Soil evaporation under different types of land use in southern African savanna ecosystems   总被引：1，自引：0，他引：1       下载免费PDF全文

Johanna Clara Metzger  Lars Landschreiber  Alexander Gröngröft  Annette Eschenbach 《植物养料与土壤学杂志》2014,177(3):468-475

For dryland ecosystems, soil evaporation is a major factor of the soil water balance. Often handled in one term with transpiration, little is known quantitatively about evaporation and impacts of soil and vegetation on it. On 12 plots at three sites in Angola, Namibia, and Botswana, potential and actual evaporation was measured using microlysimeters and parameterized. Dependencies on micrometeorological, soil, and site properties were statistically examined. In simulation runs with SWAP, the microlysimeter measurements were tried to be reproduced. Measured potential evaporation rates varied from 3.0 mm d^–1 to 8.6 mm d^–1. The evaporational parameter β ranged between 0.9 mm^1/2 and 4.3 mm^1/2. Evaporation was found to be strongly impacted by vegetation and land use, increasing from homogeneous bush areas over heterogeneous, more open woodlands to sparsely covered dryland agricultures. Correlations of evaporation variables with temperature, humidity, shading, topsoil water content, pF, bulk density, texture, and C content were found. Relationships were non‐explicit, which could be achieved by combining different factors. The simulation showed satisfying results with small deviations, confirming the model's general ability to depict the process. The application of the Boesten‐Stroosnijder‐model in combination with the used methods showed to be very useful to express evaporational properties, yet further research is necessary to improve consistency. A basis for evaporation prediction from known plot and soil characteristics and temporal and spatial up‐scaling could be given.  相似文献   

Earthworm-Processed Organic Wastes as Components Of Horticultural Potting Media for Growing Marigold and Vegetable Seedlings     

Rola M. Atiyeh  Clive A. Edwards  Scott Subler  James D. Metzger 《Compost science & utilization》2013,21(3):215-223

We germinated and grew tomato, pepper, lettuce, and marigold seedlings in a standard commercial soilless plant growth medium (Metro-Mix 360), and in coir/perlite and peat/perlite-based container media substituted with 10% or 20%, by volume, of vermicompost derived from pig manure or food wastes. Half of the treatments were watered with liquid inorganic fertilizer while the other half received only water. Germination rates of tomato, pepper, lettuce, and marigold seeds in the coir/perlite mixture did not differ significantly from that in Metro-Mix 360. However, the germination rate of tomato, pepper and lettuce seedlings was very low in the peat/perlite mixture. Substituting some of the peat/perlite mixtures with equal amounts of vermicomposts, particularly pig manure vermicompost, enhanced germination rates greatly, making it comparable to that in the commercial medium (Metro-Mix 360). Pepper, lettuce, and marigold seedlings grown in Metro-Mix 360, which already contains a starter nutrient fertilizer in its formulation, had greater root and shoot dry weights than those grown in the control media (coir/perlite mix and peat/perlite mix). Substituting coir/perlite and peat/perlite mixtures with 10% or 20% of either vermicompost enhanced the growth of seedlings significantly, resulting in an overall plant growth as good as and sometimes better than that in Metro-Mix 360. When the plants were provided daily with a complete fertilizer solution, marigold seedlings in peat-based substrate with 20% pig waste vermicompost, and lettuce seedlings in both coir and peat-based substrates, mixed with 20% food wastes vermicompost, produced greater shoot dry weights than those grown in the commercial potting medium. The growth enhancements tended to be greater in peat/perlite-based mixes than in coir/perlite-based mixes, more so with the addition of pig manure vermicompost than with food waste vermicompost. Earthworm-processed pig manure and food wastes would be suitable materials for inclusion into the formulation of soilless potting media, since substitution of these media with relatively low concentrations of vermicomposts can promote plant growth.  相似文献   

Educating a new generation of landscape ecologists     

Jean Paul Metzger 《Landscape Ecology》2017,32(2):457-459

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Is bird incidence in Atlantic forest fragments influenced by landscape patterns at multiple scales?     

Danilo Boscolo  Jean P. Metzger 《Landscape Ecology》2009,24(7):907-918

The degree to which habitat fragmentation affects bird incidence is species specific and may depend on varying spatial scales. Selecting the correct scale of measurement is essential to appropriately assess the effects of habitat fragmentation on bird occurrence. Our objective was to determine which spatial scale of landscape measurement best describes the incidence of three bird species (Pyriglena leucoptera, Xiphorhynchus fuscus and Chiroxiphia caudata) in the fragmented Brazilian Atlantic forest and test if multi-scalar models perform better than single-scalar ones. Bird incidence was assessed in 80 forest fragments. The surrounding landscape structure was described with four indices measured at four spatial scales (400-, 600-, 800- and 1,000-m buffers around the sample points). The explanatory power of each scale in predicting bird incidence was assessed using logistic regression, bootstrapped with 1,000 repetitions. The best results varied between species (1,000-m radius for P. leucoptera; 800-m for X. fuscus and 600-m for C. caudata), probably due to their distinct feeding habits and foraging strategies. Multi-scale models always resulted in better predictions than single-scale models, suggesting that different aspects of the landscape structure are related to different ecological processes influencing bird incidence. In particular, our results suggest that local extinction and (re)colonisation processes might simultaneously act at different scales. Thus, single-scale models may not be good enough to properly describe complex pattern–process relationships. Selecting variables at multiple ecologically relevant scales is a reasonable procedure to optimise the accuracy of species incidence models.  相似文献   

Sectional notes     

C. H. Metzger  E. R. Bennett  W. B. Ward  J. G. Richard  Ralph W. Donaldson  T. M. Patterson  L. Harris  Marx Koehnke  J. M. Jenkins  W. H. Martin  Robert Schmidt  E. M. Gillig  Dan O’sBraien  John Bushnell  E. R. Jackman  S. P. Swenson  Harold L. Bailey  H. H. Zimmerly  Chas D. Gaines  John Tuker 《American Journal of Potato Research》1937,14(5):161-174

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Sectional notes     

C. H. Metzger  B. A. Brown  Eugene Whitman  W. B. Ward  H. A. Reiley  J. C. Campbell  E. V. Hardenburg  Earl B. Tussing  Chester E. Otis  C. A. Henderson  K. W. Lauer 《American Journal of Potato Research》1943,20(10):289-297

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Sectional notes     

E. Marx  C. H. Metzger  M. A. Lindsay  Eugene W. Whitman  P. T. Ecton  H. A. Reiley  J. V. Pace  Marx Koehnke  E. V. Hardenburg  C. A. Henderson  K. W. Lauer  H. H. Zimmerley 《American Journal of Potato Research》1943,20(12):320-326

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Report of committee on nomenclature     

C. F. Clark  E. V. Hardenburg  C. H. Metzger  J. C. Miller  Wm. Stuart 《American Journal of Potato Research》1941,18(7):212-215

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Wie k?nnen die ersten Durchforstungsertr?ge junger Nadelholzbest?nde mit Gewinn verwertet werden?     

Metzger 《Forstwissenschaftliches Centralblatt》1900,22(5):237-252

Ohne Zusammenfassung  相似文献   

Leanings of the professoriate     

Metzger WP 《Science (New York, N.Y.)》1976,191(4224):279-280

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