The ecophysiologic role of fog in the evergreen heath-laurel 'laurisilva' cloud forests Canary Islands has not been unequivocally demonstrated, although it is generally assumed that water important for survival and distribution this relict paleoecosystem North Atlantic Macaronesian archipelagos. To determine ecosystem, we combined direct transpiration measurements tree species, obtained with Granier's heat dissipation probes, micrometeorological artificial collection carried out a 43.7-ha...

Abstract Fog precipitation has long been assumed as an additional water source in the relic laurel ecosystems of Canary Islands, located at 500–1400 m MSL. However, to what extent fog can contribute forest balance is not yet clear. Combining data from artificial catchers and a physically based impaction model, authors evaluated potential contribution captured by needle-leafed Erica arborea L. trees selected watershed Garajonay National Park (La Gomera Island) for 2-yr period (February...

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One of the most sensitive parameters in hydrological models, saturated hydraulic conductivity (Ks), is also one problematic measurements at field scale regard to variability and uncertainty. The performance a new type simple inexpensive permeameter, Philip-Dunne permeameter (PD), compared with two established alternatives, laboratory constant head (LP) Guelph (GP). A PD prototype, protocol usage, numerical routine find Ks were developed tested on 70-point array laid out an 850-m2 volcanic...

Soil water repellency varies nonlinearly with soil moisture, describing a versus content curve. Despite this dependence, is usually characterized by indexes measured at fixed content. We provide statistically robust yet simple method to determine range of contents, proposing alternative water‐dependent parameters derived from the molarity an ethanol droplet (MED) test. Useful correlations are found between some these proposed parameters, such case integrated area below curve, which be...

Among different alternatives, dielectric capacitance sensors may provide simultaneous readings of the volumetric water content and soil solution electrical conductivity in same sample volume at low cost. Reliability capacitive be questioned, however, due to signal frequency which they work, also because effects on estimation. In this study we evaluated commercial WET Sensor (Delta‐T Devices Ltd., Burwell, UK) compared with time domain reflectometry (TDR) three volcanic soils textures....

Research oriented toward understanding the hydrologic functioning of relict “laurisilva” evergreen forests is scarce. This study focused on analysis temporal changes in soil water status under such humid subtropical stands and explored to what extent fluxes may explain topsoil dynamics. Hydrologic (potential evapotranspiration, canopy fog dripping, rainwater below canopy) were computed for a 2‐yr period using situ micrometeorological measurements Garajonay National Park cloud forest (Canary...

We present the results of fog water collection obtained with cylindrical gauges at three locations on northern side Tenerife island (Spain): La Esperanza (1093 m a.s.l.), Taborno (1015 and El Gaitero (1747 a.s.l.). Concomitant meteorological variables were also measured. show that precipitation was more frequent than rainfall. However, volumes frequency daily varied among studied sites, usually not exceeding 10–40 L d−1/m2 collecting surface. In Esperanza, harvesting occurred frequently, but...

Wetting front suction and soil sorptivity ( S ) are relevant parameters to water movement in the vadose zone. Both may be estimated with Philip–Dunne falling‐head permeameter, given moisture increment (Δθ) measured times t med max during an infiltration event. Previous studies have shown that falling head permeameter can used for estimating saturated hydraulic conductivity K s ), but its potential estimate soil's has received little attention. We investigate ability of method Green–Ampt's at...

Soil water repellency is recognized to be a widespread phenomenon which may affect wide range of spatially dependent hydrological processes that take place in the vadose zone such as infiltration, preferential flow, and soil distribution. Despite this, spatial structure has received almost no attention past. The objective this study investigate variability top horizon laurel forest watershed. Water was measured with molarity an ethanol droplet (MED) test, from saturation oven‐dry, 140...

Abstract Fog phenomena and their associated meteorological variables were continuously monitored during 4 years in an evergreen laurisilva cloud forest of the Anaga Massif Biosphere Reserve (Tenerife, Canary Islands), order to establish its current dynamics. was more frequent night through early morning afternoon, particularly from May until September, coincidental with a immersion 1025 m a.s.l. experimental site layer wind‐driven stratocumulus. The concomitant conditions different fog...

Water repellency (WR) has been classically characterized at fixed (usually oven-dry) soil water content (θg) in terms of the contact angle (CA), α. However, α previously reported to depend upon θg a nonlinear fashion, such that WR increases from wettable state close saturation (θg-min) up maximum, αmax, decreasing afterward either monotonically or rising again second local absolute maximum nearby dried state. Hence, CA versus (α-θg) curve may be described different parameters, as θg-min,...

Abstract Soil water repellency may be characterized in terms of the delayed infiltration time a droplet resting on soil surface, which is, drop penetration (WDPT), or persistence. Such persistence varies nonlinearly with content (θ g ), although no models have been proposed to reproduce variation WDPT θ soils. Dynamic factor analysis (DFA) is used identify two common patterns unexplained variability scattered dataset versus measurements. A four‐parameter lognormal distribution was fitted...