Gradients, environmental

Brown SS, Gaston GR, Rakocinski CF, Heard RW. 2000. Effects of sediment contaminants and environmental gradients on macrobenthic community trophic structure in Gulf of Mexico estuaries. Estuaries 23 411M24. 

Grether, G. F., Hudon, J., and Millie, D. F. 1999. Carotenoid limitation of sexual coloration along an environmental gradient in guppies. Proc. R. Soc. Lond. B 266 1317-1322. 

Physico-chemical characteristics of the soils were summarized in Table 1. The values were comparable to that described in the previous reports about the SERS (Doi and Sakurai 2003 Doi et al. 2004 Sakurai et al. 1998). The one-way ANOVA indicated that most of the soil variables significantly reflected the land degradation with high values of bulk density, sand content and exchangeable acidity, and low values of moisture content, pH, OM, base (K, Ca, Mg) contents, EC, CEC, base saturation rate, TN and TC contents, available phosphorus and MPN on the glucose medium with no antibiotics. These results also told that the human activities induced several soil environmental gradients. 

Fig. 4. Redundancy analysis ordination diagram based on the antibiotic resistance MPN data. The diamond ( ), the open square (o) and the triangle (A) indicate BG, DDF and DEF, respectively. The value in the parentheses indicates eigenvalue for the axis. The solid and broken arrows indicate significant environmental gradients at p=0.05 and 0.10, respectively.

Mosses and lichens accumulate nickel readily and at least nine species are used to monitor environmental gradients of nickel (Jenkins 1980a). Maximum concentrations of nickel found in whole lichens and mosses from nickel-contaminated areas range between 420 and 900 mg/kg DW vs. 12 mg/kg DW from reference sites (Jenkins 1980a). Nickel concentrations in herbarium mosses worldwide have increased dramatically during this century. In one case, nickel concentrations in Brachythecium salebrosum from Montreal, Canada, rose from 6 mg/kg DW in 1905 to 105 mg/kg DW in 1971 (Richardson etal. 1980). 

Addy HD et ai. Distribution and molecular characterization of the root endophyte Phialocephala fortinii along an environmental gradient in the boreal forest of Alberta, Mycol Res 104 1213—1221, 2000. 

Muella-Dombois, D. (1999) Biodivasity and environmental gradients across the tropical Pacific islands a new strategy for research and conservation. Naturwissenschaften, 86, 253-61. 

An option to consider in using the WA technique is tolerance weighting. The rationale for this approach is that taxa occurring over a narrow range of an environmental gradient should be better indicators than taxa with broader tolerances. Consequently, taxa with narrower tolerances should be weighted... 

Brunke, M., and H. Fischer. 1999. Hyporheic bacteria — Relationships to environmental gradients and invertebrates in a prealpine stream. Archiv fiir Hydrobiologie 146 189-217. 

FIGURE 9.2 Different allocation patterns predicted to be adaptive along environmental gradients of abiotic stresses, competition, and predation pressures, which should select for high resource allocation to maintenance, resource acquisition, and defense, respectively. This model predicts allocation patterns for Grime s plant strategies13 and draws predictions from various chemical defense theories. Allocation to reproduction and growth are not shown for clarity. 

Callender, E., and Rice, K. C. (2000). The urban environmental gradient Anthropogenic influences on the spatial and temporal distributions of lead and zinc in sediments. Emnron. Sci. Technol. 34, 232-238. 

Bonsdorfif E., Pearson T.H. (1999) Variation in the sublittoral macrozoobenthos of the Baltic Sea along environmental gradients A functional-group approach. Australian Journal of Ecology 24 312-326. 

Francis, C. A., O MuUan, G. D., and Ward, B. B. (2003). Diversity of ammonia monooxygenase (amoA) genes across environmental gradients in Chesapeake Bay sediments. Geobiology 1, 129-140. 

Niche partitioning among Prochlorococcus ecotypes along ocean-scale environmental gradients. Science HI, 1737—1740. 

Gradients of reef health, community stmcture, biodiversity, and ecological function in near-shore coral reef systems are often associated with environmental gradients influenced by terrestrial runofi (Fabricius, 2005 Fabricius and De ath, 2004, Fabricius et al., 2005). However, the exact cause of runoff related effects are controversial (e.g., nutrients vs. sediments vs. toxicants vs. ffesh-water input) (Szmant, 2002). 

Talbot, M. M. B., Small, J. G. C., and Bate, G. C. (1988). Spatial patterns of N fixation (acetylene reduction along environmental gradients in a warm-temperature estuary. J. Exp. Mar. Biol. Ecol. 

Environmental gradients do exist in a laboratory or a field situation. A random block design to take into account such gradients should be used. 

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