Climate variation adaptations

The hydrocarbon content was between 6.6% (Laconi) and 10.8% (Sassari) in each oil in toto. The above data reveal that S. desoleana is able to adapt itself to different soil types and climatic variations. It was also found that the oil obtained from plants grown in calcareous soil was particularly rich in esters while the alcohol component was higher in plants... 

Climate variations within a defined period (for example, 30 years) are not climate change but belong to the climate value, expressed as the periodic mean and its variance including statistics of extreme values. Human societies are highly adapted to the ordinary annual rhythms of climate, which we call the seasons. Moreover, almost all climates display interannual differences, which have hitherto appeared to be unpredictable (Hare 1985). Climate change is said to occur when the differences between successive averaging periods exceed what variance can account for, i.e.. 

Figure 22. Response of the seawater U activity ratio to a sinusoidal variation of the U activity ratio of world rivers (adapted from Richter and Turekian 1993). Such a scenario could explain the apparent discrepancy between the theoretical mean riverine activity ratio of 1.25-1.35 and the estimated value of 1.17 (see text). The scenario could be supported by the preliminary conclusions from the study of U in Himalayan rivers (Chabaux et al. 2001), which assumed a climatic dependence of the Himalayan U flux, sufficient to induce a periodic variation of the mean U activity ratio of the world rivers on a glacial-interglacial time-scale (T = 10 y). The amplitude of variation proposed for the mean ratios of...

Forest chemistry appears to be related to climate (mainly amounts of precipitation), geographical location (e.g. maritime influences) and the availability of elements in the soil (Jayasekera, 1993). Furthermore organisms are quite diverse and highly adaptive in element requirements and particularly in their tolerances. Due to the specific environment in an ecosystem without marked seasonal variations, predominantly poor soils and factors like high levels of precipitation, humidity or temperature, trees from tropical rain forests might have a rather dilferent chemistry from trees of the Northern Hemisphere. In order to understand the chemistry of heavy metals particularly in tropical forests more information is needed. 

Productivity of green mass of wild clover samples Gomaya Saniba and Dargavs-ki is lower in comparison with introduced cultivars, but they have higher percent of seed number in inflorescences, which is an adaptive reaction to sharp variation of meteo-climatic factors in the highlands. 

The variation that occurs in the nature of the defensive secretions of Reticu-litermes lucifugus has parallels among nasute termites (see below). The correlation that occurs between this variation, the distribution of esterase alleles and geographical distribution could be explained as an adaptation to a different spectrum of principal predators which occur in the different ecosystems or climatic zones. We may find that, because of co-evolutionary pressures, specialized ant predators are immune to the secretions, and opportunistic predators are most affected. The development of chemical ecology of termites thus depends upon the study of the comparative effects of defensive secretions on a range of predatory species. 

Downton,W.J.S. Adaptive and evolutionary aspects of C4 photosynthesis. In Photosynthesis and photorespiration. Hatch,M.D., Osmond,C.B., Slatyer,R.O. (eds.), pp. 3-17. New York, London, Sydney, Toronto Wiley-Interscience 1971 Eickmeier,W.G., Bender, M.M. Carbon isotope ratios of Crassulacean Acid Metabolism species in relation to climate and phytosociology. Oecologia 25,341-347 (1976) Enama,M. Molecular weight variations of phosphoenolpyruvate carboxylase from C4 plants. Carnegie Inst. Yearb. 75,409-413 (1976)... 

Based on the limited data available, tamarack shows similar patterns of variation to other widespread conifers, and local seed zones and breeding programs provide locally adapted seed. Local provenances or those from slightly south of local typically appear to be among the best (Jeffers, 1975 Riemenschneider and Jeffers, 1980). In Ontario, seed for all species is managed within 38 seed zones based on a climate model for the province (D. Joyce, Ontario Ministry of Natural Resources, pers. comm.). In British Columbia, seed transfer limits are the same for tamarack as subalpine larch (see above). In Alberta, transfer of seed for all conifers including tamarack is limited to 80 km and 150 m in elevation (N. Dhir, Alberta Forest Service, pers. comm.). 

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