δ15n+values+of+an+unknown+source

... less than 20 mS mÀ1 (Davis and Annan 2002) Depth of penetration of the direct ground wave is a function of many variables including the GPR frequency, antennae offset distance, soil EC and water ... in soil in wet than in dry soil, meaning that the sampling volume changes with water content Installation of this type of probe is of critical importance as any disturbance of the soil adjacent ... is nearly constant) in the cm À150 m range for most agricultural soils (Romano and Santini 2002) Plant growth and performance is critically dependent on adequate supplies of air and water in the...

Ngày tải lên: 12/08/2014, 02:23

... stand, Ei is stand interception, ET is evapotranspiration of the stand (Penman) and EQ is transpiration of the tree layer in the stand Eres is so called “residual evapotranspiration”, i.e., transpiration ... the model tree (V T.tree) and of the stand (VT.stand) at the area of Astand Atree = Astand (VT.tree / VT.stand) crown ground plan, Actmax or similarly by the ground plan of root systems, Artmax, ... area, Astand, see equation (1)) according to the ratio of root ground plan areas of trees and stand Xrt = Xstand (Art / Astand) (7) when values for corresponding compartments were calculated analogically...

Ngày tải lên: 08/08/2014, 14:21

... conductance Forests are found over a wide range of climates and differ in many characteristics relevant to stand transpiration and canopy conductance, e.g their phenology, leaf life span, drought ... conductance and stand transpiration of an oak forest from sap flow measurements, Ann Sci For 53 (1996) 537–546 [16] Granier A., Huc R., Barigah S.T., Transpiration of natural rain forest and its ... Netherlands) Hesse (France) 30 Aubure (France) 120 Kiel (Germany) 100 Champenoux (France) 25 Champenoux (France) 21 Aubure (France) 30 Hartheim (Germany) 35 Losse (France) 37 Le Bray (France)...

Ngày tải lên: 08/08/2014, 14:22

... The lack of apparent effect in the present study may be due to an efficient repair mechanism or because changes in structure can occur without concomitant changes in cuticular resistance It is ... branch *!, decreased, revealing a mild but significant water stress Water stress occurs when the rate of water loss exceeds the rate of uptake It was clear that the rates of day and night transpiration ... resistance did not differ between treatments This result is in contradiction to those of several investigators who noted a significant effect of acid rain/mist upon cuticle structure and/or resistance...

Ngày tải lên: 09/08/2014, 04:20

... of Humans, Terrestrial and Avian Wildlife, and Aquatic Life to Dioxins and Furans from Disposal and Use of Sludge from Bleached Kraft and Sulfite Pulp and Paper Mills Office of Pesticides and Toxic ... identified 26 organic chemicals (including dioxin and furan) as contaminants of concern Of these 26 contaminants, 24 are organochlorines and are priority pollutants Only 11 have RFDs and have cancer potency ... organ” (the decision-maker) This fate and transport terminology is adopted because it is part of the vernacular of many of those providing the information and of many of the ultimate users of...

Ngày tải lên: 24/03/2014, 05:20

... for protection of soil from erosion in the mountainous areas of Vietnam d) to analyze the relationship of mangrove forest to wave attenuation; and to define minimum mangrove forest band width for ... roles of forest are different from those of the other cover types Phien and Toan (1998) demonstrated that runoff from forests was 2.5 - 27 times smaller than runoff from agricultural crops Runoff ... runoff characteristics at the different level of significant Forest cover is inversely significant effect with index of increasing and decreasing flow rate at 0.05 level, and flow coefficient of...

Ngày tải lên: 03/04/2014, 12:22

... labour and equipment The major costs of a water harvesting scheme are in the earth and/or stone work The quantity of digging of drains, collection and transport of stones, maintenance of the ... to Anne Gobin of the Institute for Land and Water Management in Leuven, Belgium, and to Pierre Chevallier of the Hydrology Department of ORSTOM in Montpellier, France, for their comments on an ... Authors: Justine Anschütz, Antoinette Kome, Marc Nederlof, Rob de Neef, Ton van de Ven Editors: Justine Anschütz, Marc Nederlof Illustrator: Barbera Oranje Translation: Sara van Otterloo Printed...

Ngày tải lên: 04/07/2014, 02:20

... often find that soils are composed of a mixture of mineral particles of different sizes For example the sandy loam soil of Table consists of an equal mixture of sand and silt particles Table 1: Typical ... water need of melons may be less than the daily water need of beans, the seasonal water need of melons will be higher than that of beans because the duration of the total growing season of melons ... types of mineral particles: sand, silt and clay A soil which consists of mainly large sand particles (a coarse textured soil) is called a sand type of soil or sandy soil; a soil which consists of...

Ngày tải lên: 04/07/2014, 02:20

... example of Figure 12) and at right angles to the ridges, to prevent flow of runoff water through the furrows (erosion) and to ensure evenly spread storage of runoff 38 Water harvesting and soil ... between and 15 cm deep, and between 10 and 30 cm in diameter (Figure 19B) The distance between two pits varies between 0.5 and m The number of Zaï per generally is between 10,000 and 25,000 Planting ... keep rainfall and runoff in the mini-basin Runoff water is channelled to the lowest point and stored in an infiltration pit The structures are easily constructed by hand Figures 20 and 21 provide...

Ngày tải lên: 04/07/2014, 02:20

... ridge and furrow system (planting distance 75 cm) Figure 30B gives an example of a broad-bed and furrow using the same crop and planting distance Figure 30C shows a combination of maize and pigeon ... maize and pigeon pea, with a planting distance of 45 cm The furrows are often planted with grasses to avoid soil erosion and they slope down at an angle of between 0.4% and 0.8% along their length, ... cereals and creeping legumes, e.g millet and groundnuts (Figure 28) An advantage of many legumes is that they fix nitrogen, which may improve overall fertility of the soil Layout The width of the...

Ngày tải lên: 04/07/2014, 02:20

... mid-season change of plan according to the amount of rain in the early part of the season ? A combination of legumes and cereals may increase the nitrogen status of the soil ? Plants with different ... against animals and humans ? Some species (e.g Euphorbia balsimifera) may provide a shelter to rodents and snakes ? There is a risk that plant diseases and pests will survive in the living plants of ... developed at the Mindanao Baptist Rural Life Centre It is a way of turning an eroded sloping piece of land into a productive upland farm Different measures and techniques of soil moisture conservation,...

Ngày tải lên: 04/07/2014, 02:20

... dry and recharge periods, respectively Comparisons of mean values of the soil physical parameters were conducted by means of two-ways ANCOVAs with distance and depth as independent variables and ... period Comparison of mean values of θ were conducted by means of three-ways ANCOVAs, with distance, depth, and season as independent variables, θ as dependent variable and trees canopy width as ... trees in the rangelands of southern Spain, Oecol Plant (1988) 405−422 364 E Cubera, G Moreno [20] Joffre R., Rambal S., How tree cover influences the water balance of Mediterranean rangelands, Ecology...

Ngày tải lên: 07/08/2014, 16:21

... importance of forest floor transpiration in the water and carbon balances of forests [7, 9, 15, 22, 26] For the water balance, Granier et al [13] cited 30% for ferns in a Pinus pinaster stand and ... lower T and In, and, as a consequence, a diminution of length and intensity of water stress [3, 5, 25] One of the most important findings is that oak transpiration is lower than herbaceous transpiration; ... (1996) 119–132 [12] Granier A., Bréda N., Modeling canopy conductance and stand transpiration of an oak forest from sap flow measurements, Ann Sci For 53 (1996) 537–546 [13] Granier A., Loustau D.,...

Ngày tải lên: 08/08/2014, 00:22

... constant of water (Kw), which is temperature-dependent, ranges from 74 to 84 and is about 20fold higher than that of mineral solids (between and 5), and about 80-fold higher than that of air (1.0005 ... the ANOVA results (two-way ANOVA with paired -values) : (a) Probe type and depth (0–20, 20–40, 40–60 and 60–80 cm); (b) Probe type and range of soil moisture (0.08– 0.14, 0.14–0.21, 0.21–0.28 and ... Rambal S., Debussche G., Water balance of Mediterranean ecosystems under a changing climate, in: Moreno J.C., Oechel W.C (Eds.), Global Change and Mediterranean-type ecosystems, Ecological studies...

Ngày tải lên: 08/08/2014, 01:21

... of irradiance, VPD, and plant hydraulic conductance, described 83.3–89.0% of the total variance of leaf conductance and demonstrated a high correspondence between the observed and predicted values ... 3.2 Effects of atmospheric evaporative demand, leaf water status and plant hydraulic conductance The effects of atmospheric evaporative demand and plant hydraulic factors on gL were analysed in ... period; b mean of the records at 0900 h; c mean of the records at 1100 h; d mean of the records at 1300 h Foliage age (yr) Year Mean leaf conductance if QP = (mmol·m–2·s–1) Mean initial slope of the...

Ngày tải lên: 08/08/2014, 01:21

... cavitation than those of F excelsior (figure 3A and D), the major differences occurring for low ψ values (ψcav at –1.0 and –1.5 MPa and ψ100 at –1.8 and –4.2 MPa for A pseudoplatanus and F excelsior ... important than the ability to transport water rapidly, and that it might be more adaptive to optimize for the avoidance of embolisms than for high hydraulic conductance In dry habitats, the rate of ... F excelsior, A pseudoplatanus and A opalus trees 2.2 Water potential, transpiration and stomatal conductance Leaf water potential (ψw), stomatal conductance (Gs) and transpiration (E) were monitored...

Ngày tải lên: 08/08/2014, 14:21

... HUNTERLAB simulating the CIE standard illuminant A (corresponding to incandescent light) and an observation angle of 10° The color is represented by the values L*; a*, b*, C* and h* (fig 2) Wood Extractions ... species’ mean values of a*, b* and C* were very small and were not significant On the average, there was some suggestion that the wood of sessile oak is slightly lighter than that of pedunculate ... INTRODUCTION d’Amance, near Nancy Three species (Q robur, Q petraea and Fagus sylvatica) from 99 plots were The color of wood is an important quality criterion and is often the decisive one...

Ngày tải lên: 08/08/2014, 19:21

... contaminants in water and soil There are also natural sources of cyanide, such as black cherry and cassava plants Indeed, there is a natural cycle of cyanide However, anthropogenic inputs of cyanide ... problems can have significant technical, regulatory, and legal implications 1.7 CYANIDE: CHEMISTRY, RISK, AND MANAGEMENT The management and regulation of cyanide in water and soil can be very ... concentrations of cyanide in water and soil are very low Most cyanide found in water and soil is the result of anthropogenic contamination from industrial sources • The major sources of cyanide in water and...

Ngày tải lên: 11/08/2014, 20:20

... OF CYANIDE Three gaseous forms of cyanide are of interest in water and soil systems: hydrogen cyanide (HCN), cyanogen chloride (CNCl), and cyanogen bromide (CNBr) Cyanogen chloride and cyanogen ... can be broadly divided into four major classes: free cyanide, metal–cyanide complexes, cyanate and thiocyanate species, and organocyanide compounds Free cyanide comprises molecular HCN and cyanide ... Cyanate and thiocyanate form by oxidation of free cyanide, in the presence of sulfide compounds in the case of thiocyanate Both of these species are anionic for the environmental pH range, and...

Ngày tải lên: 11/08/2014, 20:20

... cyanide Zinc cyanide Copper cyanide Hydrogen cyanide Cyanogen chloride (metal cleaner) Mercuric potassium cyanide (mirror manufacturing) Potassium ferrocyanide Ammonium thiocyanate Cyanogen Cyanogen ... The Chemistry of the Ferrocyanides, American Cyanamid Co., New York, NY, 1953 © 2006 by Taylor & Francis Group, LLC Manufacture and the Use of Cyanide 49 of illuminating-gas clean-up (e.g., spent ... chloride Cyanogen bromide Zinc cyanide Copper cyanide Calcium cyanide Hydrogen cyanide Ammonium thiocyanate (pesticides) Sodium cyanide Malononitrile Cyanogen bromide Barium cyanide Calcium cyanide...

Ngày tải lên: 11/08/2014, 20:20