geoscience.net logo
+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

Microenvironmental and vegetational heterogeneity induced by phytogenic nebkhas in an arid coastal ecosystem


, : Microenvironmental and vegetational heterogeneity induced by phytogenic nebkhas in an arid coastal ecosystem. Plant & Soil 247(2): 283-293, December

The nebkhas of woody plants represent distinct habitats in arid and semiarid ecosystems. Nebkhas are mounds composed of wind-borne sediment within or around shrub canopies. We studied the effects of widely spaced nebkhas of Retama raetam shrub on their microenvironment and associated herbaceous vegetation in the Mediterranean coast of Sinai Peninsula. Our measurements included nebkha size (height and width) and shrub size (canopy height and diameter). We identified four distinct microsites at each nebkha: crest, mid-slope, edge, and internebkha space. We measured soil temperature and moisture, photosynthetically active radiation (PAR), and soil properties. The plant species grown at each microsite were identified and their densities were measured. Average soil temperature and PAR were highest at internebkha space and lowest at nebkha crest. The maximum diurnal temperature and PAR of internebkhas exceeded that of nebkhas. Soil moisture and nutrient concentrations showed a gradient of spatial heterogeneity and were highest at the nebkha edge. Regression analysis indicated that total herbaceous plant density was significantly related to nebkha size, and to shrub canopy diameter and area. Detrended correspondence analysis indicated that patterns of species composition were correlated with the spatial variability in soil moisture and nutrient content along the gradient of increasing distance from the nebkha crest. It is assumed that shrub canopy and its nebkha interact in governing ecosystem functioning in this environment.

US$19.90

DOI: 10.1023/a:1021548711206


Other references

Othman, A.I.; El-Missiry, M.A.; Koriem, K.M.; El-Sayed, A.A., 2013: Alfa-lipoic acid protects testosterone secretion pathway and sperm quality against 4-tert-octylphenol induced reproductive toxicity. The protective effect of ?-lipoic acid (LA) (5<hsp sp=".25"/>mg/kg bw) against 4-tert-octylphenol (OP) (5<hsp sp=".25"/>mg/kg bw) induced reproductive toxicity in male rats was studied. LA was injected 1<hsp sp=&...

Mitchell P.; Osswald M.; Schueler D.; Brimacombe R., 1990: Selective isolation and detailed analysis of intra rna cross links induced in the large ribosomal subunit of escherichia coli a model for the tertiary structure of the transfer rna binding domain in 23s rna. Intramolecular RNA cross-links were induced within the large ribosomal subunit of E. coli by mild ultraviolet irradiation. Regions of the 23S RNA previously implicated in interactions with ribosomal-bound tRNA were then specifically excised by add...

Barrier, B.F.; Kendall, B.S.; Sharpe-Timms, K.L.; Kost, E.R., 2006: Characterization of human leukocyte antigen-G (HLA-G) expression in endometrial adenocarcinoma. Objectives. The current study sought to determine if endometrial adenocarcinomas express human leukocyte antigen-G (HLA-G), an immune-regulatory protein, and if degree of expression correlates with the stage of carcinoma.Methods. Forty-four prima...

Huber, S.C.; Rufty, T.W.; Kerr, P.S., 1984: Effect of photoperiod on photosynthate partitioning and diurnal rhythms in sucrose phosphate synthase activity in leaves of soybean (Glycine max L. (Merr.)) and tobacco (Nicotiana tabacum L.). In 3 soyabean and 2 tobacco cv., rates of starch accumulation were higher and rates of translocation, leaf sucrose levels and sucrose synthase activity were lower with 7-h than with 15-h photoperiods. With long days, soyabean cv. Ransom and Jupite...

Thyssen, J.P.; Johansen, J.D.; Menné, T.; Lidén, C.; Bruze, M.; White, I.R., 2011: Hypersensitivity reactions from metallic implants: a future challenge that needs to be addressed. British Journal of Dermatology 162(2): 235-236

Choksi, P.; Thomas, R.; Simmons, D.L., 2007: Charcot arthropathy. An often overlooked complication of diabetes mellitus. Charcot's arthropathy is a rare complication of diabetes that can result in significant morbidity. It may have a similar presentation to cellulitis, which often delays its recognition. While the pathogenesis remains unclear, timely diagnosis...

Kosuge, M.; Kimura, K.; Ishikawa, T.; Shimizu, T.; Sugano, T.; Sumita, S.; Hibi, K.; Takamura, T.; Toda, N.; Kanna, M.; Tsukahara, K.; Okuda, J.; Tahara, Y.; Nozawa, N.; Furukawa, E.; Umemura, S., 2004: Different clinical and coronary angiographic findings according to ratios of total cholesterol to high-density lipoprotein cholesterol during the acute phase of myocardial infarction. Several pathological studies have shown that a higher ratio of the serum total cholesterol concentration to the high-density lipoprotein cholesterol concentration (TC/HDL-C ratio) is associated with plaque rupture in patients with acute coronary s...

Kwon, K.I.; Bok, S.J.n; Kim, M.H.on; Lee, C.H.un, 1995: Bioavailability evaluation of two ceftriaxone formulations using two way crossover design in volunteers. For the bioequivalence study of two ceftriaxone injection formulations (Rocephin; Roche, and Triaxone; Hanmi), the HPLC analytical method for the analysis of ceftriaxone in plasma was used. Fourteen healthy volunteers completed the study and each...

Vielma, H.; Mendez, J., 1980: Gas chromatographic separation of 3-methylhistidine. Journal of Chromatography 196(1): 166-170

Raymond, S.H., 1974: A trial of the Cardiff infusion pump. New Zealand Medical Journal 79(516): 973-976