E

Fig. 3.28 Daily course of irradiance at different strata of a wet tropical forest in northern Australia on an almost cloudless day; i.e. 36 m = above the canopy, 22 m and 10 m = increasingly lower levels inside the forest. (After Doley et al. 1987)

Fig. 3.28 Daily course of irradiance at different strata of a wet tropical forest in northern Australia on an almost cloudless day; i.e. 36 m = above the canopy, 22 m and 10 m = increasingly lower levels inside the forest. (After Doley et al. 1987)

3.4.2 Temperature and Air Humidity

Diurnal variations of soil temperature and air temperature 1.5 m above the ground within a forest in Surinam in comparison to small and large clearings are shown in Fig. 3.29. There is strong dampening of daily changes of temperature inside the forest, where it remains much cooler than in the gaps and clearings.

Relative air humidity (RH) is related to temperature. Hence, the water-vapour pressure saturation deficit of the atmosphere at the top of the canopy and at various levels inside the forest shows a similar pattern (Fig. 3.30). It is close to zero at all levels at sunrise, shows a maximum at 14.00 h and decreases inside the forest from the higher to the lower strata. Since water-vapour pressure deficit of the atmosphere determines the driving force for transpiration, it constitutes a highly important ecophysiological factor. High RH also increases the CO2-sensitivity of stomata and there is acclimation of stomatal responses which may play a role for photosynthesis in the lower strata of tropical forests (Talbott et al. 2003).

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Renewable Energy 101

Renewable Energy 101

Renewable energy is energy that is generated from sunlight, rain, tides, geothermal heat and wind. These sources are naturally and constantly replenished, which is why they are deemed as renewable. The usage of renewable energy sources is very important when considering the sustainability of the existing energy usage of the world. While there is currently an abundance of non-renewable energy sources, such as nuclear fuels, these energy sources are depleting. In addition to being a non-renewable supply, the non-renewable energy sources release emissions into the air, which has an adverse effect on the environment.

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