne, 67083 Strasbourg Cedex, France; Centre de Recherches Forestières (CRF), INRA Nancy-Amance, Champenoux, 54280 Seichamps, France; Centre de Géochimie de la Surface (CGS), CNRS, 1 rue Blessig, 67084 Strasbourg Cedex, France
Journal of Hydrology 04/1993; DOI: 10.1016/0022-1694(93)90175-9

ABSTRACT In a over-mature (declining) 90-year-old Norway spruce stand (Picea abies) in the Vosges mountain area, gross precipitation, throughfall, stemflow and meteorological variables have been measured for three periods in the summers of 1988, 1989 and 1990; transpiration was measured from June to August 1989. Throughfall, interception and stemflow represent, respectively, 65.3%, 34.2% and 0.5% of the incident rainfall. A semi-logarithmic relationship between interception and gross precipitation is given. Transpiration of the stand determined by sap-flow measurements represents only 27% of the potential evapotranspiration. Evaporation of water intercepted by the vegetation is the major component of the evapotranspiration.

0 Bookmarks
 · 
63 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A wide range of basic and applied problems in water resources research requires high-quality estimates of the spatial mean of throughfall. Many throughfall sampling schemes, however, are not optimally adapted to the system under study. The application of inappropriate sampling schemes may partly reflect the lack of generally applicable guidelines on throughfall sampling strategies. In this study we conducted virtual sampling experiments using simulated fields which are based on empirical throughfall data from three structurally distinct forests (a 12-yr old teak plantation, a 5-yr old young secondary forest, and a 130-yr old secondary forest). In the virtual sampling experiments we assessed the relative error of mean throughfall estimates for 38 different throughfall sampling schemes comprising a variety of funnel- and trough-type collectors and a large range of sample sizes. Moreover, we tested the performance of each scheme for both event-based and accumulated throughfall data. The key findings of our study are threefold. First, as errors of mean throughfall estimates vary as a function of throughfall depth, the decision on which temporal scale (i.e. event-based versus accumulated data) to sample strongly influences the required sampling effort. Second, given a chosen temporal scale throughfall estimates can vary considerably as a function of canopy complexity. Accordingly, throughfall sampling in simply structured forests requires a comparatively modest effort, whereas heterogeneous forests can be extreme in terms of sampling requirements, particularly if the focus is on reliable data of small events. Third, the efficiency of trough-type collectors depends on the spatial structure of throughfall. Strong, long-ranging throughfall patterns decrease the efficiency of troughs substantially. Based on the results of our virtual sampling experiments, which we evaluated by applying two contrasting sampling approaches simultaneously, we derive readily applicable guidelines for throughfall monitoring.
    Agricultural and Forest Meteorology 06/2014; 189-190:125-139. · 3.89 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The combination of the Sr, Nd and Pb isotope systems, recognized as tracers of sources, with the Ca isotope system, known to reveal biology-related fractionations, allowed us to test the reliability of spruce (Picea abies) growth rings as environmental archives through time (from 1916 to 1983) in a forest ecosystem affected by acid atmospheric deposition. Sr and Pb isotopes have already been applied in former tree-ring studies, whereas the suitability of Nd and Ca isotope systems is checked in the present article. Our Sr and Nd isotope data indicate an evolution in the cation origin with a geogenic origin for the oldest rings and an atmospheric origin for the youngest rings. Ca isotopes show, for their part, an isotopic homogeneity which could be linked to the very low weathering flux of Ca. Since this flux is weak the spruces’ root systems have pumped the Ca mainly from the organic matter-rich top-soil over the past century. In contrast, the annual growth rings studied are not reliable and suitable archives of past Pb pollution.RésuméLa combinaison des isotopes du Sr, du Nd et du Pb, reconnus comme étant des traceurs de sources avec le système isotopique du Ca, connu comme fractionnant lors de processus biologiques, nous a permis de tester le potentiel des cernes de croissance d’un épicéas (Picea abies) en tant qu’archives environnementales (entre 1916 et 1987) d’un écosystème affecté par des dépôts atmosphériques acides. Les isotopes du Sr et du Pb ont déjà été appliqués antérieurement dans des études de cernes d’arbres, alors que le potentiel des isotopes du Nd et du Ca appliqué à ces objets est étudié dans ce présent article. Nos résultats isotopiques en Sr et Nd indiquent une évolution dans l’origine des cations, les échantillons les plus anciens traduisant une source géogénique alors que les échantillons les plus récents ont une origine atmosphérique. Les isotopes du Ca montrent pour leur part une homogénéité isotopique au cours du temps qui pourrait être liée au très faible flux d’altération du Ca. Par conséquent le système racinaire des épicéas a certainement prélevé le Ca des horizons de sols superficiels riches en matière organique au cours du siècle passé. En revanche les cernes d’arbres étudiées ne sont pas des enregistreurs des pollutions passées en Pb.
    Comptes Rendus Geosciences 05/2012; 344(5):297–311. · 1.70 Impact Factor
  • Source
    Dataset: Schulte